WorldWideScience

Sample records for lst based permafrost

  1. ESA DUE GlobTemperature project: Infrared-based LST Product

    Science.gov (United States)

    Ermida, Sofia; Pires, Ana; Ghent, Darren; Trigo, Isabel; DaCamara, Carlos; Remedios, John

    2016-04-01

    One of the purposes of the GlobTemperature project is to provide a product of global Land Surface Temperature (LST) based on Geostationary Earth Orbit (GEO) and Low Earth polar Orbit (LEO) satellite data. The objective is to use existing LST products, which are obtained from different sensors/platforms, combining them into a harmonized product for a reference view angle. In a first approach, only infra-red based retrievals are considered, and LEO LSTs will be used as a common denominator among geostationary sensors. LST data is provided by a wide range of sensors to optimize spatial coverage, namely: (i) 2 LEO sensors - the Advanced Along Track Scanning Radiometer (AATSR) series of instruments on-board ESA's Envisat, and the Moderate Resolution Imaging Spectroradiometer (MODIS) on-board NASA's TERRA and AQUA; and (ii) 3 GEO sensors - the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on-board EUMETSAT's Meteosat Second Generation (MSG), the Japanese Meteorological Imager (JAMI) on-board the Japanese Meteorological Association (JMA) Multifunction Transport SATellite (MTSAT-2), and NASA's Geostationary Operational Environmental Satellites (GOES). The merged LST product is generated in two steps: 1) calibration between each LEO and each GEO that consists in the removal of systematic differences (associated to sensor type and LST algorithms, including calibration, atmospheric and surface emissivity corrections, amongst others) represented by linear regressions; 2) angular correction that consists in bringing all LST data to reference (nadir) view. Angular effects on LST are estimated by means of a kernel model of the surface thermal emission, which describes the angular dependence of LST as function of viewing and illumination geometry. The model is adjusted to MODIS and SEVIRI/MSG LST estimates and validated against LST retrievals from those sensors obtained for other years (not used in the calibration). It is shown that the model leads to a reduction of LST

  2. Developing NASA's VIIRS LST and Emissivity EDRs using a physics based Temperature Emissivity Separation (TES) algorithm

    Science.gov (United States)

    Islam, T.; Hulley, G. C.; Malakar, N.; Hook, S. J.

    2015-12-01

    Land Surface Temperature and Emissivity (LST&E) data are acknowledged as critical Environmental Data Records (EDRs) by the NASA Earth Science Division. The current operational LST EDR for the recently launched Suomi National Polar-orbiting Partnership's (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) payload utilizes a split-window algorithm that relies on previously-generated fixed emissivity dependent coefficients and does not produce a dynamically varying and multi-spectral land surface emissivity product. Furthermore, this algorithm deviates from its MODIS counterpart (MOD11) resulting in a discontinuity in the MODIS/VIIRS LST time series. This study presents an alternative physics based algorithm for generation of the NASA VIIRS LST&E EDR in order to provide continuity with its MODIS counterpart algorithm (MOD21). The algorithm, known as temperature emissivity separation (TES) algorithm, uses a fast radiative transfer model - Radiative Transfer for (A)TOVS (RTTOV) in combination with an emissivity calibration model to isolate the surface radiance contribution retrieving temperature and emissivity. Further, a new water-vapor scaling (WVS) method is developed and implemented to improve the atmospheric correction process within the TES system. An independent assessment of the VIIRS LST&E outputs is performed against in situ LST measurements and laboratory measured emissivity spectra samples over dedicated validation sites in the Southwest USA. Emissivity retrievals are also validated with the latest ASTER Global Emissivity Database Version 4 (GEDv4). An overview and current status of the algorithm as well as the validation results will be discussed.

  3. [Monitoring of farmland drought based on LST-LAI spectral feature space].

    Science.gov (United States)

    Sui, Xin-Xin; Qin, Qi-Ming; Dong, Heng; Wang, Jin-Liang; Meng, Qing-Ye; Liu, Ming-Chao

    2013-01-01

    Farmland drought has the characteristics of wide range and seriously affecting on agricultural production, so real-time dynamic monitored has been a challenging problem. By using MODIS land products, and constructing the spectral space of LST and LAI, the temperature LAI drought index (TLDI) was put forward and validated using ground-measured 0-10 cm averaged soil moisture of Ningxia farmland. The results show that the coefficient of determination (R2) of both them varies from 0.43 to 0.86. Compared to TVDI, the TLDI has higher accuracy for farmland moisture monitoring, and solves the saturation of NDVI during the late development phases of the crop. Furthermore, directly using MODIS land products LST and LAI and avoiding the complicated process of using the original MODIS data provide a new technical process to the regular operation of farmland drought monitoring.

  4. Evaluation Case Studies and Intercomparison with Regional Climate Model Simulations based on the DUE PERMAFROST Circumpolar Remote Sensing Service for Permafrost

    Science.gov (United States)

    Heim, Birgit; Bartsch, Annett; Elger, Kirsten; Rinke, Annette; Matthes, Heidrun; Zhou, Xu; Klehmet, Katharina; Buchhorn, Marcel; Duguay, Claude

    2014-05-01

    Permafrost is a subsurface phenomenon. However, monitoring from Earth Observation (EO) platforms can provide spatio-temporal data sets on permafrost-related indicators and geophysical parameters used in modelling and monitoring. The ESA Data User Element (DUE) Permafrost project (2009-2012) developed a suite of EO satellite-derived products: Land Surface Temperature (LST), Surface Soil Moisture (SSM), Surface Frozen and Thawed State (Freeze/Thaw), Terrain, Land Cover, and Surface Water. The satellite-derived products are weekly and monthly averages of the bio- and geophysical terrestrial parameters and static circum-Arctic maps. The final DUE Permafrost products cover the years 2007 to 2011 with a circum-Arctic coverage (north of 50°N). The products were released in 2012, and updated in 2013. Further information is available at geo.tuwien.ac.at/permafrost/. The remote sensing service also supports the EU-FP7 funded project PAGE21 - Changing Permafrost in the Arctic and its Global Effects in the 21st Century (www.page21.eu). The Global Terrestrial Network for Permafrost (GTN-P), initiated by the International Permafrost Association (IPA), is the prime program concerned with monitoring of permafrost. It provides an important database for the evaluation of EO-derived products and climate and permafrost models. GTN-P ground data ranges from air-, ground-, and borehole temperature data to active layer monitoring, soil moisture measurements, and the description of landform and vegetation. The involvement of scientific stakeholders and the IPA, and the ongoing evaluation of the satellite-derived products make the DUE Permafrost products relevant to the scientific community. The Helmholtz Climate Initiative REKLIM (Regionale KlimaAnderungen/Regional Climate Change) is a climate research program where regional observations and process studies are coupled with model simulations (http://www.reklim.de/en/home/). ESA DUE Permafrost User workshops initiated the use of EO

  5. Regional permafrost distribution based on remote sensing data

    Science.gov (United States)

    Prantl, Hannah; Sailer, Rudolf; Stötter, Johann; Nagler, Thomas

    2017-04-01

    The detection of permafrost phenomena and its distribution in mountain environments as well as the monitoring of changes of permafrost with respect to climatic changes is important for alpine risk, infrastructure, natural hazards and climate change studies. It is assumed that in Iceland less than ten percent of the land surface is underlain by permafrost and that most of it may disappear under global warming in the 21st century. In particular regions these changes will cause sincere problems for the society in mountainous regions. But because of the complexity of permafrost detection, the knowledge about its distribution in Iceland is currently not very well evaluated and only based on small-scale observations. As permafrost is at most not directly observable, different indicators, e.g. rock glaciers and perennial snow patches, can be mapped to identify the distribution of permafrost. The study site is situated on the Tröllaskagi peninsula, in Northern Iceland. The peninsula is situated between Skagafjörður and Eyjafjörður and the highest summits reach an altitude of about 1400. For large-scale identification of perennial snow patches (PSP) over the Tröllaskagi peninsula remote sensing techniques are a practicable technique. In our study, we use optical satellite (Landsat-5/7/8 and Sentinel-2B) data in combination with aerial images to map and monitor the spatial distribution of perennial snow patches, indicating a low or negative ground temperature underneath. After an atmospheric correction of the satellite data, pan sharpening of the Landsat data and resampling the Sentinel-2B data, and Normalized Difference Snow Index (NDSI) calculations, the perennial snow patches are classified in i) mainly permafrost, ii) mainly wind and iii) mainly avalanche induced origin. For that purpose, topographic information such as slope angle, aspect and curvature are determined from a DEM of Tröllaskagi peninsula. In a first step a digital elevation model with a grid size

  6. GlobPermafrost- How Space-BasedEarth Observation Supports Understanding of Permafrost

    Science.gov (United States)

    Bartsch, Annett; Grosse, Guido; Kaab, Andreas; Westermann, Sebastian; Strozzi, Tazio; Wiesmann, Andreas; Duguay, Claude; Seifert, Frank Martin; Obu, Jaroslav; Goler, Robert

    2016-08-01

    The GlobPermafrost project develops, validates and implements Earth Observation (EO) products to support research communities and international organisations in their work on better understanding permafrost characteristics and dynamics. To facilitate usability of these products by the target audience, user requirements with respect to the planned products have been requested and collected through an online community survey as well as by interview. This paper provides an overview on the planned thematic EO products as well as results of the user requirement survey.

  7. Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by Integration of Ground-Based Geophysical Permafrost Characterization and Numerical Modeling

    Science.gov (United States)

    2015-05-01

    FINAL REPORT Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by Integration of Ground-Based Geophysical...From - To) 03-2010 to 04-2015 4. TITLE AND SUBTITLE Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by...interior Alaska; hence frozen ground affects water resources, ecosystem state, landscape evolution, and soil stability. Despite its hydrologic

  8. Landsat-based trend analysis of lake dynamics across northern permafrost regions

    Science.gov (United States)

    Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

    2017-01-01

    Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

  9. Permafrost distribution map of San Juan Dry Andes (Argentina) based on rock glacier sites

    Science.gov (United States)

    Esper Angillieri, María Yanina

    2017-01-01

    Rock glaciers are frozen water reservoirs in mountainous areas. Water resources are important for the local populations and economies. The presence of rock glaciers is commonly used as a direct indicator of mountain permafrost conditions. Over 500 active rock glaciers have been identified, showing that elevations between 3500 and 4500 m asl., a south-facing or east-facing aspect, areas with relatively low solar radiation and low mean annual air temperature (-4 to 0 °C) favour the existence of rock glaciers in this region. The permafrost probability model, for Dry Andes of San Juan Province between latitudes 28º30‧S and 32°30‧S, have been analyzed by logistic regression models based on the active rock glaciers occurrence in relation to some topoclimatic variables such as altitude, aspect, mean annual temperature, mean annual precipitation and solar radiation, using optical remote sensing techniques in a GIS environment. The predictive performances of the model have been estimated by known rock glaciers locations and by the area under the receiver operating characteristic curve (AUROC). This regional permafrost map can be applied by the Argentinean Government for their recent initiatives which include creating inventories, monitoring and studying ice masses along the Argentinean Andes. Further, this generated map provides valuable input data for permafrost scenarios and contributes to a better understanding of our geosystem.

  10. Estimating Rates of Permafrost Degradation and their Impact on Ecosystems across Alaska and Northwest Canada using the Process-based Permafrost Dynamics Model GIPL as a Component of the Integrated Ecosystem Model (IEM)

    Science.gov (United States)

    Marchenko, S. S.; Genet, H.; Euskirchen, E. S.; Breen, A. L.; McGuire, A. D.; Rupp, S. T.; Romanovsky, V. E.; Bolton, W. R.; Walsh, J. E.

    2016-12-01

    The impact of climate warming on permafrost and the potential of climate feedbacks resulting from permafrost thawing have recently received a great deal of attention. Permafrost temperature has increased in most locations in the Arctic and Sub-Arctic during the past 30-40 years. The typical increase in permafrost temperature is 1-3°C. The process-based permafrost dynamics model GIPL developed in the Geophysical Institute Permafrost Lab, and which is the permafrost module of the Integrated Ecosystem Model (IEM) has been using to quantify the nature and rate of permafrost degradation and its impact on ecosystems, infrastructure, CO2 and CH4fluxes and net C storage following permafrost thaw across Alaska and Northwest Canada. The IEM project is a multi-institutional and multi-disciplinary effort aimed at understanding potential landscape, habitat and ecosystem change across the IEM domain. The IEM project also aims to tie three scientific models together Terrestrial Ecosystem Model (TEM), the ALFRESCO (ALaska FRame-based EcoSystem Code) and GIPL so that they exchange data at run-time. The models produce forecasts of future fire, vegetation, organic matter, permafrost and hydrology regimes. The climate forcing data are based on the historical CRU3.1 data set for the retrospective analysis period (1901-2009) and the CMIP3 CCCMA-CGCM3.1 and MPI-ECHAM5/MPI-OM climate models for the future period (2009-2100). All data sets were downscaled to a 1 km resolution, using a differencing methodology (i.e., a delta method) and the Parameter-elevation Regressions on Independent Slopes Model (PRISM) climatology. We estimated the dynamics of permafrost temperature, active layer thickness, area occupied by permafrost, and volume of thawed soils across the IEM domain. The modeling results indicate how different types of ecosystems affect the thermal state of permafrost and its stability. Although the rate of soil warming and permafrost degradation in peatland areas are slower than

  11. The effect of vegetation type and fire on permafrost thaw: An empirical test of a process based model

    Science.gov (United States)

    Thierry, Aaron; Estop-Aragones, Cristian; Fisher, James; Hartley, Iain; Murton, Julian; Phoenix, Gareth; Street, Lorna; Williams, Mathew

    2015-04-01

    As conditions become more favourable for plant growth in the high latitudes, most models predict that these areas will take up more carbon during the 21st century. However, vast stores of carbon are frozen in boreal and arctic permafrost, and warming may result in some of this carbon being released to the atmosphere. The recent inclusion of permafrost thaw in large-scale model simulations has suggested that the permafrost feedback could potentially substantially reduce the predicted global net uptake of carbon by terrestrial ecosystems, with major implications for the rate of climate change. However, large uncertainties remain in predicting rates of permafrost thaw and in determining the impacts of thaw in contrasting ecosystems, with many of the key processes missing from carbon-climate models. The role that different plant communities play in insulating soils and protecting permafrost is poorly quantified, with key groups such as mosses absent in many models. But it is thought that they may play a key role in determining permafrost resilience. In order to test the importance of these ecological processes we use a new specially acquired dataset from sites in the Canadian arctic to develop, parameterise and evaluate a detailed process-based model of vegetation-soil-permafrost interactions which includes an insulating moss understory. We tested the sensitivity of modelled active layer depth to a series of factors linked to fire disturbance, which is common in boreal permafrost areas. We show how simulations of active layer depth (ALD) respond to removals of (i) vascular vegetation, (ii) moss cover, and (iii) organic soil layers. We compare model responses to observed patterns from Canada. We also describe the sensitivity of our modelled ALD to changes in temperature and precipitation. We found that four parameters controlled most of the sensitivity in the modelled ALD, linked to conductivity of organic soils and mosses.

  12. Modelling the angular effects on satellite retrieved LST at global scale using a land surface classification

    Science.gov (United States)

    Ermida, Sofia; DaCamara, Carlos C.; Trigo, Isabel F.; Pires, Ana C.; Ghent, Darren

    2017-04-01

    stratified by means of a cluster analysis using information on land cover type, fraction of vegetation cover and topography. The kernel model is then adjusted to LST data corresponding to each cluster. It is shown that the quality of the cluster based kernel model is very close to the pixel based one. Furthermore, the reduced number of parameters (limited to the number of identified clusters, instead of a pixel-by-pixel model calibration) allows improving the kernel model trough the incorporation of a seasonal component. The application of the here discussed procedure towards the harmonization of LST products from multi-sensors is on the framework of the ESA DUE GlobTemperature project.

  13. An observation-based constraint on permafrost loss as a function of global warming

    Science.gov (United States)

    Chadburn, S. E.; Burke, E. J.; Cox, P. M.; Friedlingstein, P.; Hugelius, G.; Westermann, S.

    2017-04-01

    Permafrost, which covers 15 million km2 of the land surface, is one of the components of the Earth system that is most sensitive to warming. Loss of permafrost would radically change high-latitude hydrology and biogeochemical cycling, and could therefore provide very significant feedbacks on climate change. The latest climate models all predict warming of high-latitude soils and thus thawing of permafrost under future climate change, but with widely varying magnitudes of permafrost thaw. Here we show that in each of the models, their present-day spatial distribution of permafrost and air temperature can be used to infer the sensitivity of permafrost to future global warming. Using the same approach for the observed permafrost distribution and air temperature, we estimate a sensitivity of permafrost area loss to global mean warming at stabilization of million km2 °C-1 (1σ confidence), which is around 20% higher than previous studies. Our method facilitates an assessment for COP21 climate change targets: if the climate is stabilized at 2 °C above pre-industrial levels, we estimate that the permafrost area would eventually be reduced by over 40%. Stabilizing at 1.5 °C rather than 2 °C would save approximately 2 million km2 of permafrost.

  14. A view on global permafrost distribution

    Science.gov (United States)

    Gruber, S.

    2009-12-01

    The response of permafrost to climate change has diverse effects of diverse magnitude and timing. These include feedbacks to the climate system as well as effects on landscape dynamics, ecosystems, and humans. In this context - especially near the limits of permafrost existence - permafrost maps and models are an important source of information. Here I present a global permafrost model at a resolution of 30 arc seconds (New Zealand. Based on this, questions like: How much permafrost area exists? How much of this is in mountains? Can be answered more consistently than before. Additionally, the number of people potentially affected by permafrost or its changes is investigated as a further metric of interest.

  15. Establishing Permafrost Temperature Data Reanalysis

    Science.gov (United States)

    Romanovsky, V. E.; Sazonova, T. S.; Tipenko, G. S.

    2003-12-01

    permafrost temperature data that were obtained during the 1950s and early 1960s by Max Brewer of USGS in Barrow region. Those measurements were of very high quality, with a precision of generally 0.01oC. A specific numerical model for the Barrow permafrost temperature regime was developed in 1997 at the GI Permafrost Lab. The model was calibrated using data from shallow (down to one meter) soil temperatures obtained by Ken Hinkel at a Barrow site with surface conditions similar to the Brewer site. No data from the Brewer sites were used for the calibration. The daily air temperatures and snow cover thickness during the entire period of measurements (1924-2001) at the Barrow meteorological station were used as input data for this calibrated model. As a result, a time series of daily ground temperatures for the depths between 0 and 200 meters were obtained. To compare calculated temperatures with measured data, we used the time interval between September 1951 and October 1952, when weekly measurements were available. The results of this comparison were much better than expected. For the entire period, which covers more than one year, the differences between calculated and measured permafrost temperatures were typically smaller than 0.3oC in the depth interval between 2 and 18 meters. They practically never exceeded 1oC in the upper two meters of soil and permafrost. The same approach of permafrost temperature data reanalysis was used for many other sites in Alaska and in the Russian Arctic and Sub-Arctic. The results of reconstruction of the permafrost temperature dynamics in 20th century and forecasts for the 21st century based on this approach for the Fairbanks, Barrow, Yakutsk, Tiksi, and Vorkuta sites will be presented.

  16. Permafrost degradation in West Greenland

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2012-01-01

    Important aspects of civil engineering in West Greenland relate to the presence of permafrost and mapping of the annual and future changes in the active layer due to the ongoing climatically changes in the Arctic. The Arctic Technology Centre (ARTEK) has worked more than 10 years on this topic......, Kangerlussuaq, Sisimiut and Nuuk. They are situated in continuous, discontinuous and sporadic permafrost zones. We will show examples of detoriation of permafrost related to present local scale climate observations and large scale climate and permafrost simulations modeled numerically with the GIPL model driven...... by HIRHAM climate projections for Greenland up to 2075. The engineering modelling is based on a risk assessment methodology based on a flow diagram which classify the risk of permafrost degradation causing settlement and stability problems for buildings and infrastructures based on relatively simple...

  17. Scenario-based climate change modelling for a regional permafrost probability model of the southern Yukon and northern British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    P. P. Bonnaventure

    2012-10-01

    Full Text Available Scenario-based climate change modelling for equilibrium conditions was applied to a Regional Model of permafrost probability for the southern Yukon and northwestern British Columbia. Under a −1 K cooling scenario, permafrost area expands from 58% (present day of the 490 000 km2 to 76%, whereas warming scenarios of +1 K, +2 K and +5 K decrease the terrain underlain by permafrost to 38%, 24% and 9% respectively. The morphology of permafrost gain/loss under these scenarios is controlled by the Surface Lapse Rate (SLR, which varies across the region below and above treeline. The SLR is an air temperature elevation gradient that that is noticeably different across the study region. As a result of this attribute three distinct patterns of loss morphology can be identified. Areas that are more maritime exhibit SLRs characteristically similar above and below treeline resulting in low probabilities of permafrost in valley bottoms. Consequently, a loss front moves to upper elevations when warming scenarios are applied (Simple Unidirectional Spatial Loss. Areas where SLRs are gentle below treeline (but normal/negative and normal above treeline show lower permafrost probabilities with a loss front moving up mountain according to two separate SLRs (Complex Unidirectional Spatial Loss. Finally areas that display high continentally exhibit Bidirectional Spatial Loss where the loss front of lower permafrost probabilities moves up mountain above treeline and down mountain below treeline. Areas that are most affected by permafrost loss are zones with SLRs close to 0 K km−1 where permafrost is extensive, whereas the least susceptible areas to changes in MAAT are above treeline and are highly elevation dependent.

  18. Hydrogeochemistry of groundwaters in and below the base of thick permafrost at Lupin, Nunavut, Canada

    Science.gov (United States)

    Stotler, Randy L.; Frape, Shaun K.; Ruskeeniemi, Timo; Ahonen, Lasse; Onstott, Tullis C.; Hobbs, Monique Y.

    2009-06-01

    SummaryShield fluids are commonly understood to evolve through water-rock interaction. However, fluids may also concentrate during ice formation. Very little is currently known about groundwater conditions beneath thick permafrost in crystalline environments. This paper evaluates three possible Shield fluid evolution pathways at a crystalline Shield location currently under 500+ meters of permafrost, including surfical cryogenic concentration of seawater, in situ cryogenic concentration and water-rock interaction. A primary goal of this study was to further scientific understanding of permafrost and its role in influencing deep flow system evolution, fluid movement and chemical evolution of waters in crystalline rocks. Precipitation, surface, permafrost and subpermafrost water samples were collected, as well as dissolved and free gas samples, fracture fillings and matrix fluid samples to characterize the site. Investigations of groundwater conditions beneath thick permafrost provides valuable information which can be applied to safety assessment of deep, underground nuclear waste repositories, effects of long-term mining in permafrost areas and understanding analogues to potential life-bearing zones on Mars. The study was conducted in the Lupin gold mine in Nunavut, Canada, located within the zone of continuous permafrost. Through-taliks beneath large lakes in the area provided potential hydraulic connections through the permafrost. Na-Cl and Na-Cl-SO 4 type permafrost waters were contaminated by mining activities, affecting the chloride and nitrate concentrations. High nitrate concentrations (423-2630 mg L -1) were attributed to remnants of blasting. High sulfate concentrations in the permafrost (578-5000 mg L -1) were attributed to naturally occurring and mining enhanced sulfide oxidation. Mine dewatering created an artificial hydraulic gradient, resulting in methane hydrate dissociation at depth. Less contaminated basal waters had medium sulfate concentrations

  19. A new web-based course: dealing with glaciers and permafrost hazards

    Science.gov (United States)

    Oswald, S.; Kaeaeb, A.; Haeberli, W.

    2003-04-01

    The intensive human use of high mountains intersects more and more with the hazard zones of such environments. Because of the complexity of such processes and impacts, dealing with such risks requires a broad education in many sub-domains of the earth sciences and the socio-economic field. Inter- and trans-disciplinary training and education of professionals is therefore essential. Thus the goal of the Swiss Virtual Campus project "Dealing with Natural Hazards" is to provide such a course program covering the basics of dealing with natural hazards, including technical, environmental and social aspects. In the field of natural hazards and risk management, education at the Swiss universities is mostly structured in narrow sectors. Using the advantages of the internet, the Virtual Campus provides teachers and students an interdisciplinary discussion platform on the integral approach and the handling with natural hazards. The course content is organised in 5 modules: 1 basic knowledge and tools, 2 hydrological / meteorological hazards, 3 geological hazards, 4 vulnerability of property and of socio-economic systems and 5 integral natural risk management. To ensure a national and international access the courses are designed in English and published on the internet. Within the scope of this project we are developing lessons in the subject area of natural hazards related to glaciers and permafrost. These are ice avalanches, glacier floods, glacier length variations and permafrost. The content is divided into chapters, which are consistent over the entire module: (1) processes: characterisation of the different processes, (2) triggering: initiating events, (3) data acquisition, mapping and monitoring: appropriate methods, (4) estimation models: application of the adequate model, (5) combinations and interactions: interrelation and impacts of different hazards, (6) long-term effects: global change effects, (7) integral hazard recognition and assessment: integral proceedings

  20. 1,100,000 year history of Siberian permafrost based on U-Pb chronology of speleothems

    Science.gov (United States)

    Vaks, Anton; Mason, Andrew J.; Breitenbach, Sebastian F. M.; Kononov, Alexander M.; Osintcev, Alexander V.; Henderson, Gideon M.

    2014-05-01

    We have used U-Pb dating of the speleothems from Siberian Ledyanaya Lenskaya Cave for tracing of permafrost thawing events during the last 1.1 million years. Rain and snowmelt waters can penetrate into caves only when the soil and subsoil temperatures are above 0° C and permafrost above the cave is discontinuous or absent. Therefore, speleothems in regions currently affected by permafrost provide a tracer of past permafrost thawing events. Ledyanaya Lenskaya Cave is located at 60° 22'N-116° 57'E, on the southern boundary of continuous permafrost zone, with no present-day water seepage in the cave. Temperatures in the region range from -32° C (January) to +18° C (July), with mean annual temperature of ~-6° C. U-Th dating of speleothems from this cave in a previous study [1] showed that the youngest speleothem growth period occurred at 427±23 thousand years ago (ka), during the early Marine Isotope Stage (MIS) 11. During this episode global temperature was 1.5° C higher than pre-industrial levels, and ~0.7° C above the present. In the current study two horizons at the base of a stalagmite were dated using U-Pb chronology [2]. Isochron ages of 1074.1 +7.9/-6.9 ka and 951.4 +3.6/-4.4 ka were obtained. Timing of these permafrost thawing events correlates with events of exceptionally high Pacific Warm Pool sea surface temperature (~+30° C)[3]. During these warm episodes the average global temperature was 1.2-1.3° C higher than pre-industrial temperatures. These findings put the threshold of thawing of the continuous permafrost near its southern boundary slightly lower than it was found previously. The dating work is still in process and is now focusing on growth periods older than MIS-11 but younger than 950 ka. The oldest horizon of the stalagmite grew on the bedrock. This layer was probably amongst the first vadose speleothems that formed after the cave was uplifted above the groundwater table (associated with the nearby Lena River). Today the cave is ~50

  1. Highly specific and rapid immuno-fluorescent visualization and detection of E. coli O104:H4 with protein-A coated magnetic beads based LST-MUG assay.

    Science.gov (United States)

    Barizuddin, Syed; Balakrishnan, Baskar; Stringer, R Cody; Dweik, Majed

    2015-08-01

    A method combining immunomagnetic separation and fluorescent sensing was developed to detect Escherichia coli (E. coli) O104:H4. The antibody specific to E. coli O104:H4 was immobilized on protein A-coated magnetic beads. This protein-A-anti E. coli O104:H4 complex was used to bind Fluorescein IsoThioCyanate (FITC) labeled E. coli O104:H4 antigen (whole cell) on it. The goal was to achieve a fluorescently detectable protein-A-anti E. coli O104:H4-E. coli O104:H4 complex on the magnetic beads. Fluorescent microscopy was used to image the magnetic beads. The resulting fluorescence on the beads was due to the FITC labeled antigen binding on the protein-A-anti E. coli O104:H4 immobilized magnetic beads. This visually proves the antigen-antibody binding. The fluorescent imaging results were obtained in 2 h if the minimum available bacteria in the sample were at least 10(5) CFU/ml. If no fluorescence was observed on the magnetic beads during fluorescent imaging, it indicates the bacterial concentration in the sample to be too low for it to have bound to the magnetic beads and hence no detection was possible. To detect bacterial concentration less than 10(5) CFU/ml in the sample, an additional step was required for detection. The magnetic bead complex was added to the LST-MUG (lauryl sulfate tryptose-4-methylumbelliferyl-β-D-glucuronide), a signaling reporter. The E. coli O104:H4 grows in LST-MUG and releases β-glucuronidase enzyme. This enzyme cleaves the MUG substrate that produces 4-methylumbelliferone, a highly fluorescent species. This fluorescence was detected using a spectrofluorometer. The emission peak in the fluorescent spectrum was found to be at 450 nm. The lower and upper detection range for this LST-MUG assay was found to be 2.05×10(5)-4.09×10(8) CFU/ml. The results for the LST-MUG assay for concentrations below 10(5) CFU/ml were ascertained in 8h. The advantages of this technique include the specific detection of bacteria without an enrichment step and

  2. Determination of Land Surface Temperature (LST) and Potential ...

    African Journals Online (AJOL)

    Determination of Land Surface Temperature (LST) and Potential Urban Heat Island Effect in Parts of Lagos State using Satellite ... Changes in temperature appear to be closely related to concentrations of atmospheric carbon dioxide.

  3. Thule Air Base Airfield White Painting and Permafrost Investigation. Phases I-IV

    Science.gov (United States)

    2013-06-01

    overlying an 18-ft thick perma- nently frozen till. Figure 40 shows that the swales at the transition from the embankment to the native soil grade...the warmest. The depth of thaw after one season is represented by the blue dotted line. The raised permafrost table into the fill produces swales at

  4. Thule Air Base Airfield White Painting and Permafrost Investigation. Phases 1-4

    Science.gov (United States)

    2013-06-01

    overlying an 18-ft thick perma- nently frozen till. Figure 40 shows that the swales at the transition from the embankment to the native soil grade...the warmest. The depth of thaw after one season is represented by the blue dotted line. The raised permafrost table into the fill produces swales at

  5. Geotechnical problems of construction on permafrost in Mongolia

    Institute of Scientific and Technical Information of China (English)

    D. Dashjamts; Z. Binderya; J. Altantsetseg

    2013-01-01

    Permafrost is found on 63%of the territory of Mongolia. This paper provides evidence that the main influences on per-mafrost formation are meso and micro factors of climate and geographical location. Regional classifications of permafrost areas in order to select the optimal principle of foundation design on permafrost are suggested based on many years’ ex-perience and lessons learned from past construction works in Mongolian geotechnical and climatic conditions. Finally, optimal alternatives for designing foundations for construction on permafrost are presented based on the specific charac-teristics of permafrost in the classification areas and certain building dimensions.

  6. Estimating permafrost distribution in the maritime Southern Alps, New Zealand, based on climatic conditions at rock glacier sites

    Directory of Open Access Journals (Sweden)

    Katrin eSattler

    2016-02-01

    Full Text Available Alpine permafrost occurrence in maritime climates has received little attention, despite suggestions that permafrost may occur at lower elevations than in continental climates. To assess the spatial and altitudinal limits of permafrost in the maritime Southern Alps, we developed and tested a catchment-scale distributed permafrost estimate. We used logistic regression to identify the relationship between permafrost presence at 280 active and relict rock glacier sites and the independent variables a mean annual air temperature and b potential incoming solar radiation in snow free months. The statistical relationships were subsequently employed to calculate the spatially-distributed probability of permafrost occurrence, using a probability of ≥ 0.6 to delineate the potential permafrost extent. Our results suggest that topoclimatic conditions are favorable for permafrost occurrence in debris-mantled slopes above ~ 2000 m in the central Southern Alps and above ~ 2150 m in the more northern Kaikoura ranges. Considering the well-recognized latitudinal influence on global permafrost occurrences, these altitudinal limits are lower than the limits observed in other mountain regions. We argue that the Southern Alps’ lower distribution limits may exemplify an oceanic influence on global permafrost distribution. Reduced ice-loss due to moderate maritime summer temperature extremes may facilitate the existence of permafrost at lower altitudes than in continental regions at similar latitude. Empirical permafrost distribution models derived in continental climates may consequently be of limited applicability in maritime settings.

  7. Uncertainty Estimates of NASA Satellite LST over the Greenland and Antarctic Plateau: 2003-2015

    Science.gov (United States)

    Knuteson, R.; Borbas, E. E.; Burgess, G.

    2015-12-01

    Jin and Dickinson (2010) identify three reasons why LST has not been adopted as a climate variable. Paraphrasing the authors, the three roadblocks for use of satellite LST products in climate studies are; 1) unknown accuracy (What are surface emissivity and atmospheric correction uncertainties?)2) spatial scale ambiguity (Are satellite footprints too large to be physically meaningful?)3) lack of consistency over decadal time scales (How far backward/forward can we go in time?). These issues apply particularly to the cryosphere where the lack of surface measurement sites make the proper use of satellite observations critical for monitoring climate change. This paper will address each of these three issues but with a focus on the high and dry Greenland and Antarctic plateaus and the contrast in trends between the two. Recent comparisons of MODIS LST products with AIRS version 6 LST products show large differences over Greenland (Lee et al. 2014). In this paper we take the logical next step of creating a bottoms up uncertainty budget for a new synergistic AIRS/MODIS LST product for ice and snow conditions. This new product will address the issue of unknown accuracy by providing a local LST uncertainty along with each estimate of surface temperature. The combination of the high spatial resolution of the MODIS and the high spectral resolution of the AIRS observations of radiance allow the combination of the two sensors to provide information with lower uncertainty than what is possible from the current separate operational products. The issue of surface emissivity and atmospheric correction uncertainties will be addressed explicitly using spectrally resolved models that cover the infrared region. The issue of spatial scale ambiguity is overcome by creating a classification of the results based on the spatial homogenity of surface temperatures. The issue of lack of consistency over long time scales is addressed by demonstrating an algorithm using collocated NASA MODIS

  8. Application of matter-element analysis based on entropy right to evaluate the pavement condition in permafrost region

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Evaluation of pavement performance is one of the most important issues in a pavement-management system.By employing the concept of entropy,the matter-element model for evaluating pavement is established,and the weights of the evaluation indices are obtained from surveying data.By calculating the degree of dependence of the matter-element model,the pavement performance evaluation can be obtained by this method.The results show that the matter-element model based on entropy right has good performance for evaluating the pavement condition in permafrost region.

  9. Vulnerability and feedbacks of permafrost to climate change

    Science.gov (United States)

    Guido Grosse; Vladimir Romanovsky; Torre Jorgenson; Katey Walter Anthony; Jerry Brown; Pier Paul Overduin; Alfred. Wegener

    2011-01-01

    The effects of permafrost degradation on terrestrial and offshore environments in polar regions and on the Earth's atmosphere are significant. Field-based observations, remote sensing, and modeling document regional warming and thawing of permafrost. However, major research questions regarding vulnerability of permafrost to thawing, the projected decline in...

  10. Permafrost: It's a gas

    Science.gov (United States)

    Christensen, Torben R.

    2016-09-01

    Climate change is causing widespread permafrost thaw in the Arctic. Measurements at 33 Arctic lakes show that old carbon from thawing permafrost is being emitted as methane, though emission rates have not changed during the past 60 years.

  11. Surface Deformation Monitoring in Permafrost Regions of Tibetan Plateau Based on Alos Palsar Data

    Science.gov (United States)

    Chen, L. M.; Qiao, G.; Lu, P.

    2017-09-01

    The permafrost region of Qinghai-Tibet Plateau is widely distributed with the freeze/thaw processes that cause surface structural damage. The differential interferometry synthetic aperture radar (DInSAR) can detect large scale surface deformation with high precision, thus can be used to monitor the freeze/thaw processes of frozen soil area. In this paper, the surface deformation pattern of Qinghai-Tibet railway was analyzed by using the PALSAR 1.0 raw data of the ALOS satellite (L band) and 90m resolution SRTM DEM data, with the help of two-pass DInSAR method in GAMMA software, and the differential interferograms and deformation maps were obtained accordingly. Besides, the influence of temperature, topography and other factors on deformation of frozen soil were also studied. The following conclusions were obtained: there is a negative correlation between deformation and temperature, and there is a delay between the deformation change and that of temperature; deformation and elevation are positively correlated; the permafrost deformation is also affected by solar radiation that could form variable amplitude variation.

  12. Use of a New Low-Power Laser-Based Instrumentation to Measure Methane Emissions from Remote Permafrost Regions

    Science.gov (United States)

    Burba, George; Sturtevant, Cove; Peltola, Olli; Schreiber, Peter; Zulueta, Rommel; Haapanala, Sami; Mammarella, Ivan; Rinne, Janne; Vesala, Timo; McDermitt, Dayle; Oechel, Walt

    2013-04-01

    . Remote permafrost wetlands of Arctic tundra, northern boreal peatlands of Canada and Siberia, and other highly methanogenic ecosystems have few eddy covariance methane measurement stations. Those existing are often located near grid power sources and roads rather than in the middle of the methane-producing ecosystem, while those that are placed appropriately may require extraordinary efforts to build and maintain them, with large investments into man-power and infrastructure. Alternatively, open-path instrumentation allows methane flux measurements at normal pressure without a need for a pump. As a result, the measurements can be done with very low-power (e.g., 7-10 Watts) light (5 .2 kg) instruments permitting solar- and wind- powered remote deployments in hard-to-reach sites from permanent, portable or mobile stations, and cost-effective additions of a methane measurement to the present array of CO2 and H2O measurements. The low-power operation and light weight of open-path eddy covariance station is important for number of ecosystems (rice fields, landfills, wetlands, cattle yards, etc.), but it is especially important for permafrost and other cold regions where grid power and access roads are generally not available, and logistics of running the experiment is particularly expensive. Emerging research using low-power laser-based instrumentation to measure CH4 emissions are presented from several permafrost ecosystems with contrasting setups, weather, and moisture conditions. Principles of open-path instrument operation, station characteristics and requirements are also discussed, as well as concurrent measurements of CO2 and H2O emissions using open-path and enclosed instrumentation.

  13. Estimating Understory Temperatures Using MODIS LST in Mixed Cordilleran Forests

    Directory of Open Access Journals (Sweden)

    David N. Laskin

    2016-08-01

    Full Text Available Satellite remote sensing provides a rapid and broad-scale means for monitoring vegetation phenology and its relationship with fluctuations in air temperature. Investigating the response of plant communities to climate change is needed to gain insight into the potentially detrimental effects on ecosystem processes. While many studies have used satellite-derived land surface temperature (LST as a proxy for air temperature, few studies have attempted to create and validate models of forest understory temperature (Tust, as it is obscured from these space-borne observations. This study worked to predict instantaneous values of Tust using daily Moderate Resolution Imaging Spectroradiometer (MODIS LST data over a 99,000 km2 study area located in the Rocky Mountains of western Alberta, Canada. Specifically, we aimed to identify the forest characteristics that improve estimates of Tust over using LST alone. Our top model predicted Tust to within a mean absolute error (MAE of 1.4 °C with an overall model fit of R2 = 0.89 over two growing seasons. Canopy closure and the LiDAR-derived standard deviation of canopy height metric were found to significantly improve estimations of Tust over MODIS LST alone. These findings demonstrate that canopy structure and forest stand-type function to differentiate understory air temperatures from ambient canopy temperature as seen by the sensor overhead.

  14. Review article: Inferring permafrost and permafrost thaw in the mountains of the Hindu Kush Himalaya region

    Science.gov (United States)

    Gruber, Stephan; Fleiner, Renate; Guegan, Emilie; Panday, Prajjwal; Schmid, Marc-Olivier; Stumm, Dorothea; Wester, Philippus; Zhang, Yinsheng; Zhao, Lin

    2017-01-01

    The cryosphere reacts sensitively to climate change, as evidenced by the widespread retreat of mountain glaciers. Subsurface ice contained in permafrost is similarly affected by climate change, causing persistent impacts on natural and human systems. In contrast to glaciers, permafrost is not observable spatially and therefore its presence and possible changes are frequently overlooked. Correspondingly, little is known about permafrost in the mountains of the Hindu Kush Himalaya (HKH) region, despite permafrost area exceeding that of glaciers in nearly all countries. Based on evidence and insight gained mostly in other permafrost areas globally, this review provides a synopsis on what is known or can be inferred about permafrost in the mountains of the HKH region. Given the extreme nature of the environment concerned, it is to be expected that the diversity of conditions and phenomena encountered in permafrost exceed what has previously been described and investigated. We further argue that climate change in concert with increasing development will bring about diverse permafrost-related impacts on vegetation, water quality, geohazards, and livelihoods. To better anticipate and mitigate these effects, a deepened understanding of high-elevation permafrost in subtropical latitudes as well as the pathways interconnecting environmental changes and human livelihoods are needed.

  15. Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard, TSP NORWAY

    Science.gov (United States)

    Christiansen, H.; Berthling, I.; Blikra, L.; Dehls, J.; Etzelmuller, B.; Farbrot, H.; Humlum, O.; Isaksen, K.; Juliussen, H.; Lauknes, T.; Midttomme, K.; Rønning, J.

    2007-12-01

    The Norwegian funded IPY project 'Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard', (TSP NORWAY) is part of the TSP cluster. The main goal of TSP NORWAY is to measure and model the permafrost distribution in Norway and Svalbard, focussing on its thermal state, thickness and associated periglacial processes, including increased knowledge of the mountain permafrost distribution related to geohazard studies on rockslides. TSP NORWAY will contribute to IPY by providing a spatially distributed set of observations on the present status of permafrost temperatures and active layer thicknesses, and periglacial processes in Svalbard and Norway. Special focus is given to empirical and numerical modelling of permafrost distribution and thermal ground heat fluxes to address future climate variability on permafrost distribution and associated geomorphic activity. Permafrost distribution in the North Atlantic area is strongly climatically controlled, mainly by the North Atlantic Drift, providing much less permafrost than in any other high latitude terrestrial region on the Northern Hemisphere. Hopefully a first Nordic permafrost map will be based on Nordic permafrost collaboration during IPY. The TSP NORWAY project has established two permafrost observatories with intensive permafrost and periglacial monitoring sites in maritime and continental areas. One in Troms, northern Norway, which will be part of the north Scandinavian Permafrost Observatory extending into northernmost Sweden and Finland, and the Svalbard Nordenskiöld Land Permafrost Observatory also with both maritime and continental sites. The first Norwegian permafrost database, NORPERM, with all permafrost data from Norway and Svalbard, collected before and during IPY, has been established at the Norwegian Geological Survey. NORPERM shall contribute data as requested in the IPY data protocol and the TSP cluster to the international Global Terrestrial Network on

  16. DUE PERMAFROST: A Circumpolar Remote Sensing Service for Permafrost - Evaluation Case Studies and Intercomparison with Regional Climate Model Simulations

    Science.gov (United States)

    Heim, B.; Bartsch, A.; Elger, K. K.; Rinke, A.; Matthes, H.; Zhou, X.; Klehmet, K.; Buchhorn, M.; Soliman, A. S.; Duguay, C. R.

    2013-12-01

    The objective of the ESA Data User Element DUE Permafrost project (https://www.ipf.tuwien.ac.at/permafrost/) was to establish a Remote Sensing Service for permafrost applications. Permafrost has been addressed as one of the Essential Climate Variables (ECVs) in the Global Climate Observing System (GCOS). Permafrost is a subground phenomenon but Earth Observation can provide permafrost-related indicators and geophysical parameters used in modelling and monitoring. Climate and permafrost modelers as well as field investigators are associated users including the International Permafrost Association (IPA). http://www.page21.eu/ The ESA DUE Permafrost project (2009-2012) developed a suite of remote sensing products indicative for the subsurface phenomenon permafrost: Land Surface Temperature (LST), Surface Soil Moisture (SSM), Surface Frozen and Thawed State (Freeze/Thaw), Terrain, Land Cover, and Surface Water. Snow parameters (Snow Extent and Snow Water Equivalent) are being developed through the DUE GlobSnow project (Global Snow Monitoring for Climate Research, 2008-2011). The final DUE Permafrost remote sensing products cover the years 2007 to 2011 with a circumpolar coverage (north of 50°N). The products were released in 2012, to be used to analyze the temporal dynamics and map the spatial patterns of permafrost indicators. Further information is available at www.ipf.tuwien.ac.at/ permafrost. The remote sensing service also supports the FP7 funded project PAGE21 - Changing Permafrost in the Arctic and its Global Effects in the 21st Century, http://www.page21.eu/. The primary programme providing various ground data for the evaluation is the Global Terrestrial Network for Permafrost (GTN-P) initiated by the International Permafrost Association (IPA). Ground data ranges from active layer- and snow depths, to air-, ground-, and borehole temperature data as well as soil moisture measurements and the description of landform and vegetation. The involvement of scientific

  17. A microbial functional group-based module for simulating methane production and consumption: Application to an incubated permafrost soil

    Science.gov (United States)

    Xu, Xiaofeng; Elias, Dwayne A.; Graham, David E.; Phelps, Tommy J.; Carroll, Sue L.; Wullschleger, Stan D.; Thornton, Peter E.

    2015-07-01

    Accurately estimating methane (CH4) flux in terrestrial ecosystems is critically important for investigating and predicting biogeochemistry-climate feedbacks. Improved simulations of CH4 flux require explicit representations of the microbial processes that account for CH4 dynamics. A microbial functional group-based module was developed, building on the decomposition subroutine of the Community Land Model 4.5. This module considers four key mechanisms for CH4 production and consumption: methanogenesis from acetate or from single-carbon compounds and CH4 oxidation using molecular oxygen or other inorganic electron acceptors. Four microbial functional groups perform these processes: acetoclastic methanogens, hydrogenotrophic methanogens, aerobic methanotrophs, and anaerobic methanotrophs. This module was used to simulate dynamics of carbon dioxide (CO2) and CH4 concentrations from an incubation experiment with permafrost soils. The results show that the model captures the dynamics of CO2 and CH4 concentrations in microcosms with top soils, mineral layer soils, and permafrost soils under natural and saturated moisture conditions and three temperature conditions of -2°C, 3°C, and 5°C (R2 > 0.67 P temperature conditions. Sensitivity analysis confirmed the importance of acetic acid's direct contribution as substrate and indirect effects through pH feedback on CO2 and CH4 production and consumption. This study suggests that representing the microbial mechanisms is critical for modeling CH4 production and consumption; it is urgent to incorporate microbial mechanisms into Earth system models for better predicting trace gas dynamics and the behavior of the climate system.

  18. Genetic and bibliographic information: LST1 [GenLibi

    Lifescience Database Archive (English)

    Full Text Available LST1 leukocyte specific transcript 1 human Myocardial Infarction (MeSH) Cardiovascular Diseases... (C14) > Heart Diseases (C14.280) > Myocardial Ischemia (C14.280.647) > Myocardial Infarction (C...14.280.647.500) Cardiovascular Diseases (C14) > Vascular Diseases (C14.907) > Myocardial Ischemia (C14.907.585) > Myocardial Infarction (C14.907.585.500) 03A0779575 ...

  19. Access to Permafrost Data: A Continuing Challenge

    Science.gov (United States)

    Brown, J.; Nelson, F. E.; Smith, S.; Parsons, M.; Romanovsky, V. E.; Zhang, T.

    2006-12-01

    The formation, preservation, and degradation of permafrost terrains are significant indicators of the historical, present and future changes in the Earth's cryosphere. Historically, permafrost investigations date back to the 19th century starting in Russia. During the 20th century, permafrost was investigated for both scientific and engineering purposes throughout the Northern Hemisphere and to a more limited extent in the Southern Hemisphere. Not unlike other disciplines, these investigations were conducted by individuals, and private and governmental organizations, and with an increasing intensity during and following World War II. In many cases, data were classified or considered proprietary or simply ended up in personal files, and therefore not available to the public. The magnitude and diversity of these data resources became more obvious as the permafrost communities began to meet at the international permafrost conferences, the first of which was in 1963 at Purdue University. During the 1988 Fifth International Conference on Permafrost in Trondheim, Norway, a workshop was convened to assess the magnitude of permafrost data and information and related access issues. The International Permafrost Association 's working groups took the lead in organizing a series of meetings that culminated in a workshop on data access and rescue in Olso, Norway in November 1994. The outgrowth of these deliberations was the development of the Global Geocryological Database (GGD) with major activities based at the National Snow and Data Center (NSIDC) in Boulder, Colorado. A number of databases and products emerged during the 1990s as research funding for international projects increased. Metadata for data sets and bibliographies of literature were compiled. Several web-based projects sites were developed and include the Global Terrestrial Network for Permafrost (GTN-P) and the Circumpolar Active layer monitoring (CALM) network. Several CDs were prepared for the Seventh and

  20. Thermal erosion of a permafrost coastline: Improving process-based models using time-lapse photography

    Science.gov (United States)

    Wobus, C.; Anderson, R.; Overeem, I.; Matell, N.; Clow, G.; Urban, F.

    2011-01-01

    Coastal erosion rates locally exceeding 30 m y-1 have been documented along Alaska's Beaufort Sea coastline, and a number of studies suggest that these erosion rates have accelerated as a result of climate change. However, a lack of direct observational evidence has limited our progress in quantifying the specific processes that connect climate change to coastal erosion rates in the Arctic. In particular, while longer ice-free periods are likely to lead to both warmer surface waters and longer fetch, the relative roles of thermal and mechanical (wave) erosion in driving coastal retreat have not been comprehensively quantified. We focus on a permafrost coastline in the northern National Petroleum Reserve-Alaska (NPR-A), where coastal erosion rates have averaged 10-15 m y-1 over two years of direct monitoring. We take advantage of these extraordinary rates of coastal erosion to observe and quantify coastal erosion directly via time-lapse photography in combination with meteorological observations. Our observations indicate that the erosion of these bluffs is largely thermally driven, but that surface winds play a crucial role in exposing the frozen bluffs to the radiatively warmed seawater that drives melting of interstitial ice. To first order, erosion in this setting can be modeled using formulations developed to describe iceberg deterioration in the open ocean. These simple models provide a conceptual framework for evaluating how climate-induced changes in thermal and wave energy might influence future erosion rates in this setting.

  1. Can We Avoid the Permafrost Carbon Tipping Point?

    Science.gov (United States)

    Schaefer, K. M.; Zhang, T.; Bruhwiler, L.; Barrett, A. P.; Li, Z.

    2011-12-01

    If we reduce fossil fuel emissions and slow the Arctic warming rate, can we delay or even avoid the permafrost carbon tipping point? Permafrost currently contains about 1466 Gt of carbon frozen during or since the last ice age. The permafrost carbon tipping point occurs when the release of carbon from thawing permafrost overpowers enhanced uptake due to warmer temperatures. The tipping point indicates when the Arctic irreversibly changes from a carbon sink to a source relative to the atmosphere and marks the start of the Permafrost Carbon Feedback. The tipping point is irreversible because once the carbon thaws and decays into the atmosphere, there is no way to put the carbon back into the permafrost. Projections based on the A1B IPCC scenario indicate that the PCF tipping point will occur between 2020 and 2030, with a total of 190±64 Gt of carbon released into the atmosphere by 2300. We ran a series of model projections out to 2300 based on the A1B scenario, but capped emissions at various levels, each representing a different overall Arctic warming. We present the area of permafrost lost, the permafrost carbon tipping point, and total permafrost carbon flux as a function of Arctic temperature increase. We show the maximum allowed Arctic temperature increase before initiating the permafrost carbon feedback.

  2. Hydrological modelling over different scales on the edge of the permafrost zone: approaching model realism based on experimentalists' knowledge

    Science.gov (United States)

    Nesterova, Natalia; Makarieva, Olga; Lebedeva, Lyudmila

    2017-04-01

    Quantitative and qualitative experimentalists' data helps to advance both understanding of the runoff generation and modelling strategies. There is significant lack of such information for the dynamic and vulnerable cold regions. The aim of the study is to make use of historically collected experimental hydrological data for modelling poorly-gauged river basins on larger scales near the southern margin of the permafrost zone in Eastern Siberia. Experimental study site "Mogot" includes the Nelka river (30.8 km2) and its three tributaries with watersheds area from 2 to 5.8 km2. It is located in the upper elevated (500 - 1500 m a.s.l.) part of the Amur River basin. Mean annual temperature and precipitation are -7.5°C and 555 mm respectively. Top of the mountains with weak vegetation has well drained soil that prevents any water accumulation. Larch forest on the northern slopes has thick organic layer. It causes shallow active layer and relatively small subsurface water storage. Soil in the southern slopes has thinner organic layer and thaws up to 1.6 m depth. Flood plains are the wettest landscape with highest water storage capacity. Measured monthly evaporation varies from 9 to 100 mm through the year. Experimental data shows importance of air temperature and precipitation changes with the elevation. Their gradient was taken into account for hydrological simulations. Model parameterization was developed according to available quantitative and qualitative data in the Mogot station. The process-based hydrological Hydrograph model was used in the study. It explicitly describes hydrological processes in different permafrost environments. Flexibility of the Hydrograph model allows take advantage from the experimental data for model set-up. The model uses basic meteorological data as input. The level of model complexity is suitable for a remote, sparsely gauged region such as Southern Siberia as it allows for a priori assessment of the model parameters. Model simulation

  3. Monitoring of the ground surface temperature and the active layer in NorthEastern Canadian permafrost areas using remote sensing data assimilated in a climate land surface scheme.

    Science.gov (United States)

    Marchand, N.; Royer, A.; Krinner, G.; Roy, A.

    2014-12-01

    Projected future warming is particularly strong in the Northern high latitudes where increases of temperatures are up to 2 to 6 °C. Permafrost is present on 25 % of the northern hemisphere lands and contain high quantities of « frozen » carbon, estimated at 1400 Gt (40 % of the global terrestrial carbon). The aim of this study is to improve our understanding of the climate evolution in arctic areas, and more specifically of land areas covered by snow. The objective is to describe the ground temperature year round including under snow cover, and to analyse the active layer thickness evolution in relation to the climate variability. We use satellite data (fusion of MODIS land surface temperature « LST » and microwave AMSR-E brightness temperature « Tb ») assimilated in the Canadian Land Surface Scheme (CLASS) of the Canadian climate model coupled with a simple radiative transfer model (HUT). This approach benefits from the advantages of each of the data type in order to complete two objectives : 1- build a solid methodology for retrieving the ground temperature, with and without snow cover, in taïga and tundra areas ; 2 - from those retrieved ground temperatures, derive the summer melt duration and the active layer depth. We describe the coupling of the models and the methodology that adjusts the meteorological input parameters of the CLASS model (mainly air temperature and precipitations derived from the NARR database) in order to minimise the simulated LST and Tb ouputs in comparison with satellite measurements. Using ground-based meteorological data as validation references in NorthEastern Canadian tundra, the results show that the proposed approach improves the soil temperatures estimates when using the MODIS LST and Tb at 10 and 19 GHz to constrain the model in comparison with the model outputs without satellite data. Error analysis is discussed for the summer period (2.5 - 4 K) and for the snow covered winter period (2 - 3.5 K). Further steps are

  4. Methane emission from sub-sea permafrost in the East Siberian Arctic shelf: model-based evaluation of potential impact on global climate

    Science.gov (United States)

    Anisimov, O. A.; Lavrov, S. A.; Borzenkova, I. I.

    2011-12-01

    Several recent publications suggest that the observed high concentration of methane over the East Siberian Shelf (ESS) may be attributed to thawing and increased gas permeability (through taliks) of the sub-sea permafrost. Methane is released from unstable gas hydrates and propagates through newly formed taliks in the bottom sediments to the water and further to the atmosphere. Under sustained warming in the following decades it may have potentially dramatic effect on global climate. In this study we examine this hypothesis using comprehensive modelling approach. Direct observations indicate that since the mid-1980s bottom waters over the ESS warmed by ca. 2.1°C. We used the model to examine whether such changes may have caused substantial degradation of methane bearing sub-sea permafrost and CH4 supersaturation of the ESS sea waters. The model is based on the heat transfer equation and explicitly accounts for the effect of salt diffusion in the bottom sediments by coupling the thermal and mass fluxes. We forced the model by the prescribed seasonal bottom water temperature and salinity to calculate changes in the thermal state of permafrost after the inundation of the ESS, and to predict the changes in the following 1000 years. We used a climate scenario suggesting that at the time of inundation (ca 8 Ky BP) the top sediment layer warmed by ca. 12 °C from -13.5 °C (mean annual air temperature) to -1.5 °C (bottom water temperature). Afterwards temperature remained unchanged until 1985. Since then in accord with modern observations we imposed 0.09°C/year trend until 2100, and prescribed temperature to constant value of 11.5 °C afterwards. The rate of temperature change in the 21st century in this highly schematic scenario by far exceeds all IPCC projections. We did it intentionally to explore the most extreme pathway for potential sub-see permafrost degradation underneath the ESS. Model results indicated ca 1 m deepening of the upper sub-sea permafrost boundary

  5. Semiautomatic mapping of permafrost in the Yukon Flats, Alaska

    Science.gov (United States)

    Gulbrandsen, Mats Lundh; Minsley, Burke J.; Ball, Lyndsay B.; Hansen, Thomas Mejer

    2016-12-01

    Thawing of permafrost due to global warming can have major impacts on hydrogeological processes, climate feedback, arctic ecology, and local environments. To understand these effects and processes, it is crucial to know the distribution of permafrost. In this study we exploit the fact that airborne electromagnetic (AEM) data are sensitive to the distribution of permafrost and demonstrate how the distribution of permafrost in the Yukon Flats, Alaska, is mapped in an efficient (semiautomatic) way, using a combination of supervised and unsupervised (machine) learning algorithms, i.e., Smart Interpretation and K-means clustering. Clustering is used to sort unfrozen and frozen regions, and Smart Interpretation is used to predict the depth of permafrost based on expert interpretations. This workflow allows, for the first time, a quantitative and objective approach to efficiently map permafrost based on large amounts of AEM data.

  6. Determining the required accuracy of LST products for estimating surface energy fluxes

    Science.gov (United States)

    Pinheiro, A. C.; Reichle, R.; Sujay, K.; Arsenault, K.; Privette, J. L.; Yu, Y.

    2006-12-01

    Land Surface Temperature (LST) is an important parameter to assess the energy state of a surface. Synoptic satellite observations of LST must be used when attempting to estimate fluxes over large spatial scales. Due to the close coupling between LST, root level water availability, and mass and energy fluxes at the surface, LST is particularly useful over agricultural areas to help determine crop water demands and facilitate water management decisions (e.g., irrigation). Further, LST can be assimilated into land surface models to help improve estimates of latent and sensible heat fluxes. However, the accuracy of LST products and its impact on surface flux estimation is not well known. In this study, we quantify the uncertainty limits in LST products for accurately estimating latent heat fluxes over agricultural fields in the Rio Grande River basin of central New Mexico. We use the Community Land Model (CLM) within the Land Information Systems (LIS), and adopt an Ensemble Kalman Filter approach to assimilate the LST fields into the model. We evaluate the LST and assimilation performance against field measurements of evapotranspiration collected at two eddy-covariance towers in semi-arid cropland areas. Our results will help clarify sensor and LST product requirements for future remote sensing systems.

  7. ESA DUE Permafrost: Evaluation of remote sensing derived products using ground data from the Global Terrestrial Network of Permafrost (GTN-P)

    Science.gov (United States)

    Elger, K. K.; Heim, B.; Lantuit, H.; Boike, J.; Bartsch, A.; Paulik, C.; Duguay, C. R.; Hachem, S.; Soliman, A. S.

    2011-12-01

    The task of the ESA DUE Permafrost project is to build up an Earth observation service for high-latitudinal permafrost applications with extensive involvement of the permafrost research community. The DUE Permafrost products derived from remote sensing are land surface temperature (LST), surface soil moisture (SSM), surface frozen and thawed state (freeze/ thaw), terrain, land cover, and surface waters. Weekly and monthly averages for most of the DUE Permafrost products will be made available for the years 2007-2010. The DUE Permafrost products are provided for the circumpolar permafrost area (north of 55°N) with 25 km spatial resolution. In addition, regional products with higher spatial resolution (300-1000 m/ pixel) were developed for five case study regions. These regions are: (1) the Laptev Sea and Eastern Siberian Sea Region (RU, continuous very cold permafrost/ tundra), (2) the Yakutsk Region (RU, continuous cold permafrost/ taiga), (3) the Western Siberian transect including Yamal Peninsula and Ob Region (RU, continuous to discontinuous/ taiga-tundra), (4) the Alaska Highway Transect (US, continuous to discontinuous/ taiga-tundra), and (5) the Mackenzie Delta and Valley Transect (CA, continuous to discontinuous/ taiga-tundra). The challenge of the programme is to adapt remote sensing products that are well established and tested in agricultural low and mid-latitudinal areas for highly heterogeneous taiga/ tundra permafrost landscapes in arctic regions. Ground data is essential for the evaluation of DUE Permafrost products and is provided by user groups and global networks. A major part of the DUE Permafrost core user group is contributing to GTN-P, the Global Terrestrial Network of Permafrost. Its main programmes, the Circumpolar Active Layer Monitoring (CALM) and the Thermal State of Permafrost (TSP) have been thoroughly overhauled during the last International Polar Year (2007-2008). Their spatial coverage has been extended to provide a true circumpolar

  8. Permafrost Distribution Modeling in the Semi-Arid Chilean Andes

    OpenAIRE

    Azócar, Guillermo F.; Brenning, Alexander; Bodin, Xavier

    2016-01-01

    Mountain permafrost and rock glaciers in the dry Andes are of growing interest due to the increase in human activities in this remote area. Empirical models of mountain permafrost distribution based on the spatial analysis of intact and relict rock glaciers and mean annual air temperature (MAAT) have been established as a tool for regional-scale assessments of permafrost favorability across entire mountain ranges; however, this kind of model approach has never been applied for a large portion...

  9. Why Permafrost Is Thawing, Not Melting

    Science.gov (United States)

    Grosse, Guido; Romanovsky, Vladimir; Nelson, Frederick E.; Brown, Jerry; Lewkowicz, Antoni G.

    2010-03-01

    As global climate change is becoming an increasingly important political and social issue, it is essential for the cryospheric and global change research communities to speak with a single voice when using basic terminology to communicate research results and describe underlying physical processes. Experienced science communicators have highlighted the importance of using the correct terms to communicate research results to the media and general public [e.g., Akasofu, 2008; Hassol, 2008]. The consequences of scientists using improper terminology are at best oversimplification, but they more likely involve misunderstandings of the facts by the public. A glaring example of scientifically incorrect terminology appearing frequently in scientific and public communication relates to reports on the degradation of permafrost. Numerous research papers have appeared in recent years, broadly echoed in the news media, describing the “melting of permafrost,” its effects in the Arctic, and its feedbacks on climate through the carbon cycle. Although permafrost researchers have attempted to distinguish between the appropriate term “permafrost thawing” and the erroneous “permafrost melting” [e.g., van Everdingen, 2005; French, 2002], the latter is still used widely. A Web-based search using the phrase “permafrost melting” reveals hundreds of occurrences, many from highly regarded news and scientific organizations, including Reuters, New Scientist, ABC, The Guardian, Discovery News, Smithsonian magazine, the National Science Foundation, and others.

  10. Using ground data of the Global Terrestrial Network of Permafrost (GTN-P) for the evaluation of ESA Data User Element (DUE) Permafrost remote sensing derived products

    Science.gov (United States)

    Elger, K.; Heim, B.; Bartsch, A.; Paulik, Ch.; Duguay, C.; Hachem, S.; Soliman, A.; Boike, J.; Langer, M.; Lantuit, H.

    2012-04-01

    Permafrost is one of the essential climate variables addressed by the Global Terrestrial Observing System (GCOS). Remote sensing data provide area-wide monitoring of e.g. surface temperatures or soil surface status (frozen or thawed state) in the Arctic and Subarctic, where ground data collection is difficult and restricted to local measurements at few monitoring sites. The task of the ESA Data User Element (DUE) Permafrost project is to build-up an Earth observation service for northern high-latitudinal permafrost applications with extensive involvement of the international permafrost research community (www.ipf.tuwien.ac.at/permafrost). The satellite-derived DUE Permafrost products are Land Surface Temperature, Surface Soil Moisture, Surface Frozen and Thawed State, Digital Elevation Model (locally as remote sensing product and circumpolar as non-remote sensing product) and Subsidence, and Land Cover. Land Surface Temperature, Surface Soil Moisture, and Surface Frozen and Thawed State will be provided for the circumpolar permafrost area north of 55° N with 25 km spatial resolution. In addition, regional products with higher spatial resolution were developed for five case study regions in different permafrost zones of the tundra and taiga (Laptev Sea [RU], Central Yakutia [RU], Western Siberia [RU], Alaska N-S transect, [US] Mackenzie River and Valley [CA]). This study shows the evaluation of two DUE Permafrost regional products, Land Surface Temperature and Surface Frozen and Thawed State, using freely available ground truth data from the Global Terrestrial Network of Permafrost (GTN-P) and monitoring data from the Russian-German Samoylov research station in the Lena River Delta (Central Siberia, RU). The GTN-P permafrost monitoring sites with their position in different permafrost zones are highly qualified for the validation of DUE Permafrost remote sensing products. Air and surface temperatures with high-temporal resolution from eleven GTN-P sites in Alaska

  11. ESA Data User Element DUE PERMAFROST Circumpolar Remote Sensing Service for Permafrost - Evaluation Case Studies and Intercomparison with Regional Climate Model Simulations

    Science.gov (United States)

    Heim, Birgit; Bartsch, Annett; Elger, Kirsten; Rinke, Annette; Matthes, Heidrun; Zhou, Xu; Klehmet, Katharina; Rockel, Burkhardt; Lantuit, Hugues; Duguay, Claude

    2015-04-01

    Permafrost is a subsurface phenomenon. However, monitoring from Earth Observation (EO) platforms can provide spatio-temporal data sets on permafrost-related indicators and quantities used in modelling and monitoring. The ESA Data User Element (DUE) Permafrost project (2009-2012) developed a suite of EO satellite-derived products: Land Surface Temperature (LST), Surface Soil Moisture (SSM), Surface Frozen and Thawed State (Freeze/Thaw), Terrain, Land Cover, and Surface Water. The satellite-derived products are weekly and monthly averages of the bio- and geophysical terrestrial parameters and static circum-Arctic maps. The final DUE Permafrost products cover the years 2007 to 2011, some products up to 2013, with a circum-Arctic coverage (north of 50°N). The products were released in 2012, and updated in 2013 and 2014. Further information is available at geo.tuwien.ac.at/permafrost/. The remote sensing service also supports the EU-FP7 funded project PAGE21 - Changing Permafrost in the Arctic and its Global Effects in the 21st Century (www.page21.eu). The Global Terrestrial Network for Permafrost (GTN-P), initiated by the International Permafrost Association (IPA), is the prime program concerned with monitoring of permafrost. It provides an important database for the evaluation of EO-derived products and climate and permafrost models. GTN-P ground data ranges from air-, ground-, and borehole temperature data to active layer monitoring, soil moisture measurements, and the description of landform and vegetation. The involvement of scientific stakeholders and the IPA, and the ongoing evaluation of the satellite-derived products make the DUE Permafrost products relevant to the scientific community. The Helmholtz Climate Initiative REKLIM (Regionale KlimaAnderungen/Regional Climate Change) is a climate research program where regional observations and process studies are coupled with model simulations (http://www.reklim.de/en/home/). ESA DUE Permafrost User workshops

  12. 1,350,000 Year History of Siberian Permafrost Based on U-Pb Chronology of Speleothems

    Science.gov (United States)

    Vaks, A.; Mason, A. J.; Breitenbach, S. F. M.; Kononov, A. M.; Osintcev, A. V.; Henderson, G. M.

    2014-12-01

    Permafrost history of the last ~1.35 millions of years (Ma) was reconstructed using chronology of speleothems from a Siberian cave. Rain and snowmelt waters can penetrate into caves only when soil and subsoil temperatures are above 0°C and permafrost above the cave is discontinuous or absent. Speleothems in regions currently affected by permafrost therefore provide a tracer of past permafrost thawing events. Ledyanaya Lenskaya Cave is located at 60°22'N-116°57'E, on the southern boundary of modern continuous permafrost, with no present-day water seepage and a mean annual temperature of -5°C ‒ -6°C. U-Th dating of speleothems from this cave in a previous study [1] showed that the youngest speleothem growth period occurred at 427±23 thousand years ago (ka), during early Marine Isotope Stage (MIS) 11. In this study we dated several horizons of older speleothems from this cave using the U-Pb method [2]. Two high precision ages indicate growth at 1074.2 +6.6/-5.2 ka and 947.8 +3.3/-3.4 ka, while new preliminary data provide strong evidence of an older growth period around 1.35-1.30 Ma. Other preliminary data mostly overlap the high precision ages, but also hint at limited growth at ~860 ka, with one data point suggesting younger, but minor growth at ~560 ka. The timing of these permafrost thawing events apparently correlates with interglacial episodes of exceptionally high Pacific Warm Pool sea surface temperature (~30°C) [3]. During these warm episodes the average global temperature was 1.1-1.5°C higher than pre-industrial temperatures. These findings put the threshold of thawing of continuous permafrost at its southern boundary at slightly more than 1.0°C above preindustrial level. References:1. Vaks, A., et al., Science, 2013. 340 (6129): p. 183-186. 2. Mason, A.J., G.M. Henderson, and A. Vaks, Geostandards and Geoanalytical Research, 2013. 37(3): p. 261-275. 3. Hansen, J., et al., Proceedings of the National Academy of Sciences, 2006. 103(39): p. 14288-14293.

  13. Impact of permafrost degradation on embankment deformation of Qinghai-Tibet Highway in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    彭惠; 马巍; 穆彦虎; 金龙

    2015-01-01

    Based on long-term monitoring data, the relationships between permafrost degradation and embankment deformation are analyzed along the Qinghai−Tibet Highway (QTH). Due to heat absorbing effect of asphalt pavement and climate warming, permafrost beneath asphalt pavement experienced significant warming and degradation. During the monitoring period, warming amplitude of the soil at depth of 5 m under asphalt ranged from 0.21 °C at the XD1 site to 0.5 °C at the KL1 site. And at depth of 10 m, the increase amplitude of ground temperature ranged from 0.47 °C at the NA1 site to 0.07 °C at the XD1 site. Along with ground temperature increase, permafrost table beneath asphalt pavement decline considerably. Amplitude of permafrost table decline varied from 0.53 m at the KL1 site to 3.51 m at the NA1 site, with mean amplitude of 1.65 m for 8 monitoring sites during the monitoring period. Due to permafrost warming and degradation, the embankment deformation all performed as settlement at these sites. At present, those settlements still develop quickly and are expected to continue to increase in the future. The embankment deformations can be divided into homogeneous deformation and inhomogeneous deformation. Embankment longitudinal inhomogeneous deformation causes the wave deformations and has adverse effects on driving comfort and safety, while lateral inhomogeneous deformation causes longitudinal cracks and has an adverse effect on stability. Corresponding with permafrost degradation processes, embankment settlement can be divided into four stages. For QTH, embankment settlement is mainly comprised of thawing consolidation of ice-rich permafrost and creep of warming permafrost beneath permafrost table.

  14. Towards reducing the cloud-induced sampling biases in MODIS LST data: a case study from Greenland

    Science.gov (United States)

    Karami, M.; Hansen, B. U.

    2016-12-01

    Satellite-driven Land Surface Temperature (LST) datasets are essential for characterizing climate change impacts on terrestrial ecosystems, as well as a wide range of surface-atmosphere studies. In the past one and a half decade, NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) has provided the scientific community with LST estimates on a global scale with reasonable spatial resolution and revisit time. However, the use of MODIS LST for climate studies is complicated by the simple fact that the observations can only be made under clear-sky conditions. In regions with frequent overcast skies, this can result in the calculated climatic variables deviating from the actual surface conditions. In the present study, we propose and validate a framework based on model-driven downwelling radiation data from ERA-Interim and instantenous LST observations from both MODIS Terra and Aqua, in order to minimize the clear-sky sampling bias. The framework is validated on a cloud-affected MODIS scene covering parts of Greenland (h15v02), and by incorporating in-situ data from a number of monitoring stations in the area. The results indicate that the proposed method is able to increase the number of daily LST estimates by a factor of 2.07 and reduce the skewnewss of monthly distribution of the successful estimates by a factor of 0.22. Considering that these improvements are achieved mainly through introducing data from partially overcast days, the estimated climatic variables show better agreement with the ground truth. The overall accuracy of the model in estimating in-situ mean daily LST remained satisfactory even after incoprporating the daily downweling radiation from ERA-interim (RMSE=0.41 °K, R-squared=0.992). Nonetheless, since technical constraints are expected to continue limiting the use of high temporal resolution satellites in high latitudes, more research is required to quantify and deal with various types of cloud-induced biases present in the data from

  15. Coupled Northern Hemisphere permafrost-ice sheet evolution over the last glacial cycle

    Directory of Open Access Journals (Sweden)

    M. Willeit

    2015-02-01

    Full Text Available Permafrost influences a number of processes which are relevant for local and global climate. For example, it is well known that permafrost plays an important role in global carbon and methane cycles. Less is known about the interaction between permafrost and ice sheets. In this study a permafrost module is included in the Earth system model CLIMBER-2 and the coupled Northern Hemisphere (NH permafrost-ice sheet evolution over the last glacial cycle is explored. The model performs generally well at reproducing present-day permafrost extent and thickness. Modelled permafrost thickness is sensitive to the values of ground porosity, thermal conductivity and geothermal heat flux. Permafrost extent at the last glacial maximum (LGM agrees well with reconstructions and previous modelling estimates. Present-day permafrost thickness is far from equilibrium over deep permafrost regions. Over Central Siberia and the Arctic Archipelago permafrost is presently up to 200–500 m thicker than it would be at equilibrium. In these areas, present-day permafrost depth strongly depends on the past climate history and simulations indicate that deep permafrost has a memory of surface temperature variations going back to at least 800 kya. Over the last glacial cycle permafrost has a relatively modest impact on simulated NH ice sheet volume except at LGM, when including permafrost increases ice volume by about 15 m sea level equivalent. This is explained by a delayed melting of the ice base from below by the geothermal heat flux when the ice sheet sits on a porous sediment layer and permafrost has to be melted first. Permafrost affects ice sheet dynamics only when ice extends over areas covered by thick sediments, which is the case at LGM.

  16. Amino Acids Stimulate TORC1 through Lst4-Lst7, a GTPase-Activating Protein Complex for the Rag Family GTPase Gtr2

    Directory of Open Access Journals (Sweden)

    Marie-Pierre Péli-Gulli

    2015-10-01

    Full Text Available Rag GTPases assemble into heterodimeric complexes consisting of RagA or RagB and RagC or RagD in higher eukaryotes, or Gtr1 and Gtr2 in yeast, to relay amino acid signals toward the growth-regulating target of rapamycin complex 1 (TORC1. The TORC1-stimulating state of Rag GTPase heterodimers, containing GTP- and GDP-loaded RagA/B/Gtr1 and RagC/D/Gtr2, respectively, is maintained in part by the FNIP-Folliculin RagC/D GAP complex in mammalian cells. Here, we report the existence of a similar Lst4-Lst7 complex in yeast that functions as a GAP for Gtr2 and that clusters at the vacuolar membrane in amino acid-starved cells. Refeeding of amino acids, such as glutamine, stimulated the Lst4-Lst7 complex to transiently bind and act on Gtr2, thereby entailing TORC1 activation and Lst4-Lst7 dispersal from the vacuolar membrane. Given the remarkable functional conservation of the RagC/D/Gtr2 GAP complexes, our findings could be relevant for understanding the glutamine addiction of mTORC1-dependent cancers.

  17. Terrain Segmentation of Egypt from Multi-Temporal Night LST Imagery and Elevation Data

    Directory of Open Access Journals (Sweden)

    Panagiotis Partsinevelos

    2010-09-01

    Full Text Available Monthly night averaged land surface temperature (LST MODIS imagery was analyzed throughout a year-period (2006, in an attempt to segment the terrain of Egypt into regions with different LST seasonal variability, and represent them parametrically. Regions with distinct spatial and temporal LST patterns were outlined using several clustering techniques capturing aspects of spatial, temporal and temperature homogeneity or differentiation. Segmentation was supplemented, taking into consideration elevation, morphological features and landcover information. The northern coastal region along the Mediterranean Sea occupied by lowland plain areas corresponds to the coolest clusters indicating a latitude/elevation dependency of seasonal LST variability. On the other hand, for the inland regions, elevation and terrain dissection plays a key role in LST seasonal variability, while an east to west variability of clusters’ spatial distribution is evident. Finally, elevation biased clustering revealed annual LST differences among the regions with the same physiographic/terrain characteristics. Thermal terrain segmentation outlined the temporal variation of LST during 2006, as well as the spatial distribution of LST zones.

  18. LST data management and mission operations concept. [pointing control optimization for maximum data

    Science.gov (United States)

    Walker, R.; Hudson, F.; Murphy, L.

    1977-01-01

    A candidate design concept for an LST ground facility is described. The design objectives were to use NASA institutional hardware, software and facilities wherever practical, and to maximize efficiency of telescope use. The pointing control performance requirements of LST are summarized, and the major data interfaces of the candidate ground system are diagrammed.

  19. The microbial ecology of permafrost.

    Science.gov (United States)

    Jansson, Janet K; Taş, Neslihan

    2014-06-01

    Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost features and between sites. Some microorganisms are even active at subzero temperatures in permafrost. An emerging concern is the impact of climate change and the possibility of subsequent permafrost thaw promoting microbial activity in permafrost, resulting in increased potential for greenhouse-gas emissions. This Review describes new data on the microbial ecology of permafrost and provides a platform for understanding microbial life strategies in frozen soil as well as the impact of climate change on permafrost microorganisms and their functional roles.

  20. Permafrost carbon: Catalyst for deglaciation

    Science.gov (United States)

    MacDougall, Andrew H.

    2016-09-01

    The sources contributing to the deglacial rise in atmospheric CO2 concentrations are unclear. Climate model simulations suggest thawing permafrost soils were the initial source, highlighting the vulnerability of modern permafrost carbon stores.

  1. Developing a synergy algorithm for land surface temperature: the SEN4LST project

    Science.gov (United States)

    Sobrino, Jose A.; Jimenez, Juan C.; Ghent, Darren J.

    2013-04-01

    Land surface Temperature (LST) is one of the key parameters in the physics of land-surface processes on regional and global scales, combining the results of all surface-atmosphere interactions and energy fluxes between the surface and the atmosphere. An adequate characterization of LST distribution and its temporal evolution requires measurements with detailed spatial and temporal frequencies. With the advent of the Sentinel 2 (S2) and 3 (S3) series of satellites a unique opportunity exists to go beyond the current state of the art of single instrument algorithms. The Synergistic Use of The Sentinel Missions For Estimating And Monitoring Land Surface Temperature (SEN4LST) project aims at developing techniques to fully utilize synergy between S2 and S3 instruments in order to improve LST retrievals. In the framework of the SEN4LST project, three LST retrieval algorithms were proposed using the thermal infrared bands of the Sea and Land Surface Temperature Retrieval (SLSTR) instrument on board the S3 platform: split-window (SW), dual-angle (DA) and a combined algorithm using both split-window and dual-angle techniques (SW-DA). One of the objectives of the project is to select the best algorithm to generate LST products from the synergy between S2/S3 instruments. In this sense, validation is a critical step in the selection process for the best performing candidate algorithm. A unique match-up database constructed at University of Leicester (UoL) of in situ observations from over twenty ground stations and corresponding brightness temperature (BT) and LST match-ups from multi-sensor overpasses is utilised for validating the candidate algorithms. Furthermore, their performance is also evaluated against the standard ESA LST product and the enhanced offline UoL LST product. In addition, a simulation dataset is constructed using 17 synthetic images of LST and the radiative transfer model MODTRAN carried under 66 different atmospheric conditions. Each candidate LST

  2. Evaluation of MODIS LST Products Using Longwave Radiation Ground Measurements in the Northern Arid Region of China

    Directory of Open Access Journals (Sweden)

    Wenping Yu

    2014-11-01

    Full Text Available This study presents preliminary results of the validation of the Moderate Resolution Imaging Spectroradiometer (MODIS daily LST products (MOD/MYD11A1, Version 5 using longwave radiation ground measurements obtained at 12 stations in the North Arid and Semi-Arid Area Cooperative Experimental Observation Integrated Research program. In this evaluation process, the broadband emissivity at each station was obtained from the ASTER Spectral Library or estimated from the MODIS narrowband emissivity Collection 5. A comparison of the validation results based on those two methods shows that no significant differences occur in the short-term validation, and a sensitivity analysis of the broadband emissivity demonstrates that it has a limited effect on the evaluation results. In general, the results at the 12 stations indicate that the LST products have a lower accuracy in China’s arid and semi-arid areas than in other areas, with a mean absolute error of 2–3 K. Compared with the temporal mismatch, the spatial mismatch has a stronger effect on the validation results in this study, and the stations with homogeneous land cover have more comparable MODIS LST accuracies. Comparisons between the stations indicate that the spatial mismatch can increase the influence of the temporal mismatch.

  3. A permafrost glacial hypothesis – Permafrost carbon might help explaining the Pleistocene ice ages

    Directory of Open Access Journals (Sweden)

    Roland Zech

    2012-05-01

    Full Text Available Over the past several ~100 ka glacial-interglacial cycles, the concentration of atmospheric CO2 was closely coupled to global temperature, which indicates the importance of CO2 as a greenhouse gas. The reasons for changes in atmospheric CO2 have mainly been sought in the ocean, but remain elusive. Moreover, the mid-Pleistocene transition from the ‘41 ka world’ during the early Pleistocene before ~0.7 Ma to the ~100 ka ice age cycles is poorly understood. The classical Milankovitch theory of summer insolation forcing at high northern latitudes can not fully explain the Pleistocene ice age rhythm. Based on the recent findings that the amount of soil organic carbon stored in high-latitude permafrost regions has been greatly underestimated and the simple logic that permafrost regions and respective carbon pools were likely much larger during glacials than during interglacials, a ‘permafrost glacial hypothesis’ is proposed: (i Gradual sequestration of CO2 in permafrost soils during coolings and rapid release of CO2 and methane during terminations, respectively, provide important positive feedbacks for the climate. (ii Integrated annual insolation at the southern and thus most sensitive permafrost boundary may act as a trigger for global climate changes. (iii The mid-Pleistocene transition might be readily explained with permafrost extents reaching ~45°N during the long-term Pleistocene cooling, resulting in a transition from high-latitude obliquity (~41 ka to mid-latitude eccentricity (~100 ka forcing.

  4. Longshore sediment transport in the surf zone based on different formulae: A case study along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Shanas, P.R.; Dora, G.U.; Johnson, G.; Philip, C.S.

    Understanding longshore sediment transport (LST) is a prerequisite for designing an effective coastal zone management strategy. The present study estimates the LST along the central west coast of India based on four bulk LST formulae: (1...

  5. The microbial ecology of permafrost

    DEFF Research Database (Denmark)

    Jansson, Janet; Tas, Neslihan

    2014-01-01

    Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost......-gas emissions. This Review describes new data on the microbial ecology of permafrost and provides a platform for understanding microbial life strategies in frozen soil as well as the impact of climate change on permafrost microorganisms and their functional roles....

  6. Dynamic response of wind turbine towers in warm permafrost

    Institute of Scientific and Technical Information of China (English)

    Benjamin Still; ZhaoHui Joey Yang; Simon Evans; FuJun Niu

    2014-01-01

    Wind is a great source of renewable energy in western Alaska. Consistent winds blow across the barren tundra underlain by warm permafrost in the winter season, when the energy demand is the highest. Foundation engineering in warm permafrost has always been a challenge in wind energy development. Degrading warm permafrost poses engineering issues to design, construction, and operation of wind turbines. This paper describes the foundation design of a wind turbine built in western Alaska. It presents a sys-tem for response monitoring and load assessment, and data collected from September 2013 to March 2014. The dynamic proper-ties are assessed based on the monitoring data, and seasonal changes in the dynamic properties of the turbine tower-foundation system and likely resonance between the spinning blades and the tower structure are discussed. These analyses of a wind turbine in warm permafrost are valuable for designing or retrofitting of foundations in warm permafrost.

  7. Web-GIS visualisation of permafrost-related Remote Sensing products for ESA GlobPermafrost

    Science.gov (United States)

    Haas, A.; Heim, B.; Schaefer-Neth, C.; Laboor, S.; Nitze, I.; Grosse, G.; Bartsch, A.; Kaab, A.; Strozzi, T.; Wiesmann, A.; Seifert, F. M.

    2016-12-01

    The ESA GlobPermafrost (www.globpermafrost.info) provides a remote sensing service for permafrost research and applications. The service comprises of data product generation for various sites and regions as well as specific infrastructure allowing overview and access to datasets. Based on an online user survey conducted within the project, the user community extensively applies GIS software to handle remote sensing-derived datasets and requires preview functionalities before accessing them. In response, we develop the Permafrost Information System PerSys which is conceptualized as an open access geospatial data dissemination and visualization portal. PerSys will allow visualisation of GlobPermafrost raster and vector products such as land cover classifications, Landsat multispectral index trend datasets, lake and wetland extents, InSAR-based land surface deformation maps, rock glacier velocity fields, spatially distributed permafrost model outputs, and land surface temperature datasets. The datasets will be published as WebGIS services relying on OGC-standardized Web Mapping Service (WMS) and Web Feature Service (WFS) technologies for data display and visualization. The WebGIS environment will be hosted at the AWI computing centre where a geodata infrastructure has been implemented comprising of ArcGIS for Server 10.4, PostgreSQL 9.2 and a browser-driven data viewer based on Leaflet (http://leafletjs.com). Independently, we will provide an `Access - Restricted Data Dissemination Service', which will be available to registered users for testing frequently updated versions of project datasets. PerSys will become a core project of the Arctic Permafrost Geospatial Centre (APGC) within the ERC-funded PETA-CARB project (www.awi.de/petacarb). The APGC Data Catalogue will contain all final products of GlobPermafrost, allow in-depth dataset search via keywords, spatial and temporal coverage, data type, etc., and will provide DOI-based links to the datasets archived in the

  8. The WATERMED field experiment: validation of the AATSR LST product with in situ measurements

    Science.gov (United States)

    Noyes, E.; Soria, G.; Sobrino, J.; Remedios, J.; Llewellyn-Jones, D.; Corlett, G.

    The Advanced Along-Track Scanning Radiometer (AATSR) onboard ESA's Envisat Satellite, is the third in a series of a precision radiometers designed to measure Sea Surface Temperature (SST) with accuracies of better than ± 0.3 K (within 1-sigma limit). Since its launch in March 2001, a prototype AATSR Land Surface Temperature (LST) product has been produced for validation purposes only, with the product becoming operational from mid-2004. The (A)ATSR instrument design is unique in that it has both a nadir- and a forward-view, allowing the Earth's surface to be viewed along two different atmospheric path lengths, thus enabling an improved atmospheric correction to be made when retrieving surface temperature. It also uses an innovative and exceptionally stable on-board calibration system for its infrared channels, which, together with actively cooled detectors, gives extremely high radiometric sensitivity and precision. In this presentation, results from a comparison of the prototype LST product with ground-based measurements obtained at the WATERMED (WATer use Efficiency in natural vegetation and agricultural areas by Remote sensing in the MEDiterranean basin) field site near Marrakech, Morocco, are presented. The comparison shows that the AATSR has a positive bias of + 1.5 K, with a standard deviation of 0.7 K, indicating that the product is operating within the target specification (± 2.5 K) over the WATERMED field site. However, several anomalous validation points were observed during the analysis and we will discuss possible reasons for the occurrence of these data, including their coincidence with the presence of an Envisat blanking pulse (indicating the presence of a radar pulse at the time of AATSR pixel integration). Further investigation into this matter is required as previous investigations have always indicated that the presence of a payload radar pulse does not have any effect on (A)ATSR data quality.

  9. Permafrost-carbon complexities

    NARCIS (Netherlands)

    Vonk, J.E.; Gustafsson, Ö.

    2013-01-01

    The thawing and decomposition of carbon stored in permafrost generates greenhouse gases that could further intensify global warming. Currently, most of the thawed carbon is assumed to be converted to greenhouse gases, such as carbon dioxide and methane, and carbon decomposition is thought

  10. Decomposing Person and Occasion-Specific Effects: An Extension of Latent State-Trait (LSI) Theory to Hierarchical LST Models

    Science.gov (United States)

    Schermelleh-Engel, Karin; Keith, Nina; Moosbrugger, Helfried; Hodapp, Volker

    2004-01-01

    An extension of latent state-trait (LST) theory to hierarchical LST models is presented. In hierarchical LST models, the covariances between 2 or more latent traits are explained by a general 3rd-order factor, and the covariances between latent state residuals pertaining to different traits measured on the same measurement occasion are explained…

  11. Permafrost distribution modelling in the semi-arid Chilean Andes

    Science.gov (United States)

    Azócar, Guillermo F.; Brenning, Alexander; Bodin, Xavier

    2017-04-01

    Mountain permafrost and rock glaciers in the dry Andes are of growing interest due to the increase in mining industry and infrastructure development in this remote area. Empirical models of mountain permafrost distribution based on rock glacier activity status and temperature data have been established as a tool for regional-scale assessments of its distribution; this kind of model approach has never been applied for a large portion of the Andes. In the present study, this methodology is applied to map permafrost favourability throughout the semi-arid Andes of central Chile (29-32° S), excluding areas of exposed bedrock. After spatially modelling of the mean annual air temperature distribution from scarce temperature records (116 station years) using a linear mixed-effects model, a generalized additive model was built to model the activity status of 3524 rock glaciers. A permafrost favourability index (PFI) was obtained by adjusting model predictions for conceptual differences between permafrost and rock glacier distribution. The results indicate that the model has an acceptable performance (median AUROC: 0.76). Conditions highly favourable to permafrost presence (PFI ≥ 0.75) are predicted for 1051 km2 of mountain terrain, or 2.7 % of the total area of the watersheds studied. Favourable conditions are expected to occur in 2636 km2, or 6.8 % of the area. Substantial portions of the Elqui and Huasco watersheds are considered to be favourable for permafrost presence (11.8 % each), while in the Limarí and Choapa watersheds permafrost is expected to be mostly limited to specific sub-watersheds. In the future, local ground-truth observations will be required to confirm permafrost presence in favourable areas and to monitor permafrost evolution under the influence of climate change.

  12. CMIP5 permafrost degradation projection:A comparison among different regions

    Science.gov (United States)

    Guo, Donglin; Wang, Huijun

    2016-05-01

    The considerable impact of permafrost degradation on hydrology and water resources, ecosystems, human engineering facilities, and climate change requires us to carry out more in-depth studies, at finer spatial scales, to investigate the issue. In this study, regional differences of the future permafrost changes are explored with respect to the regions (high altitude and high latitude, and in four countries) based on the surface frost index (SFI) model and multimodel and multiscenario data from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Results show the following: (1) Compared with seven other sets of driving data, Climatic Research Unit air temperature combined with Climate Forecast System Reanalysis snow data (CRU_CFSR) yield a permafrost extent with the least absolute area bias and was thus used in the simulation. The SFI model, driven by CRU_CFSR data climatology plus multimodel mean anomalies, produces a present-day (1986-2005) permafrost area of 15.45 × 106 km2 decade-1, which compares reasonably with observations of 15.24 × 106 km2 decade-1. (2) The high-altitude (Tibetan Plateau) permafrost area shows a larger decreasing percentage trend than the high-latitude permafrost area. This indicates that, in terms of speed, high-altitude permafrost thaw is faster than high-latitude permafrost, mainly due to the larger percentage sensitivity to rising air temperature of the high-altitude permafrost compared to the high-latitude permafrost, which is likely related to their thermal conditions. (3) Permafrost in China shows the fastest thaw, which is reflected by the percentage trend in permafrost area, followed by the United States, Russia, and Canada. These discrepancies are mainly linked to different percentage sensitivities of permafrost areas in these four countries to air temperature change. (4) In terms of the ensemble mean, permafrost areas in all regions are projected to decrease by the period 2080-2099. Under representative

  13. Process-based hydrological modeling using SWAT: The effect of permafrost on water resources in the large-scale river catchment Kharaa / Mongolia

    Science.gov (United States)

    Hülsmann, L.; Geyer, T.; Karthe, D.; Priess, J.; Schweitzer, C.

    2012-04-01

    In this study, the Soil Water Assessment Tool (SWAT) was applied to obtain a better understanding of hydrological processes in the semi-arid catchment of the Kharaa River in Northern Mongolia. The transient, physical-based model SWAT was set up using spatial datasets on soil, land use, climate, and stream network provided by the project "IWRM-MoMo" to (i.) simulate the water balance components of the basin and (ii.) to identify potential gaps in the input data. We found that the SWAT model satisfactorily reflects the hydrological processes in the catchment and simulates river runoff as a response to strong rainfall events as well as to snow and ice melt. To obtain correct runoff volumes during spring, permafrost has to be considered. Permafrost-influenced soils constrain water flow in the frozen layer, so that percolation out of the active layer is hampered (Woo 2011). This effect is reproduced in SWAT by assigning an impermeable layer in the subsurface to the areas dominated by permafrost. The simulations indicate that in these regions groundwater resources are limited as a consequence of impermeable ground ice. In addition, groundwater recharge rates in the catchment are generally low due to high evaporation rates (80-90 %). Consequently the base flow contribution is small. Further studies on the estimation of groundwater recharge rates should be carried out, since groundwater is an important resource for water supply. Model results indicate that the non-uniformity of the precipitation distribution was not sufficiently covered by the interpolated input data, so that precipitation and runoff volumes are partially over- or underestimated. Since precipitation defines the overall water availability in river catchments (Baumgartner 1982), additional climate records would considerably improve model outputs. As a consequence of large evapotranspiration losses, discharge as well as groundwater recharge estimates were identified to be highly sensitive to

  14. A novel gene, lstC, of Listeria monocytogenes is implicated in high salt tolerance.

    Science.gov (United States)

    Burall, Laurel S; Simpson, Alexandra C; Chou, Luoth; Laksanalamai, Pongpan; Datta, Atin R

    2015-06-01

    Listeria monocytogenes, causative agent of human listeriosis, has been isolated from a wide variety of foods including deli meats, soft cheeses, cantaloupes, sprouts and canned mushrooms. Standard control measures for restricting microbial growth such as refrigeration and high salt are often inadequate as L. monocytogenes grows quite well in these environments. In an effort to better understand the genetic and physiological basis by which L. monocytogenes circumvents these controls, a transposon library of L. monocytogenes was screened for changes in their ability to grow in 7% NaCl and/ or at 5 °C. This work identified a transposon insertion upstream of an operon, here named lstABC, that led to a reduction in growth in 7% NaCl. In-frame deletion studies identified lstC which codes for a GNAT-acetyltransferase being responsible for the phenotype. Transcriptomic and RT-PCR analyses identified nine genes that were upregulated in the presence of high salt in the ΔlstC mutant. Further analysis of lstC and the genes affected by ΔlstC is needed to understand LstC's role in salt tolerance. Published by Elsevier Ltd.

  15. Late Quaternary climate and environmental changes in a permafrost section near Igarka, Northern Siberia based on leaf wax analyses

    Science.gov (United States)

    Schaefer, Imke; Schweri, Lea; Zech, Jana; Tananaev, Nikita; Zech, Roland

    2016-04-01

    Leaf wax biomarkers, such as long chain n-alkanes and n-alkanoic acids, and their carbon isotopic composition are a promising tool for reconstructing past climate and environmental changes and gain more and more attention in paleoresearch. Here we present the results of leaf wax analyses from a permafrost outcrop at the left banks of the Yenisei River near the city of Igarka, Northern Russia. Fluvio-glacial sediments are exposed in the lower part of the outcrop and probably date back to ~60 ka. The upper part consist of aeolian sediments deposited since, overprinted by various pedogenetic processes. First results indicate a continuous contribution of deciduous trees to the vegetation during the last glacial. Compound specific deuterium and radiocarbon analyses are in progress in order to investigate changes in paleoclimate and to establish a robust chronology.

  16. Permafrost soils and carbon cycling

    OpenAIRE

    Ping, C. L.; J. D. Jastrow; Jorgenson, M. T.; G. J. Michaelson; Y. L. Shur

    2015-01-01

    Knowledge of soils in the permafrost region has advanced immensely in recent decades, despite the remoteness and inaccessibility of most of the region and the sampling limitations posed by the severe environment. These efforts significantly increased estimates of the amount of organic carbon stored in permafrost-region soils and improved understanding of how pedogenic processes unique to permafrost environments built enormous organic carbon stocks during the Quaternary. This...

  17. Improving permafrost distribution modelling using feature selection algorithms

    Science.gov (United States)

    Deluigi, Nicola; Lambiel, Christophe; Kanevski, Mikhail

    2016-04-01

    The availability of an increasing number of spatial data on the occurrence of mountain permafrost allows the employment of machine learning (ML) classification algorithms for modelling the distribution of the phenomenon. One of the major problems when dealing with high-dimensional dataset is the number of input features (variables) involved. Application of ML classification algorithms to this large number of variables leads to the risk of overfitting, with the consequence of a poor generalization/prediction. For this reason, applying feature selection (FS) techniques helps simplifying the amount of factors required and improves the knowledge on adopted features and their relation with the studied phenomenon. Moreover, taking away irrelevant or redundant variables from the dataset effectively improves the quality of the ML prediction. This research deals with a comparative analysis of permafrost distribution models supported by FS variable importance assessment. The input dataset (dimension = 20-25, 10 m spatial resolution) was constructed using landcover maps, climate data and DEM derived variables (altitude, aspect, slope, terrain curvature, solar radiation, etc.). It was completed with permafrost evidences (geophysical and thermal data and rock glacier inventories) that serve as training permafrost data. Used FS algorithms informed about variables that appeared less statistically important for permafrost presence/absence. Three different algorithms were compared: Information Gain (IG), Correlation-based Feature Selection (CFS) and Random Forest (RF). IG is a filter technique that evaluates the worth of a predictor by measuring the information gain with respect to the permafrost presence/absence. Conversely, CFS is a wrapper technique that evaluates the worth of a subset of predictors by considering the individual predictive ability of each variable along with the degree of redundancy between them. Finally, RF is a ML algorithm that performs FS as part of its

  18. The impact of the permafrost carbon feedback on global climate

    Science.gov (United States)

    Schaefer, Kevin; Lantuit, Hugues; Romanovsky, Vladimir E.; Schuur, Edward A. G.; Witt, Ronald

    2014-08-01

    Degrading permafrost can alter ecosystems, damage infrastructure, and release enough carbon dioxide (CO2) and methane (CH4) to influence global climate. The permafrost carbon feedback (PCF) is the amplification of surface warming due to CO2 and CH4 emissions from thawing permafrost. An analysis of available estimates PCF strength and timing indicate 120 ± 85 Gt of carbon emissions from thawing permafrost by 2100. This is equivalent to 5.7 ± 4.0% of total anthropogenic emissions for the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathway (RCP) 8.5 scenario and would increase global temperatures by 0.29 ± 0.21 °C or 7.8 ± 5.7%. For RCP4.5, the scenario closest to the 2 °C warming target for the climate change treaty, the range of cumulative emissions in 2100 from thawing permafrost decreases to between 27 and 100 Gt C with temperature increases between 0.05 and 0.15 °C, but the relative fraction of permafrost to total emissions increases to between 3% and 11%. Any substantial warming results in a committed, long-term carbon release from thawing permafrost with 60% of emissions occurring after 2100, indicating that not accounting for permafrost emissions risks overshooting the 2 °C warming target. Climate projections in the IPCC Fifth Assessment Report (AR5), and any emissions targets based on those projections, do not adequately account for emissions from thawing permafrost and the effects of the PCF on global climate. We recommend the IPCC commission a special assessment focusing on the PCF and its impact on global climate to supplement the AR5 in support of treaty negotiation.

  19. Structure of Syngenetic Permafrost: New Data from the CRREL Permafrost Tunnel, Fox, Alaska

    Science.gov (United States)

    Kanevskiy, M.; Fortier, D.; Cysewski, M.; Shur, Y.; Jorgenson, T.

    2006-12-01

    Syngenetic permafrost formation is a complex process related to sedimentation in cold conditions when the base of the active layer rises up step by step in phase with the accumulation of deposits of various origin (alluvial, slope, aeolian, lacustrine, etc.) at the surface. Syngenetically frozen sediments usually have high silt particles content (up to 70-80%); slightly decomposed rootlets and buried organic-rich horizons; high ice content; ice wedges with big vertical length; rhythmically organized cryogenic structure specific for syngenetic permafrost. The well-known CRREL Permafrost Tunnel near Fairbanks Alaska offers excellent exposures of syngenetic permafrost. The section of Late Pleistocene deposits in the Tunnel is comprised mostly of syngenetically frozen aeolian and fluvial silts with sand lenses, partly reworked by thermal erosion which proceeded mainly along the large ice wedges. Gullies and underground channels cut in the Late Pleistocene permafrost were filled with ice and soils of different origins and cryogenic structures. The Permafrost Tunnel consists of a main shaft and an inclined winze. The former has been extensively studied during the last 40 years. However the permafrost in the winze has not been studied thoroughly even though the Late Wisconsinian syngenetic permafrost is better preserved there than in the main shaft. The main objective of our work was to map the cryostratigraphy (scale 1:20) of the winze. The results show the prevalence of syngenetic permafrost with a micro-lenticular cryostructure. The gravimetric moisture content of such sediments is very high and varies from 100 to 240%. The sediments which were formed in the tunnels cut in the permafrost and in the filled gullies are mostly stratified silts with lenses of sands and (sometimes) gravel. The gravimetric moisture content of these sediments varies from 70 to100% which is smaller than the water content of the Late Wisconsinian syngenetic permafrost. In the upper part of the

  20. Permafrost Hazards and Linear Infrastructure

    Science.gov (United States)

    Stanilovskaya, Julia; Sergeev, Dmitry

    2014-05-01

    The international experience of linear infrastructure planning, construction and exploitation in permafrost zone is being directly tied to the permafrost hazard assessment. That procedure should also consider the factors of climate impact and infrastructure protection. The current global climate change hotspots are currently polar and mountain areas. Temperature rise, precipitation and land ice conditions change, early springs occur more often. The big linear infrastructure objects cross the territories with different permafrost conditions which are sensitive to the changes in air temperature, hydrology, and snow accumulation which are connected to climatic dynamics. One of the most extensive linear structures built on permafrost worldwide are Trans Alaskan Pipeline (USA), Alaska Highway (Canada), Qinghai-Xizang Railway (China) and Eastern Siberia - Pacific Ocean Oil Pipeline (Russia). Those are currently being influenced by the regional climate change and permafrost impact which may act differently from place to place. Thermokarst is deemed to be the most dangerous process for linear engineering structures. Its formation and development depend on the linear structure type: road or pipeline, elevated or buried one. Zonal climate and geocryological conditions are also of the determining importance here. All the projects are of the different age and some of them were implemented under different climatic conditions. The effects of permafrost thawing have been recorded every year since then. The exploration and transportation companies from different countries maintain the linear infrastructure from permafrost degradation in different ways. The highways in Alaska are in a good condition due to governmental expenses on annual reconstructions. The Chara-China Railroad in Russia is under non-standard condition due to intensive permafrost response. Standards for engineering and construction should be reviewed and updated to account for permafrost hazards caused by the

  1. Discovery of a novel methanogen prevalent in thawing permafrost.

    Science.gov (United States)

    Mondav, Rhiannon; Woodcroft, Ben J; Kim, Eun-Hae; McCalley, Carmody K; Hodgkins, Suzanne B; Crill, Patrick M; Chanton, Jeffrey; Hurst, Gregory B; VerBerkmoes, Nathan C; Saleska, Scott R; Hugenholtz, Philip; Rich, Virginia I; Tyson, Gene W

    2014-01-01

    Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Here we determine microbial community composition along a permafrost thaw gradient in northern Sweden. Partially thawed sites were frequently dominated by a single archaeal phylotype, Candidatus 'Methanoflorens stordalenmirensis' gen. nov. sp. nov., belonging to the uncultivated lineage 'Rice Cluster II' (Candidatus 'Methanoflorentaceae' fam. nov.). Metagenomic sequencing led to the recovery of its near-complete genome, revealing the genes necessary for hydrogenotrophic methanogenesis. These genes are highly expressed and methane carbon isotope data are consistent with hydrogenotrophic production of methane in the partially thawed site. In addition to permafrost wetlands, 'Methanoflorentaceae' are widespread in high methane-flux habitats suggesting that this lineage is both prevalent and a major contributor to global methane production. In thawing permafrost, Candidatus 'M. stordalenmirensis' appears to be a key mediator of methane-based positive feedback to climate warming.

  2. Assessment of permafrost distribution maps in the Hindu Kush Himalayan region using rock glaciers mapped in Google Earth

    Science.gov (United States)

    Schmid, M.-O.; Baral, P.; Gruber, S.; Shahi, S.; Shrestha, T.; Stumm, D.; Wester, P.

    2015-11-01

    The extent and distribution of permafrost in the mountainous parts of the Hindu Kush Himalayan (HKH) region are largely unknown. A long tradition of permafrost research, predominantly on rather gentle relief, exists only on the Tibetan Plateau. Two permafrost maps are available digitally that cover the HKH and provide estimates of permafrost extent, i.e., the areal proportion of permafrost: the manually delineated Circum-Arctic Map of Permafrost and Ground Ice Conditions (Brown et al., 1998) and the Global Permafrost Zonation Index, based on a computer model (Gruber, 2012). This article provides a first-order assessment of these permafrost maps in the HKH region based on the mapping of rock glaciers. Rock glaciers were used as a proxy, because they are visual indicators of permafrost, can occur near the lowermost regional occurrence of permafrost in mountains, and can be delineated based on high-resolution remote sensing imagery freely available on Google Earth. For the mapping, 4000 square samples (~ 30 km2) were randomly distributed over the HKH region. Every sample was investigated and rock glaciers were mapped by two independent researchers following precise mapping instructions. Samples with insufficient image quality were recorded but not mapped. We use the mapping of rock glaciers in Google Earth as first-order evidence for permafrost in mountain areas with severely limited ground truth. The minimum elevation of rock glaciers varies between 3500 and 5500 m a.s.l. within the region. The Circum-Arctic Map of Permafrost and Ground Ice Conditions does not reproduce mapped conditions in the HKH region adequately, whereas the Global Permafrost Zonation Index does so with more success. Based on this study, the Permafrost Zonation Index is inferred to be a reasonable first-order prediction of permafrost in the HKH. In the central part of the region a considerable deviation exists that needs further investigations.

  3. Application of 2-D geoelectrical resistivity tomography for mountain permafrost detection in sporadic permafrost environments: Experiences from Eastern Austria

    Science.gov (United States)

    Kellerer-Pirklbauer, Andreas

    2015-04-01

    Mountain permafrost covers some 2000 km² of the Austrian Alps which is less than 2.5% of the national territory. Delineating the altitudinal lower limit of permafrost in the mountains of Austria is difficult due the complex topography, the rather sparseness of field verification data and the lack of long-term permafrost monitoring data. Such monitoring data should cover different slope aspects, different elevations, different substrates and different mountain regions of Austria. In this study it was attempted to delineate the lower limit of permafrost at two study sites in the Tauern Range, Austria, applying two-dimensional geoelectrical resistivity tomography (ERT). In addition, multi-annual ground temperature data collected by miniature temperature datalogger (MDT) were used to validate the results. At the study site Hochreichart (maximum elevation 2416 m asl), located in the Seckauer Tauern Range, 14 ERT profiles (lengths 48-196 m; electrode spacing 2, 2.5 or 4 m) were measured at elevations between 1805 and 2416 m asl. Measurements were carried out at two cirques (Reichart, Schöneben) and at the summit plateau of Hochreichart. Results at this site indicate that permafrost lenses are detectable at elevations down to c.1900 m asl at radiation-sheltered sites. Furthermore, at the summit plateau permafrost only occurs as rather small lenses. The ERT-based permafrost pattern is generally confirmed by the MTD data with negative mean annual ground temperature values at only a few monitoring sites. However, the possibility of air-filled cavities causing higher resistive zones faking permafrost existence cannot be excluded because coarse-grained sediments (i.e. relict rock glaciers and autochthonous block fields) are widespread at this study site. At the second study site Kögele Cirque (maximum elevation 3030 m asl) located in the Schober Mountains 12 ERT profiles (lengths 48 m; electrode spacing 2 m) were measured at elevations between 2631 and 2740 m asl. Spatially

  4. The application of refraction seismics in alpine permafrost studies

    Science.gov (United States)

    Draebing, Daniel

    2017-04-01

    laboratory scale. At landform scale, saturation shows temporal and spatial variation which is partially reflected in variation of seismic velocities of the active-layer (Draebing, 2016). Environmental factors result in a high spatial variation of rock or soil properties that affect seismic velocities. However, in landforms such as rock glaciers and moraines active-layer and permafrost can be distinguished based on seismic velocities alone while p-wave velocity differences of these layers in talus slopes and debris-covered slopes decrease and, therefore, require additional geophysical techniques or boreholes for layer differentiation (Draebing, 2016). Draebing, D., Krautblatter, M. 2012. P-wave velocity changes in freezing hard low-porosity rocks: a laboratory- based time-average model. The Cryosphere 6, 1163-1174. Draebing, D. 2016. Application of refraction seismics in alpine permafrost studies: A review. Earth-Science Reviews 155, 136-152. Draebing D., Haberkorn A., Krautblatter M., Kenner R., Phillips M. 2016. Spatial and temporal snow cover variability and resulting thermal and mechanical response in a permafrost rock wall. Permafrost and Periglacial Processes. Krautblatter M., Draebing D. 2014. Pseudo 3D - P-wave refraction seismic monitoring of permafrost in steep unstable bedrock. Journal of Geophysical Research: Earth Surface 119, 287-99. Phillips M., Haberkorn A., Draebing D., Krautblatter M., Rhyner H., Kenner R. 2016. Seasonally intermittent water flow through deep fractures in an Alpine rock ridge: Gemsstock, central Swiss Alps. Cold Regions Science and Technology 125, 117-127.

  5. NORPERM, the Norwegian Permafrost Database - a TSP NORWAY IPY legacy

    Science.gov (United States)

    Juliussen, H.; Christiansen, H. H.; Strand, G. S.; Iversen, S.; Midttømme, K.; Rønning, J. S.

    2010-10-01

    NORPERM, the Norwegian Permafrost Database, was developed at the Geological Survey of Norway during the International Polar Year (IPY) 2007-2009 as the main data legacy of the IPY research project Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard (TSP NORWAY). Its structural and technical design is described in this paper along with the ground temperature data infrastructure in Norway and Svalbard, focussing on the TSP NORWAY permafrost observatory installations in the North Scandinavian Permafrost Observatory and Nordenskiöld Land Permafrost Observatory, being the primary data providers of NORPERM. Further developments of the database, possibly towards a regional database for the Nordic area, are also discussed. The purpose of NORPERM is to store ground temperature data safely and in a standard format for use in future research. The IPY data policy of open, free, full and timely release of IPY data is followed, and the borehole metadata description follows the Global Terrestrial Network for Permafrost (GTN-P) standard. NORPERM is purely a temperature database, and the data is stored in a relation database management system and made publically available online through a map-based graphical user interface. The datasets include temperature time series from various depths in boreholes and from the air, snow cover, ground-surface or upper ground layer recorded by miniature temperature data-loggers, and temperature profiles with depth in boreholes obtained by occasional manual logging. All the temperature data from the TSP NORWAY research project is included in the database, totalling 32 temperature time series from boreholes, 98 time series of micrometeorological temperature conditions, and 6 temperature depth profiles obtained by manual logging in boreholes. The database content will gradually increase as data from previous and future projects are added. Links to near real-time permafrost temperatures, obtained

  6. Impacts of climate change on infrastructure in permafrost regions

    Science.gov (United States)

    Beloloutskaia, M.; Anisimov, O.

    2003-04-01

    There is a growing evidence of enhanced warming over the permafrost regions, and significant impacts on natural and human systems are expected. Changes in the temperature, distribution, and depth of seasonal thawing of permafrost will have direct and immediate implications for the infrastructure built upon it. The mechanical strength of permafrost decreases with warming, resulting in damage to and possible failure of buildings, pipelines, and transportation facilities. Extensive infrastructure was developed in the Arctic largely in association with the extraction and transportation industries. Several large cities in Russia with few hundred thousand population are of particular concern since many buildings there have already been affected by the changes in permafrost properties. Detrimental changes in permafrost conditions are often not abrupt. Instead, they evolve gradually and can be predicted and monitored, allowing avoidance of catastrophic events and mitigation of negative consequences. Climate-induced threats to infrastructure in permafrost regions may be evaluated using a numerical "settlement" index, Iset, which allows to classify modern permafrost with respect to its potential for thermokarst development: Iset = dZ * W, where dZ is the relative change in the depth of seasonal thawing predicted by permafrost model for the conditions of the future climate and W is the volumetric proportion of near surface soil occupied by ground ice. Permafrost model of intermediate complexity (Koudriavtcev's model) was used with selected GCM-based scenarios of climate change to construct predictive maps of "settlement" index for the mid-21st century. Circumpolar permafrost area was partitioned into zones of high, moderate, and low hazard potential. Despite discrepancies in details, all scenarios yield a zone in the high-risk category distributed discontinuously around the margins of the Arctic Ocean, indicating high potential for coastal erosion. Several population centers

  7. Permafrost in the Yukon-Kuskokwim Delta, Alaska: a case for a holistic and integrated view of permafrost degradation

    Science.gov (United States)

    Herman-Mercer, N. M.; Schuster, P. F.; Laituri, M.; Elder, K.; Mutter, E. A.; Massey, M.; Matkin, E.; Toohey, R.

    2016-12-01

    The Yukon-Kuskokwim Delta (YKD) region of Alaska is a vast, marshy, lowland plain, underlain by discontinuous permafrost vulnerable to degradation. This region has been home to the Yup'ik and Cup'ik people, subsisting on local resources for centuries. Permafrost thaw in northern latitudes has become the focus of extensive scientific research in recent decades. However, the indigenous residents that live in these areas of degrading permafrost have been largely left out of scientific discussion and studies. More than fifty semi-structured interviews were conducted in four YKD communities. Interview questions were focused on the broad themes of seasonality of subsistence systems and observations of weather and landscape change. Responses revealed the myriad ways people interact with and observe permafrost in their day to day lives. For instance, permafrost is still utilized for food storage, people encounter permafrost when digging graves, and observe permafrost thaw in damage to their homes and other infrastructure in their communities. Yup'ik and Cup'ik residents have an intimate knowledge of the landscape owing to their subsistence based lifestyle and have reported observations of slumping ground, eroding river banks and coast lines as well as land that seems to be rising. Indigenous knowledge and observations complement broader scientific studies and should be used to inform permafrost research and assist in reconstructing historical baselines of permafrost distribution and active layer depth. Further, results of scientific research must be communicated to the people that may be impacted by present and future changes to permafrost that will likely result in changes to hydrologic flowpaths and ultimately ecosystem dynamics that may impact subsistence. Over millennia, northern indigenous communities have developed flexibility in resource harvesting and have exhibited adaptability to a variable and harsh environment. However, changes are being experienced at an

  8. A new empirical method based on log-transformation regressions for the estimation of static formation temperatures of geothermal, petroleum and permafrost boreholes

    Science.gov (United States)

    Espinoza-Ojeda, O. M.; Santoyo, E.

    2016-08-01

    A new practical method based on logarithmic transformation regressions was developed for the determination of static formation temperatures (SFTs) in geothermal, petroleum and permafrost bottomhole temperature (BHT) data sets. The new method involves the application of multiple linear and polynomial (from quadratic to eight-order) regression models to BHT and log-transformation (Tln) shut-in times. Selection of the best regression models was carried out by using four statistical criteria: (i) the coefficient of determination as a fitting quality parameter; (ii) the sum of the normalized squared residuals; (iii) the absolute extrapolation, as a dimensionless statistical parameter that enables the accuracy of each regression model to be evaluated through the extrapolation of the last temperature measured of the data set; and (iv) the deviation percentage between the measured and predicted BHT data. The best regression model was used for reproducing the thermal recovery process of the boreholes, and for the determination of the SFT. The original thermal recovery data (BHT and shut-in time) were used to demonstrate the new method's prediction efficiency. The prediction capability of the new method was additionally evaluated by using synthetic data sets where the true formation temperature (TFT) was known with accuracy. With these purposes, a comprehensive statistical analysis was carried out through the application of the well-known F-test and Student's t-test and the error percentage or statistical differences computed between the SFT estimates and the reported TFT data. After applying the new log-transformation regression method to a wide variety of geothermal, petroleum, and permafrost boreholes, it was found that the polynomial models were generally the best regression models that describe their thermal recovery processes. These fitting results suggested the use of this new method for the reliable estimation of SFT. Finally, the practical use of the new method was

  9. Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Climate warming must lead the mainly air temperature controlled permafrost to degrade.Based on the numerical simulation,the process of permafrost degradation can be divided into five stages,i.e.,starting stage,temperature rising stage,zero geothermal gradient stage,talic layers stage,and disappearing stage,according to the shape of ground temperature profile.Permafrost on the Qinghai-Tibet Plateau (QTP) is generally considered a relic from late Pleistocene,and has been degenerating as a whole during Holocene.According to spatial-temporal compensation,the present thermal state discrepancy of permafrost in different areas on the QTP may correspond with their degradation stages.On the QTP,permafrost in the high and middle mountains belongs to temperature rising stage,the permafrost thermal state is transiting from late rising temperature stage to zero geothermal gradient stage that is distributed in the middle-low-mountains.Permafrost that is in a zero gradient stage mainly appears in the high plateau and valley,whereas the transition from zero gradient stage to talic layers stage of permafrost is located in the vicinity of the lower limit of permafrost,and permafrost is disappearing from margin of perennially frozen ground.There are two modes of perennially frozen ground thawing,thawing from top to bottom and thawing from bottom to top respectively.During the temperature rising stage,when the heat flux in the perennially frozen soil layer is less than that in the unfrozen soil underlying frozen soil layer,the geothermal flux is partly used to thaw the base of permafrost,and permafrost thaws from bottom to top.With the decrease of thermal gradient in the perennially frozen ground,the heat that is used to thaw permafrost base increases,and geothermal heat will be entirely consumed to thaw the base of permafrost until the temperature gradient reaches zero thermal gradient state.On the other hand,the disappearance of permafrost may be delayed by "thermal offset" and

  10. Characteristics of ground motion at permafrost sites along the Qinghai-Tibet railway

    Science.gov (United States)

    Wang, L.; Wu, Z.; Sun, Jielun; Liu, Xiuying; Wang, Z.

    2009-01-01

    Based on 14 typical drilling holes distributed in the permafrost areas along the Qinghai-Tibet railway, the distribution of wave velocities of soils in the permafrost regions were determined. Using results of dynamic triaxial tests, the results of dynamic triaxiality test and time histories of ground motion acceleration in this area, characteristics of ground motion response were analyzed for these permafrost sites for time histories of ground accelerations with three exceedance probabilities (63%, 10% and 2%). The influence of ground temperature on the seismic displacement, velocity, acceleration and response spectrum on the surface of permafrost were also studied. ?? 2008 Elsevier Ltd. All rights reserved.

  11. Mapping air temperature using time series analysis of LST: the SINTESI approach

    NARCIS (Netherlands)

    Alfieri, S.M.; De Lorenzi, F.; Menenti, M.

    2013-01-01

    This paper presents a new procedure to map time series of air temperature (Ta) at fine spatial resolution using time series analysis of satellite-derived land surface temperature (LST) observations. The method assumes that air temperature is known at a single (reference) location such as in gridded

  12. Using Landsat, MODIS, and a Biophysical Model to Evaluate LST in Urban Centers

    Directory of Open Access Journals (Sweden)

    Mohammad Z. Al-Hamdan

    2016-11-01

    Full Text Available In this paper, we assessed and compared land surface temperature (LST in urban centers using data from Landsat, MODIS, and the Simple Biosphere model (SiB2. We also evaluated the sensitivity of the model’s LST to different land cover types, fractions (percentages, and emissivities compared to reference points derived from Landsat thermal data. This was demonstrated in three climatologically- and morphologically-different cities of Atlanta, GA, New York, NY, and Washington, DC. Our results showed that in these cities SiB2 was sensitive to both the emissivity and the land cover type and fraction, but much more sensitive to the latter. The practical implications of these results are rather significant since they imply that the SiB2 model can be used to run different scenarios for evaluating urban heat island (UHI mitigation strategies. This study also showed that using detailed emissivities per land cover type and fractions from Landsat-derived data caused a convergence of the model results towards the Landsat-derived LST for most of the studied cases. This study also showed that SiB2 LSTs are closer in magnitude to Landsat-derived LSTs than MODIS-derived LSTs. It is important, however, to emphasize that both Landsat and MODIS LSTs are not direct observations and, as such, do not represent a ground truth. More studies will be needed to compare these results to in situ LST data and provide further validation.

  13. Assessment of permafrost distribution maps in the Hindu Kush-Himalayan region using rock glaciers mapped in Google Earth

    Science.gov (United States)

    Schmid, M.-O.; Baral, P.; Gruber, S.; Shahi, S.; Shrestha, T.; Stumm, D.; Wester, P.

    2014-10-01

    The extent and distribution of permafrost in the mountainous parts of the Hindu Kush-Himalayan (HKH) region have barely been investigated and are largely unknown. Only on the Tibetan Plateau a long tradition of permafrost research on rather gentle relief exists. Two permafrost maps are available that cover the HKH and provide estimates of permafrost extent, i.e. the areal proportion of permafrost: the manually delineated Circum-Arctic Map of Permafrost and Ground Ice Conditions (Brown et al., 1998) and the Global Permafrost Zonation Index, based on a computer model (Gruber, 2012). This article provides first-order assessment of permafrost maps of the HKH region based on the mapping of rock glaciers. Rock glaciers were used as a proxy, because they are visual indicators of permafrost, often occurring near the lowermost regional occurrence of permafrost in mountains, and because they can be delineated based on high-resolution remote sensing imagery freely available on Google Earth. For the mapping 4000 square samples (approx. 30 km2) were randomly distributed over the HKH region. Every sample was investigated and rock glaciers were mapped by two independent researchers following precise mapping instructions. Samples with insufficient image quality were recorded but not mapped. It is shown that mapping of rock glaciers in Google Earth can be used as first-order evidence for permafrost in mountain areas with severely limited ground truth. The minimum elevation of rock glaciers varies between 3500 and 5500 m a.s.l. within the region. The Circum-Arctic Map of Permafrost and Ground Ice Conditions does not reproduce mapped conditions in the HKH region adequately, whereas the Global Permafrost Zonation Index appears to be a reasonable first-order prediction of permafrost in the HKH. Only in the central part of the region a considerable deviation exists that needs further investigations.

  14. Effect of permafrost properties on gas hydrate petroleum system in the Qilian Mountains, Qinghai, Northwest China.

    Science.gov (United States)

    Wang, Pingkang; Zhang, Xuhui; Zhu, Youhai; Li, Bing; Huang, Xia; Pang, Shouji; Zhang, Shuai; Lu, Cheng; Xiao, Rui

    2014-12-01

    The gas hydrate petroleum system in the permafrost of the Qilian Mountains, which exists as an epigenetic hydrocarbon reservoir above a deep-seated hydrocarbon reservoir, has been dynamic since the end of the Late Pleistocene because of climate change. The permafrost limits the occurrence of gas hydrate reservoirs by changing the pressure-temperature (P-T) conditions, and it affects the migration of the underlying hydrocarbon gas because of its strong sealing ability. In this study, we reconstructed the permafrost structure of the Qilian Mountains using a combination of methods and measured methane permeability in ice-bearing sediment permafrost. A relationship between the ice saturation of permafrost and methane permeability was established, which permitted the quantitative evaluation of the sealing ability of permafrost with regard to methane migration. The test results showed that when ice saturation is >80%, methane gas can be completely sealed within the permafrost. Based on the permafrost properties and genesis of shallow gas, we suggest that a shallow "gas pool" occurred in the gas hydrate petroleum system in the Qilian Mountains. Its formation was related to a metastable gas hydrate reservoir controlled by the P-T conditions, sealing ability of the permafrost, fault system, and climatic warming. From an energy perspective, the increasing volume of the gas pool means that it will likely become a shallow gas resource available for exploitation; however, for the environment, the gas pool is an underground "time bomb" that is a potential source of greenhouse gas.

  15. Examining Environmental Gradients with Remotely Sensed Data - the ESA GlobPermafrost project

    Science.gov (United States)

    Bartsch, Annett; Grosse, Guido; Kääb, Andreas; Westermann, Sebastian; Strozzi, Tazio; Wiesmann, Andreas; Duguay, Claude; Seifert, Frank Martin; Obu, Jaroslav; Nitze, Ingmar; Heim, Birgit; Haas, Antoni; Widhalm, Barbara

    2017-04-01

    Permafrost cannot be directly detected from space, but many surface features of permafrost terrains and typical periglacial landforms are observable with a variety of EO sensors ranging from very high to medium resolution at various wavelengths. In addition, landscape dynamics associated with permafrost changes and geophysical variables relevant for characterizing the state of permafrost, such as land surface temperature or freeze-thaw state can be observed with space-based Earth Observation. Suitable regions to examine environmental gradients across the Arctic have been defined in a community white paper (Bartsch et al. 2014). These transects have been updated within the ESA DUE GlobPermafrost project. The ESA DUE GlobPermafrost project develops, validates and implements Earth Observation (EO) products to support research communities and international organisations in their work on better understanding permafrost characteristics and dynamics. Prototype product cases will cover different aspects of permafrost by integrating in situ measurements of subsurface properties and surface properties, Earth Observation, and modelling to provide a better understanding of permafrost today. The project will extend local process and permafrost monitoring to broader spatial domains, support permafrost distribution modelling, and help to implement permafrost landscape and feature mapping in a GIS framework. It will also complement active layer and thermal observing networks. Both lowland (latitudinal) and mountain (altitudinal) permafrost issues are addressed. The selected transects and first results will be presented. This includes identified needs from the user requirements survey, a review of existing land surface products available for the Arctic as well as prototypes of GlobPermafrost datasets, and the permafrost information system through which they can be accessed. Bartsch, Annett; Allard, Michel; Biskaborn, Boris Kolumban; Burba, George; Christiansen, Hanne H; Duguay

  16. The Nitrogen Inventory of the Yedoma Permafrost Domain

    Science.gov (United States)

    Strauss, J.; Abbott, B. W.; Biasi, C.; Grosse, G.; Horn, M. A.; Liebner, S.; Sanders, T.; Schirrmeister, L.; Schneider von Deimling, T.; Wetterich, S.; Winkel, M.; Zubrzycki, S.

    2016-12-01

    Fossil organic matter (OM) stored in permafrost is an important subject in climate research. Such OM represents a huge reservoir of carbon (C). Multiple studies suggest its source potential for C release into the active C cycle through permafrost thaw and subsequent microbial turnover in a warming Arctic. However, net ecosystem OM balance in the permafrost region depends on more than just carbon. The abundance and availability of nitrogen (N) following permafrost thaw will influence plant growth, nutrient delivery to aquatic and estuarine ecosystems, and N oxide (N2O) emissions. Despite its central importance to predicting permafrost impacts and feedbacks to climate change, relatively little is known about permafrost N stocks and composition. In this study, we present the most extensive dataset to date of permafrost N in the Siberian and Alaskan Yedoma domain. The Yedoma domain comprises decameter thick ice-rich silts intersected by syngenetic ice wedges, which formed in late Pleistocene tundra-steppe environments, as well as other deposits resulting from permafrost degradation during the Holocene. Together, the deposits in this region constitute a large C inventory storing several hundred Gt C, but are also known to be nutrient-rich due to rapid burial and freezing of plant remains. Hitherto, the total organic C pool of the Yedoma region was quantified, while the total N inventory is lacking so far. Based on the most comprehensive data set of N content in permafrost to date, our study aims to estimate the present pool of N stored in the different stratigraphic units of the Yedoma domain: 1) late Pleistocene Yedoma deposits, 2) in-situ thawed and diagenetically altered Yedoma deposits (taberite), 3) Holocene thermokarst deposits, 4) Holocene cover deposits on top of Yedoma, and 5) the modern active layer of soils. To quantify measurement uncertainty, we estimated nitrogen stocks with bootstrapping techniques. We show that the deposits of the Yedoma region store a

  17. Quantifying uncertainties of permafrost carbon–climate feedbacks

    Directory of Open Access Journals (Sweden)

    E. J. Burke

    2017-06-01

    Full Text Available The land surface models JULES (Joint UK Land Environment Simulator, two versions and ORCHIDEE-MICT (Organizing Carbon and Hydrology in Dynamic Ecosystems, each with a revised representation of permafrost carbon, were coupled to the Integrated Model Of Global Effects of climatic aNomalies (IMOGEN intermediate-complexity climate and ocean carbon uptake model. IMOGEN calculates atmospheric carbon dioxide (CO2 and local monthly surface climate for a given emission scenario with the land–atmosphere CO2 flux exchange from either JULES or ORCHIDEE-MICT. These simulations include feedbacks associated with permafrost carbon changes in a warming world. Both IMOGEN–JULES and IMOGEN–ORCHIDEE-MICT were forced by historical and three alternative future-CO2-emission scenarios. Those simulations were performed for different climate sensitivities and regional climate change patterns based on 22 different Earth system models (ESMs used for CMIP3 (phase 3 of the Coupled Model Intercomparison Project, allowing us to explore climate uncertainties in the context of permafrost carbon–climate feedbacks. Three future emission scenarios consistent with three representative concentration pathways were used: RCP2.6, RCP4.5 and RCP8.5. Paired simulations with and without frozen carbon processes were required to quantify the impact of the permafrost carbon feedback on climate change. The additional warming from the permafrost carbon feedback is between 0.2 and 12 % of the change in the global mean temperature (ΔT by the year 2100 and 0.5 and 17 % of ΔT by 2300, with these ranges reflecting differences in land surface models, climate models and emissions pathway. As a percentage of ΔT, the permafrost carbon feedback has a greater impact on the low-emissions scenario (RCP2.6 than on the higher-emissions scenarios, suggesting that permafrost carbon should be taken into account when evaluating scenarios of heavy mitigation and stabilization

  18. Distinct summer and winter bacterial communities in the active layer of Svalbard permafrost revealed by DNA- and RNA-based analyses

    Energy Technology Data Exchange (ETDEWEB)

    Schostag, Morten; Stibal, Marek; Jacobsen, Carsten S.; Baelum, Jacob; Tas, Neslihan; Elberling, Bo; Jansson, Janet K.; Semenchuk, Phillip; Prieme, Anders

    2015-04-30

    The active layer of soil overlaying permafrost in the Arctic is subjected to dramatic annual changes in temperature and soil chemistry, which likely affect bacterial activity and community structure. We studied seasonal variations in the bacterial community of active layer soil from Svalbard (78°N) by co-extracting DNA and RNA from 12 soil cores collected monthly over a year. PCR amplicons of 16S rRNA genes (DNA) and reverse transcribed transcripts (cDNA) were quantified and sequenced to test for the effect of low winter temperature and seasonal variation in concentration of easily degradable organic matter on the bacterial communities. The copy number of 16S rRNA genes and transcripts revealed no distinct seasonal changes indicating potential bacterial activity during winter despite soil temperatures well below -10°C. Multivariate statistical analysis of the bacterial diversity data (DNA and cDNA libraries) revealed a season-based clustering of the samples, and, e.g., the relative abundance of potentially active Cyanobacteria peaked in June and Alphaproteobacteria increased over the summer and then declined from October to November. The structure of the bulk (DNA-based) community was significantly correlated with pH and dissolved organic carbon, while the potentially active (RNA-based) community structure was not significantly correlated with any of the measured soil parameters. A large fraction of the 16S rRNA transcripts was assigned to nitrogen-fixing bacteria (up to 24% in June) and phototrophic organisms (up to 48% in June) illustrating the potential importance of nitrogen fixation in otherwise nitrogen poor Arctic ecosystems and of phototrophic bacterial activity on the soil surface.

  19. Circumpolar Active-Layer Permafrost System (CAPS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Circumpolar Active-Layer Permafrost System (CAPS) contains over 100 data sets pertaining to permafrost and frozen ground topics. It also contains detailed...

  20. The suitability of using ASTER GDEM2 for terrain-based extraction of stream channel networks in a lowland Arctic permafrost catchment

    Directory of Open Access Journals (Sweden)

    Anna Maria Trofaier

    2015-03-01

    Full Text Available Seasonally inundated areas and water-saturated soils are common features of lowland Arctic and sub-Arctic permafrost environments. With the onset of snow melt, and water percolation down through the snowpack, a principal factor controlling stream channel flow, aside from active layer depth, is topography. This paper investigates stream channel networks derived from the advanced spaceborne thermal emission and reflection radiometer (ASTER global digital elevation model (GDEM version 2 in a static terrain-based GIS-model. The suitability of using the ASTER GDEM2 for modelling the drainage network over a low-relief terrain is assessed. The aim is to use GDEM2 for the analysis of the stream channel network and to establish the network’s connectivity to previously observed spring flood patterns over the Yamal peninsula. As such, there are two parts to this study: 1 DEM validation and 2 stream channel network analysis. The results of the DEM validation study show that the root mean square error (RMSE of the GDEM2 and reference data is approx. 10 m when compared to both reference data sets (RMSE = 12.17 m, N = 86 and RMSE = 9.64, N = 506,877, implying that the GDEM2 is sufficiently accurate for terrain-based modelling. The low connectivity between the stream channel network and seasonal inundation suggests that topographic controls play a less important role compared to the possible overbanking of lakes and basin overflow. However, drainage densities for investigated drainage basins were significantly lower than those expected from typical Arctic basins. Both more sophisticated modelling techniques as well as higher spatial resolution DEMs are needed to extract the stream channel network more accurately and hence establish a more comprehensive link between the drainage network and seasonally inundated areas.

  1. Permafrost Characteristics of the Qinghai-Tibet Plateau and Methods of Roadbed Construction of Railway

    Institute of Scientific and Technical Information of China (English)

    NIU Fujun; XU Jian; LIN Zhanju; WU Qingbai; CHENG Guodong

    2008-01-01

    Permafrost along the Qinghai.Tibet railway is featured by abundant ground ice and high ground temperature. Under the influence of climate warming and engineering activities, the permafrost is under degradation process. The main difficulty in railway roadbed construction is how to prevent thawing settlement caused by degradation of permafrost. Therefore the proactively cooling methods based on controlling solar radiation, heat conductivity and heat convection were adopted instead of the traditional passive methods, which is simply increasing thermal resistance. The cooling methods used in the Qinghai-Tibet railway construction include sunshine-shielding roadbeds,crushed rock based roadbeds, roadbeds with rock revetments, duct-ventilated roadbeds, thermosyphon installed roadbeds and land bridges. The field monitored data show that the cooling methods are effective in protecting the underlying permafrost, the permafrost table was uplifted under the embankments and therefore the roadbed stability was guaranteed.

  2. Characterization of urban heat island effects over Asian megacities with hourly LST maps derived from Japanese geostationary satellite data

    Science.gov (United States)

    Oyoshi, K.; Tamura, M.

    2009-12-01

    Asian countries are expected to continue economic growth with high rate and urban structure can be transformed dramatically. Urbanization and increase in anthropogenic energy consumption cause urban heat island effect. And, Heat island effect increases cooling cost in summer and induces health problem such as heat stroke. Remotely sensed data can be powerful tool to characterize urban area and measure urban thermal conditions, because it is able to capture spatio-temporal variations in urban environments. Japanese geostationary meteorological satellite, MTSAT which covers east Asia and the western Pacific region from 140 degrees East above the equator was launched in February 2005. MTSAT provides hourly visible and thermal infrared image, and hourly Land Surface Temperature (LST) can be retrieved. Therefore, compared to polar orbiting satellites such as MODIS or AVHRR, MTSAT is expected to characterize urban thermal conditions in much detailed temporal scale. In this study, in order to evaluate thermal conditions over Asian megacities with MTSAT data, we investigated methodology for monitoring urban LST with satellite data and characterize thermal conditions by using hourly LST data. Firstly, LST were retrieved from MTSAT thermal infrared data with split-window algorithm, and it was confirmed that MTSAT is able to capture hourly spatio-temporal changes and detect urban heat island effects. Then, we constructed LST database of Asian megacities and the database was open to public on the WWW (http://eiserv.uee.kyoto-u.ac.jp/MTSAT/LST/index_e.php). Finally, by using developed LST database, characteristics of hourly temperature changes of Asian megacities were compared and categorized. And it is found that these characteristics were depend on urban structure of each city. Near-real time land surface temperature (LST) monitoring system on the WWW. Latest LST images of Asian megacities are displayed on the top page.

  3. Evolutionary conservation of TORC1 components, TOR, Raptor, and LST8, between rice and yeast.

    Science.gov (United States)

    Maegawa, Kentaro; Takii, Rumi; Ushimaru, Takashi; Kozaki, Akiko

    2015-10-01

    Target of rapamycin (TOR) is a conserved eukaryotic serine/threonine kinase that functions as a central controller of cell growth. TOR protein is structurally defined by the presence several conserved domains such as the HEAT repeat, focal adhesion target (FAT), FKBP12/rapamycin binding (FRB), kinase, and FATC domains starting from the N-terminus. In most eukaryotes, TOR forms two distinct physical and functional complexes, which are termed as TOR complex 1 (TORC1) and TORC2. However, plants contain only TORC1 components, i.e., TOR, Raptor, and LST8. In this study, we analyzed the gene structure and functions of TORC components in rice to understand the properties of the TOR complex in plants. Comparison of the locations of introns in these genes among rice and other eukaryotes showed that they were well conserved among plants except for Chlamydomonas. Moreover, the intron positions in the coding sequence of human Raptor and LST8 were closer to those of plants than of fly or nematode. Complementation tests of rice TOR (OsTOR) components in yeast showed that although OsTOR did not complement yeast tor mutants, chimeric TOR, which consisted of the HEAT repeat and FAT domain from yeast and other regions from rice, rescued the tor mutants, indicating that the HEAT repeat and FAT domains are important for species-specific signaling. OsRaptor perfectly complemented a kog1 (yeast Raptor homolog) mutant, and OsLST8 partially complemented an lst8 mutant. Together, these data suggest the importance of the N-terminal region of the TOR, HEAT, and FAT domains for functional diversification of the TOR complex.

  4. Characteristics of discontinuous permafrost, Southern Yukon Territory, Canada

    Science.gov (United States)

    Etzelmueller, B.; Lewkowicz, A. G.; Smith, S.

    2009-04-01

    Two-dimensional DC resistivity profiling was used to examine the characteristics of shallow permafrost at three lowland and eight mountain sites in the southern Yukon Territory. Ground temperatures from logged thermistor cables or annual manual readings were available for most of the sites. Frost table depths along the transects also helped constrain the interpretations. Ground temperatures at or close to the depth of zero annual amplitude were all warmer than -0.5°C. Interpreted permafrost depths were generally less than 10 m but reached 25 m at one location. Sites with coarse materials showed sharp transitions in resistivity values at the base of permafrost while those in fine-grained materials showed gradational boundaries, interpreted as being due to progressively increasing unfrozen moisture contents close to 0°C. There were large differences in the relative resistivity values for frozen and unfrozen ground but the absolute values for permafrost were lower than many others reported in the literature for mountain sites. The DC resistivity technique proved to be extremely useful in characterizing the distribution and continuity of frozen ground at these shallow and sensitive permafrost sites and provided a baseline data-set for monitoring future change.

  5. International Field School on Permafrost, Polar Urals, 2012

    Science.gov (United States)

    Streletskiy, D. A.; Grebenets, V.; Ivanov, M.; Sheinkman, V.; Shiklomanov, N. I.; Shmelev, D.

    2012-12-01

    The international field school on permafrost was held in the Polar Urals region from June, 30 to July 9, 2012 right after the Tenth International Conference on Permafrost which was held in Salekhard, Russia. The travel and accommodation support generously provided by government of Yamal-Nenets Autonomous Region allowed participation of 150 permafrost young research scientists, out of which 35 students from seven countries participated in the field school. The field school was organized under umbrella of International Permafrost Association and Permafrost Young Research Network. The students represented diverse educational backgrounds including hydrologists, engineers, geologists, soil scientists, geocryologists, glaciologists and geomorphologists. The base school camp was located near the Harp settlement in the vicinity of Polar Urals foothills. This unique location presented an opportunity to study a diversity of cryogenic processes and permafrost conditions characteristic for mountain and plain regions as well as transition between glacial and periglacial environments. A series of excursions was organized according to the following topics: structural geology of the Polar Urals and West Siberian Plain (Chromite mine "Centralnaya" and Core Storage in Labitnangy city); quaternary geomorphology (investigation of moraine complexes and glacial conditions of Ronamantikov and Topographov glaciers); principles of construction and maintains of structures built on permafrost (Labitnangy city and Obskaya-Bovanenkovo Railroad); methods of temperature and active-layer monitoring in tundra and forest-tundra; cryosols and soil formation in diverse landscape condition; periglacial geomorphology; types of ground ice, etc. Every evening students and professors gave a series of presentations on climate, vegetation, hydrology, soil conditions, permafrost and cryogenic processes of the region as well as on history, economic development, endogenous population of the Siberia and the

  6. Monitoring of Permafrost in the Hovsgol Mountain Region, Mongolia

    Science.gov (United States)

    Sharkhuu, A.; Natsagdorj, S.; Etzelmuller, B.; Heggem, E. S.; Nelson, F. E.; Shiklomanov, N.; Goulden, C.

    2005-12-01

    The Hovsgol Mountain Region is located between the coordinates of N 49°-52° and E 98°-102 ° in territory of Hovsgol Province, Mongolia. The territory is characterized by mountain permafrost, sporadic to continuous in its distribution, and occupies the southern fringe of the Siberian continuous permafrost zone. The main goal of permafrost monitoring in the region is to study recent degradation of permafrost under the influence of climate warming and human activities. Monitoring of permafrost is conducted within the framework of the Circumpolar Active Layer Monitoring (CALM) and the Global Terrestrial Network for Permafrost (GTN-P) programs. The main parameters being monitored are active layer depth and mean annual permafrost temperature at the level of the zero annual amplitude. Long-term CALM and GTN-P programs are based on ground temperature measurements in shallow to deep boreholes. Each borehole for monitoring is installed using instrumentation designed specifically to protect against air convection in them. Temperature measurements in the boreholes are made using identical thermo-resistors at corresponding depths, and carried out on the same dates each year. In addition, temperature dataloggers and thaw tubes are installed in most of the boreholes. At present, there are eight long-term (15-35 years) CALM and GTN-P active borehole sites. Boreholes are located in the Sharga valley (southwest), Burehkhan and Hovsgol phosphorite areas and Hatgal village (central part of the region) and in the Darhad depression. Initial results of the long term monitoring show that average rates of increase in active layer depth and mean annual permafrost temperature under influence of recent climate warming in the Hovsgol Mountain Region are 5-15 cm and 0.15-0.25°C per decade, respectively. The rate of permafrost degradation in bedrock is greater than in unconsolidated sediments, in ice-poor sediments more than ice-rich ones, and on north-facing slopes more than on south

  7. Methane emissions proportional to permafrost carbon thawed in Arctic lakes since the 1950s

    Science.gov (United States)

    Walter Anthony, Katey; Daanen, Ronald; Anthony, Peter; Schneider von Deimling, Thomas; Ping, Chien-Lu; Chanton, Jeffrey P.; Grosse, Guido

    2016-09-01

    Permafrost thaw exposes previously frozen soil organic matter to microbial decomposition. This process generates methane and carbon dioxide, and thereby fuels a positive feedback process that leads to further warming and thaw. Despite widespread permafrost degradation during the past ~40 years, the degree to which permafrost thaw may be contributing to a feedback between warming and thaw in recent decades is not well understood. Radiocarbon evidence of modern emissions of ancient permafrost carbon is also sparse. Here we combine radiocarbon dating of lake bubble trace-gas methane (113 measurements) and soil organic carbon (289 measurements) for lakes in Alaska, Canada, Sweden and Siberia with numerical modelling of thaw and remote sensing of thermokarst shore expansion. Methane emissions from thermokarst areas of lakes that have expanded over the past 60 years were directly proportional to the mass of soil carbon inputs to the lakes from the erosion of thawing permafrost. Radiocarbon dating indicates that methane age from lakes is nearly identical to the age of permafrost soil carbon thawing around them. Based on this evidence of landscape-scale permafrost carbon feedback, we estimate that 0.2 to 2.5 Pg permafrost carbon was released as methane and carbon dioxide in thermokarst expansion zones of pan-Arctic lakes during the past 60 years.

  8. Mapping ice-bonded permafrost with electrical methods in Sisimiut, West Greenland

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas

    2006-01-01

    Permafrost delineation and thickness determination is of great importance in engineering related projects in arctic areas. In this paper, 2D geoelectrical measurements are applied and evaluated for permafrost mapping in an area in West Greenland. Multi-electrode resistivity profiles (MEP) have been...... collected and are compared with borehole information. It is shown that the permafrost thickness in this case is grossly overestimated by a factor of two to three. The difference between the inverted 2D resistivity sections and the borehole information is explained by macro-anisotropy due to the presence...... of horizontal ice-lenses in the frozen clay deposits. It is concluded that where the resistivity method perform well for lateral permafrost mapping, great care should be taken in evaluating permafrost thickness based on 2D resistivity profiles alone. Additional information from boreholes or other geophysical...

  9. Permafrost thawing from different technical systems in Arctic regions

    Science.gov (United States)

    Filimonov, M.; Vaganova, N.

    2017-06-01

    A new three-dimensional model of thermal interaction in a “heat source-and-soil” system is proposed to study the process of permafrost degradation from various engineering facilities operating in the Arctic regions, taking into account a number of physical and climatic factors that affect the heat distribution. On the base of the proposed model, a software complex was developed to predict long-term dynamics of permafrost thawing in the upper layer of soil, and this approach was used in the design of 11 northern Russian oil and gas fields and is in a good agreement with numerical rezults and experimental data. Numerical calculations are presented for illustration the possibility of carrying out long-term forecasts for the determination of permafrost zone defrosting during operation of production wells in northern oil and gas field.

  10. Present and LGM permafrost from climate simulations: contribution of statistical downscaling

    Directory of Open Access Journals (Sweden)

    G. Levavasseur

    2011-11-01

    Full Text Available We quantify the agreement between permafrost distributions from PMIP2 (Paleoclimate Modeling Intercomparison Project climate models and permafrost data. We evaluate the ability of several climate models to represent permafrost and assess the variability between their results.

    Studying a heterogeneous variable such as permafrost implies conducting analysis at a smaller spatial scale compared with climate models resolution. Our approach consists of applying statistical downscaling methods (SDMs on large- or regional-scale atmospheric variables provided by climate models, leading to local-scale permafrost modelling. Among the SDMs, we first choose a transfer function approach based on Generalized Additive Models (GAMs to produce high-resolution climatology of air temperature at the surface. Then we define permafrost distribution over Eurasia by air temperature conditions. In a first validation step on present climate (CTRL period, this method shows some limitations with non-systematic improvements in comparison with the large-scale fields.

    So, we develop an alternative method of statistical downscaling based on a Multinomial Logistic GAM (ML-GAM, which directly predicts the occurrence probabilities of local-scale permafrost. The obtained permafrost distributions appear in a better agreement with CTRL data. In average for the nine PMIP2 models, we measure a global agreement with CTRL permafrost data that is better when using ML-GAM than when applying the GAM method with air temperature conditions. In both cases, the provided local information reduces the variability between climate models results. This also confirms that a simple relationship between permafrost and the air temperature only is not always sufficient to represent local-scale permafrost.

    Finally, we apply each method on a very different climate, the Last Glacial Maximum (LGM time period, in order to quantify the ability of climate models to represent LGM

  11. Transpiration response of boreal forest plants to permafrost thaw

    Science.gov (United States)

    Cable, J.; Ogle, K.; Welker, J. M.

    2011-12-01

    Shifts in the rate and patterns of evapotranspiration with permafrost thaw, vegetation change, and altered climatic conditions are unknown in boreal systems. Specifically, the response of transpiration is not well understood but critical to quantify given its non-linear response to climate. We asked: what is the effect of permafrost thaw on the transpiration dynamics of sub-Arctic boreal plants? We utilized a Bayesian analysis approach to quantify the responses of plants located in areas with and without stable permafrost to current and antecedent vapor pressure deficit, soil moisture, soil temperature, and the prior year's soil temperature. We measured stomatal conductance (gs) on six species of plants over two summers. For the analysis, the plants were grouped into three functional types: deciduous shrubs, evergreen sub-shrubs, and black spruce trees. The model we constructed includes a VPD (current and antecedent) sensitivity term modeled as a function of soil moisture (current and antecedent), and a "base" gs term modeled as a function of current soil temperature (at different depths), thaw depth, and the prior growing season's soil temperature (for each month, May - September). Current VPD was more important early in the growing season, but antecedent VPD was more important later in the growing season. The memory of gs for antecedent VPD was ~ three weeks in the past. The daily trends were less resolved for the site with degrading permafrost. Deeper thaw resulted in higher sensitivity to VPD and higher gs, particularly at the site with stable permafrost. Deciduous shrubs showed the strongest effect. At the site with thawing permafrost, soil water positively affected the sensitivity of gs to VPD for the deciduous shrubs but had a negative effect on black spruce. Current soil moisture was important early in the growing season but antecedent moisture was important at the end. The site with thawing permafrost had a longer memory (two weeks) for antecedent moisture

  12. Electromagnetic Method for Exogenetic Geodynamic Elements Mapping in Permafrost Environment

    Science.gov (United States)

    Gordeev, V. F.; Malyshkov, S. Y.; Polyvach, V. I.

    2017-04-01

    Taking into account the global warming, there is a pressing need to detect thermokarsts and to monitor permafrosts during the design and construction of industry infrastructure in Northern regions. The paper suggests a permafrost probing method based on the Earth’s natural pulsed electromagnetic field parameters recording. Authors describe the architecture and algorithms for the recording hardware. Examples of thermokarst detecting in poleward region are demonstrated. Pulsed electromagnetic fields intensity over thermokarst funnels is 30 times higher than the background levels. Authors substantiate the method’s eligibility to monitor geocryologial processes.

  13. New insights in permafrost modelling

    Science.gov (United States)

    Tubini, Niccolò; Serafin, Francesco; Gruber, Stephan; Casulli, Vincenzo; Rigon, Riccardo

    2017-04-01

    Simulating freezing soil has ignored for long time in mainstream surface hydrology. However, it has indubitably a large influence on soil infiltrability and an even larger influence on the soil energy budget, and, over large spatial scales, a considerable feedback on climate. The topic is difficult because it involves concepts of disequilibrium Thermodynamics and also because, once solved the theoretical problem, integration of the resulting partial differential equations in a robust manner, is not trivial at all. In this abstract, we are presenting a new algorithm to estimate the water and energy budget in freezing soils. The first step is a derivation of a new equation for freezing soil mass budget (called generalized Richards equation) based on the freezing equals drying hypothesis (Miller 1965). The second step is the re-derivation of the energy budget. Finally there is the application of new techniques based on the double nested Newton algorithm (Casulli and Zanolli, 2010) to integrate the coupled equations. Some examples of the freezing dynamics and comparison with the Dall'Amico et al. (2011) algorithm are also shown. References Casulli, V., & Zanolli,P. (2010). A nested newton-type algorithm for finite colume methods solving Richards' equation in mixed form. SIAM J. SCI. Comput., 32(4), 2225-2273. Dall'Amico, M., Endrizzi, S., Gruber, S., & Rigon, R. (2011). A robust and energy-conserving model of freezing variably-saturated soil. The Cryosphere, 5(2), 469-484. http://doi.org/10.5194/tc-5-469-2011 Miller, R.: Phase equilibria and soil freezing, in: Permafrost: Proceedings of the Second International Conference. Washington DC: National Academy of Science-National Research Council, 287, 193-197, 1965.

  14. Cartografía del permafrost de montaña en los Pirineos españoles

    Directory of Open Access Journals (Sweden)

    Juan González-Trueba

    2009-06-01

    Full Text Available Mountain permafrost map of the Spanish Pyrenees. Since the 1980’s with the development of research on rock glaciers and periglacial landforms as permafrost indicators that the mountain permafrost is known to occur in the Pyrenees. In this paper we present a map of the distribution of mountain permafrost in the Pyrenees. The mapping is based on indicators of permafrost (rock glaciers, gelifluctionprocesses, ice caves, patterned ground, vertical electric sounding and ground thermal regimes and geographical information extracted from a Digital Elevation Model, such as slope angle and aspect, altitude and potential direct solar radiation. The map represents the spatial distribution of “probable” and “possible permafrost”and represents the present-day state of the art on Pyrenean permafrost.

  15. Permafrost: occurrence and physiochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Ahonen, L. [Geological Survey of Finland, Espoo (Finland)

    2001-10-01

    Bedrock of the Northern Hemisphere areas to the north of about the 60th latitude are nowadays dominated by permafrost conditions. Fennoscandia is a major exception being characterised by temperate climate. In studying deep geological disposal of long-living nuclear waste, long-term climatic changes have to be taken into account. One of the scenarios to be studied is the extension of the deep permafrost conditions to the disposal site. Quaternary climatic fluctuations and their possible reasons are discussed shortly. The author's conclusion is that future climatic changes cannot be undoubtedly derived from the past variations, mainly because of the current anthropogenic involvement and of the poorly known dynamics of the major climate-affecting factors like ocean currents, which cannot be treated in a deterministic way. In low-porosity crystalline rocks permafrost may propagate to the depth of about 500 metres in some thousands to ten thousands of years. On the other hand, the major effects of permafrost are related to the freezing of water in the pores. Water expands about 9 percent in freezing, and the increasing stress may lead to pressure melting of ice. Dissolved salts in water do not accommodate into the solid ice, but they form saline water or brine segregations having freezing point of even less than minus ten degrees. A front of saline water may develop beneath the frozen bedrock. Pockets of saline water may also occur in ice, and unfrozen adsorption water may occur on the grain boundaries. With respect to the radionuclide transport processes, permafrost as such is a barrier, while the unfrozen domains (taliks) beneath major lake and river systems are potential flow paths. (orig.)

  16. Towards a Global Permafrost Electrical Resistivity Survey (GPERS) database

    Science.gov (United States)

    Lewkowicz, Antoni G.; Douglas, Thomas; Hauck, Christian

    2017-04-01

    Hundreds, and perhaps thousands, of Electrical Resistivity Tomography (ERT) surveys have been undertaken over the past two decades in permafrost areas in North America, Europe, and Asia. Two main types of ERT configurations have been conducted: galvanic surveys using metallic rods as conductors and capacitive-coupled surveys using towed cable arrays. ERT surveys have been carried out in regions with mountain permafrost, lowland permafrost, and coastal saline permafrost, and in undisturbed, naturally-disturbed (e.g. fire-affected), and anthropogenically-affected sites (e.g. around buildings and infrastructure). Some surveys are associated with local validation of frozen ground conditions, through borehole temperatures, frost probing or creep phenomena. Others are in locations without boreholes or with clast-rich or bedrock active layers which preclude this direct confirmation. Most surveys have been carried out individually on particular dates but there are increasing numbers of repeated ERT measurements being made to detect change, either at intervals using a fixed array of electrodes, or at high frequency with a fixed and automated measurement apparatus. Taken as a group, ERT profiles represent an untapped knowledge base relating to permafrost presence, absence, or partial presence (i.e. discontinuous permafrost), and in some cases to the thickness of permafrost and ice content. When combined with borehole information, ERT measurements can identify massive ice features and provides information on soil stratigraphy. The Global Permafrost Electrical Resistivity Survey (GPERS) database is planned as a freely available on-line repository of data from two-dimensional electrical resistivity surveys undertaken in permafrost regions. Its development is supported by the Permafrost Carbon Network and an application for an International Permafrost Association (IPA) Action Group is also underway. When the future GPERS records are compared with the GTN-P database it will be

  17. Airborne electromagnetic imaging of discontinuous permafrost

    Science.gov (United States)

    Minsley, Burke J.; Abraham, Jared D.; Smith, Bruce D.; Cannia, James C.; Voss, Clifford I.; Jorgenson, M. Torre; Walvoord, Michelle A.; Wylie, Bruce K.; Anderson, Lesleigh; Ball, Lyndsay B.; Deszcz-Pan, Maryla; Wellman, Tristan P.; Ager, Thomas A.

    2012-01-01

    The evolution of permafrost in cold regions is inextricably connected to hydrogeologic processes, climate, and ecosystems. Permafrost thawing has been linked to changes in wetland and lake areas, alteration of the groundwater contribution to streamflow, carbon release, and increased fire frequency. But detailed knowledge about the dynamic state of permafrost in relation to surface and groundwater systems remains an enigma. Here, we present the results of a pioneering ˜1,800 line-kilometer airborne electromagnetic survey that shows sediments deposited over the past ˜4 million years and the configuration of permafrost to depths of ˜100 meters in the Yukon Flats area near Fort Yukon, Alaska. The Yukon Flats is near the boundary between continuous permafrost to the north and discontinuous permafrost to the south, making it an important location for examining permafrost dynamics. Our results not only provide a detailed snapshot of the present-day configuration of permafrost, but they also expose previously unseen details about potential surface - groundwater connections and the thermal legacy of surface water features that has been recorded in the permafrost over the past ˜1,000 years. This work will be a critical baseline for future permafrost studies aimed at exploring the connections between hydrogeologic, climatic, and ecological processes, and has significant implications for the stewardship of Arctic environments.

  18. Searching for eukaryotic life preserved in Antarctic permafrost

    DEFF Research Database (Denmark)

    Zucconi, L.; Selbmann, L.; Buzzini, P.

    2012-01-01

    Fungi and yeasts isolated in pure culture from Antarctic permafrost collected at different depths in the McMurdo Dry Valleys were identified with cultural, physiological and molecular methods. Fungi belonged to the genera Penicillium, Eurotium, Cladosporium, Alternaria, Engyodonthium, Aureobasidi...... ancestral strains have been found on the base of metabolic profiles....

  19. Technological monitoring of subgrade construction on high-temperature permafrost

    Institute of Scientific and Technical Information of China (English)

    Svyatoslav Ya. Lutskiy; Taisia V. Shepitko; Alexander M. Cherkasov

    2015-01-01

    Three stages of complex technological monitoring for the increase of high-temperature-permafrost soil bearing capacity are described. The feasibility of process monitoring to improve the targeted strength properties of subgrade bases on frozen soils is demonstrated. The rationale for the necessity of predictive modeling of freeze-thaw actions during the subgrade construction period is provided.

  20. The Impact of Global Warming on the Carbon Cycle of Arctic Permafrost: An Experimental and Field Based Study

    Energy Technology Data Exchange (ETDEWEB)

    Onstott, Tullis C [Princeton University; Pffifner, Susan M; Chourey, Karuna [Oak Ridge National Laboratory

    2014-11-07

    Our results to date indicate that CO2 and CH4 fluxes from organic poor, Arctic cryosols on Axel Heiberg Island are net CH4 sinks and CO2 emitters in contrast to organic-rich peat deposits at sub-Arctic latitudes. This is based upon field observations and a 1.5 year long thawing experiment performed upon one meter long intact cores. The results of the core thawing experiments are in good agreement with field measurements. Metagenomic, metatranscriptomic and metaproteomic analyses indicate that high affinity aerobic methanotrophs belong to the uncultivated USCalpha are present in <1% abundance in these cryosols are are active in the field during the summer and in the core thawing experiments. The methanotrophs are 100 times more abundant than the methanogens. As a result mineral cryosols, which comprise 87% of Arctic tundra, are net methane sinks. Their presence and activity may account for the discrepancies observed between the atmospheric methane concentrations observed in the Arctic predicted by climate models and the observed seasonal fluctuations and decadal trends. This has not been done yet.

  1. 青藏铁路多年冻土工程地质勘察%Permafrost Engineering Geological Characteristics of Qinghai-Xizang Railway

    Institute of Scientific and Technical Information of China (English)

    张钊

    2004-01-01

    The effective and assured measures in criteria of formulation, procedures, techniques and methods for geological prospecting of Qinghai-Xizang Railway have been made. The permafrost engineering geological investigation indicate the talik and those sections with annual average ground temperature higher than 1 ℃ takes up 68.8% of total amount; the high ice content permafrost also account for 50% of real permafrost section. The distribution of permafrost characteristics is obviously influenced by altitude and latitude. The prospecting also shows the distribution of permafrost characteristics is rather complicated. Based on two predications of air temperature-rising tendency, by calculating climate model of permafrost thermal status, and comparing and analyzing geological distribution of Qinghai-Xizang Railway, the tendency of permafrost recession range has been predicated.

  2. Geophysical Investigations of Saline Permafrost at Ilulissat, Greenland

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Foged, Niels Nielsen; Butzbach, Rune

    2008-01-01

    The technical properties and general state of permafrost in Greenland is not well documented. A new coordinated investigation has been initiated, for ground temperature measurements and permafrost mapping in Greenlandic towns in sporadic, discontinuous and continuous permafrost zones. We present ...

  3. Permafrost distribution in the European Alps: calculation and evaluation of an index map and summary statistics

    Directory of Open Access Journals (Sweden)

    L. Boeckli

    2012-07-01

    Full Text Available The objective of this study is the production of an Alpine Permafrost Index Map (APIM covering the entire European Alps. A unified statistical model that is based on Alpine-wide permafrost observations is used for debris and bedrock surfaces across the entire Alps. The explanatory variables of the model are mean annual air temperatures, potential incoming solar radiation and precipitation. Offset terms were applied to make model predictions for topographic and geomorphic conditions that differ from the terrain features used for model fitting. These offsets are based on literature review and involve some degree of subjective choice during model building. The assessment of the APIM is challenging because limited independent test data are available for comparison and these observations represent point information in a spatially highly variable topography. The APIM provides an index that describes the spatial distribution of permafrost and comes together with an interpretation key that helps to assess map uncertainties and to relate map contents to their actual expression in the terrain. The map can be used as a first resource to estimate permafrost conditions at any given location in the European Alps in a variety of contexts such as research and spatial planning.

    Results show that Switzerland likely is the country with the largest permafrost area in the Alps, followed by Italy, Austria, France and Germany. Slovenia and Liechtenstein may have marginal permafrost areas. In all countries the permafrost area is expected to be larger than the glacier-covered area.

  4. Permafrost Meta-Omics and Climate Change

    Science.gov (United States)

    Mackelprang, Rachel; Saleska, Scott R.; Jacobsen, Carsten Suhr; Jansson, Janet K.; Taş, Neslihan

    2016-06-01

    Permanently frozen soil, or permafrost, covers a large portion of the Earth's terrestrial surface and represents a unique environment for cold-adapted microorganisms. As permafrost thaws, previously protected organic matter becomes available for microbial degradation. Microbes that decompose soil carbon produce carbon dioxide and other greenhouse gases, contributing substantially to climate change. Next-generation sequencing and other -omics technologies offer opportunities to discover the mechanisms by which microbial communities regulate the loss of carbon and the emission of greenhouse gases from thawing permafrost regions. Analysis of nucleic acids and proteins taken directly from permafrost-associated soils has provided new insights into microbial communities and their functions in Arctic environments that are increasingly impacted by climate change. In this article we review current information from various molecular -omics studies on permafrost microbial ecology and explore the relevance of these insights to our current understanding of the dynamics of permafrost loss due to climate change.

  5. Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG; Genxu; LI; Yuanshou

    2006-01-01

    Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage,grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the permafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment.Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the Iow mountain and plateau area will have a relatively

  6. 利用MATLAB实现FY-3/MERSI地表温度反演及专题制图%Utilization of MATLAB to Realize LST Retrieval and Thematic Mapping from FY-3/MERSI Data

    Institute of Scientific and Technical Information of China (English)

    杨何群; 尹球; 周红妹; 葛伟强

    2012-01-01

    Currently, application - oriented researches on the data of Medium Resolution Spectral Imager (MERSI) , which is on board China ' s new generation polar orbit meteorological satellite FY - 3 , are very insufficient, due to the reason that the data as a new source have been delivered only since 2008. With the normal operation of FY - 3 satellite system, it is necessary to develop an operational module for FY - 3/MERSI regional land surface temperature (LST) retrieval and its post - processing, since LST is required for a wide variety of scientific studies but FY - 3/MERSI' s operational LST products have not yet been provided by National Satellite Meteorological Center (NSMC ). Rased on an analysis of FY - 3/MERSI LI data' s HDF5 format and its channel characteristics, the authors selected the generalized single - channel algorithm developed by Jimenez - Munoz & Sobrino to directly realize the LST retrieval at 250 m spatial resolution with MATLAR programming and the thematic mapping of LST derivative products. This paper describes the parametric processes of LST retrieval algorithm in detail, which include radiometric calibration, cloud detection, estimation of two intermediate parameters - surface emissivity and atmospheric water vapor, and calculation of thermal indexes from LST. On these bases, an automatic flowchart for FY - 3/MERSI LST retrieval and thematic mapping was established. Experimental results of this flowchart applied in Shanghai thermal environmental monitoring show that it can process FY - 3/MERSI LI data in a fast, real - time and automatic way, thus suitable for operational products producing and sharing, with the saving of human resources. It is also proved that FY - 3/MERSI data and various forms of LST products can reveal the spatial pattern of Shanghai thermal field and the urban heat island effect more finely and intuitively.%我国新型自主研发的风云三号卫星MERSI(FY-3/MERSI)数据目前多见于试验研究,国家卫星气象

  7. Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, northwest Alaska

    Science.gov (United States)

    Lenz, Josefine; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey M. Walter; Bobrov, Anatoly; Wulf, Sabine; Wetterich, Sebastian

    2016-01-01

    Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyse a ~ 4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemical, geochronological, micropalaeontological (ostracoda, testate amoebae) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by the deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP and drained catastrophically in spring 2005. The present study emphasises that Arctic lake systems and periglacial landscapes are highly dynamic and that permafrost formation as well as degradation in central Beringia was controlled by regional to global climate patterns as well as by local disturbances.

  8. Sensitivity of airborne geophysical data to sublacustrine permafrost thaw

    Directory of Open Access Journals (Sweden)

    B. J. Minsley

    2014-12-01

    Full Text Available A coupled hydrogeophysical forward and inverse modeling approach is developed to illustrate the ability of frequency-domain airborne electromagnetic (AEM data to characterize subsurface physical properties associated with sublacustrine permafrost thaw during lake talik formation. Several scenarios are evaluated that consider the response to variable hydrologic forcing from different lake depths and hydrologic gradients. The model includes a physical property relationship that connects the dynamic distribution of subsurface electrical resistivity based on lithology as well as ice-saturation and temperature outputs from the SUTRA groundwater simulator with freeze/thaw physics. Electrical resistivity models are used to simulate AEM data in order to explore the sensitivity of geophysical observations to permafrost thaw. Simulations of sublacustrine talik formation over a 1000 year period modeled after conditions found in the Yukon Flats, Alaska, are evaluated. Synthetic geophysical data are analyzed with a Bayesian Markov chain Monte Carlo algorithm that provides a probabilistic assessment of geophysical model uncertainty and resolution. Major lithological and permafrost features are well resolved in the examples considered. The subtle geometry of partial ice-saturation beneath lakes during talik formation cannot be resolved using AEM data, but the gross characteristics of sub-lake resistivity models reflect bulk changes in ice content and can be used to determine the presence of a talik. A final example compares AEM and ground-based electromagnetic responses for their ability to resolve shallow permafrost and thaw features in the upper 1–2 m below ground.

  9. Assessment of Mono- and Split-Window Approaches for Time Series Processing of LST from AVHRR—A TIMELINE Round Robin

    Directory of Open Access Journals (Sweden)

    Corinne Myrtha Frey

    2017-01-01

    Full Text Available Processing of land surface temperature from long time series of AVHRR (Advanced Very High Resolution Radiometer requires stable algorithms, which are well characterized in terms of accuracy, precision and sensitivity. This assessment presents a comparison of four mono-window (Price 1983, Qin et al., 2001, Jiménez-Muñoz and Sobrino 2003, linear approach and six split-window algorithms (Price 1984, Becker and Li 1990, Ulivieri et al., 1994, Wan and Dozier 1996, Yu 2008, Jiménez-Muñoz and Sobrino 2008 to estimate LST from top of atmosphere brightness temperatures, emissivity and columnar water vapour. Where possible, new coefficients were estimated matching the spectral response curves of the different AVHRR sensors of the past and present. The consideration of unique spectral response curves is necessary to avoid artificial anomalies and wrong trends when processing time series data. Using simulated data on the base of a large atmospheric profile database covering many different states of the atmosphere, biomes and geographical regions, it was assessed (a to what accuracy and precision LST can be estimated using before mentioned algorithms and (b how sensitive the algorithms are to errors in their input variables. It was found, that the split-window algorithms performed almost equally well, differences were found mainly in their sensitivity to input bands, resulting in the Becker and Li 1990 and Price 1984 split-window algorithm to perform best. Amongst the mono-window algorithms, larger deviations occurred in terms of accuracy, precision and sensitivity. The Qin et al., 2001 algorithm was found to be the best performing mono-window algorithm. A short comparison of the application of the Becker and Li 1990 coefficients to AVHRR with the MODIS LST product confirmed the approach to be physically sound.

  10. Distinct summer and winter bacterial communities in the active layer of Svalbard permafrost revealed by DNA- and RNA-based analyses

    DEFF Research Database (Denmark)

    Schostag, Morten; Stibal, Marek; Jacobsen, Carsten S.

    2015-01-01

    N) by co-extracting DNA and RNA from 12 soil cores collected monthly over a year. PCR amplicons of 16S rRNA genes (DNA) and reverse transcribed transcripts (cDNA) were quantified and sequenced to test for the effect of low winter temperature and seasonal variation in concentration of easily degradable......The active layer of soil overlaying permafrost in the Arctic is subjected to dramatic annual changes in temperature and soil chemistry, which likely affect bacterial activity and community structure. We studied seasonal variations in the bacterial community of active layer soil from Svalbard (78º...

  11. Inversion of Land Surface Temperature (LST Using Terra ASTER Data: A Comparison of Three Algorithms

    Directory of Open Access Journals (Sweden)

    Milton Isaya Ndossi

    2016-12-01

    Full Text Available Land Surface Temperature (LST is an important measurement in studies related to the Earth surface’s processes. The Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER instrument onboard the Terra spacecraft is the currently available Thermal Infrared (TIR imaging sensor with the highest spatial resolution. This study involves the comparison of LSTs inverted from the sensor using the Split Window Algorithm (SWA, the Single Channel Algorithm (SCA and the Planck function. This study has used the National Oceanic and Atmospheric Administration’s (NOAA data to model and compare the results from the three algorithms. The data from the sensor have been processed by the Python programming language in a free and open source software package (QGIS to enable users to make use of the algorithms. The study revealed that the three algorithms are suitable for LST inversion, whereby the Planck function showed the highest level of accuracy, the SWA had moderate level of accuracy and the SCA had the least accuracy. The algorithms produced results with Root Mean Square Errors (RMSE of 2.29 K, 3.77 K and 2.88 K for the Planck function, the SCA and SWA respectively.

  12. Titan's GOO-Sphere: Glacial, Permafrost, Evaporite, and Other Familiar Processes Involving Exotic Materials

    Science.gov (United States)

    Kargel, J. S.; Furfaro, R.; Hays, C. C.; Lopes, R. M. C.; Lunine, J. I.; Mitchell, K. L.; Wall, S. D.; Cassini RADAR Team

    2007-03-01

    A new Geologic Operating Organon (GOO) for Titan is based on the cryogenic activity of many hydrocarbon and organic substances. This model derives insight from volcanic, fluvial, lacustrine, permafrost, and glacial processes on Earth and beyond.

  13. Development of a Permafrost Modeling Cyberinfrastructure

    Science.gov (United States)

    Overeem, I.; Jafarov, E. E.; Piper, M.; Schaefer, K. M.

    2016-12-01

    Permafrost is seen as an essential Arctic climate indicator, and feedback of thawing permafrost to the global climate system through the impacts on the global carbon cycle remain an important research topic. Observations can assess the current state of permafrost, but models are eventually essential to make predictions of future permafrost extent. The purpose of our project, which we call PermaModel, is to develop an easy-to-access and comprehensive cyberinfrastructure aimed at promoting and improving permafrost modeling. The PermaModel Integrated Modeling Toolbox (IMT) includes three permafrost models of increasing complexity. The IMT will be housed within the existing cyberinfrastructure of the Community Surface Dynamics Modeling System (CSDMS), and made publically accessible through the CSDMS Web Modeling Tool (WMT). The WMT will provide easy online access to students, scientists, and stakeholders who want to use permafrost models, but lack the expertise. We plan to include multiple sets of sample inputs, representing a variety of conditions and locations, to enable immediate use of the IMT. We present here the first permafrost model, which is envisioned to be the most suitable for teaching purposes. The model promotes understanding of a 1D heat equation and permafrost active layer dynamics under monthly temperature/climate drivers in an online environment. Modeling labs are presented through the CSDMS Educational Repository and we solicit feedback from faculty for further design of these resources.

  14. Northern Alaska Landscape/Permafrost GIS Data

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — This data set represents an updated Ecological Subsection Map for Northern Alaska. This update includes permafrost mapping to include the following new layers:...

  15. Suggested best practice for geotechnical characterisation of permafrost in the Nordic countries

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas; Foged, Niels Nielsen

    2012-01-01

    . It is proposed that a best practice for permafrost characterisation employs sample volume determination based on the Archimedes principle and that ice contents are presented as the volume fraction of excess ice to the frozen sample volume. Furthermore, direct measurements of unfrozen water content and thermal......Even though permafrost is a specialty within Nordic geotechnical engineering, engineers and researcher will be faced with managing the consequences of projected climatic influences to construction design in permafrost areas. This requires the determination of the frozen soil engineering properties...

  16. Permafrost-associated gas hydrate: is it really approximately 1% of the global system?

    Science.gov (United States)

    Ruppel, Carolyn

    2015-01-01

    Permafrost-associated gas hydrates are often assumed to contain ∼1 % of the global gas-in-place in gas hydrates based on a study26 published over three decades ago. As knowledge of permafrost-associated gas hydrates has grown, it has become clear that many permafrost-associated gas hydrates are inextricably linked to an associated conventional petroleum system, and that their formation history (trapping of migrated gas in situ during Pleistocene cooling) is consistent with having been sourced at least partially in nearby thermogenic gas deposits. Using modern data sets that constrain the distribution of continuous permafrost onshore5 and subsea permafrost on circum-Arctic Ocean continental shelves offshore and that estimate undiscovered conventional gas within arctic assessment units,16 the done here reveals where permafrost-associated gas hydrates are most likely to occur, concluding that Arctic Alaska and the West Siberian Basin are the best prospects. A conservative estimate is that 20 Gt C (2.7·1013 kg CH4) may be sequestered in permafrost-associated gas hydrates if methane were the only hydrate-former. This value is slightly more than 1 % of modern estimates (corresponding to 1600 Gt C to 1800 Gt C2,22) for global gas-in-place in methane hydrates and about double the absolute estimate (11.2 Gt C) made in 1981.26

  17. On the connection of permafrost and debris flow activity in Austria

    Science.gov (United States)

    Huber, Thomas; Kaitna, Roland

    2016-04-01

    Debris flows represent a severe hazard in alpine regions and typically result from a critical combination of relief energy, water, and sediment. Hence, besides water-related trigger conditions, the availability of abundant sediment is a major control on debris flows activity in alpine regions. Increasing temperatures due to global warming are expected to affect periglacial regions and by that the distribution of alpine permafrost and the depth of the active layer, which in turn might lead to increased debris flow activity and increased interference with human interests. In this contribution we assess the importance of permafrost on documented debris flows in the past by connecting the modeled permafrost distribution with a large database of historic debris flows in Austria. The permafrost distribution is estimated based on a published model approach and mainly depends of altitude, relief, and exposition. The database of debris flows includes more than 4000 debris flow events in around 1900 watersheds. We find that 27 % of watersheds experiencing debris flow activity have a modeled permafrost area smaller than 5 % of total area. Around 7 % of the debris flow prone watersheds have an area larger than 5 %. Interestingly, our first results indicate that watersheds without permafrost experience significantly less, but more intense debris flow events than watersheds with modeled permafrost occurrence. Our study aims to contribute to a better understanding of geomorphic activity and the impact of climate change in alpine environments.

  18. Warming but not thawing of the cold permafrost in northern Alaska during the past 50 years

    Institute of Scientific and Technical Information of China (English)

    Max; C.; Brewer

    2009-01-01

    Climate warming has not resulted in measurable thawing of the cold (-5°C to -10°C) permafrost in northern Alaska during the last half century. The maximum depths of summer thaw at five locations near Barrow, Alaska, in 2005 were within the ranges of the depths obtained at those same locations during the early 1950s. However, there has been a net warming of about 2°C, after a cooling of 0.4°C during 1953-1960, at the upper depths of the permafrost column at two of the locations. Thawing of permafrost from above (increase in active layer thickness) is determined by the summer thawing index for the specific year; any warming, or cooling, of the upper permafrost column results from the cumulative effect of changes in the average annual air temperatures over a period of years, assuming no change in surface conditions. Theoretically, thawing from the base of permafrost should be negligible even in areas of thin (about 100-200 m) permafrost in northern Alaska. The reported shoreline erosion along the northern Alaska coast is a secondary result from changes in the adjacent ocean ice coverage during the fall stormy period, and is not directly because of any "thawing" of the permafrost.

  19. Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints

    Science.gov (United States)

    Ruppel, Carolyn; Herman, Bruce M.; Brothers, Laura L.; Hart, Patrick E.

    2016-01-01

    Borehole logging data from legacy wells directly constrain the contemporary distribution of subsea permafrost in the sedimentary section at discrete locations on the U.S. Beaufort Margin and complement recent regional analyses of exploration seismic data to delineate the permafrost's offshore extent. Most usable borehole data were acquired on a ∼500 km stretch of the margin and within 30 km of the contemporary coastline from north of Lake Teshekpuk to nearly the U.S.-Canada border. Relying primarily on deep resistivity logs that should be largely unaffected by drilling fluids and hole conditions, the analysis reveals the persistence of several hundred vertical meters of ice-bonded permafrost in nearshore wells near Prudhoe Bay and Foggy Island Bay, with less permafrost detected to the east and west. Permafrost is inferred beneath many barrier islands and in some nearshore and lagoonal (back-barrier) wells. The analysis of borehole logs confirms the offshore pattern of ice-bearing subsea permafrost distribution determined based on regional seismic analyses and reveals that ice content generally diminishes with distance from the coastline. Lacking better well distribution, it is not possible to determine the absolute seaward extent of ice-bearing permafrost, nor the distribution of permafrost beneath the present-day continental shelf at the end of the Pleistocene. However, the recovery of gas hydrate from an outer shelf well (Belcher) and previous delineation of a log signature possibly indicating gas hydrate in an inner shelf well (Hammerhead 2) imply that permafrost may once have extended across much of the shelf offshore Camden Bay.

  20. Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints

    Science.gov (United States)

    Ruppel, Carolyn D.; Herman, Bruce M.; Brothers, Laura L.; Hart, Patrick E.

    2016-11-01

    Borehole logging data from legacy wells directly constrain the contemporary distribution of subsea permafrost in the sedimentary section at discrete locations on the U.S. Beaufort Margin and complement recent regional analyses of exploration seismic data to delineate the permafrost's offshore extent. Most usable borehole data were acquired on a ˜500 km stretch of the margin and within 30 km of the contemporary coastline from north of Lake Teshekpuk to nearly the U.S.-Canada border. Relying primarily on deep resistivity logs that should be largely unaffected by drilling fluids and hole conditions, the analysis reveals the persistence of several hundred vertical meters of ice-bonded permafrost in nearshore wells near Prudhoe Bay and Foggy Island Bay, with less permafrost detected to the east and west. Permafrost is inferred beneath many barrier islands and in some nearshore and lagoonal (back-barrier) wells. The analysis of borehole logs confirms the offshore pattern of ice-bearing subsea permafrost distribution determined based on regional seismic analyses and reveals that ice content generally diminishes with distance from the coastline. Lacking better well distribution, it is not possible to determine the absolute seaward extent of ice-bearing permafrost, nor the distribution of permafrost beneath the present-day continental shelf at the end of the Pleistocene. However, the recovery of gas hydrate from an outer shelf well (Belcher) and previous delineation of a log signature possibly indicating gas hydrate in an inner shelf well (Hammerhead 2) imply that permafrost may once have extended across much of the shelf offshore Camden Bay.

  1. Potential methane production in thawing permafrost is constrained by methanogenic population size, carbon density, and substrate

    Science.gov (United States)

    Liebner, S.; Lehr, C.; Wagner, D.; Obu, J.; Lantuit, H.; Fritz, M.

    2016-12-01

    The release of carbon from newly thawed permafrost is estimated to add between 0.05 and 0.39 °C to the simulated global mean surface air temperature by the year 2300. The release of the potent greenhouse gas CH4 following permafrost thaw is thereby of particular concern. Models simulated a contribution of CH4 to the radiative forcing from thawing permafrost of up to 40% for the maximum extent of thermokarst (1). Batch experiments on thawed permafrost samples, however, have rendered the contribution of anaerobically produced carbon and in particular of CH4 to be surprisingly weak (2) and CH4 production which is realized through methanogenic archaea was reported to be low and associated with long lag phases . This leads to the hypotheses that initial methanogenic population sizes and/or substrates are limiting factors in permafrost. The objective of this study is to identify constraints for CH4 production in thawing permafrost. We analyzed several low Arctic permafrost cores of up to 3 m depth of different land cover types, sediment properties, age and stratigraphy for methanogenic abundance, potential methane production and predictors of both. We found that methanogenic population size and substrate pool are constraints on methane production but unlike expected, they do not fully explain low CH4 production rates in thawing permafrost. Even when both, population size and substrate concentrations, were large, the potential production of CH4 was still comparably low. Furthermore we show that the potential production of CH4 in thawing permafrost is a function of the methanogenic population size if substrate is not the limiting factor and that the methanogenic population size in turn is a function of the carbon density. Based on our study we propose that on the long term after permafrost has thawed, growth and community shifts within the methanogenic population will occur which potentially will increase methane production by orders of magnitude. 1. Schneider von

  2. Assessing the Reliability of Geoelectric Imaging Results for Permafrost Investigations

    Science.gov (United States)

    Marescot, L.; Loke, M.; Abbet, D.; Delaloye, R.; Hauck, C.; Hilbich, C.; Lambiel, C.; Reynard, E.

    2007-12-01

    The effects of global climate change on mountain permafrost are of increasing concern; warming thaws permafrost, thereby increasing the risk of slope instabilities. Consequently, knowledge of the extent and location of permafrost are important for construction and other geotechnical and land-management activities in mountainous areas. Geoelectric imaging is a useful tool for mapping and characterizing permafrost occurrences. To overcome the generally poor electrical contacts in the active layer, geoelectric surveys usually involve coupling the electrodes to the ground via sponges soaked in salt water. The data are processed and inverted in terms of resistivity models of the subsurface. To monitor the evolution of mountain permafrost, time-lapse geoelectric imaging may be employed. A challenging aspect in geoelectric imaging of permafrost is the very large resistivity contrast between frozen and unfrozen material. Such a contrast makes inversion and interpretation difficult. To assess whether features at depth are required by the data or are artifacts of the inversion process, the reliability of models needs to be evaluated. We use two different approaches to assess the reliability of resistivity images in permafrost investigations: (i) depth of investigation (DOI) and (ii) resolution matrix maps. To compute the DOI, two inversions of the same data set using quite different reference resistivity models are carried out. At locations where the resistivity is well constrained by the data, the inversions yield the same results. At other locations, the inversions yield different values that are controlled by the reference models. The resolution matrix, which is based on the sensitivity matrix calculated during the inversion, quantifies the degree to which each resistivity cell in the model can be resolved by the data. Application of these two approaches to field data acquired in the Swiss Alps and Jura Mountains suggests that it is very difficult to obtain dependable

  3. Hydrogeochemical characterisation of groundwater in a small watershed in a discontinuous permafrost zone.

    Science.gov (United States)

    Cochand, Marion; Molson, John; Barth, Johannes A. C.; van Geldern, Robert; Lemieux, Jean-Michel; Fortier, Richard; Therrien, René

    2017-04-01

    recharge conditions of permafrost ice were similar to current conditions, or freeze-thaw cycles have drawn modern water into the permafrost mounds. The stream appears to be fed by groundwater exfiltrating at the base of permafrost mounds in the lower part of the watershed. Linking this hydrogeochemical characterisation to groundwater and thermal modelling at the watershed and permafrost mound scales will improve our knowledge on hydrogeological interactions in degrading permafrost environments.

  4. Derivation and analysis of a high-resolution estimate of global permafrost zonation

    Directory of Open Access Journals (Sweden)

    S. Gruber

    2012-02-01

    Full Text Available Permafrost underlies much of Earth's surface and interacts with climate, eco-systems and human systems. It is a complex phenomenon controlled by climate and (sub- surface properties and reacts to change with variable delay. Heterogeneity and sparse data challenge the modeling of its spatial distribution. Currently, there is no data set to adequately inform global studies of permafrost. The available data set for the Northern Hemisphere is frequently used for model evaluation, but its quality and consistency are difficult to assess. Here, a global model of permafrost extent and dataset of permafrost zonation are presented and discussed, extending earlier studies by including the Southern Hemisphere, by consistent data and methods, by attention to uncertainty and scaling. Established relationships between air temperature and the occurrence of permafrost are re-formulated into a model that is parametrized using published estimates. It is run with a high-resolution (<1 km global elevation data and air temperatures based on the NCAR-NCEP reanalysis and CRU TS 2.0. The resulting data provide more spatial detail and a consistent extrapolation to remote regions, while aggregated values resemble previous studies. The estimated uncertainties affect regional patterns and aggregate number, and provide interesting insight. The permafrost area, i.e. the actual surface area underlain by permafrost, north of 60° S is estimated to be 13–18 × 106 km2 or 9–14 % of the exposed land surface. The global permafrost area including Antarctic and sub-sea permafrost is estimated to be 16–21 × 106 km2. The global permafrost region, i.e. the exposed land surface below which some permafrost can be expected, is estimated to be 22 ± 3 × 106 km2. A large proportion of this exhibits considerable topography and spatially-discontinuous permafrost, underscoring the importance of attention to scaling issues

  5. Data analysis and mapping of the mountain permafrost distribution

    Science.gov (United States)

    Deluigi, Nicola; Lambiel, Christophe; Kanevski, Mikhail

    2017-04-01

    In Alpine environments mountain permafrost is defined as a thermal state of the ground and corresponds to any lithosphere material that is at or below 0°C for, at least, two years. Its degradation is potentially leading to an increasing rock fall activity, rock glacier accelerations and an increase in the sediment transfer rates. During the last 15 years, knowledge on this phenomenon has significantly increased thanks to many studies and monitoring projects. They revealed a spatial distribution extremely heterogeneous and complex. As a consequence, modelling the potential extent of the mountain permafrost recently became a very important task. Although existing statistical models generally offer a good overview at a regional scale, they are not always able to reproduce its strong spatial discontinuity at the micro scale. To overcome this lack, the objective of this study is to propose an alternative modelling approach using three classification algorithms belonging to statistics and machine learning: Logistic regression (LR), Support Vector Machines (SVM) and Random forests (RF). The former is a linear parametric classifier that commonly used as a benchmark classification algorithm to be employed before using more complex classifiers. Non-linear SVM is a non-parametric learning algorithm and it is a member of the so-called kernel methods. RF are an ensemble learning method based on bootstrap aggregating and offer an embedded measure of the variable importance. Permafrost evidences were selected in a 588 km2 area of the Western Swiss Alps and serve as training examples. They were mapped from field data (thermal and geoelectrical data) and ortho-image interpretation (rock glacier inventorying). The dataset was completed with environmental predictors such as altitude, mean annual air temperature, aspect, slope, potential incoming solar radiation, normalized difference vegetation index and planar, profile and combined terrain curvature indices. Aiming at predicting

  6. Distinct summer and winter bacterial communities in the active layer of Svalbard permafrost revealed by DNA- and RNA-based analyses

    DEFF Research Database (Denmark)

    Schostag, Morten; Stibal, Marek; Jacobsen, Carsten S.

    2015-01-01

    N) by co-extracting DNA and RNA from 12 soil cores collected monthly over a year. PCR amplicons of 16S rRNA genes (DNA) and reverse transcribed transcripts (cDNA) were quantified and sequenced to test for the effect of low winter temperature and seasonal variation in concentration of easily degradable...... organic matter on the bacterial communities. The copy number of 16S rRNA genes and transcripts revealed no distinct seasonal changes indicating potential bacterial activity during winter despite soil temperatures well below -10ºC. Multivariate statistical analysis of the bacterial diversity data (DNA......The active layer of soil overlaying permafrost in the Arctic is subjected to dramatic annual changes in temperature and soil chemistry, which likely affect bacterial activity and community structure. We studied seasonal variations in the bacterial community of active layer soil from Svalbard (78º...

  7. Permafrost Active Layer Seismic Interferometry Experiment (PALSIE).

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knox, Hunter Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); James, Stephanie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lee, Rebekah [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cole, Chris [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    We present findings from a novel field experiment conducted at Poker Flat Research Range in Fairbanks, Alaska that was designed to monitor changes in active layer thickness in real time. Results are derived primarily from seismic data streaming from seven Nanometric Trillium Posthole seismometers directly buried in the upper section of the permafrost. The data were evaluated using two analysis methods: Horizontal to Vertical Spectral Ratio (HVSR) and ambient noise seismic interferometry. Results from the HVSR conclusively illustrated the method's effectiveness at determining the active layer's thickness with a single station. Investigations with the multi-station method (ambient noise seismic interferometry) are continuing at the University of Florida and have not yet conclusively determined active layer thickness changes. Further work continues with the Bureau of Land Management (BLM) to determine if the ground based measurements can constrain satellite imagery, which provide measurements on a much larger spatial scale.

  8. Collapsing permafrost coasts in the Arctic

    Science.gov (United States)

    Fritz, Michael; Lantuit, Hugues

    2017-04-01

    Arctic warming is exposing permafrost coastlines, which account for 34% of the Earth's coasts, to rapid thaw and erosion. Coastal erosion rates as high as 25 m yr-1 together with the large amount of organic matter frozen in permafrost are resulting in an annual release of 14.0 Tg (1012 gram) particulate organic carbon into the nearshore zone. The nearshore zone is the primary recipient of higher fluxes of carbon and nutrients from thawing permafrost. We highlight the crucial role the nearshore zone plays in Arctic biogeochemical cycling, as here the fate of the released material is determined to: (1) degrade into greenhouse gases, (2) fuel marine primary production, (3) be buried in nearshore sediments or (4) be transported offshore. With Arctic warming, coastal erosion fluxes have the potential to increase by an order of magnitude until 2100. Such increases would result in drastic impacts on global carbon fluxes and their climate feedbacks, on nearshore food webs and on local communities, whose survival still relies on marine biological resources. Quantifying the potential impacts of increasing erosion on coastal ecosystems is crucial for food security of northern residents living in Arctic coastal communities. We need to know how the traditional hunting and fishing grounds might be impacted by high loads of sediment and nutrients released from eroding coasts, and to what extent coastal retreat will lead to a loss of natural habitat. Quantifying fluxes of organic carbon and nutrients is required, both in nearshore deposits and in the water column by sediment coring and systematic oceanographic monitoring. Ultimately, this will allow us to assess the transport and degradation pathways of sediment and organic matter derived from erosion. We need to follow the complete pathway, which is multi-directional including atmospheric release, lateral transport, transitional retention in the food web, and ultimate burial in seafloor sediments. We present numbers of multi

  9. Permafrost monitoring K12 outreach program

    Science.gov (United States)

    Yoshikawa, K.; Saito, T.; Romanovsky, V.

    2007-12-01

    The objective of this project is to establish long-term permafrost monitoring sites adjacent to schools along the circum polar permafrost region. Permafrost will be one of the important indicators for monitoring climatic change in the future. Change in permafrost conditions also affects local ecosystems, hydrological regimes and natural disasters. The purpose of the long-term permafrost observation is fitting for future science objectives, and can also benefit students and teachers in remote village schools. Most remote villages depend on a subsistence lifestyle and will be directly affected by changing climate and permafrost condition. Monitoring the permafrost temperature in the arctic for a better understanding of the spatial distribution of permafrost and having students participate to collect the data is an ideal IPY project. Our outreach project involves drilling boreholes at village schools and installing the micro data logger with temperature sensors to measure hourly air and permafrost temperatures. Trained teachers help students download data several times a year and discuss the results in class. The data gathered from these stations is shared and can be viewed by anyone through the Internet (http://www.uaf.edu/permafrost). Using the Internet teachers can also compare their data with data form other monitoring stations. This project is becoming an useful science project for these remote villages, which tends to have limited exposure to science, despite the changing surroundings that they're daily lives depend on. NSF (EPSCoR) funded the previous seeding outreach program. Currently NSF/NASA and the International Polar Year (IPY) program support this project. In the 2006 field season, thirty-one schools participated in installing the monitoring stations. In 2007 we propose the expansion of this project to involve an additional 100 villages along the arctic. The broader impacts of this project are 1). This project will provide opportunities for field

  10. Low below-ground organic carbon storage in a subarctic Alpine permafrost environment

    Science.gov (United States)

    Fuchs, M.; Kuhry, P.; Hugelius, G.

    2015-03-01

    This study investigates the soil organic carbon (SOC) storage in Tarfala Valley, northern Sweden. Field inventories, upscaled based on land cover, show that this alpine permafrost environment does not store large amounts of SOC, with an estimate mean of 0.9 ± 0.2 kg C m-2 for the upper meter of soil. This is 1 to 2 orders of magnitude lower than what has been reported for lowland permafrost terrain. The SOC storage varies for different land cover classes and ranges from 0.05 kg C m-2 for stone-dominated to 8.4 kg C m-2 for grass-dominated areas. No signs of organic matter burial through cryoturbation or slope processes were found, and radiocarbon-dated SOC is generally of recent origin (distribution in Tarfala Valley, based on the bottom temperature of snow measurements and a logistic regression model, showed that at an altitude where permafrost is probable the SOC storage is very low. In the high-altitude permafrost zones (above 1500 m), soils store only ca. 0.1 kg C m-2. Under future climate warming, an upward shift of vegetation zones may lead to a net ecosystem C uptake from increased biomass and soil development. As a consequence, alpine permafrost environments could act as a net carbon sink in the future, as there is no loss of older or deeper SOC from thawing permafrost.

  11. Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

    Directory of Open Access Journals (Sweden)

    S. W. Lyon

    2009-05-01

    Full Text Available Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. While permafrost thawing due to climate change has been observed in the arctic and sub-arctic, direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

  12. Purification and characterization of organic solvent-stable lipase from organic solvent-tolerant Pseudomonas aeruginosa LST-03.

    Science.gov (United States)

    Ogino, H; Nakagawa, S; Shinya, K; Muto, T; Fujimura, N; Yasuda, M; Ishikawa, H

    2000-01-01

    An organic solvent-stable lipase (LST-03 lipase) secreted into the culture broth of the organic solvent-tolerant Pseudomonas aeruginosa LST-03 was purified by ion-exchange and hydrophobic interaction chromatography in the presence of 2-propanol. The purified enzyme was homogeneous as determined by SDS-PAGE. The molecular mass of the lipase was estimated to be 27.1 kDa by SDS-PAGE and 36 kDa by gel filtration. The optimum pH and temperature were 6.0 and 37 degrees C. LST-03 lipase was stable at pH 5-8 and below 40 degrees C. Its hydrolytic activity was highest against tricaproin (C6), methyl octanoate (C8), and coconut oil respectively among the triacylglycerols, fatty acid methyl esters, and natural oils investigated. The enzyme cleaved not only the 1,3-positioned ester bonds, but also the 2-positioned ester bond of triolein. It exhibited high levels of activity in the presence of n-decane, n-octane, DMSO, and DMF as well as in the absence of an organic solvent. In addition, LST-03 lipase was stabler in the presence of n-decane, ethyleneglycol, DMSO, n-octane, n-heptane, isooctane, and cyclohexane than in the absence of an organic solvent.

  13. Cloning and expression of gene, and activation of an organic solvent-stable lipase from Pseudomonas aeruginosa LST-03.

    Science.gov (United States)

    Ogino, Hiroyasu; Katou, Yoshikazu; Akagi, Rieko; Mimitsuka, Takashi; Hiroshima, Shinichi; Gemba, Yuichi; Doukyu, Noriyuki; Yasuda, Masahiro; Ishimi, Kosaku; Ishikawa, Haruo

    2007-11-01

    Organic solvent-tolerant Pseudomonas aeruginosa LST-03 secretes an organic solvent-stable lipase, LST-03 lipase. The gene of the LST-03 lipase (Lip9) and the gene of the lipase-specific foldase (Lif9) were cloned and expressed in Escherichia coli. In the cloned 2.6 kbps DNA fragment, two open reading frames, Lip9 consisting of 933 nucleotides which encoded 311 amino acids and Lif9 consisting of 1,020 nucleotides which encoded 340 amino acids, were found. The overexpression of the lipase gene (lip9) was achieved when T7 promoter was used and the signal peptide of the lipase was deleted. The expressed amount of the lipase was greatly increased and overexpressed lipase formed inclusion body in E. coli cell. The collected inclusion body of the lipase from the cell was easily solubilized by urea and activated by using lipase-specific foldase of which 52 or 58 amino acids of N-terminal were deleted. Especially, the N-terminal methionine of the lipase of which the signal peptide was deleted was released in E. coli and the amino acid sequence was in agreement with that of the originally-produced lipase by P. aeruginosa LST-03. Furthermore, the overexpressed and solubilized lipase of which the signal peptide was deleted was more effectively activated by lipase-specific foldase.

  14. Northern Watershed Change, Modeled Permafrost Temperatures in the Yukon River Watershed

    Science.gov (United States)

    Bryan, R.; Hinzman, L. D.

    2009-12-01

    Changes in the terrestrial hydrologic cycle in northern watersheds can be seen through permafrost warming. Furthermore, vegetation shifts occur with climate changes coupled with permafrost degradation. Permafrost warming is resultant from warming air temperatures and the collection of buffers between the atmosphere and the cryosphere: the active layer, snow, and vegetation. Our modeling methods combine a meteorological model with a permafrost temperature model in 1 km2 resolution in the 847,642 km2 Yukon River Watershed. The MicroMet model is a quasi-physically based model developed in 2006 by Liston & Elder to spatially interpolate irregularly spaced point meteorological data using known temperature-elevation, wind-topography, humidity-cloudiness, and radiation-cloud-topography relationships. We call on 1997-2007 data from 104 Integrated Surface Data meteorological stations and 100 grid points in a 5 best models ensemble A1B 2090-2100 projection. The Temperature at the Top of the Permafrost (TTOP) model is a numerical model for estimating the thermal state of permafrost. This model is attributed to Smith & Riseborough, 1996. TTOP relates more readily available near surface temperatures to temperatures at the depth of seasonal variation using user-defined landcover n-factors (to relate air temperature to soil surface temperature) and soil thermal conductivities (to simulate the propagation of heat through the active layer). TTOP simulates warm top of the permafrost temperatures for high soil thermal conductivity, land cover with high n-factor, and a high number of thawing degree-days/ year. Here we compare the present and future thermal stability of permafrost in the Yukon River Watershed.

  15. NORPERM, the Norwegian Permafrost Database – a TSP NORWAY IPY legacy

    Directory of Open Access Journals (Sweden)

    H. Juliussen

    2010-10-01

    Full Text Available NORPERM, the Norwegian Permafrost Database, was developed at the Geological Survey of Norway during the International Polar Year (IPY 2007-2009 as the main data legacy of the IPY research project Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard (TSP NORWAY. Its structural and technical design is described in this paper along with the ground temperature data infrastructure in Norway and Svalbard, focussing on the TSP NORWAY permafrost observatory installations in the North Scandinavian Permafrost Observatory and Nordenskiöld Land Permafrost Observatory, being the primary data providers of NORPERM. Further developments of the database, possibly towards a regional database for the Nordic area, are also discussed.

    The purpose of NORPERM is to store ground temperature data safely and in a standard format for use in future research. The IPY data policy of open, free, full and timely release of IPY data is followed, and the borehole metadata description follows the Global Terrestrial Network for Permafrost (GTN-P standard. NORPERM is purely a temperature database, and the data is stored in a relation database management system and made publically available online through a map-based graphical user interface. The datasets include temperature time series from various depths in boreholes and from the air, snow cover, ground-surface or upper ground layer recorded by miniature temperature data-loggers, and temperature profiles with depth in boreholes obtained by occasional manual logging. All the temperature data from the TSP NORWAY research project is included in the database, totalling 32 temperature time series from boreholes, 98 time series of micrometeorological temperature conditions, and 6 temperature depth profiles obtained by manual logging in boreholes. The database content will gradually increase as data from previous and future projects are added. Links to

  16. Investigating talus slope geomorphology as impacted by permafrost thaw (Valais, Switzerland): stipulating a research framework

    Science.gov (United States)

    Hendrickx, Hanne; Delaloye, Reynald; Nyssen, Jan; Frankl, Amaury

    2017-04-01

    Climate change is altering temperature regimes and precipitation patterns worldwide. In the European Alps, atmospheric temperatures have risen twice as fast as the global average since 1900, while precipitation regimes are changing as well. Snow cover duration and extent has significantly decreased in the Swiss Alps, mainly due to earlier spring melt and rise in winter temperatures. Moreover, future projections predict a continuation of these trends. Spatial distribution and thermal properties of permafrost are highly influenced by ground surface conditions (snow and vegetation) and air temperature. Climate induced permafrost degradation is, therefore, expected. While alpine permafrost research has mainly focused on rock glaciers, less attention has been given to talus slopes. The latter are subjected to different kinds of slope processes such as debris flows, solifluction, permafrost creep, avalanches and rock fall. These processes are especially effective under a changing periglacial climate. Therefore, it is important to study permafrost distribution in these talus slopes, since it is believed to have large influence on slope stability. In this study, permafrost distribution will be mapped on several talus slope segments (10 - 40 ha) using geomorphological evidence, temperature data and measuring electrical resistivity tomography (ERT) profiles in addition to already existing data. The current dynamics of the study area will be studied by constructing detailed 3D models, using ground based and aerial photography (Unmanned Aerial Vehicles, UAV) and the Structure-from-Motion method (SfM). The resulting Digital Elevation Models (DEM) will be used to quantify and understand the current geomorphological processes acting on these talus slopes. Historical aerial and terrestrial photographs will be used to give an idea about the magnitude and frequency of past geomorphic processes (e.g. debris flows). Historical and current dynamics can then be compared and contrasted

  17. Dynamics of the larch taiga-permafrost coupled system in Siberia under climate change

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ningning [Graduate School of Environmental Studies, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Yasunari, Tetsuzo [Hydrospheric Atmospheric Research Center, Nagoya University, Nagoya 464-8601 (Japan); Ohta, Takeshi, E-mail: zhangningning@lasg.iap.ac.cn [Study Consortium for Earth-Life Interactive Systems (SELIS) of Nagoya University, Nagoya (Japan)

    2011-04-15

    Larch taiga, also known as Siberian boreal forest, plays an important role in global and regional water-energy-carbon (WEC) cycles and in the climate system. Recent in situ observations have suggested that larch-dominated taiga and permafrost behave as a coupled eco-climate system across a broad boreal zone of Siberia. However, neither field-based observations nor modeling experiments have clarified the synthesized dynamics of this system. Here, using a new dynamic vegetation model coupled with a permafrost model, we reveal the processes of interaction between the taiga and permafrost. The model demonstrates that under the present climate conditions in eastern Siberia, larch trees maintain permafrost by controlling the seasonal thawing of permafrost, which in turn maintains the taiga by providing sufficient water to the larch trees. The experiment without permafrost processes showed that larch would decrease in biomass and be replaced by a dominance of pine and other species that suffer drier hydroclimatic conditions. In the coupled system, fire not only plays a destructive role in the forest, but also, in some cases, preserves larch domination in forests. Climate warming sensitivity experiments show that this coupled system cannot be maintained under warming of about 2 deg. C or more. Under such conditions, a forest with typical boreal tree species (dark conifer and deciduous species) would become dominant, decoupled from the permafrost processes. This study thus suggests that future global warming could drastically alter the larch-dominated taiga-permafrost coupled system in Siberia, with associated changes of WEC processes and feedback to climate.

  18. Use Of Amino Acid Racemization To Investigate The Metabolic Activity Of ?Dormant? Microorganisms In Siberian Permafrost

    Science.gov (United States)

    Tsapin, A.; McDonald, G.

    2002-12-01

    search for extraterrestrial life or its remnants is based on studying the most probable environments in which life (extant or extinct) may be found, and determining the maximum period of time over which such life could be preserved. The terrestrial permafrost, inhabited by cold adapted microbes, can be considered as an extraterrestrial analog environment. The cells and their metabolic end-products in Earth's permafrost can be used in the search for possible ecosystems and potential inhabitants on extraterrestrial cryogenic bodies. The study of microorganisms (or their remnants) that were buried for a few million years in permafrost provides us with a unique opportunity to determine the long-term viability of (micro)organisms. We have analyzed the degree of racemization of aspartic acid in permafrost samples from Northern Siberia (Brinton et al. 2002, Astrobiology 2, 77), an area from which microorganisms of apparent ages up to a few million years have previously been isolated and cultured. We find that the extent of aspartic acid racemization in permafrost cores increases very slowly up to an age of approximately 25,000 years (around 5 m depth). The apparent temperature of racemization over the age range 0-25,000 years, determined using measured aspartic acid racemization rate constants, is ?19 C. This apparent racemization temperature is significantly lower than the measured environmental temperature (?11 to ?13 C), and suggests active recycling of D-aspartic acid in Siberian permafrost up to an age of around 25,000 years. This indicates that permafrost organisms are capable of repairing some molecular damage incurred while they are in a ?dormant? state over geologic time.

  19. A statistical permafrost distribution model for the European Alps

    Directory of Open Access Journals (Sweden)

    L. Boeckli

    2011-05-01

    Full Text Available Permafrost distribution modeling in densely populated mountain regions is an important task to support the construction of infrastructure and for the assessment of climate change effects on permafrost and related natural systems. In order to analyze permafrost distribution and evolution on an Alpine-wide scale, one consistent model for the entire domain is needed.

    We present a statistical permafrost model for the entire Alps based on rock glacier inventories and rock surface temperatures. Starting from an integrated model framework, two different sub-models were developed, one for debris covered areas (debris model and one for steep rock faces (rock model. For the debris model a generalized linear mixed-effect model (GLMM was used to predict the probability of a rock glacier being intact as opposed to relict. The model is based on the explanatory variables mean annual air temperature (MAAT, potential incoming solar radiation (PISR and the mean annual sum of precipitation (PRECIP, and achieves an excellent discrimination (area under the receiver-operating characteristic, AUROC = 0.91. Surprisingly, the probability of a rock glacier being intact is positively associated with increasing PRECIP for given MAAT and PISR conditions. The rock model was calibrated with mean annual rock surface temperatures (MARST and is based on MAAT and PISR. The linear regression achieves a root mean square error (RMSE of 1.6 °C. The final model combines the two sub-models and accounts for the different scales used for model calibration. Further steps to transfer this model into a map-based product are outlined.

  20. Marine heat flow measurements across subsea permafrost limit in the eastern Mackenzie Trough, Canadian Beaufort Sea

    Science.gov (United States)

    Kim, Y. G.; Hong, J. K.; Jin, Y. K.; Riedel, M.; Melling, H.; Kang, S. G.; Dallimore, S.

    2015-12-01

    Marine heat flow measurements using a 5 m-long Ewing-type heat probe were made during Korean icebreaker R/V Araon's Arctic expeditions (ARA04C in 2013 and ARA05B in 2014) to better know the shallow subsurface thermal structure in the eastern slope of Mackenzie Trough, the Canadian Beaufort Sea, in which associative geological processes of permafrost degradation and gas hydrate dissociation occur because of long-term warming since the Last Glacial Maximum. Heat flow in the continental slope was collected for the first time and is rather higher than those from deep boreholes (up to a few km below the seafloor) in the continental shelf. However, the smaller geothermal gradient and thermal conductivity were observed from sites along a transect line across permafrost limit on the eastern slope of the trough. It is noted that geothermal gradients are relatively constant in the vicinity of permafrost limit but are much smaller (even minus) only at deeper depths with positive bottom water temperature. Reason for such distribution is unclear yet. Based on observed geothermal gradient and bottom water temperature, permafrost table shown in subbottom profile seems to be controlled not by temperature. On the other hand, our finding of permafrost evidence on the other subbottom profile located landward may support that permafrost limit in the trough is along with ~100 m isobath.

  1. Scaling-up permafrost thermal measurements in western Alaska using an ecotype approach

    Science.gov (United States)

    Cable, William L.; Romanovsky, Vladimir E.; Torre Jorgenson, M.

    2016-10-01

    Permafrost temperatures are increasing in Alaska due to climate change and in some cases permafrost is thawing and degrading. In areas where degradation has already occurred the effects can be dramatic, resulting in changing ecosystems, carbon release, and damage to infrastructure. However, in many areas we lack baseline data, such as subsurface temperatures, needed to assess future changes and potential risk areas. Besides climate, the physical properties of the vegetation cover and subsurface material have a major influence on the thermal state of permafrost. These properties are often directly related to the type of ecosystem overlaying permafrost. In this paper we demonstrate that classifying the landscape into general ecotypes is an effective way to scale up permafrost thermal data collected from field monitoring sites. Additionally, we find that within some ecotypes the absence of a moss layer is indicative of the absence of near-surface permafrost. As a proof of concept, we used the ground temperature data collected from the field sites to recode an ecotype land cover map into a map of mean annual ground temperature ranges at 1 m depth based on analysis and clustering of observed thermal regimes. The map should be useful for decision making with respect to land use and understanding how the landscape might change under future climate scenarios.

  2. Study on the technology for highway construction and engineering practices in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In order to systemically summarize and integrate technology of highway construction in permafrost regions on the Qinghai-Tibet Plateau,we studied disciplines and mechanisms of formation and development of problems and challenges in highway engineer-ing in high-altitude permafrost regions based on construction experiences for 50 years and on 30 years of research regarding the Qinghai-Tibet and Xikang highways.Embankments,pavements,bridges,and countermeasures for ecosystem protection in per-mafrost regions were the main study objects.We combined extensive analysis of key problems of engineering stability with inter-action between permafrost and highways,theoretical models,indoor tests,and field tests to reveal the interaction between em-bankments,pavements,bridge piles,and permafrost.In this paper,we propose a series of engineering measures for highway sta-bility,design parameters,key indexes for pavement durability in low temperature,relationships between re-freezing time of bridge-pile foundation and strength development as well as ecosystem recovery in high-latitude cold regions;these eventually form a construction technology package for permafrost regions.

  3. A GIS-aided response model of high-altitude permafrost to global change

    Institute of Scientific and Technical Information of China (English)

    李新; 程国栋

    1999-01-01

    Two models are used to simulate the high-altitude permafrost distribution on the Qinghai-Xizang Plateau. The two models are the "altitude model", a Gaussian distribution function used to describe the latitudinal zonation of permafrost based on the three-dimensional rules of high-altitude permafrost, and the "frost number model", a dimensionless ratio defined by manipulation of freezing and thawing degree-day sums. The results show that the "altitude model" can simulate the high-altitude permafrost distribution under present climate conditions accurately. Given the essential hypotheses and using the GCM scenarios from HADCM2, the "altitude model" is used for predicting the permafrost distribution change on the Qinghai-Xizang Plateau. The results show that the permafrost on the plateau will not change significantly during 20—50 a, the percentage of the total disappeared area will not be over 19%. However, by the year 2099, if the air temperature increases by an average of 2.91℃ on the plateau, the decre

  4. Study on the technology for highway construction and engineering practices in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    ShuangJie Wang; JianBing Chen; JiLin Qi

    2009-01-01

    In order to systemically summarize and integrate technology of highway construction in permafrost regions on the Qinghai-Tibet Plateau, we studied disciplines and mechanisms of formation and development of problems and challenges in highway engineering in high-altitude permafrost regions based on construction experiences for 50 years and on 30 years of research regarding the Qinghai-Tibet and Xikang highways. Embankments, pavements, bridges, and countermeasures for ecosystem protection in permafrost regions were the main study objects. We combined extensive analysis of key problems of engineering stability with interaction between permafrost and highways, theoretical models, indoor tests, and field tests to reveal the interaction between embankments, pavements, bridge piles, and permafrost. In this paper, we propose a series of engineering measures for highway stability, design parameters, key indexes for pavement durability in low temperature, relationships between re-freezing time of bridge-pile foundation and strength development as well as ecosystem recovery in high-latitude cold regions; these eventually form a construction technology package for permafrost regions.

  5. European Mountain Permafrost: Geothermal Change and Associated Geomorphological Impacts

    Science.gov (United States)

    Harris, C.; Haeberli, W.; Gruber, S.; Kohl, T.

    2002-12-01

    . An alternative approach, using scaled geotechnical centrifuge modeling of degrading permafrost slopes, was developed within the PACE project, and results are briefly reviewed in the context of process-based permafrost hazard assessment.

  6. 多年冻土区路桥过渡段的一种新结构%A New Structure of Roadbed-Abutment Transition Part on Permafrost

    Institute of Scientific and Technical Information of China (English)

    刘建坤; 鲍维猛; 黎明; 葛建军

    2004-01-01

    The design of roadbed-abutment transition part is always a challenging problem in transportation engineering, especially in permafrost distribution zone. A new type of roadbed-abutment transition part on permafrost was presented, and long-term observation was conducted for the deformation and the thermal regime of a roadbed-abutment transition part in the constructing Qinghai-Tibet Railway. In this paper, a new structure was presented and the observed settlements both in the subgrade and the base and its dependency with the thermal regime (permafrost table) were analyzed. In conclusion the roadbed-a-butment transition method for permafrost distribution zone was evaluated.

  7. Railway Construction Techniques Adapting to Climate Warming in Permafrost Regions%青藏铁路适应气候变化的筑路工程技术

    Institute of Scientific and Technical Information of China (English)

    吴青柏; 程国栋; 马巍

    2008-01-01

    The climate warming,which has an evident effect on the warm/ice-rich permafrost,should be considered in the engineering design of the Qinghai-Tibet Railway in permafrost areas.Based on the rule mentioned above,many design ideas and measures such as cooling embankment and controling of heat conduction,radiation and convection were proposed during the construction of the Qinghai-Tibet Railway to reduce the permafrost temperature and to reduce the impact of climate warming on the railway.These measures ensure the stability of the railway embankment in permafrost regions.

  8. Biodiversity of cryopegs in permafrost.

    Science.gov (United States)

    Gilichinsky, David; Rivkina, Elizaveta; Bakermans, Corien; Shcherbakova, Viktoria; Petrovskaya, Lada; Ozerskaya, Svetlana; Ivanushkina, Natalia; Kochkina, Galina; Laurinavichuis, Kyastus; Pecheritsina, Svetlana; Fattakhova, Rushania; Tiedje, James M

    2005-06-01

    This study describes the biodiversity of the indigenous microbial community in the sodium-chloride water brines (cryopegs) derived from ancient marine sediments and sandwiched within permafrost 100-120,000 years ago after the Arctic Ocean regression. Cryopegs remain liquid at the in situ temperature of -9 to -11 degrees C and make up the only habitat on the Earth that is characterized by permanently subzero temperatures, high salinity, and the absence of external influence during geological time. From these cryopegs, anaerobic and aerobic, spore-less and spore-forming, halotolerant and halophilic, psychrophilic and psychrotrophic bacteria, mycelial fungi and yeast were isolated and their activity was detected below 0 degrees C.

  9. Permafrost Meta-Omics and Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Mackelprang, Rachel; Saleska, Scott R.; Jacobsen, Carsten Suhr; Jansson, Janet K.; Taş, Neslihan

    2016-06-29

    Permafrost (i.e., soil that has been frozen for at least 2 consecutive years) represents a habitat for microbial life at subzero temperatures (Gilichinsky et al. 2008). Approximately one quarter of the Earth’s surface is underlain by permafrost, which contains 25-50% of the total global soil carbon pool (Schuur et al. 2008, Tarnocai et al. 2009). This carbon is largely protected from microbial decomposition by reduced microbial activity in frozen conditions, but climate change is threatening to induce large-scale permafrost thaw thus exposing it to degradation. The resulting emissions of greenhouse gasses (GHGs) can produce a positive feedback loop and significantly amplify the effects of global warming. Increasing temperatures at high latitudes, changes in precipitation patterns, and frequent fire events have already initiated a widespread degradation of permafrost (Schuur et al. 2015).

  10. Permafrost Soils Database for Northern Alaska 2014

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — This database contains soil and permafrost stratigraphy for northern Alaska compiled from numerous project data files and reports. The Access Database has main data...

  11. Permafrost Meta-Omics and Climate Change

    DEFF Research Database (Denmark)

    Mackelprang, Rachel; Saleska, Scott R.; Jacobsen, Carsten Suhr

    2016-01-01

    from thawing permafrost regions. Analysis of nucleic acids and proteins taken directly from permafrost-associated soils has provided new insights into microbial communities and their functions in Arctic environments that are increasingly impacted by climate change. In this article we review current...... carbon produce carbon dioxide and other greenhouse gases, contributing substantially to climate change. Next-generation sequencing and other -omics technologies offer opportunities to discover the mechanisms by which microbial communities regulate the loss of carbon and the emission of greenhouse gases...... information from various molecular -omics studies on permafrost microbial ecology and explore the relevance of these insights to our current understanding of the dynamics of permafrost loss due to climate change....

  12. Experimental study of UTM-LST generic half model transport aircraft

    Science.gov (United States)

    Ujang, M. I.; Mat, S.; Perumal, K.; Mohd. Nasir, M. N.

    2016-10-01

    This paper presents the experimental results from the investigation carried out at the UTM Low Speed wind tunnel facility (UTM-LST) on a half model generic transport aircraft at several configurations of primary control surfaces (flap, aileron and elevator). The objective is to measure the aerodynamic forces and moments due to the configuration changes. The study is carried out at two different speeds of 26.1 m/s and 43.1 m/s at corresponding Reynolds number of 1 × 106 and 2 × 106, respectively. Angle of attack of the model is varied between -2o to 20o. For the flaps, the deflection applied is 0o, 5o and 10o. Meanwhile, for aileron and elevator, the deflection applied is between -10o and 10o. The results show the differences in aerodynamic characteristics of the aircraft at different control surfaces configurations. The results obtained indicate that a laminar separation bubble developed on the surface of the wing at lower angles of attack and show that the separation process is delayed when the Reynolds number is increased.

  13. Searching for eukaryotic life preserved in Antarctic permafrost

    Science.gov (United States)

    Onofri, Silvano; Zucconi, Laura; Selbmann, Laura; Ripa, Caterina; Frisvad, Jens Christian; Guglielmin, Mauro; Turchetti, Benedetta; Buzzini, Pietro

    Permafrost is defined as a soil remaining at 0 C or below throughout two or more consecutive years. Mainly present in polar areas, it occurs in all ice-free areas of Continental Antarc-tica. With the evidences of the possible presence of water ice below the surface of Mars and Moon, permafrost is now considered a possible reservoir of prokaryotic and eukaryotic spores outside the Earth. Cultivable fungi and yeasts have been isolated from Antarctic permafrost collected at different depths (233, 316 and 335 cm) in the McMurdo Dry Valleys, the largest ice-free area in Antarctica, and identified with cultural, physiological and molecular methods. Filamentous fungi belonged to the genera Penicillium, Eurotium, Cladosporium, Alternaria, Engyodonthium, Cordiceps, Rhizopus, Aureobasidium, whereas yeasts belonged to the genera Cryptococcus and Sporidiobolus. Penicillia were the most represented, and the most frequently recorded species were Penicillium palitans and P. chrysogenum. Most of the species found have been already recorded in Antarctic ecosystems as well as in other cold habitats (Onofri et al., 2007); for Eurotium amstelodami and Cryptococcus stepposus these are the first isolations in Antarctica. All the filamentous fungal isolates can be defined as mesophilic having optimal growth temperatures at 20-25 C and poor growth at 0 C after prolonged incubation. All the yeast isolates grew within a wide range of temperature (from 4 to 25 C). The molecular anal-yses based on the ITS rDNA sequences, for filamentous fungi, and on D1/D2 domain of LSU rRNA gene and ITS sequences for yeasts, revealed that these genotypes do not deviate from the global gene pool of microorganisms commonly spreading worldwide at present. Annual mean permafrost temperature (MAPT) in the sampling area was -18.8 C in 2008, with daily fluctuations lower than 1 C/day at 1 m of depth, but less 0.5 C/year at the depth of 17 m (Guglielmin pers. com.), and maximum thaw depth not exceeding 1 m

  14. Hydrogeology, chemical and microbial activity measurement through deep permafrost

    Energy Technology Data Exchange (ETDEWEB)

    Stotler, R.L.; Frape, S.K.; Freifeld, B.M.; Holden, B.; Onstott, T.C.; Ruskeeniemi, T.; Chan, E.

    2010-04-01

    Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples <40% drill fluid. The salinity of the non-drill fluid component was <20,000 mg/L, had a Ca/Na ratio above 1, with {delta}{sup 18}O values {approx}5{per_thousand} lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH{sub 4} was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH{sub 4} is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination.

  15. Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland

    Directory of Open Access Journals (Sweden)

    A. Marmy

    2015-09-01

    Full Text Available Permafrost is a widespread phenomenon in the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which facilitate the projection of the future evolution of permafrost. Due to the complexity of the processes involved and the heterogeneity of Alpine terrain, models must be carefully calibrated and results should be compared with observations at the site (borehole scale. However, a large number of local point data are necessary to obtain a broad overview of the thermal evolution of mountain permafrost over a larger area, such as the Swiss Alps, and the site-specific model calibration of each point would be time-consuming. To face this issue, this paper presents a semi-automated calibration method using the Generalized Likelihood Uncertainty Estimation (GLUE as implemented in a 1-D soil model (CoupModel and applies it to six permafrost sites in the Swiss Alps prior to long-term permafrost evolution simulations. We show that this automated calibration method is able to accurately reproduce the main thermal condition characteristics with some limitations at sites with unique conditions such as 3-D air or water circulation, which have to be calibrated manually. The calibration obtained was used for RCM-based long-term simulations under the A1B climate scenario specifically downscaled at each borehole site. The projection shows general permafrost degradation with thawing at 10 m, even partially reaching 20 m depths until the end of the century, but with different timing among the sites. The degradation is more rapid at bedrock sites whereas ice-rich sites with a blocky surface cover showed a reduced sensitivity to climate change. The snow cover duration is expected to be reduced drastically (between −20 to −37 % impacting the ground thermal

  16. Effect of Submarine Groundwater Discharge on Relict Arctic Submarine Permafrost and Gas Hydrate

    Science.gov (United States)

    Frederick, J. M.; Buffett, B. A.

    2014-12-01

    Permafrost-associated gas hydrate deposits exist at shallow depths within the sediments of the circum-Arctic continental shelves. Degradation of this shallow water reservoir has the potential to release large quantities of methane gas directly to the atmosphere. Gas hydrate stability and the permeability of the shelf sediments to gas migration is closely linked with submarine permafrost. Submarine permafrost extent depends on several factors, such as the lithology, sea level variations, mean annual air temperature, ocean bottom water temperature, geothermal heat flux, and the salinity of the pore water. The salinity of the pore water is especially relevant because it partially controls the freezing point for both ice and gas hydrate. Measurements of deep pore water salinity are few and far between, but show that deep off-shore sediments are fresh. Deep freshening has been attributed to large-scale topographically-driven submarine groundwater discharge, which introduces fresh terrestrial groundwater into deep marine sediments. We investigate the role of submarine ground water discharge on the salinity field and its effects on the seaward extent of relict submarine permafrost and gas hydrate stability on the Arctic shelf with a 2D shelf-scale model based on the finite volume method. The model tracks the evolution of the temperature, salinity, and pressure fields given imposed boundary conditions, with latent heat of water ice and hydrate formation included. The permeability structure of the sediments is coupled to changes in permafrost. Results show that pore fluid is strongly influenced by the permeability variations imposed by the overlying permafrost layer. Groundwater discharge tends to travel horizontally off-shore beneath the permafrost layer and the freshwater-saltwater interface location displays long timescale transient behavior that is dependent on the groundwater discharge strength. The seaward permafrost extent is in turn strongly influenced by the

  17. Due Permafrost: a Circumpolar Remote Sensing Service for Permafrost - Evaluation and Application Case Studies

    Science.gov (United States)

    Heim, B.; Bartsch, A.; Elger, K. K.; Rinke, A.; Gellhorn, C.; Matthes, H.; Buchhorn, M.; Klehmet, K.; Soliman, A. S.; Duguay, C.; Hachem, S.; Schwamborn, G.; Muster, S.; Langer, M.; Boike, J.; Lantuit, H.; Herzschuh, U.; Seifert, F.

    2012-12-01

    The task of the ESA Data User Element DUE Permafrost project is to build up a Remote Sensing Service for permafrost applications. The DUE Permafrost remote sensing products are land temperature, soil moisture, frozen/thawed surface status, terrain parameters, land cover, and surface waters. The DUE Permafrost products are freely available for download under http://www.ipf.tuwien.ac.at/permafrost/. The products are also published at the world data centre PANGAEA (doi:10.1594/PANGAEA.780111, 2012: ESA Data User Element Permafrost), Snow parameters (snow extent and snow water equivalent) can be derived from the ESA DUE project GlobSnow. A major component is the evaluation of the DUE Permafrost products to test their scientific validity for high-latitudinal permafrost landscapes. The primary programme providing ground data is the Global Terrestrial Network for Permafrost (GTN-P) initiated by the International Permafrost Association (IPA). The involvement of scientific stakeholders and the IPA, and the ongoing evaluation of the remote sensing derived products make the DUE Permafrost products accepted by the scientific community. We show evaluation case studies of DUE Permafrost remote sensing products using GTN-P in-situ data in Alaska and Siberia. The Helmholtz Climate Initiative REKLIM (Regionale Klimaänderungen/Regional climate change) is a climate research program where regional observations and process studies are innovatively coupled with model simulations (http://www.reklim.de/en/home/). Within the REKLIM framework we spatio-temporally compare the geophysical surface parameters derived from regional climate modelling with the DUE Permafrost and DUE GlobSnow remote sensing products. The case studies are: i) spatio-temporal comparison of the ESA GlobSnow satellite-derived snow-water equivalent data with the output from the regional climate model COSMO-CLM for Central Siberia for 1987-2010. ii) circum-arctic spatio-temporal comparison of the ESA DUE Permafrost

  18. Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses

    Science.gov (United States)

    Harris, Charles; Arenson, Lukas U.; Christiansen, Hanne H.; Etzelmüller, Bernd; Frauenfelder, Regula; Gruber, Stephan; Haeberli, Wilfried; Hauck, Christian; Hölzle, Martin; Humlum, Ole; Isaksen, Ketil; Kääb, Andreas; Kern-Lütschg, Martina A.; Lehning, Michael; Matsuoka, Norikazu; Murton, Julian B.; Nötzli, Jeanette; Phillips, Marcia; Ross, Neil; Seppälä, Matti; Springman, Sarah M.; Vonder Mühll, Daniel

    2009-02-01

    We present a review of the changing state of European permafrost within a spatial zone that includes the continuous high latitude arctic permafrost of Svalbard and the discontinuous high altitude mountain permafrost of Iceland, Fennoscandia and the Alps. The paper focuses on methodological developments and data collection over the last decade or so, including research associated with the continent-scale network of instrumented permafrost boreholes established between 1998 and 2001 under the European Union PACE project. Data indicate recent warming trends, with greatest warming at higher latitudes. Equally important are the impacts of shorter-term extreme climatic events, most immediately reflected in changes in active layer thickness. A large number of complex variables, including altitude, topography, insolation and snow distribution, determine permafrost temperatures. The development of regionally calibrated empirical-statistical models, and physically based process-oriented models, is described, and it is shown that, though more complex and data dependent, process-oriented approaches are better suited to estimating transient effects of climate change in complex mountain topography. Mapping and characterisation of permafrost depth and distribution requires integrated multiple geophysical approaches and recent advances are discussed. We report on recent research into ground ice formation, including ice segregation within bedrock and vein ice formation within ice wedge systems. The potential impacts of climate change on rock weathering, permafrost creep, landslides, rock falls, debris flows and slow mass movements are also discussed. Recent engineering responses to the potentially damaging effects of climate warming are outlined, and risk assessment strategies to minimise geological hazards are described. We conclude that forecasting changes in hazard occurrence, magnitude and frequency is likely to depend on process-based modelling, demanding improved

  19. Thermal preconditioning of mountain permafrost towards instability

    Science.gov (United States)

    Hauck, Christian; Etzelmüller, Bernd; Hilbich, Christin; Isaksen, Ketil; Mollaret, Coline; Pellet, Cécile; Westermann, Sebastian

    2017-04-01

    Warming permafrost has been detected worldwide in recent years and is projected to continue during the next century as shown in many modelling studies from the polar and mountain regions. In mountain regions, this can lead to potentially hazardous impacts on short time-scales by an increased tendency for slope instabilities. However, the time scale of permafrost thaw and the role of the ice content for determining the strength and rate of permafrost warming and degradation (= development of talik) are still unclear, especially in highly heterogeneous terrain. Observations of permafrost temperatures near the freezing point show complex inter-annual responses to climate forcing due to latent heat effects during thawing and the influence of the snow-cover, which is formed and modulated by highly non-linear processes itself. These effects are complicated by 3-dimensional hydrological processes and interactions between snow melt, infiltration and drainage which may also play an important role in the triggering of mass movements in steep permafrost slopes. In this contribution we demonstrate for the first time a preconditioning effect within near-surface layers in mountain permafrost that causes non-linear degradation and accelerates permafrost thaw. We hypothesise that an extreme regional or global temperature anomaly, such as the Central European summers 2003 and 2015 or the Northern European summers 2006 and 2014, will enhance permafrost degradation if the active layer and the top of the permafrost layer are already preconditioned, i.e. have reduced latent heat content. This preconditioning can already be effectuated by a singular warm year, leading to exceptionally strong melting of the ground ice in the near-surface layers. On sloping terrain and in a context of quasi-continuous atmospheric warming, this ice-loss can be considered as irreversible, as a large part of the melted water will drain/evaporate during the process, and the build-up of an equivalent amount of

  20. Permafrost and the International Polar Year

    Science.gov (United States)

    Brown, J.; Boelhouwers, J.; Rachold, V.; Christiansen, H. H.

    2005-12-01

    Three permafrost projects are in the planning stages for 2007-2008 IPY. (1) The Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost (TSP) will obtain a "snapshot" of permafrost temperatures in existing and new boreholes throughout both hemispheres. The project is a field campaign of the existing Global Terrestrial Network on Permafrost (GTN-P) that also includes the Circumpolar Active Layer Monitoring (CALM) project. (2) The Antarctic and sub-Antarctic Permafrost, Periglacial and Soil Environments project (ANTPAS) is aimed at integrating existing and new data on the distribution, thickness, age, history and physical and geochemical properties of permafrost, soils and the active-layer on the Antarctic continent and sub-Antarctic islands. A monitoring network, a regional subset of GTN-P and consisting of borehole temperatures, active-layer thickness, and periglacial and soil observations, will be established along selected environmental gradients. (3) The Arctic Circum-Polar Coastal Observatory Network (ACCO-Net) proposes to investigate approximately 20 key coastal sites including deltas and estuaries of major Siberian and North American rivers at which physical, ecological, biochemical and socio-economic changes will be observed. Both educational outreach and data management activities are key elements in the three projects and will contribute to the overall IPY goals and its legacy. Our Permafrost Legacy is to create the basis for a new generation of researcher and the "snapshot" of existing conditions as a baseline for future change assessment. The Joint Committee of the IPY has approved the three projects that include approximately 150 individuals from the 25- member International Permafrost Association (IPA). The IPA is coordinating these projects in cooperation with the International Union of Geological Sciences (IUGS), the Scientific Committee for Antarctic Research (SCAR), the Land-Ocean Interactions in the Coastal Zone (LOICZ

  1. Simulations of permafrost evolution at Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Hartikainen, J. [Aalto Univ., Espoo (Finland)

    2013-07-15

    This report provides numerical estimations of the evolution of permafrost and perennially frozen ground at Olkiluoto on time-scales of 60,000 and 125,000 years using Olkiluoto's site-specific information on time histories of ground level temperatures, ice sheet thickness, basal conditions, shoreline migration, soil and vegetation cover as well as heat generation from the spent fuel at a depth of 420 metres. When considering environmental conditions akin to the last glacial cycle for a 125,000 years long period, the maximum permafrost depth over the repository area can exceed the depth of 300 m and the maximum depth of perennially frozen ground the depth of 270 m. If Olkiluoto, after a 50,000 years long temperate phase of boreal climate, was subjected to a 10,000 years long periglacial period with air temperature decreased between -5 deg C and -10 deg C, the maximum permafrost depth would range between 60 and 240 m and the maximum depth of perennially frozen ground between 50 and 220 m. Furthermore, permafrost would reach the repository depth in 10,000 years, if the air temperature was lowered down to -15 deg C and the ground surface had a very thin vegetation and snow cover. Alternatively, if Olkiluoto experienced a 125,000 years long glacial cycle with a very long periglacial periods of low air temperatures and thin vegetation and snow cover and without any ice sheet development, permafrost would reach the depth of 400 m in 98,000 years and perennially frozen ground in 101,000 years. The areal distribution of permafrost and perennially frozen ground are broadly affected by the snow cover, lakes and the peat areas, especially when an extensive peat growth occurs. The lack of snow cover can enhance the evolution of the maximum depth of permafrost and perennially frozen ground by over 50 %. In addition, ground thermal conditions and the heat generation from the spent fuel modify the spatial and temporal development of permafrost and perennially frozen ground. A

  2. Association of CAD, a multifunctional protein involved in pyrimidine synthesis, with mLST8, a component of the mTOR complexes

    Science.gov (United States)

    2013-01-01

    Background mTOR is a genetically conserved serine/threonine protein kinase, which controls cell growth, proliferation, and survival. A multifunctional protein CAD, catalyzing the initial three steps in de novo pyrimidine synthesis, is regulated by the phosphorylation reaction with different protein kinases, but the relationship with mTOR protein kinase has not been known. Results CAD was recovered as a binding protein with mLST8, a component of the mTOR complexes, from HEK293 cells transfected with the FLAG-mLST8 vector. Association of these two proteins was confirmed by the co-immuoprecipitaiton followed by immunoblot analysis of transfected myc-CAD and FLAG-mLST8 as well as that of the endogenous proteins in the cells. Analysis using mutant constructs suggested that CAD has more than one region for the binding with mLST8, and that mLST8 recognizes CAD and mTOR in distinct ways. The CAD enzymatic activity decreased in the cells depleted of amino acids and serum, in which the mTOR activity is suppressed. Conclusion The results obtained indicate that mLST8 bridges between CAD and mTOR, and plays a role in the signaling mechanism where CAD is regulated in the mTOR pathway through the association with mLST8. PMID:23594158

  3. 同化MODIS温度产品估算地表水热通量%Estimation of sensible and latent heat flux by assimilating MODIS LST products

    Institute of Scientific and Technical Information of China (English)

    徐同仁; 刘绍民; 秦军; 梁顺林

    2009-01-01

    In this paper, a land surface temperature data assimilation scheme is developed based on Ensemble Kalman Filter (EnKF) and Common Land Model version 1.0 (CLM), which is mainly used to improve the estimation of the sensible and latent heat fluxes by assimilating MODIS land surface temperature (LST) products. Leaf area index (LAI) is also updated dynamically by MODIS LAI products. In this study, the relationship between the MODIS LST and the CLM surface temperature is determined and taken as the observation operator of the assimilation scheme. Meanwhile, the MODIS LST is compared with the ground-measured surface temperature, and the Root Mean Square Error (RMSE) is taken as the observation error. The scheme is tested and validated based on measurements in three observation stations (Blackhill, Bondville and Brookings) of Ameriflux. Results indicate that data assimilation method improves the estimation of surface temperature and sensible heat flux. The RMSE of sensible heat flux reduced from 81.5W·m~(-2) to 58.4W·m~(-2) at the Blackhill site, from 47.0W·m~(-2) to 31.8W·m~(-2) at the Bondville site, from 46.5W·m~(-2) to 45.1W·m~(-2) at the Brookings site. The RMSE of latent heat fluxes reduced from 88.6W·m~(-2) to 57.7W·m~(-2) at the Bondville site, from 53.4W·m~(-2) to 47.2W·m~(-2) at the Blackhill site. In addition, it is a practical way to improve the estimation of sensible and latent heat flux by assimilating MODIS LST into land surface model.%基于集合卡尔曼滤波和通用陆面模型(CLM 1.0)发展了一个地表温度的同化系统.这个系统同化了MODIS温度产品,并将MODIS的叶面积指数引入CLM模型中,主要用于改进地表水热通量的估算精度.将CLM输出的地表温度与MODIS地表温度建立关系,并作为同化系统的观测算子.将MODIS地表温度与实测地表温度进行了比较,将其均方差(Root Mean Square Error,RMSE)作为观测误差.选取3个美国通量网站点(Blackhill、 Bondville

  4. The development of permafrost bacterial communities under submarine conditions

    Science.gov (United States)

    Mitzscherling, Julia; Winkel, Matthias; Winterfeld, Maria; Horn, Fabian; Yang, Sizhong; Grigoriev, Mikhail N.; Wagner, Dirk; Overduin, Pier P.; Liebner, Susanne

    2017-07-01

    Submarine permafrost is more vulnerable to thawing than permafrost on land. Besides increased heat transfer from the ocean water, the penetration of salt lowers the freezing temperature and accelerates permafrost degradation. Microbial communities in thawing permafrost are expected to be stimulated by warming, but how they develop under submarine conditions is completely unknown. We used the unique records of two submarine permafrost cores from the Laptev Sea on the East Siberian Arctic Shelf, inundated about 540 and 2500 years ago, to trace how bacterial communities develop depending on duration of the marine influence and pore water chemistry. Combined with geochemical analysis, we quantified total cell numbers and bacterial gene copies and determined the community structure of bacteria using deep sequencing of the bacterial 16S rRNA gene. We show that submarine permafrost is an extreme habitat for microbial life deep below the seafloor with changing thermal and chemical conditions. Pore water chemistry revealed different pore water units reflecting the degree of marine influence and stages of permafrost thaw. Millennia after inundation by seawater, bacteria stratify into communities in permafrost, marine-affected permafrost, and seabed sediments. In contrast to pore water chemistry, the development of bacterial community structure, diversity, and abundance in submarine permafrost appears site specific, showing that both sedimentation and permafrost thaw histories strongly affect bacteria. Finally, highest microbial abundance was observed in the ice-bonded seawater unaffected but warmed permafrost of the longer inundated core, suggesting that permafrost bacterial communities exposed to submarine conditions start to proliferate millennia after warming.

  5. Degradation and Local Survival of Permafrost Through the Last Interglaciation in Interior Alaska and Yukon Territory

    Science.gov (United States)

    Reyes, A. V.; Froese, D. G.; Jensen, B. J.

    2006-12-01

    Permafrost in northern North America is warming, and recent modeling efforts have predicted the widespread disappearance of permafrost through much of the northern hemisphere over the next century. However, little is known of the impacts of past sustained warm intervals on permafrost dynamics, antiquity, and distribution due to difficulties in establishing reliable chronologies. Permafrost thus remains the last element of the Arctic cryosphere for which there is poor understanding of its adaptability to past warmer-than-present climate. Here we present observations from three sites in the region of interior Alaska and Yukon Territory that remained ice-free during Plio-Pleistocene glaciations, which collectively demonstrate the variable nature of the response of permafrost to warming during the last interglaciation. Chronology for all sites is based on identification of Old Crow tephra (OCt; 140±10 ka) by glass major element composition. Throughout the study region, OCt is consistently associated with organic-rich sediments that represent the last interglaciation on the basis of pollen, insect, and macrofossil assemblages. At the Palisades site on the Yukon River, 250 km west of Fairbanks, OCt is 1.5-3.5 m below thick (>1m) organic-rich silts and peats that are locally rich in beaver-chewed wood and large wood stumps, some of which are in growth position. In contrast, placer mining at Thistle Creek in central Yukon Territory exposes a dramatic thaw unconformity that is presumably related to local, but incomplete, permafrost degradation during the last interglaciation. In upslope positions at Thistle Creek, OCt is incorporated into a steeply dipping, 30 cm thick, organic-rich silt horizon that truncates at least one intact, relict ice wedge. The steeply dipping organic- rich horizon grades downslope into organic-rich silt with dense accumulations of wood fragments, including tree stems up to 2 m long. Evidence for similar permafrost degradation during the last

  6. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Richard Sigal; Kent Newsham; Thomas Williams; Barry Freifeld; Timothy Kneafsey; Carl Sondergeld; Shandra Rai; Jonathan Kwan; Stephen Kirby; Robert Kleinberg; Doug Griffin

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu Formation and approximately 215 ft of porous sandstone were recovered in the West Sak Formation. There were gas shows in the bottom

  7. 10-15 years of GST monitoring over mountain permafrost in Switzerland: Indicators for driving forces for permafrost evolution

    Science.gov (United States)

    Staub, Benno; Delaloye, Reynald; Hilbich, Christin; Lambiel, Christophe; Nötzli, Jeannette; Völksch, Ingo

    2013-04-01

    different landform types (e.g. debris mantled terrain, talus slopes, rock glaciers, ice-cored moraines, push moraines), the topographical context (e.g. exposure to wind and solar radiation, remobilization of snow by avalanches) and regional aspects (e.g. precipitation events, timing and duration of the insulating snow cover). GST anomalies, indices and derivatives are analyzed over a large data set (~15 field sites) provided by the PERMOS network and different institutions within the SNF Sinergia project «The Evolution of Mountain Permafrost in Switzerland» (TEMPS, 2011-2014). First results show that GST anomalies observed during the past 10 to 15 years show largest disparities for different types of landforms and topographical contexts (because of modified snow cover dynamics). Despite of the complex and highly variable pattern of precipitation in the Swiss Alps, regional differences in GST anomalies remain remarkable small. These findings implicate that future permafrost monitoring based on GST does not necessarily depend on a dense network with a high number of field sites, but should cover at least one suitable spot per region with a variety of different topographical contexts.

  8. MODIS/LST Product Validation for Mixed Pixels at Linzhi of Tibet%西藏林芝地区混合像元MODIS地表温度产品验证

    Institute of Scientific and Technical Information of China (English)

    王圆圆; 闵文彬

    2014-01-01

    Southeastern part of Tibet is featured with complicated terrain and diverse land cover types.Valida-tion of MODIS/LST product (1-km spatial resolution)in this region is faced with mixed pixel issue.Point-based LST measurements cannot represent the pixel well.To obtain ground LST measurements at pixel scale,traditional method usually depends on the high spatial resolution of thermal images,such as Aster and TM.However,these data are often unavailable due to persistent cloud cover and long repeat cycle. Therefore,a new simple method called area-weighted average (AWA)method is proposed,in which land cover map at high spatial resolution is combined with multi-site field observations to model the hypothetical observations at moderate pixel scale.The assumption of AWA method is that field observations can be shared within the same land cover.The AWA method is applied and analyzed on the case of Linzhi (with an area of 20 km2 )which locates in southeastern part of Tibet.First,5 field stations are set up on 5 typi-cal land covers:Grassland,farmland,floodplain,forest at sunny slope,and forest at shadowy slope.The upward and downward long-wave radiations are measured simultaneously.Then the land cover map at 30 m spatial resolution is derived from TM image using maximum likelihood classification method.For ev-ery 1-km MODIS pixel,the fraction of each typical land cover is calculated,and the radiation at MODIS pixel-scale is estimated through area-weighted averaging.The broadband emissivity is calculated using lin-ear combination of narrowband emissivity of MODIS band 31 and 32.Finally,LST at MODIS pixel-scale can be calculated based on Stefan-Boltzmann law.The AWA method is used for validating daily product of MODIS/LST from Terra and Aqua platforms on 10 June 2013 (LST at night is used because it changes slowly both in temporal and spatial domain).Results show that the RMSE of MODIS/LST is below 1 .4 K (n= 30)when applying the AWA method.If a point-based measurement is used

  9. Dissolved organic matter composition of Arctic rivers: Linking permafrost and parent material to riverine carbon

    Science.gov (United States)

    O'Donnell, Jonathan A.; Aiken, George R.; Swanson, David K.; Panda, Santosh; Butler, Kenna D.; Baltensperger, Andrew P.

    2016-12-01

    Recent climate change in the Arctic is driving permafrost thaw, which has important implications for regional hydrology and global carbon dynamics. Permafrost is an important control on groundwater dynamics and the amount and chemical composition of dissolved organic matter (DOM) transported by high-latitude rivers. The consequences of permafrost thaw for riverine DOM dynamics will likely vary across space and time, due in part to spatial variation in ecosystem properties in Arctic watersheds. Here we examined watershed controls on DOM composition in 69 streams and rivers draining heterogeneous landscapes across a broad region of Arctic Alaska. We characterized DOM using bulk dissolved organic carbon (DOC) concentration, optical properties, and chemical fractionation and classified watersheds based on permafrost characteristics (mapping of parent material and ground ice content, modeling of thermal state) and ecotypes. Parent material and ground ice content significantly affected the amount and composition of DOM. DOC concentrations were higher in watersheds underlain by fine-grained loess compared to watersheds underlain by coarse-grained sand or shallow bedrock. DOC concentration was also higher in rivers draining ice-rich landscapes compared to rivers draining ice-poor landscapes. Similarly, specific ultraviolet absorbance (SUVA254, an index of DOM aromaticity) values were highest in watersheds underlain by fine-grained deposits or ice-rich permafrost. We also observed differences in hydrophobic organic acids, hydrophilic compounds, and DOM fluorescence across watersheds. Both DOC concentration and SUVA254 were negatively correlated with watershed active layer thickness, as determined by high-resolution permafrost modeling. Together, these findings highlight how spatial variations in permafrost physical and thermal properties can influence riverine DOM.

  10. The impacts of recent permafrost thaw on land-atmosphere greenhouse gas exchange

    Science.gov (United States)

    Hayes, Daniel J.; Kicklighter, David W.; McGuire, Anthony; Chen, Min; Zhuang, Qianlai; Yuan, Fengming; Melillo, Jerry M.; Wullschleger, Stan D.

    2014-01-01

    Permafrost thaw and the subsequent mobilization of carbon (C) stored in previously frozen soil organic matter (SOM) have the potential to be a strong positive feedback to climate. As the northern permafrost region experiences as much as a doubling of the rate of warming as the rest of the Earth, the vast amount of C in permafrost soils is vulnerable to thaw, decomposition and release as atmospheric greenhouse gases. Diagnostic and predictive estimates of high-latitude terrestrial C fluxes vary widely among different models depending on how dynamics in permafrost, and the seasonally thawed 'active layer' above it, are represented. Here, we employ a process-based model simulation experiment to assess the net effect of active layer dynamics on this 'permafrost carbon feedback' in recent decades, from 1970 to 2006, over the circumpolar domain of continuous and discontinuous permafrost. Over this time period, the model estimates a mean increase of 6.8 cm in active layer thickness across the domain, which exposes a total of 11.6 Pg C of thawed SOM to decomposition. According to our simulation experiment, mobilization of this previously frozen C results in an estimated cumulative net source of 3.7 Pg C to the atmosphere since 1970 directly tied to active layer dynamics. Enhanced decomposition from the newly exposed SOM accounts for the release of both CO2 (4.0 Pg C) and CH4 (0.03 Pg C), but is partially compensated by CO2 uptake (0.3 Pg C) associated with enhanced net primary production of vegetation. This estimated net C transfer to the atmosphere from permafrost thaw represents a significant factor in the overall ecosystem carbon budget of the Pan-Arctic, and a non-trivial additional contribution on top of the combined fossil fuel emissions from the eight Arctic nations over this time period.

  11. Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland

    Science.gov (United States)

    Marmy, Antoine; Rajczak, Jan; Delaloye, Reynald; Hilbich, Christin; Hoelzle, Martin; Kotlarski, Sven; Lambiel, Christophe; Noetzli, Jeannette; Phillips, Marcia; Salzmann, Nadine; Staub, Benno; Hauck, Christian

    2016-11-01

    Permafrost is a widespread phenomenon in mountainous regions of the world such as the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which allow for the projection of the future evolution of permafrost. Due to the complexity of the processes involved and the heterogeneity of Alpine terrain, models must be carefully calibrated, and results should be compared with observations at the site (borehole) scale. However, for large-scale applications, a site-specific model calibration for a multitude of grid points would be very time-consuming. To tackle this issue, this study presents a semi-automated calibration method using the Generalized Likelihood Uncertainty Estimation (GLUE) as implemented in a 1-D soil model (CoupModel) and applies it to six permafrost sites in the Swiss Alps. We show that this semi-automated calibration method is able to accurately reproduce the main thermal condition characteristics with some limitations at sites with unique conditions such as 3-D air or water circulation, which have to be calibrated manually. The calibration obtained was used for global and regional climate model (GCM/RCM)-based long-term climate projections under the A1B climate scenario (EU-ENSEMBLES project) specifically downscaled at each borehole site. The projection shows general permafrost degradation with thawing at 10 m, even partially reaching 20 m depth by the end of the century, but with different timing among the sites and with partly considerable uncertainties due to the spread of the applied climatic forcing.

  12. ESA Data User Element PERMAFROST: a spaceborne permafrost monitoring and information system

    Science.gov (United States)

    Bartsch, A.; Heim, B.; Boike, J.; Elger, K.; Muster, S.; Langer, M.; Westermann, S.; Sobiech, J.

    2010-12-01

    Permafrost is a subsurface phenomenon whose ground thermal regime is mainly influenced by air temperature, land cover, soil and rock properties and snow parameters. Many spaceborne applications are potentially indicative for the thermal state of Permafrost, such as ‘land surface temperature’, ‘surface moisture’, ‘freeze/thaw’, ‘terrain’, ‘vegetation’ and ‘changes of surface waters’. The major task of the ESA Data User Element Permafrost project is to develop circumarctic/-boreal Earth Observation services of these parameters with extensive involvement of the permafrost research community The DUE PERMAFROST datasets will be processed in the EO-PERMAFROST Information System and provided via a WebGIS-interface. Further information is available at www.ipf.tuwien.ac.at/ permafrost. In order to set up the required validation tasks and information services, a target area approach with specified case study regions is used. Most of the foreseen DUE PERMAFROST remote sensing applications are well established and can optimally become operational. The goal of DUE PERMAFROST is to lend confidence in their scientific utility for high-latitude permafrost landscapes. Therefore, a major component is the evaluation of the DUE PERMAFROST products. Ground measurements in the high-latitude landscapes involve challenging logistics and are networked on multidisciplinary and circum-arctic level by the Permafrost community. The International Permafrost Association (IPA) has built up the Global Terrestrial Network for Permafrost (GTN-P) that is a network of the Circumpolar Active Layer Monitoring (CALM) and the Thermal State of Permafrost (TSP) projects. A major part of the DUE PERMAFROST core User group is contributing to GTN-P. Additional members of these programs and circum-arctic networks have also been involved in the consulting process and ground data providing process. Match-up data sets of ground data and remote sensing products coincident in time and

  13. Satellite-derived changes in the permafrost landscape of central Yakutia, 2000-2011: wetting, drying, and fires

    Science.gov (United States)

    Boike, Julia; Grau, Thomas; Heim, Birgit; Günther, Frank; Langer, Moritz; Muster, Sina; Gouttevin, Isabelle; Lange, Stephan

    2016-04-01

    The focus of this research has been on detecting changes in lake areas, vegetation, land surface temperatures, and the area covered by snow, using data from remote sensing. The study area covers the main (central) part of the Lena River catchment in the Yakutia region of Siberia (Russia), extending from east of Yakutsk to the central Siberian Plateau, and from the southern Lena River to north of the Vilyui River. Approximately 90% of the area is underlain by continuous permafrost. Remote sensing products were used to analyze changes in water bodies, land surface temperature (LST), and leaf area index (LAI), as well as the occurrence and extent of forest fires, and the area and duration of snow cover. The remote sensing analyses (for LST, snow cover, LAI, and fire) were based on MODIS-derived NASA products for 2000 to 2011. Changes in water bodies were calculated from two mosaics of (USGS) Landsat high resolution (30 m) satellite images from 2002 and 2009. Within the study area's 315,000 km² the total area covered by lakes increased by 17.5% between 2002 and 2009, but this increase varied in different parts of the study area, ranging between 11% and 42%. The land surface temperatures showed a consistent warming trend, with an average increase of about 0.12°C/year. The average rate of warming during the April-May transition period was 0.15°C/year and 0.19°C/year in the September-October period, but ranged up to 0.45°C/year in some areas during April-May. Regional differences in the rates of land surface temperature change, and possible reasons for the temperature changes, are discussed with respect to changes in the land cover. Our analysis of a broad spectrum of variables over the study area suggests that the spring warming trend is very likely to be due to changes in the area covered by snow. The warming trend observed in fall does not, however, appear to be directly related to any changes in the area of snow cover, or to the atmospheric conditions, or to the

  14. Numerical modeling of seasonally freezing ground and permafrost

    Science.gov (United States)

    Nicolsky, Dmitry J.

    2007-12-01

    dependence of the frost heave on specific environmental properties of the ecosystem. In the final part, simulation of the soil temperature dynamics on the global scale is addressed. General Circulation Models are used to understand and predict future climate change, but most of them do not simulate permafrost dynamics and its potentially critical feedback on climate. In this part, a widely used climate model is evaluated and the simulated temperatures are compared against observations. Based on this comparison, several modifications to the Global Circulation Models are identified to improve the fidelity of permafrost and soil temperature simulations. These modifications include increasing the total soil depth by adding new layers, incorporating a surface organic layer, and modifying the numerical scheme to include unfrozen water dynamics.

  15. Frozen in Time? Microbial strategies for survival and carbon metabolism over geologic time in a Pleistocene permafrost chronosequence

    Science.gov (United States)

    Mackelprang, R.; Douglas, T. A.; Waldrop, M. P.

    2014-12-01

    Permafrost soils have received tremendous interest due to their importance as a global carbon store with the potential to be thawed over the coming centuries. Instead of being 'frozen in time,' permafrost contains active microbes. Most metagenomic studies have focused on Holocene aged permafrost. Here, we target Pleistocene aged ice and carbon rich permafrost (Yedoma), which can differ in carbon content and stage of decay. Our aim was to understand how microbes in the permafrost transform organic matter over geologic time and to identify physiological and biochemical adaptations that enable long-term survival. We used next-generation sequencing to characterize microbial communities along a permafrost age gradient. Samples were collected from the Cold Regions Research and Engineering Laboratory (CRREL) Permafrost Tunnel near Fox, AK, which penetrates a hillside providing access to permafrost ranging in age from 12 to 40 kyr. DNA was extracted directly from unthawed samples. 16S rRNA amplicon (16S) and shotgun metagenome sequencing revealed significant age-driven differences. First, microbial diversity declines with permafrost age, likely due to long-term exposure to environmental stresses and a reduction in metabolic resources. Second, we observed taxonomic differences among ages, with an increasing abundance of Firmicutes (endospore-formers) in older samples, suggesting that dormancy is a common survival strategy in older permafrost. Ordination of 16S and metagenome data revealed age-based clustering. Genes differing significantly between age categories included those involved in lipopolysaccharide assembly, cold-response, and carbon processing. These data point to the physiological adaptations to long-term frozen conditions and to the metabolic processes utilized in ancient permafrost. In fact, a gene common in older samples is involved in cadaverine production, which could potentially explain the putrefied smell of Pleistocene aged permafrost. Coupled with soil

  16. Potential remobilization of belowground permafrost carbon under future global warming

    Science.gov (United States)

    P. Kuhry; E. Dorrepaal; G. Hugelius; E.A.G. Schuur; C. Tarnocai

    2010-01-01

    Research on permafrost carbon has dramatically increased in the past few years. A new estimate of 1672 Pg C of belowground organic carbon in the northern circumpolar permafrost region more than doubles the previous value and highlights the potential role of permafrost carbon in the Earth System. Uncertainties in this new estimate remain due to relatively few available...

  17. High biolability of ancient permafrost carbon upon thaw

    NARCIS (Netherlands)

    Vonk, Jorien E.; Mann, Paul J.; Davydov, Sergey; Davydova, Anna; Spencer, Robert G. M.; Schade, John; Sobczak, William V.; Zimov, Nikita; Zimov, Sergei; Bulygina, Ekaterina; Eglinton, Timothy I.; Holmes, Robert M.

    2013-01-01

    Ongoing climate warming in the Arctic will thaw permafrost and remobilize substantial terrestrial organic carbon (OC) pools. Around a quarter of northern permafrost OC resides in Siberian Yedoma deposits, the oldest form of permafrost carbon. However, our understanding of the degradation and fate of

  18. High biolability of ancient permafrost carbon upon thaw

    NARCIS (Netherlands)

    Vonk, Jorien E.; Mann, Paul J.; Davydov, Sergey; Davydova, Anna; Spencer, Robert G. M.; Schade, John; Sobczak, William V.; Zimov, Nikita; Zimov, Sergei; Bulygina, Ekaterina; Eglinton, Timothy I.; Holmes, Robert M.

    2013-01-01

    Ongoing climate warming in the Arctic will thaw permafrost and remobilize substantial terrestrial organic carbon (OC) pools. Around a quarter of northern permafrost OC resides in Siberian Yedoma deposits, the oldest form of permafrost carbon. However, our understanding of the degradation and fate of

  19. Landscape Effects of Wildfire on Permafrost Distribution in Interior Alaska Derived from Remote Sensing

    Directory of Open Access Journals (Sweden)

    Dana R.N. Brown

    2016-08-01

    Full Text Available Climate change coupled with an intensifying wildfire regime is becoming an important driver of permafrost loss and ecosystem change in the northern boreal forest. There is a growing need to understand the effects of fire on the spatial distribution of permafrost and its associated ecological consequences. We focus on the effects of fire a decade after disturbance in a rocky upland landscape in the interior Alaskan boreal forest. Our main objectives were to (1 map near-surface permafrost distribution and drainage classes and (2 analyze the controls over landscape-scale patterns of post-fire permafrost degradation. Relationships among remote sensing variables and field-based data on soil properties (temperature, moisture, organic layer thickness and vegetation (plant community composition were analyzed using correlation, regression, and ordination analyses. The remote sensing data we considered included spectral indices from optical datasets (Landsat 7 Enhanced Thematic Mapper Plus (ETM+ and Landsat 8 Operational Land Imager (OLI, the principal components of a time series of radar backscatter (Advanced Land Observing Satellite—Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR, and topographic variables from a Light Detection and Ranging (LiDAR-derived digital elevation model (DEM. We found strong empirical relationships between the normalized difference infrared index (NDII and post-fire vegetation, soil moisture, and soil temperature, enabling us to indirectly map permafrost status and drainage class using regression-based models. The thickness of the insulating surface organic layer after fire, a measure of burn severity, was an important control over the extent of permafrost degradation. According to our classifications, 90% of the area considered to have experienced high severity burn (using the difference normalized burn ratio (dNBR lacked permafrost after fire. Permafrost thaw, in turn, likely increased drainage and resulted

  20. Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia

    Science.gov (United States)

    Overduin, Pier Paul; Wetterich, Sebastian; Günther, Frank; Grigoriev, Mikhail N.; Grosse, Guido; Schirrmeister, Lutz; Hubberten, Hans-Wolfgang; Makarov, Aleksandr

    2016-07-01

    Coastal erosion and flooding transform terrestrial landscapes into marine environments. In the Arctic, these processes inundate terrestrial permafrost with seawater and create submarine permafrost. Permafrost begins to warm under marine conditions, which can destabilize the sea floor and may release greenhouse gases. We report on the transition of terrestrial to submarine permafrost at a site where the timing of inundation can be inferred from the rate of coastline retreat. On Muostakh Island in the central Laptev Sea, East Siberia, changes in annual coastline position have been measured for decades and vary highly spatially. We hypothesize that these rates are inversely related to the inclination of the upper surface of submarine ice-bonded permafrost (IBP) based on the consequent duration of inundation with increasing distance from the shoreline. We compared rapidly eroding and stable coastal sections of Muostakh Island and find permafrost-table inclinations, determined using direct current resistivity, of 1 and 5 %, respectively. Determinations of submarine IBP depth from a drilling transect in the early 1980s were compared to resistivity profiles from 2011. Based on borehole observations, the thickness of unfrozen sediment overlying the IBP increased from 0 to 14 m below sea level with increasing distance from the shoreline. The geoelectrical profiles showed thickening of the unfrozen sediment overlying ice-bonded permafrost over the 28 years since drilling took place. We use geoelectrical estimates of IBP depth to estimate permafrost degradation rates since inundation. Degradation rates decreased from over 0.4 m a-1 following inundation to around 0.1 m a-1 at the latest after 60 to 110 years and remained constant at this level as the duration of inundation increased to 250 years. We suggest that long-term rates are lower than these values, as the depth to the IBP increases and thermal and porewater solute concentration gradients over depth decrease. For the

  1. Extraction of Water from Lunar Permafrost

    Science.gov (United States)

    Ethridge, Edwin C.; Kaukler, William

    2009-01-01

    Remote sensing indicates the presence of hydrogen rich regions associated with the lunar poles. The logical hypothesis is that there is cryogenically trapped water ice located in craters at the lunar poles. Some of the craters have been in permanent darkness for a billion years. The presence of water at the poles as well as other scientific advantages of a polar base, have influenced NASA plans for the lunar outpost. The lunar outpost has water and oxygen requirements on the order of 1 ton per year scaling up to as much as 5 tons per year. Microwave heating of the frozen permafrost has unique advantages for water extraction. Proof of principle experiments have successfully demonstrated that microwaves will couple to the cryogenic soil in a vacuum and the sublimed water vapor can be successfully captured on a cold trap. Dielectric property measurements of lunar soil simulant have been measured. Microwave absorption and attenuation in lunar soil simulant has been correlated with measured dielectric properties. Future work will be discussed.

  2. Modelling and mapping climate change impacts on permafrost at high spatial resolution for an Arctic region with complex terrain

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2013-07-01

    Full Text Available Most spatial modelling of climate change impacts on permafrost has been conducted at half-degree latitude/longitude or coarser spatial resolution. At such coarse resolution, topographic effects on insolation cannot be considered accurately and the results are not suitable for land-use planning and ecological assessment. Here we mapped climate change impacts on permafrost from 1968 to 2100 at 10 m resolution using a process-based model for Ivvavik National Park, an Arctic region with complex terrain in northern Yukon, Canada. Soil and drainage conditions were defined based on ecosystem types, which were mapped using SPOT imagery. Leaf area indices were mapped using Landsat imagery and the ecosystem map. Climate distribution was estimated based on elevation and station observations, and the effects of topography on insolation were calculated based on slope, aspect and viewshed. To reduce computation time, we clustered climate distribution and topographic effects on insolation into discrete types. The modelled active-layer thickness and permafrost distribution were comparable with field observations and other studies. The map portrayed large variations in active-layer thickness, with ecosystem types being the most important controlling variable, followed by climate, including topographic effects on insolation. The results show deepening in active-layer thickness and progressive degradation of permafrost, although permafrost will persist in most of the park during the 21st century. This study also shows that ground conditions and climate scenarios are the major sources of uncertainty for high-resolution permafrost mapping.

  3. A first estimate of mountain permafrost distribution in the Mount Cook region of New Zealand’s southern alps

    OpenAIRE

    Allen, S; Owens, I.; Huggel, C

    2008-01-01

    The heavily glaciated Mount Cook Region of New Zealand has experienced several recent large rock instabilities, but permafrost conditions related to these events remain unknown. This work presents the first systematic approach for investigating the distribution of mountain permafrost in New Zealand. At this level of the investigation, a firstorder estimate is based upon the adaptation of established topo-climatic relationships from the European Alps. In the southeast of the study region...

  4. The growth of permafrost-free bogs at the southern margin of permafrost, 1947-2010

    Science.gov (United States)

    Quinton, W. L.; Sonnentag, O.; Connon, R.; Chasmer, L.

    2013-12-01

    In the high-Boreal region of NW Canada, permafrost occurs predominantly in the form of tree-covered peat plateaus within a permafrost-free and treeless terrain dominated by flat bogs. This region is experiencing unprecedented rates of thaw. Over the last several decades, such thaw has significantly expanded the permafrost-free, treeless terrain at the expense of the plateaus. This rapid change in land-cover has raised concerns over its impact on northern water resources, since remotely sensed data and ground observations indicate that the two major land-covers in this region have very different hydrological functions. Peat plateaus have a limited capacity to store water, a relatively large snowmelt water supply and hydraulic gradients that direct excess water into adjacent permafrost-free wetlands. As such, the plateaus function primarily as runoff generators. Plateaus also obstruct and redirect water movement in adjacent wetlands since the open water surfaces of the latter occupy an elevation below the permafrost table. By contrast, bogs are primarily water storage features since they are surrounded by raised permafrost and therefore less able to exchange surface and near-surface flows with the basin drainage network. Accurate estimate of the permafrost and permafrost-free areas is needed for accurate predictions of basin runoff and storage. This study examines the perimeter-area characteristics of bogs and permafrost plateaus, using fractal geometry as a basis for quantifying these properties. Image analyses are applied to aerial photographs and satellite imagery of Scotty Creek, NWT over the period 1947-2010. Preliminary analyses suggest that the expanding bogs and shrinking permafrost plateaus behave as fractals, meaning that their perimeter-area characteristics can be described by simple power equations. The area-frequency characteristics of bogs and plateaus have a hyperbolic distribution with relatively few large bogs and plateaus and numerous small ones

  5. Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

  6. Carbon loss and chemical changes from permafrost collapse in the northern Tibetan Plateau

    Science.gov (United States)

    Mu, Cuicui; Zhang, Tingjun; Zhang, Xiankai; Li, Lili; Guo, Hong; Zhao, Qian; Cao, Lin; Wu, Qingbai; Cheng, Guodong

    2016-07-01

    Permafrost collapse, known as thermokarst, can alter soil properties and carbon emissions. However, little is known regarding the effects of permafrost collapse in upland landscapes on the biogeochemical processes that affect carbon balance. In this study, we measured soil carbon and physiochemical properties at a large thermokarst feature on a hillslope in the northeastern Tibetan Plateau. We categorized surfaces into three different microrelief patches based on type and extent of collapse (control, drape, and exposed areas). Permafrost collapse resulted in substantial decreases of surface soil carbon and nitrogen stocks, with losses of 29.6 ± 4.2% and 28.9 ± 3.1% for carbon and nitrogen, respectively, in the 0-10 cm soil layer. Laboratory incubation experiments indicated that control soil had significantly higher CO2 production rates than that of drapes. The results from Fourier transform infrared spectroscopy analysis showed that exposed soils accumulated some organic matter due to their low position within the feature, which was accompanied by substantial changes in the chemical structure and characteristics of the soil carbon. Exposed soils had higher hydrocarbon and lignin/phenol backbone content than in control and drape soils in the 0-10 cm layer. This study demonstrates that permafrost collapse can cause abundant carbon and nitrogen loss, potentially from mineralization, leaching, photodegradation, and lateral displacement. These results demonstrate that permafrost collapse redistributes the soil organic matter, changes its chemical characteristics, and leads to losses of organic carbon due to the greenhouse gas emission.

  7. Frozen Stiff: Cartographic Design and Permafrost Mapping

    Science.gov (United States)

    Nelson, F. E.; Li, J.; Nyland, K. E.

    2016-12-01

    Maps are the primary vehicle used to communicate geographical relationships. Ironically, interest in the formal practice of cartography, the art and science of geographic visualization, has fallen significantly during a period when the sophistication and availability of GIS software has increased dramatically. Although the number of geographically oriented permafrost studies has increased significantly in recent years, little discussion about competing visualization strategies, map accuracy, and the psychophysical impact of cartographic design is evident in geocryological literature. Failure to use the full potential of the tools and techniques that contemporary cartographic and spatial-analytic theory makes possible affects our ability to effectively and accurately communicate the impacts and hazards associated with thawing permafrost, particularly in the context of global climate change. This presentation examines recent permafrost studies involving primarily small-scale (large area) mapping, and suggests cartographic strategies for rectifying existing problems.

  8. Metagenomics Reveals Microbial Community Composition And Function With Depth In Arctic Permafrost Cores

    Science.gov (United States)

    Jansson, J.; Tas, N.; Wu, Y.; Ulrich, C.; Kneafsey, T. J.; Torn, M. S.; Hubbard, S. S.; Chakraborty, R.; Graham, D. E.; Wullschleger, S. D.

    2013-12-01

    The Arctic is one of the most climatically sensitive regions on Earth and current surveys show that permafrost degradation is widespread in arctic soils. Biogeochemical feedbacks of permafrost thaw are expected to be dominated by the release of currently stored carbon back into the atmosphere as CO2 and CH4. Understanding the dynamics of C release from permafrost requires assessment of microbial functions from different soil compartments. To this end, as part of the Next Generation Ecosystem Experiment in the Arctic, we collected two replicate permafrost cores (1m and 3m deep) from a transitional polygon near Barrow, AK. At this location, permafrost starts from 0.5m in depth and is characterized by variable ice content and higher pH than surface soils. Prior to sectioning, the cores were CT-scanned to determine the physical heterogeneity throughout the cores. In addition to detailed geochemical characterization, we used Illumina MiSeq technology to sequence 16SrRNA genes throughout the depths of the cores at 1 cm intervals. Selected depths were also chosen for metagenome sequencing of total DNA (including phylogenetic and functional genes) using the Illumina HiSeq platform. The 16S rRNA gene sequence data revealed that the microbial community composition and diversity changed dramatically with depth. The microbial diversity decreased sharply below the first few centimeters of the permafrost and then gradually increased in deeper layers. Based on the metagenome sequence data, the permafrost microbial communities were found to contain members with a large metabolic potential for carbon processing, including pathways for fermentation and methanogenesis. The surface active layers had more representatives of Verrucomicrobia (potential methane oxidizers) whereas the deep permafrost layers were dominated by several different species of Actinobacteria. The latter are known to have a diverse metabolic capability and are able to adapt to stress by entering a dormant yet

  9. The new database of the Global Terrestrial Network for Permafrost (GTN-P)

    Science.gov (United States)

    Biskaborn, B. K.; Lanckman, J.-P.; Lantuit, H.; Elger, K.; Streletskiy, D. A.; Cable, W. L.; Romanovsky, V. E.

    2015-09-01

    The Global Terrestrial Network for Permafrost (GTN-P) provides the first dynamic database associated with the Thermal State of Permafrost (TSP) and the Circumpolar Active Layer Monitoring (CALM) programs, which extensively collect permafrost temperature and active layer thickness (ALT) data from Arctic, Antarctic and mountain permafrost regions. The purpose of GTN-P is to establish an early warning system for the consequences of climate change in permafrost regions and to provide standardized thermal permafrost data to global models. In this paper we introduce the GTN-P database and perform statistical analysis of the GTN-P metadata to identify and quantify the spatial gaps in the site distribution in relation to climate-effective environmental parameters. We describe the concept and structure of the data management system in regard to user operability, data transfer and data policy. We outline data sources and data processing including quality control strategies based on national correspondents. Assessment of the metadata and data quality reveals 63 % metadata completeness at active layer sites and 50 % metadata completeness for boreholes. Voronoi tessellation analysis on the spatial sample distribution of boreholes and active layer measurement sites quantifies the distribution inhomogeneity and provides a potential method to locate additional permafrost research sites by improving the representativeness of thermal monitoring across areas underlain by permafrost. The depth distribution of the boreholes reveals that 73 % are shallower than 25 m and 27 % are deeper, reaching a maximum of 1 km depth. Comparison of the GTN-P site distribution with permafrost zones, soil organic carbon contents and vegetation types exhibits different local to regional monitoring situations, which are illustrated with maps. Preferential slope orientation at the sites most likely causes a bias in the temperature monitoring and should be taken into account when using the data for global

  10. Mapping permafrost change hot-spots with Landsat time-series

    Science.gov (United States)

    Grosse, G.; Nitze, I.

    2016-12-01

    Recent and projected future climate warming strongly affects permafrost stability over large parts of the terrestrial Arctic with local, regional and global scale consequences. The monitoring and quantification of permafrost and associated land surface changes in these areas is crucial for the analysis of hydrological and biogeochemical cycles as well as vegetation and ecosystem dynamics. However, detailed knowledge of the spatial distribution and the temporal dynamics of these processes is scarce and likely key locations of permafrost landscape dynamics may remain unnoticed. As part of the ERC funded PETA-CARB and ESA GlobPermafrost projects, we developed an automated processing chain based on data from the entire Landsat archive (excluding MSS) for the detection of permafrost change related processes and hotspots. The automated method enables us to analyze thousands of Landsat scenes, which allows for a multi-scaled spatio-temporal analysis at 30 meter spatial resolution. All necessary processing steps are carried out automatically with minimal user interaction, including data extraction, masking, reprojection, subsetting, data stacking, and calculation of multi-spectral indices. These indices, e.g. Landsat Tasseled Cap and NDVI among others, are used as proxies for land surface conditions, such as vegetation status, moisture or albedo. Finally, a robust trend analysis is applied to each multi-spectral index and each pixel over the entire observation period of up to 30 years from 1985 to 2015, depending on data availability. Large transects of around 2 million km² across different permafrost types in Siberia and North America have been processed. Permafrost related or influencing landscape dynamics were detected within the trend analysis, including thermokarst lake dynamics, fires, thaw slumps, and coastal dynamics. The produced datasets will be distributed to the community as part of the ERC PETA-CARB and ESA GlobPermafrost projects. Users are encouraged to

  11. Climate change and the permafrost carbon feedback

    Science.gov (United States)

    Schuur, E.A.G.; McGuire, Anthony; Schädel, C.; Grosse, G.; Harden, J.W.; Hayes, D.J.; Hugelius, G.; Koven, C.D.; Kuhry, P.; Lawrence, D.M.; Natali, Susan M.; Olefeldt, David; Romanovsky, V.E.; Schaefer, K.; Turetsky, M.R.; Treat, C.C.; Vonk, J.E.

    2015-01-01

    Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.

  12. Evolution of permafrost landscapes under technogenic impacts

    Science.gov (United States)

    Kerimov, A. G.; Grebenets, V. I.; Streletskiy, D. A.; Shiklomanov, N. I.; Nyland, K. E.

    2014-12-01

    Economic development of Russian Northern Regions on permafrost resulted in a new pattern of geocryological conditions, different from natural environment. This pattern is characterized by drastic landscape transformations; changes of heat and mass transfer in the permafrost/atmosphere system; and by engineering and technical pressure upon the permafrost, leading to alteration of its physical, thermal and mechanical properties. In the northern cities this causes increase of ground temperature and intensification of hazardous cryogenic processes in areas under engineering development, reducing stability of geotechnical environment. For example, facility deformations in Norilsk in the last 15 years, became much more abundant than these revealed throughout the previous 50 years. Increase in accident risk for facilities (pipelines, industrial enterprises, etc.) enhances the technogenic pressure on permafrost of the territories under development, leading to the new milestone of changes in permafrost, i.e. to creation of a new set of geocryological conditions. Cryogenic processes within the urban cryolithozone are seldom similar with these under the natural conditions: they either occur more intensively or, vice versa, attenuate under technogenic impacts, new cryogenic processes and phenomena occur, which have not been typical for a given region hitherto. A geographical distribution, evolution and other features of cryogenic processes differ considerably from natural conditions or are unprecedented at all. Peculiar natural-technogenic geocryological complices (NTGC) are formed in the urban centers, which are remarkable by the vector of permafrost evolution, by the set of cryogenic processes, by temperature trends and the other characteristics. NTGC types depend on initial natural settings and on kinds, intensity and duration of technogenic pressure. Our field surveys of permafrost and geological conditions resulted in mapping of 17 NTGC types in Norilsk, 11 types in

  13. Permafrost temperature and active-layer thickness of Yakutia with 0.5 degree spatial resolution for model evaluation

    Directory of Open Access Journals (Sweden)

    C. Beer

    2013-05-01

    Full Text Available Based on the map of landscapes and permafrost conditions in Yakutia (Merzlotno-landshaftnaya karta Yakutskoi0 ASSR, Gosgeodeziya SSSR, 1991, rasterized maps of permafrost temperature and active-layer thickness of Yakutia, East Siberia were derived. The mean and standard deviation at 0.5 degree grid cell size are estimated by assigning a probability density function at 0.001 degree spatial resolution. The gridded datasets can be accessed at the PANGAEA repository (doi:10.1594/PANGAEA.808240. Spatial pattern of both variables are dominated by a climatic gradient from north to south, and by mountains and the soil type distribution. Uncertainties are highest in mountains and in the isolated permafrost zone in the south. The maps are best suited as a benchmark for land surface models which include a permafrost module.

  14. Permafrost temperature and active-layer thickness of Yakutia with 0.5-degree spatial resolution for model evaluation

    Science.gov (United States)

    Beer, C.; Fedorov, A. N.; Torgovkin, Y.

    2013-09-01

    Based on the map of landscapes and permafrost conditions in Yakutia (Merzlotno-landshaftnaya karta Yakutskoi0 ASSR, Gosgeodeziya SSSR, 1991), rasterized maps of permafrost temperature and active-layer thickness of Yakutia, East Siberia were derived. The mean and standard deviation at 0.5-degree grid cell size are estimated by assigning a probability density function at 0.001-degree spatial resolution. The gridded datasets can be accessed at the PANGAEA repository (doi:10.1594/PANGAEA.808240). Spatial pattern of both variables are dominated by a climatic gradient from north to south, and by mountains and the soil type distribution. Uncertainties are highest in mountains and in the sporadic permafrost zone in the south. The maps are best suited as a benchmark for land surface models which include a permafrost module.

  15. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire

    DEFF Research Database (Denmark)

    Abbott, Benjamin W.; Jones, Jeremy B.; Schuur, Edward A. G.

    2016-01-01

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust......-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments...... estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost...

  16. Habitability of Mars: hyperthermophiles in permafrost

    Science.gov (United States)

    Gilichinsky, David; Rivkina, Elizaveta; Vishnivetskaya, Tatiana; Felipe, Gomez; Mironov, Vasilii; Blamey, Jenny; Ramos, Miguel; Ángel de Pablo, Miguel; Castro, Miguel; Boehmwald, Freddy

    This is a first microbiological study of volcanic permafrost carried out on Kluchevskaya volcano group (Kamchatka Peninsula) and Deception Island (Antarctica). By culture-and culture-independent methods we showed the presence of viable hyper(thermophilic) microorganisms and their genes within volcanic permafrost. The optimal temperature for sulfide producing bacteria was 65, whereas acetogens and methanogens were able to produce acetate and methane at temperatures up to 75o C, while sulphur-reducers showed optimal growth at 85-92o C. Hy-per(thermophiles) were never found in permafrost outside the volcanic areas before. The only way they are to appear within a frozen material is a concurrent deposition during the eruption, together with products associated with volcano heated subsurface geothermal oases. The elo-quent evidence to the hypothesis is the presence among clones of the sequences affiliated with (hyper)thermophilic bacteria, both, aerobic and anaerobic, in the environmental DNA derived from ashes freshly deposited on snow in close proximity to volcano Shiveluch (Kamchatka) and aerobic bacteria incubated at 80o C from ashes freshly deposited on the top of Llaima Vol-cano glacier (Andes). Thus, in the areas of active volcanism the catastrophic geological events transports the life from the depths to the surface and this life from high-temperature ecological niches might survive in permafrost over a long period of time. The results obtained give insights for habitability of Mars. Terrestrial permafrost represents a possible ecosystem for Mars as an Earth-like cryogenic planet. But permafrost on Earth and Mars vary in age, from a few million years on Earth to a few billion years on Mars. Because such difference in age, the longevity of life forms preserved within terrestrial permafrost may only serve as an approximate model for Mars. On the other hand, numerous ancient extinct volcanoes are known on Mars. Their past eruptions periodically burn-through the

  17. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (similar to 200 km north of the Arctic Circle). Multivariate statistical...... validation: R-2 = 0.87, RMSEP = 5.25 cm). The new transfer function was applied to a short core from Stordalen mire, and reveals a major shift in peatland ecohydrology coincident with the onset of the Little Ice Age (c. AD 1400). We also applied the model to an independent contemporary dataset from Stordalen...

  18. Paleo-Eskimo kitchen midden preservation in permafrost under future climate conditions at Qajaa, West Greenland

    DEFF Research Database (Denmark)

    Elberling, Bo; Matthiesen, Henning; Jørgensen, Christian Juncher;

    2011-01-01

    Remains from Paleo-Eskimo cultures are well-documented, but complete preservation is rare. Two kitchen middens in Greenland are known to hold extremely well-preserved organic artefacts. Here, we assess the fate of the Qajaa site in Western Greenland under future climate conditions based on site...... characteristics measured in situ and from permafrost cores. Measurements of thermal properties, heat generation, oxygen consumption and CO2 production show that the kitchen midden can be characterized as peat but produces 4–7 times more heat than natural sediment. An analytical model from permafrost research has...

  19. Climate change and the permafrost carbon feedback

    NARCIS (Netherlands)

    Schuur, E. A G; McGuire, A. D.; Schädel, C.; Grosse, G.; Harden, J. W.; Hayes, D. J.; Hugelius, G.; Koven, C. D.; Kuhry, P.; Lawrence, D. M.; Natali, S. M.; Olefeldt, D.; Romanovsky, V. E.; Schaefer, K.; Turetsky, M. R.; Treat, C. C.; Vonk, J. E.|info:eu-repo/dai/nl/370832833

    2015-01-01

    Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This

  20. Global Policy Implications of Thawing Permafrost

    Science.gov (United States)

    Schaefer, K. M.; Zhang, T.; Bruhwiler, L.; Barrett, A. P.; Li, Z.

    2011-12-01

    Global treaties to reduce fossil fuel emissions should include a 15% allocation for permafrost carbon emissions or we will overshoot our target CO2 concentration and end up with a warmer climate than planned. Arctic permafrost currently contains 1466 Gt of carbon frozen since the last ice age, roughly double the amount of carbon in the atmosphere. We estimate 190±64 Gt of this carbon will thaw out, decay, and end up in the atmosphere by 2300, potentially increasing atmospheric CO2 concentrations by 87±29 ppm. A carbon release of this magnitude is equal to 15% of the total allowed emissions to hit a target CO2 concentration of 700 ppm. Global targets for fossil fuel emissions must be reduced an additional 15% to account for the release of carbon from thawing permafrost. Current treaty negotiations do not include a 15% allocation for permafrost carbon emissions. We present the scientific basis for our results and summarize our successes and failures in trying to influence international treaty negotiations to reduce fossil fuel emissions.

  1. Trace elements transport in western Siberia rivers across a permafrost gradient

    Directory of Open Access Journals (Sweden)

    O. S. Pokrovsky

    2015-11-01

    Full Text Available Towards a better understanding of trace element transport in permafrost-affected Earth surface environments, we sampled ∼ 60 large and small rivers (2 watershed area of Western Siberia Lowland (WSL during spring flood and summer and winter base-flow across a 1500 km latitudinal gradient covering continuous, discontinuous, sporadic and permafrost-free zones. Analysis of ∼ 40 major and trace elements in dissolved ( The Principal Component Analysis demonstrated two main factors potentially controlling the ensemble of TE concentration variation. The first factor, responsible for 16–20 % of overall variation, included trivalent and tetravalent hydrolysates, Cr, V, and DOC and presumably reflected the presence of organo-mineral colloids, as also confirmed by previous studies in Siberian rivers. The 2nd factor (8–14 % variation was linked to the latitude of the watershed and acted on elements affected by the groundwater feeding (DIC, Sr, Mo, As, Sb, U, whose concentration decreased significantly northward during all seasons. Overall, the rank of environmental factors on TE concentration in western Siberian rivers was latitude (3 permafrost zones > season > watershed size. The effect of the latitude was minimal in spring for most TE but highly visible for Sr, Mo, Sb and U. The main factors controlling the shift of river feeding from surface and subsurface flow to deep underground flow in the permafrost-bearing zone were the depth of the active (unfrozen seasonal layer and its position in organic or mineral horizons of the soil profile. In the permafrost-free zone, the relative role of carbonate mineral-bearing base rock feeding vs. bog water feeding determined the pattern of trace element concentration and fluxes in rivers of various size as a function of season. Comparison of obtained TE fluxes in WSL rivers with those of other subarctic rivers demonstrated reasonable agreement for most trace elements; the lithology of base rocks was the major

  2. Vulnerability of permafrost carbon research coordination network

    Science.gov (United States)

    Schädel, C.; Schuur, E. A. G.; McGuire, A. D.; Canadell, J. G.; Harden, J.; Kuhry, P.; Romanovsky, V. E.; Turetsky, M. R.

    2012-04-01

    Approximately 1700 Pg of soil carbon are stored in the northern circumpolar permafrost zone, more than twice as much carbon than currently contained in the atmosphere. Permafrost thaw, and the microbial decomposition of previously frozen organic carbon, is considered one of the most likely positive feedbacks from terrestrial ecosystems to the atmosphere in a warmer world. Yet, the rate and form of release is highly uncertain but crucial for predicting the strength and timing of this carbon cycle feedback this century and beyond. Here we report on the first products of a new research coordination network (RCN) whose objective is to link biological C cycle research with well-developed networks in the physical sciences focused on the thermal state of permafrost. We found that published literature in the Science Citation Index identified with the search terms 'permafrost' and 'carbon' have increased dramatically in the last decade. Of total publications including those keywords, 86% were published since 2000, 65% since 2005, and 36% since 2008. The first RCN activity consisted of an expert elicitation that revealed the total effect of carbon release from permafrost zone soils in climate is expected to be up to 30-46 Pg C over the next three decades, reaching 242-324 Pg C by 2100 and potentially up to 551-710 Pg C over the next several centuries under the strongest warming scenario presented to the group. These values, expressed in billions of tons of C in CO2 equivalents, combine the effect of C released both as CO2 and as CH4 by accounting for the greater heat-trapping capacity of CH4. However, the higher global warming potential of CH4 means that almost half of the effect of future permafrost zone carbon emissions on climate forcing was expected by this group to be a result of CH4 emissions from wetlands, lakes, and other oxygen-limited environments where organic matter will be decomposing. These results demonstrate the vulnerability of organic C stored in near

  3. Urban Landscapes on Permafrost: Oganer Case Study

    Science.gov (United States)

    Streletskiy, D. A.; Grebenets, V. I.

    2013-12-01

    Norilsk with a population of 205,000 is by far the biggest city ever built on permafrost. Oganer, located near Norilsk is the latest administrative unit of the city with a population of about 7,000 people. It was originally designed as a satellite city for about 50-80 thousand workers and their families. Idea of a satellite city became apparent in mid-80th, when Norilsk was unable to grow to extent needed to accommodate large workforce. Located in a valley, the city was already surrounded by two metallurgy plants and steep mountains slopes. The only direction of city limit extension was east, but the area was previously occupied by garages and barracks resulting in deterioration of cold permafrost and decrease in high bearing capacity of the ground required for construction of large residential houses. Oganer was built 8 km east from the Norilsk, where initial geologic survey shown close location of bedrock to the surface making possible construction of large structures on permafrost. First houses were built in 1986 according to the passive principle of construction on permafrost. Additional geologic surveys in Oganer revealed that original bedrock extent is quite small and subsequent construction had to deal with ice-reach (40-60%) permafrost in fine-grained sediments (silt and clay). The change in economic direction in the beginning of 1990s resulted in population outmigration from Norilsk, so Oganer originally planned as a large 5-district city was never complete. Presently, it is represented by only one district, with several 9-storey tall buildings which were never complete. Despite that mean annual temperature is -9.7 C, permafrost temperature is relatively warm -1..-3 C. High permafrost temperature, presence of ground ice and large bodies of tabular ground ice in the area made construction quite challenging. In the paper we demonstrate how climateand various construction practices and designs used in the city modified natural landscapes, and how periglacial

  4. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

    Science.gov (United States)

    Benjamin W. Abbott,; Jeremy B. Jones,; Edward A.G. Schuur,; F.S. Chapin, III; William B. Bowden,; M. Syndonia Bret-Harte,; Howard E. Epstein,; Michael D. Flannigan,; Tamara K. Harms,; Teresa N. Hollingsworth,; Michelle Mack,; McGuire, Anthony; Susan M. Natali,; Adrian V. Rocha,; Suzanne E. Tank,; Merrit R. Turetsky,; Jorien E. Vonk,; Wickland, Kimberly P.; Aiken, George R.

    2016-01-01

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

  5. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, Benjamin; Jones, Jeremy B.; Schuur, Edward A.; Chapin, F. S.; Bowden, William B.; Bret-Harte, M. Syndonia; Epstein, Howard E.; Flannigan, Michael D.; Harms, Tamara K.; Hollingsworth, Teresa N.; Mack, Michelle; McGuire, A. David; Natali, Susan M.; Rocha, Adrian; Tank, Suzanne E.; Turetsky, Merritt; Vonk, Jorien E.; Wickland, Kimberly P.; Aiken, George R.; Alexander, Heather D.; Amon, Rainer M.; Benscoter, Brian W.; Bergeron, Yves; Bishop, Kevin; Blarquez, Olivier; Bond-Lamberty, Benjamin; Breen, Amy L.; Buffam, Ishi; Cai, Yihua; Carcaillet, Christopher; Carey, Sean K.; Chen, Jing Ming; Chen, Han Y.; Christensen, Torben R.; Cooper, Lee W.; Cornelissen, J Hans C.; de Groot, William J.; DeLuca, Thomas H.; Dorrepaal, Ellen; Fetcher, Ned; Finlay, Jacques C.; Forbes, Bruce C.; French, Nancy H.; Gauthier, Sylvie; Girardin, Martin P.; Goetz, Scott J.; Goldammer, Johann G.; Gough, Laura; Grogan, Paul; Guo, Laodong; Higuera, Philip E.; Hinzman, Larry; Hu, Feng S.; Hugelius, Gustaf; Jafarov, Elchin E.; Jandt, Randi; Johnstone, Jill F.; Karlsson, J.; Kasischke, Eric S.; Kattner, Gerhard; Kelly, Ryan; Keuper, Frida; Kling, George; Kortelainen, Pirkko; Kouki, Jari; Kuhry, Peter; Laudon, Hjalmar; Laurion, Isabelle; Macdonald, Robie W.; Mann, Paul J.; Martikainen, Pertti; McClelland, James W.; Molau, Ulf; Oberbauer, Steven F.; Olefeldt, David; Pare, David; Parisien, Marc-Andre; Payette, Serge; Peng, Changhui; Pokrovesky, Oleg S.; Rastetter, Edward B.; Raymond, Peter A.; Raynolds, Martha K.; Rein, Guillermo; Reynolds, James F.; Robards, Martin; Rogers, Brendan M.; Schadel, Christina; Schaefer, Kevin; Schmidt, Inger K.; Shvidenko, Anatoly; Sky, Jasper; Spencer, Robert G.; Starr, Gregory; Striegl, Robert G.; Teisserenc, Roman; Tranvik, Lars J.; Virtanen, Tarmo; Welker, Jeffrey M.; Zimov, Sergei

    2016-03-07

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

  6. Permafrost thaw and soil moisture driving CO2 and CH4 release from upland tundra

    Science.gov (United States)

    Natali, Susan M.; Schuur, Edward A. G.; Mauritz, Marguerite; Schade, John D.; Celis, Gerardo; Crummer, Kathryn G.; Johnston, Catherine; Krapek, John; Pegoraro, Elaine; Salmon, Verity G.; Webb, Elizabeth E.

    2015-03-01

    As permafrost degrades, the amount of organic soil carbon (C) that thaws during the growing season will increase, but decomposition may be limited by saturated soil conditions common in high-latitude ecosystems. However, in some areas, soil drying is expected to accompany permafrost thaw as a result of increased water drainage, which may enhance C release to the atmosphere. We examined the effects of ecosystem warming, permafrost thaw, and soil moisture changes on C balance in an upland tundra ecosystem. This study was conducted at a water table drawdown experiment, established in 2011 and located within the Carbon in Permafrost Experimental Heating Research project, an ecosystem warming and permafrost thawing experiment in Alaska. Warming and drying increased cumulative growing season ecosystem respiration by 20% over 3 years of this experiment. Warming caused an almost twofold increase in decomposition of a common substrate in surface soil (0-10 cm) across all years, and drying caused a twofold increase in decomposition (0-20 cm) relative to control after 3 years of drying. Decomposition of older C increased in the dried and in the combined warmed + dried plots based on soil pore space 14CO2. Although upland tundra systems have been considered CH4 sinks, warming and ground thaw significantly increased CH4 emission rates. Water table depth was positively correlated with monthly respiration and negatively correlated with CH4 emission rates. These results demonstrate that warming and drying may increase loss of old permafrost C from tundra ecosystems, but the form and magnitude of C released to the atmosphere will be driven by changes in soil moisture.

  7. Spatial distribution and characteristics of permafrost in Hurd Peninsula, Livingston Island, Maritime Antarctic

    Science.gov (United States)

    Vieira, G.; Ramos, M.; Trindade, A.; Gruber, S.; Hauck, C.; Mora, C.; Batista, V.; Neves, M.; Pimpirev, C.; Kenderova, R.

    2009-04-01

    The Antarctic Peninsula is one of Earth's regions experiencing a faster increase on temperatures, with Mean Annual Air Temperatures (MAAT) rising ca. 2.5 °C in the last 50 years. The northerly location of the Antarctic Peninsula in respect to the Antarctic and its oceanic setting originate a milder and moister climate than in the Antarctic continent. The Northern Antarctic Peninsula is roughly located between the isotherms of MAAT of -1 °C to -8 °C at sea-level and therefore the northern tip and especially the South Shetlands are close to the limits of permafrost occurrence. If the observed warming trend is to continue in the near future, the region might suffer widespread permafrost degradation. Research on the permafrost environment of Hurd Peninsula has been taking place with systematical measurements by our group since January 2000 and currently we are able to provide a good overview of the spatial distribution and characteristics of permafrost terrain in Hurd Peninsula. Our research is based on shallow boreholes (Collado Ramos (115m). In 2006 Electrical Tomography Resistivity and refraction seismic profiles have been performed, providing us with a good overview of the general conditions of the permafrost terrain in the area. Air temperatures are measured at different sites accounting for altitude since a few years and during 3 summer campaigns the radiation balance was monitored continuously at two sites. Detailed geomorphological mapping of periglacial features has been conducted at a scale 1:5,000 providing important information about the geomorphological dynamics. Using the data gathered since 2000 it is now possible to present the general characteristics of the permafrost distribution in Hurd Peninsula as a first step towards a more comprehensive approach that is now starting that involves empirico-statistical modeling, remote sensing, as well as downscaling of mesoscale climate data.

  8. Permafrost landscapes in transition - towards modeling interactions, thresholds and feedbacks related to ice-rich ground

    Science.gov (United States)

    Westermann, Sebastian; Langer, Moritz; Lee, Hanna; Berntsen, Terje; Boike, Julia; Krinner, Gerhard; Aalstad, Kristoffer; Schanke Aas, Kjetil; Peter, Maria; Heikenfeld, Max; Etzelmüller, Bernd

    2016-04-01

    Thawing of permafrost is governed by a complex interplay of different processes, of which only conductive heat transfer is taken into account in most model studies. However, heat conduction alone can not account for the dynamical evolution of many permafrost landscapes, e.g. in areas rich in ground ice shaped by thermokarst ponds and lakes. Novel process parameterizations are required to include such phenomena in future projections of permafrost thaw and hereby triggered climatic feedbacks. Recently, we have demonstrated a physically-based parameterization for thaw process in ice-rich ground in the permafrost model CryoGrid 3, which can reproduce the formation of thermokarst ponds and subsidence of the ground following thawing of ice-rich subsurface layers. Long-term simulations for different subsurface stratigraphies in the Lena River Delta, Siberia, demonstrate that the hydrological regime can both accelerate and delay permafrost thawing. If meltwater from thawed ice-rich layers can drain, the ground subsides while at the same time the formation of a talik is delayed. If the meltwater pools at the surface, a pond is formed which enhances heat transfer in the ground and leads to the formation of a talik. The PERMANOR project funded by the Norwegian Research Council until 2019 will extend this work by integrating such small-scale processes in larger-scale Earth System Models (ESMs). For this purpose, the project will explore and develop statistical approaches, in particular tiling, to represent permafrost landscape dynamics on subgrid scale. Ultimately, PERMANOR will conceptualize process understanding from in-situ studies to develop new model algorithms and pursue their implementation in a coupled ESM framework.

  9. Improved simulation of the terrestrial hydrological cycle in permafrost regions by the Community Land Model

    Directory of Open Access Journals (Sweden)

    Sean Claude Swenson

    2012-08-01

    Full Text Available Plausible predictions of future climate require realistic representations of past and current climate. Simulations of the distribution of permafrost in the 21st century made with the Community Climate System Model (CCSM4 indicate that substantial decreases in permafrost extent can be expected, especially under high emissions scenarios. One of the implications of permafrost loss is the potential release of carbon from newly thawed soils into the atmosphere, thus raising its concentration of greenhouse gases and amplifying the initial warming trend. However, the biogeochemical cycle simulated by CCSM4 presents significant biases in carbon fluxes such as gross primary production, net primary production, and vegetation carbon storage in permafrost regions. The biases in the carbon cycle simulated by CCSM4 are in part due to excessively dry soils in permafrost regions. In this study, we show that the CCSM4 dry soil bias results from the model's formulation of soil hydraulic permeability when soil ice is present. The calculation of the hydraulic properties of frozen soils is first modified by replacing their dependence on total water content with liquid water content only. Then an ice impedance function having a power-law form is incorporated. When the parameterization of the hydraulic properties of frozen soil is corrected, the model simulates significantly higher moisture contents in near-surface soils in permafrost regions, especially during spring. This result is validated qualitatively by comparing soil moisture profiles to descriptions based on field studies, and quantitatively by comparing simulated hydrographs of two large Siberian rivers to observed hydrographs. After the dry soil bias is reduced, the vegetation productivity simulated by the model is improved, which is manifested in leaf area indices that at some locations are twice as large as in the original model.

  10. Permafrost response to last interglacial warming: field evidence from non-glaciated Yukon and Alaska

    Science.gov (United States)

    Reyes, Alberto V.; Froese, Duane G.; Jensen, Britta J. L.

    2010-11-01

    We present stratigraphic observations from three sites in eastern Beringia - Ch'ijee's Bluff in northern Yukon and nearby exposures on the Old Crow River, the Palisades on the Yukon River in Alaska, and placer mining exposures at Thistle Creek in west-central Yukon - which provide insight into the response of permafrost to regional warming during the last interglaciation. Chronology is based on the presence of Old Crow tephra, an important regional stratigraphic marker that dates to late Marine Isotope Stage 6, supplemented by paleoecology and non-finite 14C ages on wood-rich organic silts. Old Crow tephra overlies several relict ice wedges at the Palisades and Thistle Creek, indicating that permafrost at these sites did not thaw completely during the last interglaciation. Prominent deposits of last interglacial wood-rich organic silt are present at multiple sites in eastern Beringia, and probably represent accumulations of reworked forest vegetation due to thaw slumping or deposition into thermokarst ponds or depressions. Consistent stratigraphic relations between these deposits, Old Crow tephra, and ice wedge pseudomorphs at our three study sites, and at least six other sites in eastern Beringia, suggest that thaw of shallow permafrost was widespread during the last interglaciation. Limited stratigraphic evidence suggests that thaw was probably on the order of meters, rather than 10s of meters. The ubiquity of shallow permafrost degradation during the last interglaciation suggests that current ground warming may foreshadow widespread near-surface thaw under even modest future warming scenarios. However, the persistence of relict pre-last interglacial ice wedges highlights the potential for the regional antiquity of discontinuous permafrost, and provides compelling field evidence for the long-term resilience of deep permafrost during sustained periods of warmer-than-present climate.

  11. Bacterial production in subarctic peatland lakes enriched by thawing permafrost

    Science.gov (United States)

    Deshpande, Bethany N.; Crevecoeur, Sophie; Matveev, Alex; Vincent, Warwick F.

    2016-08-01

    feature of all of the northern lakes sampled, including other thaw lakes and shallow rock-basin lakes (average ± SE of 25 ± 6 %). However, a distinguishing feature of the peatland thaw lakes was significantly higher bacterial specific growth rates, which averaged 4 to 7 times higher values than in the other lake types. The in situ enrichment experiment showed no difference between organic carbon or phosphorus enrichment treatments at day 5 relative to the control, however there was an apparent increase in bacterial growth rates between days 1 and 5 in the soil and the carbon plus phosphorus enrichments. Collectively these results indicate that particles, nutrients and carbon are released by degrading permafrost peatland soils into their associated thermokarst lakes, creating favorable conditions for production by particle-based as well as free-living aquatic bacterial communities. The reduced bacterial concentrations despite high cellular growth rates imply that there is control of their population size by loss-related factors such as grazing and viral lysis.

  12. Surface and subsurface conditions in permafrost areas - a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik [Bergab, Goeteborg (Sweden)

    2003-02-01

    This report contains a summary of some of the information within existing technical and scientific literature on permafrost. Permafrost is viewed as one of the future climate driven process domains that may exist in Scandinavia, and that may give rise to significantly different surface and subsurface conditions than the present. Except for changes in the biosphere, permafrost may impact hydraulic, mechanical, and chemical subsurface processes and conditions. Permafrost and its influences on the subsurface conditions are thus of interest for the performance and safety assessments of deep geological waste repositories. The definition of permafrost is 'ground that stays at or below 0 deg C for at least two consecutive years'. Permafrost will effect the geological subsurface to some depth. How deep the permafrost may grow is a function of the heat balance, thermal conditions at the surface and within the ground, and the geothermal heat flux from the Earth's inner parts. The main chapters of the report summaries the knowledge on permafrost evolution, occurrence and distribution, and extracts information concerning hydrology and mechanical and chemical impacts due to permafrost related conditions. The results of a literature review are always dependent on the available literature. Concerning permafrost there is some literature available from investigations in the field of long-term repositories and some from mining industries. However, reports of these investigations are few and the bulk of permafrost literature comes from the science departments concerned with surficial processes (e.g. geomorphology, hydrology, agriculture, etc) and from engineering concerns, such as foundation of constructions and pipeline design. This focus within the permafrost research inevitably yields a biased but also an abundant amount of information on localised surficial processes and a limited amount on regional and deep permafrost characteristics. Possible conclusions are that

  13. A comparison of radiometric correction techniques in the evaluation of the relationship between LST and NDVI in Landsat imagery.

    Science.gov (United States)

    Tan, Kok Chooi; Lim, Hwee San; Matjafri, Mohd Zubir; Abdullah, Khiruddin

    2012-06-01

    Atmospheric corrections for multi-temporal optical satellite images are necessary, especially in change detection analyses, such as normalized difference vegetation index (NDVI) rationing. Abrupt change detection analysis using remote-sensing techniques requires radiometric congruity and atmospheric correction to monitor terrestrial surfaces over time. Two atmospheric correction methods were used for this study: relative radiometric normalization and the simplified method for atmospheric correction (SMAC) in the solar spectrum. A multi-temporal data set consisting of two sets of Landsat images from the period between 1991 and 2002 of Penang Island, Malaysia, was used to compare NDVI maps, which were generated using the proposed atmospheric correction methods. Land surface temperature (LST) was retrieved using ATCOR3_T in PCI Geomatica 10.1 image processing software. Linear regression analysis was utilized to analyze the relationship between NDVI and LST. This study reveals that both of the proposed atmospheric correction methods yielded high accuracy through examination of the linear correlation coefficients. To check for the accuracy of the equation obtained through linear regression analysis for every single satellite image, 20 points were randomly chosen. The results showed that the SMAC method yielded a constant value (in terms of error) to predict the NDVI value from linear regression analysis-derived equation. The errors (average) from both proposed atmospheric correction methods were less than 10%.

  14. Simulation of permafrost and seasonal thaw depth in the JULES land surface scheme

    Directory of Open Access Journals (Sweden)

    R. Dankers

    2011-04-01

    Full Text Available Land surface models (LSMs need to be able to simulate realistically the dynamics of permafrost and frozen ground. In this paper we evaluate the performance of the LSM JULES (Joint UK Land Environment Simulator, the stand-alone version of the land surface scheme used in Hadley Centre climate models, in simulating the large-scale distribution of surface permafrost. In particular we look at how well the model is able to simulate the seasonal thaw depth or active layer thickness (ALT. We performed a number of experiments driven by observation-based climate datasets. Visually there is a very good agreement between areas with permafrost in JULES and known permafrost distribution in the Northern Hemisphere, and the model captures 97% of the area where the permafrost coverage is at least 50% of the grid cell. However, the model overestimates the total extent as it also simulates permafrost where it occurs sporadically or only in isolated patches. Consistent with this we find a cold bias in the simulated soil temperatures, especially in winter. However, when compared with observations on end-of-season thaw depth from around the Arctic, the ALT in JULES is generally too deep. Additional runs at three sites in Alaska demonstrate how uncertainties in the precipitation input affect the simulation of soil temperatures by affecting the thickness of the snowpack and therefore the thermal insulation in winter. In addition, changes in soil moisture content influence the thermodynamics of soil layers close to freezing. We also present results from three experiments in which the standard model setup was modified to improve physical realism of the simulations in permafrost regions. Extending the soil column to a depth of 60 m and adjusting the soil parameters for organic content had relatively little effect on the simulation of permafrost and ALT. A higher vertical resolution improves the simulation of ALT, although a considerable bias still remains. Future model

  15. Simulation of permafrost and seasonal thaw depth in the JULES land surface scheme

    Directory of Open Access Journals (Sweden)

    R. Dankers

    2011-09-01

    Full Text Available Land surface models (LSMs need to be able to simulate realistically the dynamics of permafrost and frozen ground. In this paper we evaluate the performance of the LSM JULES (Joint UK Land Environment Simulator, the stand-alone version of the land surface scheme used in Hadley Centre climate models, in simulating the large-scale distribution of surface permafrost. In particular we look at how well the model is able to simulate the seasonal thaw depth or active layer thickness (ALT. We performed a number of experiments driven by observation-based climate datasets. Visually there is a very good agreement between areas with permafrost in JULES and known permafrost distribution in the Northern Hemisphere, and the model captures 97% of the area where the spatial coverage of the permafrost is at least 50%. However, the model overestimates the total extent as it also simulates permafrost where it occurs sporadically or only in isolated patches. Consistent with this we find a cold bias in the simulated soil temperatures, especially in winter. However, when compared with observations on end-of-season thaw depth from around the Arctic, the ALT in JULES is generally too deep. Additional runs at three sites in Alaska demonstrate how uncertainties in the precipitation input affect the simulation of soil temperatures by affecting the thickness of the snowpack and therefore the thermal insulation in winter. In addition, changes in soil moisture content influence the thermodynamics of soil layers close to freezing. We also present results from three experiments in which the standard model setup was modified to improve physical realism of the simulations in permafrost regions. Extending the soil column to a depth of 60 m and adjusting the soil parameters for organic content had relatively little effect on the simulation of permafrost and ALT. A higher vertical resolution improves the simulation of ALT, although a considerable bias still remains. Future model

  16. Slope Edge Deformation and Permafrost Dynamics Along the Arctic Shelf Edge, Beaufort Sea, Canada

    Science.gov (United States)

    Paull, C. K.; Dallimore, S.; Caress, D. W.; Gwiazda, R.; Lundsten, E. M.; Anderson, K.; Riedel, M.; Melling, H.

    2015-12-01

    The shelf of the Canadian Beaufort Sea is underlain by relict offshore permafrost that formed in the long intervals of terrestrial exposure during glacial periods. At the shelf edge the permafrost thins rapidly and also warms. This area has a very distinct morphology that we attribute to both the formation and degradation of ice bearing permafrost. Positive relief features include circular to oval shaped topographic mounds, up to 10 m high and ~50 m in diameter which occur at a density of ~6 per km2. Intermixed are circular topographic depressions up to 20 m deep. This topography was investigated using an autonomous underwater vehicle that provides 1 m horizontal resolution bathymetry and chirp profiles, a remotely operated vehicle to document seafloor textures, and sediment cores to sample pore waters. A consistent down-core freshening at rates of 14 to 96 mM Cl- per meter was found in these pore waters near the shelf edge. Downward extrapolation of these trends indicates water with ≤335 mM Cl- should occur at 2.3 to 22.4 m sub-seafloor depths within this shelf edge deformation band. Pore water with 335 mM Cl- or less freezes at -1.4°C. As bottom water temperatures in this area are persistently (<-1.4°C) cold and ground ice was observed in some core samples, we interpret the volume changes associated with mound formation are in part due to pore water freezing. Thermal models (Taylor et al., 2014) predict brackish water along the shelf edge may be sourced in relict permafrost melting under the adjacent continental shelf. Buoyant brackish water is hypothesized to migrate along the base of the relict permafrost, to emerge at the shelf edge and then refreeze when it encounters the colder seafloor. Expansion generated by the formation of ice-bearing permafrost generates the positive relief mounds and ridges. The associated negative relief features may be related to permafrost dynamics also. Permafrost dynamics may have geohazard implications that are unique to the

  17. Permafrost aggradation in recently deglaciated alpine environments

    Science.gov (United States)

    Leopold, Matthias; Dusik, Jana; Stocker-Waldhuber, Martin; Völkel, Jörg; Becht, Michael

    2015-04-01

    Permafrost degradation is of major interest in the present discussion about alpine climate change and natural hazard prevention. Glacial retreat since the Little Ice Age (LIA) is followed by destabilisation of the surrounding mountains due to melting permafrost in bedrock and sediments. Glacial retreat also exposes huge areas of lateral and ground moraines. Areas of formerly temperate glaciers experience colder temperatures only since their ice cover has melted and basal meltwater no longer heats the ground. With a huge pore volume in the sediment body, water supply during the melt season and large daily temperature variations in high mountains, distinct freeze and thaw processes start and generate periglacial forms like patterned ground in the direct glacier forefield. Those geomorphic features are precursors for possible permafrost aggradation in proglacial areas. The work presented is part of the joint project PROSA (High-resolution measurements of morphodynamics in rapidly changing PROglacial Systems of the Alps) that aims in the quantification of a sediment budget for the upper Kaunertal valley, Austrian Central Alps. In this sense and to find out about erosion causing prerequisites and processes, permafrost and ground ice occurrence, as well as sediment thickness is measured by i.a. application of geophysical measurements, multitemporal airborne and terrestrial LiDAR, as well as aerial photographs. In this case study we examine the spatial and temporal settings for permafrost aggradation in a recently deglaciated cirque, belonging to the catchment area of the Gepatschferner glacier using electric resistivity tomography (ERT) and basal temperature of the winterly snowcover (BTS) measurements to detect the state of the permafrost, multitemporal aerial photographs dating back to 1953 to reproduce recent deglaciation of the cirque and multitemporal airborne LiDAR data to gain information about surface elevation changes. The northeast facing cirque is situated in

  18. Surface towed electromagnetic system for mapping of subsea Arctic permafrost

    Science.gov (United States)

    Sherman, Dallas; Kannberg, Peter; Constable, Steven

    2017-02-01

    Sea level has risen globally since the late Pleistocene, resulting in permafrost-bearing coastal zones in the Arctic being submerged and subjected to temperature induced degradation. Knowing the extent of permafrost and how it changes over time is important for climate change predictions and for planning engineering activities in the Arctic environment. We developed a controlled source electromagnetic (CSEM) method to obtain information on the depth, thickness, and lateral extent of marine permafrost. To operate in shallow water we used a surface towed electric dipole-dipole CSEM system suitable for deployment from small boats. This system was used to map permafrost on the Arctic shelf offshore Prudhoe Bay, Alaska. Our results show significant lateral variability in the presence of permafrost, with the thickest layers associated with a large river outflow where freshwater influx seems to have a preserving effect on relict subsea permafrost.

  19. Collaborative efforts to solve problems in permafrost science and engineering

    Science.gov (United States)

    Hinzman, Larry D.; Hinkel, Kenneth M.; Romanovsky, Vladimir E.

    2012-10-01

    Tenth International Conference on Permafrost; Salekhard, Russia, 25-29 June 2012 To recognize permafrost's growing significance in the Earth climate system, to stimulate interaction among the scientific communities, and to share results of the increasing numbers of permafrost investigations and discoveries currently taking place, the Tenth International Conference on Permafrost (TICOP) was held in late June in Salekhard, a town in the Yamal-Nenets autonomous district of Russia that is situated precisely on the Arctic Circle and underlain by discontinuous permafrost. TICOP marked the tenth iteration of the long-running conference series, which started in 1963, and is the conference's first return to Russia since the Second International Conference on Permafrost in 1973.

  20. Permafrost Degradation Risk Zone Assessment using Simulation Models

    DEFF Research Database (Denmark)

    Daanen, R.P.; Ingeman-Nielsen, Thomas; Marchenko, S.;

    2011-01-01

    In this proof-of-concept study we focus on linking large scale climate and permafrost simulations to small scale engineering projects by bridging the gap between climate and permafrost sciences on the one hand and on the other technical recommendation for adaptation of planned infrastructures...... to climate change in a region generally underlain by permafrost. We present the current and future state of permafrost in Greenland as modelled numerically with the GIPL model driven by HIRHAM climate projections up to 2080. We develop a concept called Permafrost Thaw Potential (PTP), defined...... as the potential active layer increase due to climate warming and surface alterations. PTP is then used in a simple risk assessment procedure useful for engineering applications. The modelling shows that climate warming will result in continuing wide-spread permafrost warming and degradation in Greenland...

  1. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Kristopher D [University of Alaska, Fairbanks; Harden, Jennifer [United States Geological Service (USGS), Menlo Park; McGuire, A. David [University of Alaska; Clark, Mark [United Stated Department of Agriculture (USDA), Natural Resources Conservation Service; Yuan, Fengming [ORNL; Finley, Andrew [Michigan State University, East Lansing

    2013-01-01

    Permafrost is tightly coupled to the organic layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence (PF) and organic layer thickness (OLT) in more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between PF, OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow v. deep organic layers. Permafrost probability sharply increased by 0.32 for every 10-cm OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. As temperature warmed, sandy soils varied little in PF or OLT, but PF in loamy and sandy soils decreased substantially. The change in OLT was more heterogeneous across soil types in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened as temperature warmed. Furthermore, the rate of thickening with warming for OLTd soils was on average almost 4 times greater than the rate of thinning for OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance.

  2. Spatial modeling of permafrost distribution using rock glacier inventories, topographic attributes and temperature data in the semiarid Andes, Chile

    Science.gov (United States)

    Azocar Sandoval, G.; Brenning, A.; Bodin, X.

    2012-12-01

    Statistical-empirical models have been widely used to estimate the spatial distribution of permafrost in the European Alps and North America using topographic, climatic data and geomorphic indicators of permafrost (i.e. rock glaciers). At present, little knowledge about mountain permafrost distribution is available for the Andes. As a first approximation of permafrost distribution, a logistic regression model was fitted to predict rock glacier activity status. The model is based on explanatory variables elevation and potential incoming solar radiation (PISR) derived from an ASTER G-DEM v. 2 digital elevations model and air temperature data in the Chilean Andes between 29 and 34°S. Rock glacier activity status (intact versus fossil) was obtained from several recent rock glacier inventories and is based on the interpretation of aerial photographs or satellite imagery with a resolution higher than 5 m. Constant lapse rates of temperature are obtained for several weather stations in the study region. These are used to estimate the change in temperature with elevation based on the digital elevation model. The model's predictive performance was evaluated using the area under the ROC curve. As a preliminary result using a probability threshold of 0.5, mountain permafrost may be present in up to 21% (1510 km2) of the Huasco watershed (29°S) located in the northern part of the study area. Considering a threshold > 0.75, about 12% (709 km2) of this watershed may be underlain by mountain permafrost. As next steps toward a permafrost distribution model, sources of bias related to the thermal offset and displacement of rock glaciers will be eliminated, and downscaling as well as spatial interpolation approaches will be evaluated in order to replace elevation as a proxy variable with estimates of mean annual air temperature.

  3. 多年冻土地区建筑物地基的热稳定性技术%Technique for Thermal Stabilization of Soils at Bases of Structures in Permafrost Regions

    Institute of Scientific and Technical Information of China (English)

    Refik M. Bayasan; Anatoly G. Korotchenko; Anatoly D. Lobanov; Grigory P. Pustovoit

    2004-01-01

    Thermal stabilization of soils (including freezing of thawed soils and cooling of permafrost) is known to be the effective method providing stable support for buildings and structures in cold regions.Seasonal thermo-stabilizers (STS) are mainly used in construction. The predicted climate warming because of natural and man-caused factors determines wide application of STS in permafrost regions. A STS transfers heat from its underground part (evaporator) to the aerial part (condenser) owing to natural temperature difference between them during a cold season. We have been working out and manufacturing different types of two-phase, vapor-liquid STS. Aluminum alloys are used in our STS to prevent corrosion and to increase their efficiency. They are successfully used in the northern regions of Western Siberia, in particular, at the railway Obskaya Bovanenkovo. The paper presents some technical parameters of new STS, the results of their experimental study and computer simulation, as well as experience features.

  4. Massive remobilization of permafrost carbon during post-glacial warming

    Science.gov (United States)

    Tesi, T.; Muschitiello, F.; Smittenberg, R. H.; Jakobsson, M.; Vonk, J. E.; Hill, P.; Andersson, A.; Kirchner, N.; Noormets, R.; Dudarev, O.; Semiletov, I.; Gustafsson, Ö.

    2016-11-01

    Recent hypotheses, based on atmospheric records and models, suggest that permafrost carbon (PF-C) accumulated during the last glaciation may have been an important source for the atmospheric CO2 rise during post-glacial warming. However, direct physical indications for such PF-C release have so far been absent. Here we use the Laptev Sea (Arctic Ocean) as an archive to investigate PF-C destabilization during the last glacial-interglacial period. Our results show evidence for massive supply of PF-C from Siberian soils as a result of severe active layer deepening in response to the warming. Thawing of PF-C must also have brought about an enhanced organic matter respiration and, thus, these findings suggest that PF-C may indeed have been an important source of CO2 across the extensive permafrost domain. The results challenge current paradigms on the post-glacial CO2 rise and, at the same time, serve as a harbinger for possible consequences of the present-day warming of PF-C soils.

  5. Movement of trichloroethene in a discontinuous permafrost zone.

    Science.gov (United States)

    Carlson, Andrea E; Barnes, David L

    2011-06-01

    At a site with discontinuous permafrost in Fairbanks, Alaska, releases of trichloroethene (TCE), an industrial solvent, have caused contamination of the groundwater. The objective of this study was to investigate the relationship between the migration pathway of the TCE groundwater plume and the distribution of the discontinuous permafrost at the site. The TCE plume configuration is substantially different than what regional hydrology trends would predict. Using GIS, we conducted a geostatistical analysis of field data collected during soil-boring installations and groundwater monitoring well sampling. With the analysis results, we constructed maps of the permafrost-table elevation (top of permafrost) and of the groundwater gradients and TCE concentrations from multiyear groundwater sampling events. The plume concentrations and groundwater gradients were overlain on the permafrost map to correlate permafrost locations with groundwater movement and the spatial distribution of TCE moving with groundwater. Correlation of the overlay maps revealed converging and diverging groundwater flow in response to the permafrost-table distribution, the absence of groundwater contamination in areas with a high permafrost-table elevation, and channeling of contaminants and water between areas of permafrost. In addition, we measured groundwater elevations in nested wells to quantify vertical gradients affecting TCE migration. At one set of nested wells down gradient from an area of permafrost we measured an upward vertical gradient indicating recharge of groundwater from the subpermafrost region of the aquifer causing dilution of the plume. The study indicates that the variable distribution of the permafrost is affecting the way groundwater and TCE move through the aquifer. Consequently, changes to the permafrost configuration due to thawing would likely affect both groundwater movement and TCE migration, and areas that were contaminant-free may become susceptible to contamination.

  6. Extended LTA, TNF, LST1 and HLA gene haplotypes and their association with rubella vaccine-induced immunity.

    Directory of Open Access Journals (Sweden)

    Inna G Ovsyannikova

    Full Text Available BACKGROUND: Recent studies have suggested the importance of HLA genes in determining immune responses following rubella vaccine. The telomeric class III region of the HLA complex harbors several genes, including lymphotoxin alpha (LTA, tumor necrosis factor (TNF and leukocyte specific transcript -1 (LST1 genes, located between the class I B and class II DRB1 loci. Apart from HLA, little is known about the effect of this extended genetic region on HLA haplotypic backgrounds as applied to immune responses. METHODOLOGY/PRINCIPAL FINDINGS: We examined the association between immune responses and extended class I-class II-class III haplotypes among 714 healthy children after two doses of rubella vaccination. These extended haplotypes were then compared to the HLA-only haplotypes. The most significant association was observed between haplotypes extending across the HLA class I region, ten-SNP haplotypes, and the HLA class II region (i.e. A-C-B-LTA-TNF-LST1-DRB1-DQA1-DQB1-DPA1-DPB1 and rubella-specific antibodies (global p-value of 0.03. Associations were found between both extended A*02-C*03-B*15-AAAACGGGGC-DRB1*04-DQA1*03-DQB1*03-DPA1*01-DPB1*04 (p = 0.002 and HLA-only A*02-C*03-B*15-DRB1*04-DQA1*03-DQB1*03-DPA1*01-DPB1*04 haplotypes (p = 0.009 and higher levels of rubella antibodies. The class II HLA-only haplotype DRB1*13-DQA1*01-DQB1*06-DPA1*01-DPB1*04 (p = 0.04 lacking LTA-TNF-LST1 SNPs was associated with lower rubella antibody responses. Similarly, the class I-class II HLA-only A*01-C*07-B*08-DRB1*03-DQA1*05-DQB1*02-DPA1*01-DPB1*04 haplotype was associated with increased TNF-alpha secretion levels (p = 0.009. In contrast, the extended AAAACGGGGC-DRB1*01-DQA1*01-DQB1*05-DPA1*01-DPB1*04 (p = 0.01 haplotype was found to trend with decreased rubella-specific IL-6 secretion levels. CONCLUSIONS/SIGNIFICANCE: These data suggest the importance of examining both HLA genes and genes in the class III region as part of the extended haplotypes useful in

  7. Permafrost in the Himalayas: specific characteristics, evolution vs. climate change and impacts on potential natural hazards

    Science.gov (United States)

    Fort, Monique

    2015-04-01

    Mountain environments are very sensitive to climate change, yet assessing the potential impacts of these changes is not easy because of the complexity and diversity of mountain systems. The Himalayan permafrost belt presents three main specificities: (1) it develops in a geodynamically active mountain, which means that the controlling factors are not only temperature but also seismo-tectonic activity; (2) due to the steepness of the southern flank of the Greater Himalaya and potential large scale rock failures, permafrost evidence manifests itself best in the inner valleys and on the northern, arid side of the Himalayas (elevations >4000m); (3) the east-west strike of the mountain range creates large spatial discontinuity in the "cold" belt, mostly related to precipitation nature and availability. Only limited studies have been carried to date, and there is no permanent "field laboratory", nor continuous records but a few local studies. Based on preliminary observations in the Nepal Himalayas (mostly in Mustang and Dolpo districts), and Indian Ladakh, we present the main features indicating the existence of permafrost (either continuous or discontinuous). Rock-glaciers are quite well represented, though their presence may be interpreted as a combined result from both ground ice and large rock collapse. The precise altitudinal zonation of permafrost belt (specifying potential permafrost, probable permafrost, observed permafrost belts) still requires careful investigations in selected areas. Several questions arise when considering the evolution of permafrost in a context of climate change, with its impacts on the development of potential natural hazards that may affect the mountain population. Firstly, permafrost degradation (ground ice melting) is a cause of mountain slope destabilization. When the steep catchments are developed in frost/water sensitive bedrock (shales and marls) and extend to high elevations (as observed in Mustang or Dolpo), it would supply more

  8. A central database for the Global Terrestrial Network for Permafrost (GTN-P)

    Science.gov (United States)

    Elger, Kirsten; Lanckman, Jean-Pierre; Lantuit, Hugues; Karlsson, Ævar Karl; Johannsson, Halldór

    2013-04-01

    used by as many researchers as intended by the initiators of these global programs. The European Union project PAGE21 created opportunities to develop this central database for GTN-P data during the duration of the project and beyond. The database aims to be the one location where the researcher can find data, metadata and information of all relevant parameters for a specific site. Each component of the Data Management System (DMS), including parameters, data levels and metadata formats were developed in cooperation with GTN-P and the IPA. The general framework of the GTN-P DMS is based on an object-oriented model (OOM) and implemented into a spatial database. To ensure interoperability and enable potential inter-database search, field names are following international metadata standards. The outputs of the DMS will be tailored to the needs of the modeling community but also to the ones of other stakeholders. In particular, new products will be developed in partnership with the IPA and other relevant international organizations to raise awareness on permafrost in the policy-making arena. The DMS will be released to a broader public in May 2013 and we expect to have the first active data upload - via an online interface - after 2013's summer field season.

  9. The presence of rapidly degrading permafrost plateaus in southcentral Alaska

    Science.gov (United States)

    Jones, Benjamin M.; Baughman, Carson; Romanovsky, V.adimir E; Parsekian, Andrew D.; Babcock, Esther; Jones, Miriam C.; Grosse, Guido; Berg, Edward E

    2016-01-01

    Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0°C. In this study, we document the presence of residual permafrost plateaus on the western Kenai Peninsula lowlands of southcentral Alaska, a region with a MAAT of 1.5 ± 1°C (1981 to 2010). Continuous ground temperature measurements between 16 September 2012 and 15 September 2015, using calibrated thermistor strings, documented the presence of warm permafrost (−0.04 to −0.08°C). Field measurements (probing) on several plateau features during the fall of 2015 showed that the depth to the permafrost table averaged 1.48 m but was as shallow as 0.53 m. Late winter surveys (drilling, coring, and GPR) in 2016 showed that the average seasonally frozen ground thickness was 0.45 m, overlying a talik above the permafrost table. Measured permafrost thickness ranged from 0.33 to >6.90 m. Manual interpretation of historic aerial photography acquired in 1950 indicates that residual permafrost plateaus covered 920 ha as mapped across portions of four wetland complexes encompassing 4810 ha. However, between 1950 and ca. 2010, permafrost plateau extent decreased by 60%, with lateral feature degradation accounting for 85% of the reduction in area. Permafrost loss on the Kenai Peninsula is likely associated with a warming climate, wildfires that remove the protective forest and organic layer cover, groundwater flow at depth, and lateral heat transfer from wetland surface waters in the summer. Better understanding the resilience and vulnerability of ecosystem-protected permafrost is critical for mapping and predicting future permafrost extent and degradation across all permafrost regions that are currently warming. Further work should focus on reconstructing permafrost history in

  10. Permafrost thaw in a nested groundwater-flow system

    Science.gov (United States)

    McKenzie, Jeffery M.; Voss, Clifford I.

    2013-01-01

    Groundwater flow in cold regions containing permafrost accelerates climate-warming-driven thaw and changes thaw patterns. Simulation analyses of groundwater flow and heat transport with freeze/thaw in typical cold-regions terrain with nested flow indicate that early thaw rate is particularly enhanced by flow, the time when adverse environmental impacts of climate-warming-induced permafrost loss may be severest. For the slowest climate-warming rate predicted by the Intergovernmental Panel on Climate Change (IPCC), once significant groundwater flow begins, thick permafrost layers can vanish in several hundred years, but survive over 1,000 years where flow is minimal. Large-scale thaw depends mostly on the balance of heat advection and conduction in the supra-permafrost zone. Surface-water bodies underlain by open taliks allow slow sub-permafrost flow, with lesser influence on regional thaw. Advection dominance over conduction depends on permeability and topography. Groundwater flow around permafrost and flow through permafrost impact thaw differently; the latter enhances early thaw rate. Air-temperature seasonality also increases early thaw. Hydrogeologic heterogeneity and topography strongly affect thaw rates/patterns. Permafrost controls the groundwater/surface-water-geomorphology system; hence, prediction and mitigation of impacts of thaw on ecology, chemical exports and infrastructure require improved hydrogeology/permafrost characterization and understanding

  11. Microbial diversity in European alpine permafrost and active layers.

    Science.gov (United States)

    Frey, Beat; Rime, Thomas; Phillips, Marcia; Stierli, Beat; Hajdas, Irka; Widmer, Franco; Hartmann, Martin

    2016-03-01

    Permafrost represents a largely understudied genetic resource. Thawing of permafrost with global warming will not only promote microbial carbon turnover with direct feedback on greenhouse gases, but also unlock an unknown microbial diversity. Pioneering metagenomic efforts have shed light on the permafrost microbiome in polar regions, but temperate mountain permafrost is largely understudied. We applied a unique experimental design coupled to high-throughput sequencing of ribosomal markers to characterize the microbiota at the long-term alpine permafrost study site 'Muot-da-Barba-Peider' in eastern Switzerland with an approximate radiocarbon age of 12 000 years. Compared to the active layers, the permafrost community was more diverse and enriched with members of the superphylum Patescibacteria (OD1, TM7, GN02 and OP11). These understudied phyla with no cultured representatives proposedly feature small streamlined genomes with reduced metabolic capabilities, adaptations to anaerobic fermentative metabolisms and potential ectosymbiotic lifestyles. The permafrost microbiota was also enriched with yeasts and lichenized fungi known to harbour various structural and functional adaptation mechanisms to survive under extreme sub-zero conditions. These data yield an unprecedented view on microbial life in temperate mountain permafrost, which is increasingly important for understanding the biological dynamics of permafrost in order to anticipate potential ecological trajectories in a warming world.

  12. Gas hydrates and permafrost in continental northern West Siberia; Gashydrate und Permafrost im kontinentalen noerdlichen Westsibirien

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, B. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Braun, A.; Poelchau, H.S. [Forschungszentrum Juelich (Germany). Inst. fuer Erdoel und Organische Geochemie; Littke, R. [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle

    1997-12-31

    The largest natural gas pool in the world is located in northern part of the West Siberian Basin. During the Quaternary this reservoir became overlaid with several hundreds of metres of permafrost. The pressure and temperature conditions prevailing under this permafrost zone have led to the development of gas hydrates. As far as is known today there is no genetic relationship between the formation of the gas pool and the development of gas hydrates. The present contribution deals with these questions in detail. (MSK) [Deutsch] Im Nordteil des westsibirischen Beckens liegt die groesste Erdgaslagerstaette der Erde. Darueber hat sich im Quartaer ein mehrere hundert Meter maechtiger Permafrost gebildet. Die unter der Premafrostzone herrschenden Druck-und Temperaturbedingungen ermoeglichten die Bildung von Gashydraten. Nach heutigen Erkenntnisse besteht kein genetischer Zusammenhang zwischen Lagerstaettenbildung und Gashydraten. Im Folgenden werden Einzelheiten geschildert.

  13. Mutations in the Arabidopsis homolog of LST8/GβL, a partner of the target of Rapamycin kinase, impair plant growth, flowering, and metabolic adaptation to long days.

    Science.gov (United States)

    Moreau, Manon; Azzopardi, Marianne; Clément, Gilles; Dobrenel, Thomas; Marchive, Chloé; Renne, Charlotte; Martin-Magniette, Marie-Laure; Taconnat, Ludivine; Renou, Jean-Pierre; Robaglia, Christophe; Meyer, Christian

    2012-02-01

    The conserved Target of Rapamycin (TOR) kinase forms high molecular mass complexes and is a major regulator of cellular adaptations to environmental cues. The Lethal with Sec Thirteen 8/G protein β subunit-like (LST8/GβL) protein is a member of the TOR complexes, and two putative LST8 genes are present in Arabidopsis thaliana, of which only one (LST8-1) is significantly expressed. The Arabidopsis LST8-1 protein is able to complement yeast lst8 mutations and interacts with the TOR kinase. Mutations in the LST8-1 gene resulted in reduced vegetative growth and apical dominance with abnormal development of flowers. Mutant plants were also highly sensitive to long days and accumulated, like TOR RNA interference lines, higher amounts of starch and amino acids, including proline and glutamine, while showing reduced concentrations of inositol and raffinose. Accordingly, transcriptomic and enzymatic analyses revealed a higher expression of genes involved in nitrate assimilation when lst8-1 mutants were shifted to long days. The transcriptome of lst8-1 mutants in long days was found to share similarities with that of a myo-inositol 1 phosphate synthase mutant that is also sensitive to the extension of the light period. It thus appears that the LST8-1 protein has an important role in regulating amino acid accumulation and the synthesis of myo-inositol and raffinose during plant adaptation to long days.

  14. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    Science.gov (United States)

    Johnson, Kristofer D.; Harden, Jennifer W.; McGuire, A. David; Clark, Mark; Yuan, Fengming; Finley, Andrew O.

    2013-01-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow (<28 cm) versus deep organic (≥28 cm) layers. The probability of observing permafrost sharply increased by 0.32 for every 10-cm OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. Across the MAT gradient, PF in sandy soils varied little, but PF in loamy and silty soils decreased substantially from cooler to warmer temperatures. The change in OLT was more heterogeneous across soil texture types—in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened at warmer locations. Furthermore, when soil organic carbon was estimated using a relationship with thickness, the average increase in carbon in OLTd soils was almost four times greater compared to the average decrease in carbon in OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance.

  15. Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate

    Science.gov (United States)

    Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido; Bondurant, Allen C.; Romanovksy, Vladimir E.; Hinkel, Kenneth M.; Parsekian, Andrew D.

    2016-01-01

    Interactions and feedbacks between abundant surface waters and permafrost fundamentally shape lowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceeds lake depth and mean annual bed temperatures (MABTs) remain below freezing. However, declining MIT since the 1970s is likely causing talik development below shallow lakes. Here we show high-temperature sensitivity to winter ice growth at the water-sediment interface of shallow lakes based on year-round lake sensor data. Empirical model experiments suggest that shallow (1 m depth) lakes have warmed substantially over the last 30 years (2.4°C), with MABT above freezing 5 of the last 7 years. This is in comparison to slower rates of warming in deeper (3 m) lakes (0.9°C), with already well-developed taliks. Our findings indicate that permafrost below shallow lakes has already begun crossing a critical thawing threshold approximately 70 years prior to predicted terrestrial permafrost thaw in northern Alaska.

  16. Low soil organic carbon storage in a subarctic alpine permafrost environment

    Directory of Open Access Journals (Sweden)

    M. Fuchs

    2014-07-01

    Full Text Available This study investigates the soil organic carbon (SOC storage in Tarfala Valley, Northern Sweden. Field inventories upscaled based on land cover show that this alpine permafrost environment does not store large amounts of SOC, with an estimate mean of 0.9 ± 0.2 kg C m−2 for the upper meter of soil. This is one to two orders of magnitude lower than what has been reported for lowland permafrost terrain. The SOC storage varies for different land cover classes and ranges from 0.05 kg C m−2 for stone-dominated to 8.4 kg C m−2 for grass-dominated areas. No signs of organic matter burial through cryoturbation or slope processes were found and radiocarbon dated SOC is generally of recent origin (−2. Under future climate warming an upward shift of vegetation zones may lead to a net ecosystem C uptake from increased biomass and soil development. As a consequence, alpine permafrost environments could act as a net carbon sink in the future, as there is no loss of older or deeper SOC from thawing permafrost.

  17. Climate hazards caused by thawing permafrost? Background information of the Federal Environmental Agency; Klimagefahr durch tauenden Permafrost? UBA-Hintergrundpapier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-08-15

    The thawing of permafrost regions is supposed to increase climatic change processes due to the released methane. During the last decades the temperature of permafrost soils has increased by several tenths of degree up to 2 deg C. It is supposed that 10 to 20% of the permafrost regions will thaw during the next 100 years. The southern boundary of the permafrost region will move several hundred kilometers toward the north. Besides the increased risk for the climate system there will also be disadvantageous consequences for the ecosystems. Negative economic consequences are already observed and will be enhanced in the futures with significant cost for the public.

  18. Beaded streams of Arctic permafrost landscapes

    Directory of Open Access Journals (Sweden)

    C. D. Arp

    2014-07-01

    Full Text Available Beaded streams are widespread in permafrost regions and are considered a common thermokarst landform. However, little is known about their distribution, how and under what conditions they form, and how their intriguing morphology translates to ecosystem functions and habitat. Here we report on a Circum-Arctic inventory of beaded streams and a watershed-scale analysis in northern Alaska using remote sensing and field studies. We mapped over 400 channel networks with beaded morphology throughout the continuous permafrost zone of northern Alaska, Canada, and Russia and found the highest abundance associated with medium- to high-ice content permafrost in moderately sloping terrain. In the Fish Creek watershed, beaded streams accounted for half of the drainage density, occurring primarily as low-order channels initiating from lakes and drained lake basins. Beaded streams predictably transition to alluvial channels with increasing drainage area and decreasing channel slope, although this transition is modified by local controls on water and sediment delivery. Comparison of one beaded channel using repeat photography between 1948 and 2013 indicate relatively stable form and 14C dating of basal sediments suggest channel formation may be as early as the Pleistocene–Holocene transition. Contemporary processes, such as deep snow accumulation in stream gulches effectively insulates river ice and allows for perennial liquid water below most beaded stream pools. Because of this, mean annual temperatures in pool beds are greater than 2 °C, leading to the development of perennial thaw bulbs or taliks underlying these thermokarst features. In the summer, some pools stratify thermally, which reduces permafrost thaw and maintains coldwater habitats. Snowmelt generated peak-flows decrease rapidly by two or more orders of magnitude to summer low flows with slow reach-scale velocity distributions ranging from 0.1 to 0.01 m s−1, yet channel runs still move water

  19. Trace element transport in western Siberian rivers across a permafrost gradient

    Science.gov (United States)

    Pokrovsky, Oleg S.; Manasypov, Rinat M.; Loiko, Sergey V.; Krickov, Ivan A.; Kopysov, Sergey G.; Kolesnichenko, Larisa G.; Vorobyev, Sergey N.; Kirpotin, Sergey N.

    2016-03-01

    Towards a better understanding of trace element (TE) transport in permafrost-affected Earth surface environments, we sampled ˜ 60 large and small rivers ( bogs > forest. The lakes decreased export of Mn and Co in summer and Ni, Cu, and Rb in spring, presumably due to biotic processes. The lakes enriched the rivers in insoluble lithogenic elements in summer and winter, likely due to TE mobilization from unfrozen mineral sediments. The rank of environmental factors on TE concentration in western Siberian rivers was latitude (three permafrost zones) > season > watershed size. The effect of the latitude was minimal in spring for most TEs but highly visible for Sr, Mo, Sb and U. The main factors controlling the shift of river feeding from surface and subsurface flow to deep underground flow in the permafrost-bearing zone were the depth of the active (unfrozen) seasonal layer and its position in organic or mineral horizons of the soil profile. In the permafrost-free zone, the relative role of carbonate mineral-bearing base rock feeding versus bog water feeding determined the pattern of TE concentration and fluxes in rivers of various sizes as a function of season. Comparison of obtained TE fluxes in WSL rivers with those of other subarctic rivers demonstrated reasonable agreement for most TEs; the lithology of base rocks was the major factor controlling the magnitude of TE fluxes. Climate change in western Siberia and permafrost boundary migration will essentially affect the elements controlled by underground water feeding (DIC, alkaline earth elements (Ca, Sr), oxyanions (Mo, Sb, As) and U). The thickening of the active layer may increase the export of trivalent and tetravalent hydrolysates in the form of organo-ferric colloids. Plant litter-originated divalent metals present as organic complexes may be retained via adsorption on mineral horizon. However, due to various counterbalanced processes controlling element source and sinks in plant-peat-mineral soil

  20. Soil data from fire and permafrost-thaw chronosequences in upland Picea mariana stands near Hess Creek and Tok, interior Alaska

    Science.gov (United States)

    O'Donnell, Jonathan A.; Harden, Jennifer W.; Manies, Kristen L.; Jorgenson, M. Torre; Kanevskiy, Mikhail; Xu, Xiaomei

    2013-01-01

    Soils of the Northern Circumpolar Permafrost region harbor 1,672 petagrams (Pg) (1 Pg = 1,000,000,000 kilograms) of organic carbon (OC), nearly 50 percent of the global belowground OC pool (Tarnocai and others, 2009). Of that soil OC, nearly 88 percent is presently stored in perennially frozen ground. Recent climate warming at northern latitudes has resulted in warming and thawing of permafrost in many regions (Osterkamp, 2007), which might mobilize OC stocks from associated soil reservoirs via decomposition, leaching, or erosion. Warming also has increased the magnitude and severity of wildfires in the boreal region (Turetsky and others, 2011), which might exacerbate rates of permafrost degradation relative to warming alone. Given the size and vulnerability of the soil OC pool in permafrost soils, permafrost thaw will likely function as a strong positive feedback to the climate system (Koven and others, 2011; Schaefer and others, 2011). In this report, we report soil OC inventories from two upland fire chronosequences located near Hess Creek and Tok in Interior Alaska. We sampled organic and mineral soils in the top 2 meters (m) across a range of stand ages to evaluate the effects of wildfire and permafrost thaw on soil C dynamics. These data were used to parameterize a simple process-based fire-permafrost-carbon model, which is described in detail by O’Donnell and others (2011a, b). Model simulations examine long-term changes in soil OC storage in response to fire, permafrost thaw, and climate change. These data also have been used in other papers, including Harden and others (2012), which examines C recovery post-fire, and Johnson and others (2011), which synthesizes data within the Alaska Soil Carbon Database. Findings from these studies highlight the importance of climate and disturbance (wildfire, permafrost thaw) on soil C storage, and loss of soil C from high-latitude ecosystems.

  1. Trace elements transport in western Siberia rivers across a permafrost gradient

    Science.gov (United States)

    Pokrovsky, O. S.; Manasypov, R. M.; Loiko, S.; Krickov, I. A.; Kopysov, S. G.; Kolesnichenko, L. G.; Vorobyev, S. N.; Kirpotin, S. N.

    2015-11-01

    Towards a better understanding of trace element transport in permafrost-affected Earth surface environments, we sampled ∼ 60 large and small rivers (organo-mineral colloids, as also confirmed by previous studies in Siberian rivers. The 2nd factor (8-14 % variation) was linked to the latitude of the watershed and acted on elements affected by the groundwater feeding (DIC, Sr, Mo, As, Sb, U), whose concentration decreased significantly northward during all seasons. Overall, the rank of environmental factors on TE concentration in western Siberian rivers was latitude (3 permafrost zones) > season > watershed size. The effect of the latitude was minimal in spring for most TE but highly visible for Sr, Mo, Sb and U. The main factors controlling the shift of river feeding from surface and subsurface flow to deep underground flow in the permafrost-bearing zone were the depth of the active (unfrozen) seasonal layer and its position in organic or mineral horizons of the soil profile. In the permafrost-free zone, the relative role of carbonate mineral-bearing base rock feeding vs. bog water feeding determined the pattern of trace element concentration and fluxes in rivers of various size as a function of season. Comparison of obtained TE fluxes in WSL rivers with those of other subarctic rivers demonstrated reasonable agreement for most trace elements; the lithology of base rocks was the major factor controlling the magnitude of TE fluxes. The climate change in western Siberia and permafrost boundary migration will affect essentially the elements controlled by underground water feeding (DIC, alkaline-earth elements (Ca, Sr), oxyanions (Mo, Sb, As) and U). The thickening of the active layer may increase the export of trivalent and tetravalent hydrolysates in the form of organo-ferric colloids. Plant litter-originated divalent metals present as organic complexes may be retained via adsorption on mineral horizon. However, due to various counterbalanced processes controlling

  2. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the

  3. Characteristics of Ground Surface Temperatures as in situ Observed in Elevational Permafrost on the Northeastern Qinghai-Tibet Plateau

    Science.gov (United States)

    Luo, D.; Jin, H.; Marchenko, S. S.; Romanovsky, V. E.

    2016-12-01

    Elevational permafrost is primarily distributed on the Qinghai-Tibet Plateau (QTP) at mid-latitudes, where the average elevation is higher than 4,000 m a.s.l. The topography, including the elevation and aspect, obviously is the decisive controlling factor of thermal regimes of elevational permafrost, which is warm and extremely sensitive to anthropogenic activities and climate changes. Due to the harsh weather conditions and unfavorable logistics accommodations, however, the elevational permafrost on the QTP, especially in the rugged topography, is hard to be plotted through ground-based field investigations. The exact distribution of elevational permafrost could be simulated through GST. In this study, we set up three monitoring sites of GST at the beginning of 2015. One located in the rugged mountain of the source area of the Yellow River, one located in the sunny slope of the Bayan Har Mountain Pass, and one another located in a degrading alpine meadow of the source area of the Yangtze River. Based on these GST records, the daily, monthly, seasonal and year-average values of GST, freezing and thawing indices calculated from GST, and empirical Stefan Equation to calculate the ALT, as well as the GIPL-2.0 model to simulate the freezing and thawing processes of the active layer were integrative executed for these three sites. Results demonstrate that GST could be a much more reliable driving parameter to simulate the active layer and permafrost than the air temperature and land surface temperature.

  4. Landform-related permafrost characteristics in the source area of the Yellow River, eastern Qinghai-Tibet Plateau

    Science.gov (United States)

    Li, Jing; Sheng, Yu; Wu, Jichun; Feng, Ziliang; Ning, Zuojun; Hu, Xiaoying; Zhang, Xiumin

    2016-09-01

    The source area of the Yellow River (SAYR) lies in the eastern part of the Qinghai-Tibet Plateau (QTP). Glaciers are absent in the area, but permafrost is widespread because of the high elevations, typically 4200-5000 m a.s.l. Landforms in the SAYR were classified into seven basic types, based on their morphological characteristics and genesis, and further divided into 12 sub-classes based on geomorphic processes. Permafrost development and ground temperature in boreholes were analyzed on representative landforms in the SAYR. Permafrost was discontinuously distributed at 4300-4400 m a.s.l. in fluvial plains because of variations in local topography, sediments, vegetation and water content. In hills and low-relief mountains in the western part of the study area, permafrost is continuous above 4400 m a.s.l. even on unshaded south-facing slopes. In contrast, permafrost in the central part of the study area is discontinuous over this elevation range. Analysis of ground temperature measurements revealed that three macro-scale factors, latitude, longitude, and elevation, explain 72.8% of the variation in the measured mean annual ground temperature (MAGT). The remaining 27.2% can potentially be explained by variations in topography and land cover within the SAYR.

  5. A fully coupled transient thermomechanical ice-flow/permafrost model of the Rhine Glacier, Switzerland: effects of permafrost on basal conditions

    Science.gov (United States)

    Cohen, D.; Zwinger, T.; Haeberli, W.; Fischer, U. H.

    2016-12-01

    The safe disposal of radioactive wastes in deep geological repositories requires their containment and isolation for up to one million years. Over that time period, the performance of the repositories in mid- and high-latitude regions can be impacted by future ice-age conditions which may cause deep glacial erosion, permafrost development, and changes in groundwater fluxes. In Switzerland, repositories are planned in the northern Swiss lowlands near the marginal zone of the former Rhine Glacier that repeatedly formed two extensive piedmont lobes (the Rhine and Linth lobes) over the Swiss Plateau. There, overdeepenings formed by glacial erosion indicate that the glacier was warm-based. Yet the Last Glacial Maximum (LGM) occurred under cold conditions: central Europe experienced extremely cold and dry conditions caused by the penetration of winter sea ice to low latitudes in the Atlantic Ocean and the corresponding closure of the primary humidity source north of the Alps. At the LGM, flat and extended lobes of large piedmont glaciers spreading out over much of the Swiss Plateau were polythermal, characterized by low driving stresses (typically around 30 kPa) and surrounded by continuous periglacial permafrost up to 150 m thick. Subsurface temperatures and groundwater flow conditions were strongly influenced by the presence of extended surface and subsurface ice. Using numerical models we explore the effects of permafrost on basal conditions of the piedmont lobes during the build-up of the Rhine Glacier. We apply a two-dimensional transient fully coupled thermomechanical full stress ice-flow and permafrost model along a flowline characterizing the Rhine lobe. The energy equation is solved in both ice and rock and permafrost is modeled using an effective heat capacity formulation to account for phase transitions. Transient effects during ice advances and permafrost build-up up to the LGM are resolved by modeling the full glacial cycle using reconstructed temperature

  6. Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset

    Directory of Open Access Journals (Sweden)

    E. E. Jafarov

    2012-01-01

    Full Text Available Climate projections for the 21st century indicate that there could be a pronounced warming and permafrost degradation in the Arctic and sub-Arctic regions. Climate warming is likely to cause permafrost thawing with subsequent effects on surface albedo, hydrology, soil organic matter storage and greenhouse gas emissions. To assess possible changes in the permafrost thermal state and active layer thickness, we implemented the GIPL2-MPI transient numerical model for the entire Alaska permafrost domain. Input parameters to the model are spatial datasets of mean monthly air temperature and precipitation, prescribed thermal properties of the multilayered soil column, and water content which are specific for each soil class and geographical location. As a climate forcing we used the composite of five IPCC Global Circulation Models that has been downscaled to 2 by 2 km spatial resolution by Scenarios Network for Alaska Planning (SNAP group.

    In this paper we present the preliminary modeling results based on input of five-model composite with A1B carbon emission scenario. The model has been calibrated according to the annual borehole temperature measurements for the State of Alaska. We also performed more detailed calibration for fifteen shallow borehole stations where high quality data are available on daily basis. To validate the model performance we compared simulated active layer thicknesses with observed data from CALM active layer monitoring stations. Calibrated model was used to address possible ground temperature changes for the 21st century. The model simulation results show the widespread permafrost degradation in Alaska could begin in 2040–2099 time frame within the vast area southward from the Brooks Range except for the high altitudes of the Alaska Range and Wrangell Mountains.

  7. Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset

    Directory of Open Access Journals (Sweden)

    E. E. Jafarov

    2012-06-01

    Full Text Available Climate projections for the 21st century indicate that there could be a pronounced warming and permafrost degradation in the Arctic and sub-Arctic regions. Climate warming is likely to cause permafrost thawing with subsequent effects on surface albedo, hydrology, soil organic matter storage and greenhouse gas emissions.

    To assess possible changes in the permafrost thermal state and active layer thickness, we implemented the GIPL2-MPI transient numerical model for the entire Alaska permafrost domain. The model input parameters are spatial datasets of mean monthly air temperature and precipitation, prescribed thermal properties of the multilayered soil column, and water content that are specific for each soil class and geographical location. As a climate forcing, we used the composite of five IPCC Global Circulation Models that has been downscaled to 2 by 2 km spatial resolution by Scenarios Network for Alaska Planning (SNAP group.

    In this paper, we present the modeling results based on input of a five-model composite with A1B carbon emission scenario. The model has been calibrated according to the annual borehole temperature measurements for the State of Alaska. We also performed more detailed calibration for fifteen shallow borehole stations where high quality data are available on daily basis. To validate the model performance, we compared simulated active layer thicknesses with observed data from Circumpolar Active Layer Monitoring (CALM stations. The calibrated model was used to address possible ground temperature changes for the 21st century. The model simulation results show widespread permafrost degradation in Alaska could begin between 2040–2099 within the vast area southward from the Brooks Range, except for the high altitude regions of the Alaska Range and Wrangell Mountains.

  8. The Frozen Ground Data Center: A Continuing Task for the International Permafrost Community

    Science.gov (United States)

    Parsons, M. A.; Zhang, T.; Barry, R. G.; Brown, J.

    2001-12-01

    Permafrost and seasonally frozen ground underlie about 24% and 60% of the surface of the Northern Hemisphere respectively. Data and information on frozen ground collected over many decades and in the future are critical for fundamental process understanding, environmental change detection, impact assessment, model validation, and engineering applications. However, many of these data sets and information remain widely dispersed and relatively unavailable to the science and engineering community, and some are in danger of being lost permanently. The International Permafrost Association (IPA) has long recognized the inherent and lasting value of data and information, and has developed a strategy for data and information management to meet the requirements of the cold regions science, engineering, and modeling community. NSIDC has played an active role in implementing this strategy by developing and distributing the first Circumpolar Active-Layer Permafrost System (CAPS) CD-ROM including the Global Geocryological Database (GGD). Now, NSIDC, in collaboration with the International Arctic Research Center (IARC), seeks to expand the CAPS data holdings, update the GGD, and improve frozen ground data access and utility through a new web-based "Frozen Ground Data Center." NSIDC plans to reformat several existing data sets and create value-added products such as gridded fields for model validation and analysis. We also plan to acquire and distribute certain key data sets, including data from: (1) the Global Terrestrial Network for Permafrost (GTN-P) and its Borehole and updated Circumpolar Active Layer Monitoring (CALM) components (Burgess et al 2000), (2) the Arctic Coastal Dynamics project, (3) the Cryosol database and maps, and (4) various permafrost maps and soil temperature time series for Russia and China. NSIDC seeks the help of the frozen ground research community through data contributions and suggestions on data acquisition, management and distribution. The IPA

  9. Controls on ecosystem and root respiration across a permafrost and wetland gradient in interior Alaska

    Science.gov (United States)

    McConnell, Nicole A.; Turetsky, Merritt R.; McGuire, A. David; Kane, Evan S.; Waldrop, Mark P.; Harden, Jennifer W.

    2013-01-01

    Permafrost is common to many northern wetlands given the insulation of thick organic soil layers, although soil saturation in wetlands can lead to warmer soils and increased thaw depth. We analyzed five years of soil CO2 fluxes along a wetland gradient that varied in permafrost and soil moisture conditions. We predicted that communities with permafrost would have reduced ecosystem respiration (ER) but greater temperature sensitivity than communities without permafrost. These predictions were partially supported. The colder communities underlain by shallow permafrost had lower ecosystem respiration (ER) than communities with greater active layer thickness. However, the apparent Q10 of monthly averaged ER was similar in most of the vegetation communities except the rich fen, which had smaller Q10 values. Across the gradient there was a negative relationship between water table position and apparent Q10, showing that ER was more temperature sensitive under drier soil conditions. We explored whether root respiration could account for differences in ER between two adjacent communities (sedge marsh and rich fen), which corresponded to the highest and lowest ER, respectively. Despite differences in root respiration rates, roots contributed equally (~40%) to ER in both communities. Also, despite similar plant biomass, ER in the rich fen was positively related to root biomass, while ER in the sedge marsh appeared to be related more to vascular green area. Our results suggest that ER across this wetland gradient was temperature-limited, until conditions became so wet that respiration became oxygen-limited and influenced less by temperature. But even in sites with similar hydrology and thaw depth, ER varied significantly likely based on factors such as soil redox status and vegetation composition.

  10. Bacterial community structure in two permafrost wetlands on the Tibetan Plateau and Sanjiang Plain, China.

    Science.gov (United States)

    Yun, Juanli; Ju, Yiwen; Deng, Yongcui; Zhang, Hongxun

    2014-08-01

    Permafrost wetlands are important methane emission sources and fragile ecosystems sensitive to climate change. Presently, there remains a lack of knowledge regarding bacterial communities, especially methanotrophs in vast areas of permafrost on the Tibetan Plateau in Northwest China and the Sanjiang Plain (SJ) in Northeast China. In this study, 16S rRNA-based quantitative PCR (qPCR) and 454 pyrosequencing were used to identify bacterial communities in soils sampled from a littoral wetland of Lake Namco on the Tibetan Plateau (NMC) and an alluvial wetland on the SJ. Additionally, methanotroph-specific primers targeting particulate methane monooxygenase subunit A gene (pmoA) were used for qPCR and pyrosequencing analysis of methanotrophic community structure in NMC soils. qPCR analysis revealed the presence of 10(10) 16S rRNA gene copies per gram of wet soil in both wetlands, with 10(8) pmoA copies per gram of wet soil in NMC. The two permafrost wetlands showed similar bacterial community compositions, which differed from those reported in other cold environments. Proteobacteria, Actinobacteria , and Chloroflexi were the most abundant phyla in both wetlands, whereas Acidobacteria was prevalent in the acidic wetland SJ only. These four phyla constituted more than 80 % of total bacterial community diversity in permafrost wetland soils, and Methylobacter of type I methanotrophs was overwhelmingly dominant in NMC soils. This study is the first major bacterial sequencing effort of permafrost in the NMC and SJ wetlands, which provides fundamental data for further studies of microbial function in extreme ecosystems under climate change scenarios.

  11. Resilience and vulnerability of permafrost to climate change

    Science.gov (United States)

    M.Torre Jorgenson; Vladimir Romanovsky; Jennifer Harden; Yuri Shur; Jonathan O' Donnell; Edward A.G. Schuur; Mikhail Kanevskiy; Sergei. Marchenko

    2010-01-01

    The resilience and vulnerability of permafrost to climate change depends on complex interactions among topography, water, soil, vegetation, and snow, which allow permafrost to persist at mean annual air temperatures (MAATs) as high as +2 °C and degrade at MAATs as low as -20°C. To assess these interactions, we compiled existing data and tested effects of varying...

  12. Soil organic carbon pools in the northern circumpolar permafrost region

    Science.gov (United States)

    C. Tarnocai; J.G. Canadell; E.A.G. Schuur; P. Kuhry; G. Mazhitova; S. Zimov

    2009-01-01

    The Northern Circumpolar Soil Carbon Database was developed to determine carbon pools in soils of the northern circumpolar permafrost region. Here we report a new estimate of the carbon pools in soils of the northern permafrost region, including deeper layers and pools not accounted for in previous analyses.

  13. Different shapes of constructions and their effects on permafrost

    Science.gov (United States)

    Vaganova, Nataliia; Filimonov, M. Yu.

    2016-12-01

    A heat transfer model of thermal fields in permafrost soil as a result of operation of different constructions is considered. Some positions(shapes) of engineering objects are compared in view to estimate its reliability and decrease the thermal influence on permafrost.

  14. Future permafrost conditions along environmental gradients in Zackenberg, Greenland

    DEFF Research Database (Denmark)

    Westermann, S.; Elberling, Bo; Pedersen, S. Højlund;

    2015-01-01

    The future development of ground temperatures in permafrost areas is determined by a number of factors varying on different spatial and temporal scales. For sound projections of impacts of permafrost thaw, scaling procedures are of paramount importance. We present numerical simulations of present...

  15. Report from the International Permafrost Association: carbon pools in permafrost regions

    Science.gov (United States)

    Peter Kuhry; Chien-Lu Ping; Edward A.G. Schuur; Charles Tarnocai; Sergey. Zimov

    2009-01-01

    The IPA Carbon Pools in Permafrost Regions (CAPP) Project started in 2005, with endorsement of the Earth System Science Partnership (EESP) Global Carbon Project and the World Climate Research Programme (WCRP) Climate and Cryosphere Project. CAPP is also a project of the IPY. The project was launched because there is considerable concern and increased awareness both...

  16. Martian and Ionian Analogs of Permafrost-Volcano Interactions in Alaskan Permafrost

    Science.gov (United States)

    Kargel, J. S.; Beget, J. E.; Skinner, J. A.; Wessels, R.

    2005-12-01

    Volcanic landforms in Alaskan lowland permafrost exhibit several unique morphological attributes, as described in a companion AGU abstract (Beget et al.). These features include (1) giant maar sizes (in Bering Land Bridge National Preserve) an order of magnitude larger than common in non-permafrost terrains, (2) composite volcanic forms produced by repeated maar-forming explosions (the novel Ingakslugwat-type volcano in Yukon Delta), and (3) super-inflated lava flows with marginal thermokarst pits (Lost Jim flow, Imuruk Lake Volcanic Field, Bering Land Bridge area). We have identified on Mars, in areas not indicating glaciation, several landforms and on Io an active volcanic process that might be analogs of these in Alaska. On Mars, within and near Elysium (Galaxias Fossae and Hrad Vallis region) multiple crater-like depressions occur with other volcanic features. Their characteristics suggest that the depressions are maars. The composite structures suggest similarities to Ingakslugwat volcanoes. Possible analogs of giant oversize maars also have been identified on Mars. In addition to surface gravitational differences between Earth and Mars, it seems likely that volatile composition is a key aspect controlling the explosivity and sizes of maars on both planets. In Alaska, we suspect that volcanic interactions with methane clathrate hydrate-rich permafrost tends to yield larger maar sizes than with ice-rich permafrost or ground water. This working hypothesis fits well with observations that the giant maars formed during the climatically coldest periods (Beget et al., 2005, this conference). During those periods, permafrost was thick, strong, and unpunctured by lakes and rivers, and so it could have trapped clathrate-forming gases. During interglacials, thinner permafrost and the widespread occurrence of thaw lakes and surface streams may cause the permafrost to be ineffective in confining ascending gases, and so clathrates were absent or not abundant, and volcanic

  17. Permafrost and periglacial research in Antarctica: New results and perspectives

    Science.gov (United States)

    Guglielmin, Mauro; Vieira, Gonçalo

    2014-11-01

    In the last two years the research within the Antarctic Permafrost, Periglacial Environments and Soils (ANTPAS) Expert Group of the Scientific Committee on Antarctic Research (SCAR) and Working Group of the International Permafrost Association (IPA) provided new results on the dynamics of periglacial environments both in Maritime and Continental Antarctica. In continental Antarctica despite the absence of air warming, in the last 15 years an active layer thickening and acceleration of permafrost degradation erosional phenomena were reported, these being mainly related to the increase of solar radiation. On the other hand, in Maritime Antarctica, with a dramatic air warming, permafrost degradation has been observed, but the role of snow cover on the ground energy balance and consequently on permafrost and active layer has been underlined. Moreover, many contributions on the knowledge on the characteristics of the Antarctic soils were carried out in several areas along a wide latitudinal range.

  18. Permafrost: An International Approach to 21th Century Challenges

    Science.gov (United States)

    Brown, J.

    2003-12-01

    Whereas glaciers are easily discernible to the human eye and satellites, permafrost terrains and their physical components are not easily detected from the surface without supplemental knowledge and measurements. In the Northern Hemisphere, approximately 17 million km2 of exposed land contains some extent of permafrost or ground that remains frozen for more than two years. The vast majority, or 11 million km2, of permafrost terrain has temperatures of 5° C or below, with perennially frozen ground underlying essentially all ground surfaces to considerable depths. Permafrost in the remaining regions, including mid-latitude mountains, is both warmer and is spatially variable (discontinuous). As climate warms the uppermost permafrost is subjected to increase thaw with resulting ground subsidence, accelerated erosion, and related biogeochemical modifications. The challenging questions to geocryologists, modelers and the public relate to the rate of change and the spatial variability of the projected thaw, particularly in the warmer zones where actual areal and subareal distribution of permafrost is poorly known. An international network of active layer measurements and borehole sites now exists under the Global Climate Observing System (GCOS), but requires additional sites for representative coverage. This Global Terrestrial Network for Permafrost (GTN-P) is coordinated by the 24-member, International Permafrost Association. At the Eighth International Conference on Permafrost (ICOP) in Zurich in July 2003, the IPA Council agreed on the scope of new activities for the next five years, many of which will be undertaken in cooperation with other international organizations (e.g. WCRP/CliC; ICSI, IASC, SCAR, IGU, IUGS). Examples of the activities of the IPA Working Groups are: 1. Antarctic Permafrost and Periglacial Environments (active layer processes, maps, database). 2. Coastal and Offshore Permafrost (sediment and organic transfers, subsea permafrost dynamics). 3

  19. Modelling unfrozen water content in a silty clay permafrost deposit

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas

    2011-01-01

    The mechanical properties of both unfrozen soils and permafrost soils are influenced by the amount of unfrozen water in the pore space. When dealing with foundation engineering in permafrost areas it is essential to estimate the unfrozen water content (wu). This paper deals with the establishing...... of a calibration equation for determining the unfrozen water content of a Greenlandic silty clay permafrost deposit. Calibration experiments have been conducted for water contents in the interval 0 – 10 % at both 5 °C and 22 °C. Calibration equations are verified against permittivity data from a permafrost core...... of material properties similar to the test soil. The calibration for 5°C is seen to make a good fit to the permafrost core data. Further experiments should be performed in order to extend the range of water contents tested and hence the range of validity of the calibration equation....

  20. Processes of runoff generation operating during the spring and autumn seasons in a permafrost catchment on semi-arid plateaus

    Science.gov (United States)

    Genxu, Wang; Tianxu, Mao; Juan, Chang; Chunlin, Song; Kewei, Huang

    2017-07-01

    There is a lack of knowledge about how to quantify runoff generation and the hydrological processes operating in permafrost catchments on semi-arid plateaus. To understand how freeze-thaw cycles affect runoff generation processes in permafrost catchments, a typical headwater catchment with continuous permafrost on the Tibetan Plateau was measured. A new approach is presented in this study to account for runoff processes on the spring thawing period and autumn freezing period, when runoff generation clearly differs from that of non-permafrost catchments. This approach introduces a soil temperature-based water saturation function and modifies the soil water storage curve with a soil temperature threshold. The results show that surface soil thawing induced saturation excess runoff and subsurface interflow account for approximately 66-86% and 14-34% of total spring runoff, respectively, and the soil temperature significantly affects the runoff generation pattern, the runoff composition and the runoff coefficient with the enlargement of the active layer. The suprapermafrost groundwater discharge decreases exponentially with active layer frozen processes during autumn runoff recession, whereas the ratio of groundwater discharge to total runoff and the direct surface runoff coefficient simultaneously increase. The bidirectional freezing of the active layer controls and changes the autumn runoff processes and runoff composition. The new approach could be used to further develop hydrological models of cold regions dominated by permafrost.

  1. Diversity and Distribution of Archaea Community along a Stratigraphic Permafrost Profile from Qinghai-Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Shiping Wei

    2014-01-01

    Full Text Available Accompanying the thawing permafrost expected to result from the climate change, microbial decomposition of the massive amounts of frozen organic carbon stored in permafrost is a potential emission source of greenhouse gases, possibly leading to positive feedbacks to the greenhouse effect. In this study, the community composition of archaea in stratigraphic soils from an alpine permafrost of Qinghai-Tibetan Plateau was investigated. Phylogenic analysis of 16S rRNA sequences revealed that the community was predominantly constituted by Crenarchaeota and Euryarchaeota. The active layer contained a proportion of Crenarchaeota at 51.2%, with the proportion of Euryarchaeota at 48.8%, whereas the permafrost contained 41.2% Crenarchaeota and 58.8% Euryarchaeota, based on 16S rRNA gene sequence analysis. OTU1 and OTU11, affiliated to Group 1.3b/MCG-A within Crenarchaeota and the unclassified group within Euryarchaeota, respectively, were widely distributed in all sediment layers. However, OTU5 affiliated to Group 1.3b/MCG-A was primarily distributed in the active layers. Sequence analysis of the DGGE bands from the 16S rRNAs of methanogenic archaea showed that the majority of methanogens belonged to Methanosarcinales and Methanomicrobiales affiliated to Euryarchaeota and the uncultured ZC-I cluster affiliated to Methanosarcinales distributed in all the depths along the permafrost profile, which indicated a dominant group of methanogens occurring in the cold ecosystems.

  2. Monitoring and analysis of ground temperature and deformation within Qinghai-Tibet Highway subgrade in permafrost region

    Institute of Scientific and Technical Information of China (English)

    YaHu Tian; YuPeng Shen; WenBing Yu; JianHong Fang

    2015-01-01

    In order to study the stability of the Qinghai-Tibet Highway embankment at Chumaerhe in the permafrost region of northwest China, the ground temperature and deformation at different depths were monitored under the left and right shoulders of the embankment where thermosyphons were set up only on the left shoulder. Based on the monitored data, characteristics of ground temperature and deformation of the left and right shoulders are analyzed and discussed. The results show that the start time of freezing or thawing of the seasonal active layer was about one to two months later than that of the embankment body itself. The stability of each shoulder was mainly controlled by the settlement of different soil layers, whereas frost heave of soil had scarcely any effect on the stability of the embankment. For the left shoulder, the settlement was mainly influenced by the seasonal active layer and then by the embankment body itself, due to freeze-thaw cycles which may change the soil properties; however, the permafrost layer remained fairly stable. For the right shoulder, creep of the warm permafrost layer was the main influence factor on its stability, followed by settlement of embankment body itself, and finally settlement of the seasonal active layer. Compared with the deformation of the left shoulder, the permafrost layer under the right shoulder was less stable, which indicates that the thermosyphons had a significantly positive effect on the stability of warm permafrost.

  3. Transient thermal effects in Alpine permafrost

    Directory of Open Access Journals (Sweden)

    J. Noetzli

    2009-04-01

    Full Text Available In high mountain areas, permafrost is important because it influences the occurrence of natural hazards, because it has to be considered in construction practices, and because it is sensitive to climate change. The assessment of its distribution and evolution is challenging because of highly variable conditions at and below the surface, steep topography and varying climatic conditions. This paper presents a systematic investigation of effects of topography and climate variability that are important for subsurface temperatures in Alpine bedrock permafrost. We studied the effects of both, past and projected future ground surface temperature variations on the basis of numerical experimentation with simplified mountain topography in order to demonstrate the principal effects. The modeling approach applied combines a distributed surface energy balance model and a three-dimensional subsurface heat conduction scheme. Results show that the past climate variations that essentially influence present-day permafrost temperatures at depth of the idealized mountains are the last glacial period and the major fluctuations in the past millennium. Transient effects from projected future warming, however, are likely larger than those from past climate conditions because larger temperature changes at the surface occur in shorter time periods. We further demonstrate the accelerating influence of multi-lateral warming in steep and complex topography for a temperature signal entering the subsurface as compared to the situation in flat areas. The effects of varying and uncertain material properties (i.e., thermal properties, porosity, and freezing characteristics on the subsurface temperature field were examined in sensitivity studies. A considerable influence of latent heat due to water in low-porosity bedrock was only shown for simulations over time periods of decades to centuries. At the end, the model was applied to the topographic setting of the Matterhorn

  4. Estimation of the permafrost stability on the East Arctic shelf under the extreme climate warming scenario for the XXI century

    Directory of Open Access Journals (Sweden)

    V. V. Malakhova

    2016-01-01

    Full Text Available A state of permafrost in the Arctic is the key to understanding whether methane, stored in the permafrost related gas hydrate, can release into the atmosphere. The global warming can lead to destabilization of the submarine permafrost and, thus, cause the methane releasing into the water. The near-bottom water temperature plays a significant role in the current state of the submarine permafrost, because it specifies a depth of thawing of the permafrost. We have numerically simulated evolution of the submarine permafrost on the East Siberia Arctic shelf for the last glacial cycle. In order to estimate a possible state and stability of the submarine permafrost we did carry out a numerical run based on the ICMMG SB RAS the coupled ocean-ice and submarine permafrost model. For the atmosphere forcing, the GFDL CM3 coupled climate model output, simulated under the scenario RCP8.5, was used. The scenario RCP8.5 was used since it predicted the strongest warming by the end of the 21-st century. The GFDL СM3 model, predicting the most pronounced Arctic warming, was also used in order to put the tentative upper boundary on the submarine permafrost degradation in this century.The results obtained show that the offshore permafrost exists across the vast East Siberia shelf. This permafrost occurs continuously but its thickness changes. Thickness of the permafrost within the most part of the East Siberia shelf is estimated 470–590 m when the value of 60 W/m2 was used for the geothermal flux. Our results reveal a certain rising of the bottom layer temperature on the shelf and subsequent penetration of a heat flux into the sediments. However, our results show that even the extreme warming is not sufficient to destabilize the submarine permafrost on the shelf of both, the Laptev Sea and the East Siberian Sea. By the end of the 21st century, upper boundary of the permafrost deepens by value from 1 to 11 m only due to the thermal effects, and by 5–10 m in

  5. The GTN-P Data Management System: A central database for permafrost monitoring parameters of the Global Terrestrial Network for Permafrost (GTN-P) and beyond

    Science.gov (United States)

    Lanckman, Jean-Pierre; Elger, Kirsten; Karlsson, Ævar Karl; Johannsson, Halldór; Lantuit, Hugues

    2013-04-01

    Permafrost is a direct indicator of climate change and has been identified as Essential Climate Variable (ECV) by the global observing community. The monitoring of permafrost temperatures, active-layer thicknesses and other parameters has been performed for several decades already, but it was brought together within the Global Terrestrial Network for Permafrost (GTN-P) in the 1990's only, including the development of measurement protocols to provide standardized data. GTN-P is the primary international observing network for permafrost sponsored by the Global Climate Observing System (GCOS) and the Global Terrestrial Observing System (GTOS), and managed by the International Permafrost Association (IPA). All GTN-P data was outfitted with an "open data policy" with free data access via the World Wide Web. The existing data, however, is far from being homogeneous: it is not yet optimized for databases, there is no framework for data reporting or archival and data documentation is incomplete. As a result, and despite the utmost relevance of permafrost in the Earth's climate system, the data has not been used by as many researchers as intended by the initiators of the programs. While the monitoring of many other ECVs has been tackled by organized international networks (e.g. FLUXNET), there is still no central database for all permafrost-related parameters. The European Union project PAGE21 created opportunities to develop this central database for permafrost monitoring parameters of GTN-P during the duration of the project and beyond. The database aims to be the one location where the researcher can find data, metadata, and information of all relevant parameters for a specific site. Each component of the Data Management System (DMS), including parameters, data levels and metadata formats were developed in cooperation with the GTN-P and the IPA. The general framework of the GTN-P DMS is based on an object oriented model (OOM), open for as many parameters as possible, and

  6. The Influence of Earth Temperature on the Dynamic Characteristics of Frozen Soil and the Parameters of Ground Motion on Sites of Permafrost

    Institute of Scientific and Technical Information of China (English)

    Wang Lanmin; Zhang Dongli; Wu Zhijian; Ma Wei; Li Xiaojun

    2004-01-01

    Earth temperature is one of the most important factors influencing the mechanical properties of frozen soil. Based on the field investigation of the characteristics of ground deformation and ground failure caused by the Ms8.1 earthquake in the west of the Kuniun Mountain Pass,China, the influence of temperature on the dynamic constitutive relationship, dynamic elastic modulus, damping ratio and dynamic strength of frozen soil was quantitatively studied by means of the dynamic triaxial test. Moreover, the characteristics of ground motion on a permafrost site under different temperatures were analyzed for the four profiles of permafrost along the Qinghai-Xizang (Tibet) Railway using the time histories of ground motion acceleration with 3 exceedance probabilities of the Kunlun Mountains area. The influences of temperature on the seismic displacement, velocity, acceleration and response spectrum on permafrost ground were studied quantitatively. A scientific basis was presented for earthquake disaster mitigation for engineering foundations, highways and underground engineering in permafrost areas.

  7. Baseline characteristics of climate, permafrost and land cover from a new permafrost observatory in the Lena River Delta, Siberia (1998–2011

    Directory of Open Access Journals (Sweden)

    J. Boike

    2013-03-01

    Full Text Available Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover, soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years. Data related to this article are archived under: http://doi. pangaea.de/10.1594/PANGAEA.806233 .

  8. The International Permafrost Association: current initiatives for cryospheric research

    Science.gov (United States)

    Schollaen, Karina; Lewkowicz, Antoni G.; Christiansen, Hanne H.; Romanovsky, Vladimir E.; Lantuit, Hugues; Schrott, Lothar; Sergeev, Dimitry; Wei, Ma

    2015-04-01

    The International Permafrost Association (IPA), founded in 1983, has as its objectives to foster the dissemination of knowledge concerning permafrost and to promote cooperation among persons and national or international organizations engaged in scientific investigation and engineering work on permafrost. The IPA's primary responsibilities are convening International Permafrost Conferences, undertaking special projects such as preparing databases, maps, bibliographies, and glossaries, and coordinating international field programs and networks. Membership is through adhering national or multinational organizations or as individuals in countries where no Adhering Body exists. The IPA is governed by its Executive Committee and a Council consisting of representatives from 26 Adhering Bodies having interests in some aspect of theoretical, basic and applied frozen ground research, including permafrost, seasonal frost, artificial freezing and periglacial phenomena. This presentation details the IPA core products, achievements and activities as well as current projects in cryospheric research. One of the most important core products is the circumpolar permafrost map. The IPA also fosters and supports the activities of the Global Terrestrial Network on Permafrost (GTN-P) sponsored by the Global Terrestrial Observing System, GTOS, and the Global Climate Observing System, GCOS, whose long-term goal is to obtain a comprehensive view of the spatial structure, trends, and variability of changes in the active layer thickness and permafrost temperature. A further important initiative of the IPA are the biannually competitively-funded Action Groups which work towards the production of well-defined products over a period of two years. Current IPA Action Groups are working on highly topical and interdisciplinary issues, such as the development of a regional Palaeo-map of Permafrost in Eurasia, the integration of multidisciplinary knowledge about the use of thermokarst and permafrost

  9. Development of bearing capacity of fine grained permafrost deposits in western greenland urban areas subject to soil temperature changes

    DEFF Research Database (Denmark)

    Agergaard, Frederik Ancker; Ingeman-Nielsen, Thomas

    2012-01-01

    by 2-3 °C during the 21st century. This paper presents a relation between undrained shear strength and temperature based on a series triaxial tests of fine-grained permafrost in the interval from -3 °C to -1 °C. Moderately ice-rich permafrost and excess ice free refrozen active-layer were retrieved...... with increasing temperature. Both excess ice free and moderately ice-rich samples show a strength decrease of 21 %/°C from -3 °C to -1 °C. Other authors’ data suggest the same trend for moderately ice-rich samples, whereas it is suggested that further studies are conducted to validate the trend for excess ice....... The established trends could provide a valuable tool for foundation design in fine-grained permafrost areas....

  10. Study on ground temperature change and characteristic response of engineering geology of permafrost along Qinghai-Tibet Railway

    Institute of Scientific and Technical Information of China (English)

    PAN Weidong; WANG Quancai; YU Shaoshui; ZHANG Xiaoyan

    2003-01-01

    Along with the global warming in the recent scores of years, comparatively big changes have taken place in the weather and other environmental conditions of the permafrost area in the Qinghai-Tibet Plateau, and very big changes have also occurred in the engineering geological conditions of the permafrost area. Based on a large volume of field survey data, this paper discusses the regularities of horizontal and vertical distribution of permafrost, with its focus of analysis on the temperature change characteristics of the soil in different frozen-soil zones, as well as presents simulation analysis and research for the engineering geologic characteristic response changes that would occur in the future when the temperature of the frozen soil in different zones rises by 1 and 2.6℃ respectively, which will have a tremendous impact on the stability of constructional work.

  11. Recent Trends in Permafrost Temperature From North American Sites Contributing to the Global Terrestrial Network for Permafrost

    Science.gov (United States)

    Smith, S.; Burgess, M.; Romanovsky, V.; Clow, G.; Brown, J.

    2004-05-01

    The Global Terrestrial Network for Permafrost (GTN-P) was established in 1999 to provide long-term field observations of active layer and permafrost thermal state that are required to determine the present permafrost conditions and to detect changes in permafrost stability. The data supplied by this network enhances our ability to predict the consequences of permafrost degradation associated with climate warming and to develop adaptation strategies to respond to these changes. The GTN-P contributes to the World Meteorological Organization's Global Climate Observing System and Global Terrestrial Observing System. This paper focuses on the thermal monitoring component of the GTN-P. To date, over 300 thermal monitoring sites have been identified from 16 countries for inclusion in the GTN-P. Site descriptions (metadata) and summary data are disseminated through the GTN-P web site (www.gtnp.org). Plans are being developed for a GTN-P contribution to the International Polar Year which will involve a collection of data from all monitoring sites if possible in 2006 and 2007. This paper reports initial results from North American sites. The results show that although recent warming of permafrost has been observed across the North American permafrost zone, the magnitude and timing of this warming varies. For example, warming has been observed since the early to mid 1980s in the western North American Arctic. Warming however in the Canadian eastern and high Arctic occurred in the late 1990s with cooler permafrost temperature generally occurring in the 1980s and early 1990s. These trends in permafrost temperature are consistent with air temperature trends observed since the 1970s in the Canadian Arctic. Variability in snow cover especially in the high Arctic, is also an important factor influencing the spatial and temporal trends in permafrost temperature.

  12. Computer Science in K-12 School Curricula of the 2lst Century: Why, What and When?

    Science.gov (United States)

    Webb, Mary; Davis, Niki; Bell, Tim; Katz, Yaacov J.; Reynolds, Nicholas; Chambers, Dianne P.; Syslo, Maciej M.

    2017-01-01

    In this paper we have examined the position and roles of Computer Science in curricula in the light of recent calls for curriculum change and we have proposed principles and issues to consider in curriculum design as well as identifying priority areas for further research. The paper is based on discussions within and beyond the International…

  13. The first ever application of electromagnetic sounding for mapping the submarine permafrost table on the Laptev Sea shelf

    Science.gov (United States)

    Koshurnikov, A. V.; Tumskoy, V. E.; Shakhova, N. E.; Sergienko, V. I.; Dudarev, O. V.; Gunar, A. Yu.; Pushkarev, P. Yu.; Semiletov, I. P.; Koshurnikov, A. A.

    2016-08-01

    The inconsistency between the position of the submarine permafrost table in the East Arctic seas revealed by simulation and anomalies in the distribution of dissolved methane associated with ascending torchlike ejections of bubbling methane made it necessary to develop a representative geophysical express method, which allows the position of the submarine permafrost table to be determined. The method is based on sounding of the generated primary electromagnetic field in the near zone of the medium and measurement of the induced secondary EM field. The reliability of the method is confirmed by core drilling in the Laptev Sea.

  14. Advances in thermokarst lake research in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    FuJun Niu; GuoDong Cheng; Jing Luo; ZhanJu Lin

    2014-01-01

    A-thermokarst-lake-is-defined-as-a-lake-occupying-a-closed-depression-formed-by-ground-settlement-following-thawing-of-ice-rich-permafrost-or-the-melting-of-massive-ice.-As-it-is-the-most-visible-morphologic-landscape-developed-during-the-process-of-permafrost-degradation,-we-reviewed-recent-literature-on-thermokarst-studies,-and-summarized-the-main-study-topics-as:-development-and-temporal-evolution,-carbon-release,-and-ecological-and-engineering-influence-of-thermokarst-lakes.-The-climate-warming,-forest-fires,-surface-water-pooling,-geotectonic-fault-and-anthropogenic-ac-tivity-are-the-main-influencing-factors-that-cause-an-increase-of-ground-temperatures-and-melting-of-ice-rich-permafrost,-resulting-in-thermokarst-lake-formation.-Normally-a-thermokarst-lake-develops-in-3-5-stages-from-initiation-to-perma-frost-recovery.-Geo-rectified-aerial-photographs-and-remote-sensing-images-show-that-thermokarst-lakes-have-been-mainly-experiencing-the-process-of-shrinkage-or-disappearance-in-most-regions-of-the-Arctic,-while-both-lake-numbers-and-areas-on-the-Qinghai-Tibet-Plateau-have-increased.-Field-studies-and-modeling-indicates-that-carbon-release-from-thermokarst-lakes-can-feedback-significantly-to-global-warming,-thus-enhancing-our-understanding-of-the-influences-of-thermokarst-lakes-on-the-ecological-environment,-and-on-regional-groundwater-through-drainage.-Based-on-field-mon-itoring-and-numerical-simulations,-infrastructure-stability-can-be-affected-by-thermal-erosion-of-nearby-thermokarst-lakes.-This-review-was-undertaken-to-enhance-our-understanding-of-thermokarst-lakes,-and-providing-references-for-future-comprehensive-studies-on-thermokarst-lakes.

  15. Past and future thermal characteristics of permafrost in Svalbard

    Science.gov (United States)

    Etzelmueller, B.; Isaksen, K.; Schuler, T. V.; Benestad, R.

    2009-04-01

    Within the EU-funded PACE project a 102 m deep borehole was drilled at Janssonhaugen, Svalbard, in 1998. The boreholes penetrate Cretaceous sandstone bedrock with low ice content overlain by a thin (0.2-0.5 m) weathering layer containing no organic material, the ground surface has no vegetation, and during winter snow cover is thin or completely absent due to deflation. Thus, a high correlation is observed between air temperature and ground surface temperature and the climate signal that penetrates the ground shows little disturbance by near-surface latent heat effects. The site is representative for the mountains in the area. The 10-year long series show that the permafrost has warmed considerably. Significant warming is detectable down to at least 60 m depth, and present decadal warming rate at the permafrost surface are on the order of 0.07 °C yr-1, with indications of accelerated warming during the last decade (Isaksen et al. 2007). In this study we have calibrated a surface temperature driven 1D-heat flow model with phase transitions to the temperature measurements in the borehole. This model was then forced by ground surface temperatures derived either from historical observed air temperature data for the 20th Century and an empirical statistical downscaled ensemble covering the 21st Century. The latter is based on the multi-model World Climate Research Programme (WCRP) Coupled Model Intercomparison Project (CMIP3) of the most recent Special Report Emission Scenario (SRES) A1b (in which atmospheric CO2 reaches 720 parts per million by 2100) produced for the Intergovernmental Panel on Climate Change (IPCC) Assessment Report 4 (AR4). The presentation demonstrate the possible impact of projected higher air temperatures in the high Arctic on the ground thermal regime, and geomorphological and geotechnical consequences will be discussed.

  16. Organisation and analysis of temperature data measured within the Swiss Permafrost Monitoring Network (PERMOS)

    Science.gov (United States)

    Noetzli, Jeannette; Voelksch, Ingo

    2014-05-01

    The Swiss permafrost monitoring network (PERMOS) has been running since 2000 and developed from a loose network of research sites towards an operational network with long-term funding and integration into national and international monitoring structures. The monitoring strategy follows a landform based approach to capture the interaction of subsurface thermal conditions with the atmosphere in a comprehensive picture of permafrost in the Swiss Alps and includes three observation elements: (1) ground temperatures in boreholes and at the surface around the drill site, (2) changes in unfrozen water content at the drill sites, and (3) permafrost creep velocities. They are observed in different landforms (e.g., rock walls, rock glaciers, scree slopes) because topography and site characteristics are decisive for different changes in subsurface thermal regimes. Three of the ten monitoring principles formulated by the Global Climate Observing System (GCOS) for field measurement relate to the management and quality of data and metadata and state that data management systems are an essential element of climate monitoring systems. For these purposes a data management system is built up that (1) ensures comparability and quality of the data, (2) provides secure and long-term storage in a robust and flexible system with customised access for basic and advanced users and data exchange with data centres and (3) at the same time keeps the (time) effort needed to a minimum. To this end, a relational database was set up and processing protocols are developed for standardization relying on open source products. As of today, the PERMOS data base includes data from the three key observation elements as well as other available ancillary data from most of the Swiss permafrost research sites with time series of up to more than 20 years and more for temperature measurements. This finally builds the basis for comprehensive and joint analyses across sites and parameters within the SNF

  17. Transient thermal modeling of permafrost conditions in Southern Norway

    Directory of Open Access Journals (Sweden)

    S. Westermann

    2013-04-01

    Full Text Available Thermal modeling is a powerful tool to infer the temperature regime of the ground in permafrost areas. We present a transient permafrost model, CryoGrid 2, that calculates ground temperatures according to conductive heat transfer in the soil and in the snowpack. CryoGrid 2 is forced by operational air temperature and snow-depth products for potential permafrost areas in Southern Norway for the period 1958 to 2009 at 1 km2 spatial resolution. In total, an area of about 80 000 km2 is covered. The model results are validated against borehole temperatures, permafrost probability maps from "bottom temperature of snow" measurements and inventories of landforms indicative of permafrost occurrence. The validation demonstrates that CryoGrid 2 can reproduce the observed lower permafrost limit to within 100 m at all validation sites, while the agreement between simulated and measured borehole temperatures is within 1 K for most sites. The number of grid cells with simulated permafrost does not change significantly between the 1960s and 1990s. In the 2000s, a significant reduction of about 40% of the area with average 2 m ground temperatures below 0 °C is found, which mostly corresponds to degrading permafrost with still negative temperatures in deeper ground layers. The thermal conductivity of the snow is the largest source of uncertainty in CryoGrid 2, strongly affecting the simulated permafrost area. Finally, the prospects of employing CryoGrid 2 as an operational soil-temperature product for Norway are discussed.

  18. Subsea Permafrost Climate Modeling - Challenges and First Results

    Science.gov (United States)

    Rodehacke, C. B.; Stendel, M.; Marchenko, S. S.; Christensen, J. H.; Romanovsky, V. E.; Nicolsky, D.

    2015-12-01

    Recent observations indicate that the East Siberian Arctic Shelf (ESAS) releases methane, which stems from shallow hydrate seabed reservoirs. The total amount of carbon within the ESAS is so large that release of only a small fraction, for example via taliks, which are columns of unfrozen sediment within the permafrost, could impact distinctly the global climate. Therefore it is crucial to simulate the future fate of ESAS' subsea permafrost with regard to changing atmospheric and oceanic conditions. However only very few attempts to address the vulnerability of subsea permafrost have been made, instead most studies have focused on the evolution of permafrost since the Late Pleistocene ocean transgression, approximately 14000 years ago.In contrast to land permafrost modeling, any attempt to model the future fate of subsea permafrost needs to consider several additional factors, in particular the dependence of freezing temperature on water depth and salt content and the differences in ground heat flux depending on the seabed properties. Also the amount of unfrozen water in the sediment needs to be taken into account. Using a system of coupled ocean, atmosphere and permafrost models will allow us to capture the complexity of the different parts of the system and evaluate the relative importance of different processes. Here we present the first results of a novel approach by means of dedicated permafrost model simulations. These have been driven by conditions of the Laptev Sea region in East Siberia. By exploiting the ensemble approach, we will show how uncertainties in boundary conditions and applied forcing scenarios control the future fate of the sub sea permafrost.

  19. Evaluating Ecotypes as a means of Scaling-up Permafrost Thermal Measurements in Western Alaska.

    Science.gov (United States)

    Cable, William; Romanovsky, Vladimir

    2015-04-01

    was anomalously low during both winters, while mean monthly and annual air temperature was similar to the long-term average the first year and considerably warmer (warm winter) the second year. Our results indicate that it is possible to extract information about subsurface temperature, active layer thickness, and other permafrost characteristics based on these ecotype classifications. Additionally, we find that within some ecotypes the absence of a moss layer is indicative of the absence of near surface permafrost. As a proof of concept, we used this information to translate the ecotype landcover map into a map of mean annual ground temperature ranges at 1 m depth. While this map is preliminary and would benefit from additional data and modeling exercises (both ongoing), we believe it provides useful information for decision making with respect to land use and understanding how the landscape might change under future climate scenarios.

  20. Information as Resoures ; A View toward the 2lst Century - Let's Construct Databases by Ourselves -

    Science.gov (United States)

    Ohmi, Akira

    A highly-developed information-oriented society based on “Information Network Technology” will be realized in the 21st century. In enterprises, fundamental research will be regarded as important more and more, and the effective use of information as resources will be indispensable. From the viewpoint of international distribution of information there is a criticism that Japan has been offering the information on science and technology insufficiently to the overseas countries, but, for example, in the steel industry lots of house-organ technical journals in English version has been offered overseas. And recently several information firms have started translating Japanese information into English and providing overseas. However, there are some problems to be taken into consideration; 1. The information is not integrated, 2. there is not any co-ordination among the firms, 3. others. Then the author proposes communal use of machine translation system and construction of database for overseas that integrate such firms” work preserving each individuality.

  1. The tool of microbial genomics research for interpreting the lability of permafrost carbon and potential greenhouse gas feedbacks at different scales of resolution.

    Science.gov (United States)

    Waldrop, M. P.; Machelprang, R.; Hultman, J.; Wickland, K. P.

    2012-12-01

    community composition to gain insight into greenhouse gas production. At Bonanza Creek, there are large differences in microbial community composition between intact permafrost and thermokarst bog soils. Metagenomic and metatransciptome analysis of microbial communities reveal that changes in community composition and representative functional genes reflect the dominant greenhouse gas producing processes occurring in those environments. Results indicated that the relative abundance of microbial functional groups based upon functional genes (e.g. methanogens, nitrate reducers, sulfate reducers) mirror the geochemistry of the system and pathways of potential greenhouse gas production. These data help to understand linkages between the level of detail undertaken within -omics research and the temporal scale of biogeochemical processes under examination.

  2. Sensitivity analysis of longitudinal cracking on asphalt pavement using MEPDG in permafrost region

    OpenAIRE

    Chen Zhang; Hainian Wang; Zhanping You; Biao Ma

    2015-01-01

    Longitudinal cracking is one of the most important distresses of asphalt pavement in permafrost regions. The sensitivity analysis of design parameters for asphalt pavement can be used to study the influence of every parameter on longitudinal cracking, which can help optimizing the design of the pavement structure. In this study, 20 test sections of Qinghai–Tibet Highway were selected to conduct the sensitivity analysis of longitudinal cracking on material parameter based on Mechanistic-Empiri...

  3. Assessment of three mitigation techniques for permafrost protection

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr

    The presence of permafrost is an important aspect in civil engineering in arctic regions. The construction of engineering structures, such as road and airfield embankments, will change the thermal regime of the ground, and may lead to permafrost degradation under or adjacent to such structures. T......). The results showed that the use of a reflective surface (white paint) will reduce the thickness of the active layer and avoid permafrost degradation underneath the embankment. This should promote the interest in the development and use of light-colored asphalt pavement materials....

  4. Cryopegs as destabilization factor of intra-permafrost gas hydrates

    Science.gov (United States)

    Chuvilin, Evgeny; Bukhanov, Boris; Istomin, Vladimir

    2016-04-01

    A characteristic feature of permafrost soils in the Arctic is widespread intra-permafrost unfrozen brine lenses - cryopegs. They are often found in permafrost horizons in the north part of Western Siberia, in particular, on the Yamal Peninsula. Cryopegs depths in permafrost zone can be tens and hundreds of meters from the top of frozen strata. The chemical composition of natural cryopegs is close to sea waters, but is characterized by high mineralization. They have a sodium-chloride primary composition with a minor amount of sulphate. Mineralization of cryopegs brine is often hundreds of grams per liter, and the temperature is around -6…-8 °C. The formation of cryopegs in permafrost is associated with processes of long-term freezing of sediments and cryogenic concentration of salts and salt solutions in local areas. The cryopegs' formation can take place in the course of permafrost evolution at the sea transgressions and regressions during freezing of saline sea sediments. Very important feature of cryopegs in permafrost is their transformation in the process of changing temperature and pressure conditions. As a result, the salinity and chemical composition are changed and in addition the cryopegs' location can be changed during their migration. The cryopegs migration violates the thermodynamic conditions of existence intra-permafrost gas hydrate formations, especially the relic gas hydrates deposits, which are situated in the shallow permafrost up to 100 meters depth in a metastable state [1]. The interaction cryopegs with gas hydrates accumulations can cause decomposition of intra-permafrost hydrates. Moreover, the increasing of salt and unfrozen water content in sedimentary rocks sharply reduce the efficiency of gas hydrates self-preservation in frozen soils. It is confirmed by experimental investigations of interaction of frozen gas hydrate bearing sediments with salt solutions [2]. So, horizons with elevated pressure can appear, as a result of gas hydrate

  5. Content and Vulnerability of Fossil Organic Matter in Ice-Rich Siberian Permafrost - a Case Study

    Science.gov (United States)

    Strauss, Jens; Mangelsdorf, Kai; Schirrmeister, Lutz; Wetterich, Sebastian

    2013-04-01

    During the late Pleistocene, a large pool of organic matter (OM) accumulated in ice-rich deposits of the arctic permafrost zone. Because of the potential re-introduction of this stored carbon into the global cycle from degrading permafrost (i.e. decomposed OM) as climate-relevant gases, the OM inventory of ice-rich permafrost deposits is important to current concerns about global warming. The objective of this presentation is to deduce the quality of OM stored in the studied permafrost sediments. The approach to estimate the OM quality is to use degradation parameters (e.g. C/N, δ13C) based on the assumption that low degraded OM is more labile and has higher vulnerability for decomposition. Standard sedimentological and a molecular marker (biomarker) approach are applied. The study site is located on the west coast of the Buor Khaya Peninsula (N 71.6°, E 132.2°), Laptev Sea (Russia). Stratigraphically, two sediment units are distinguished. The first unit is composed of late Pleistocene ice-rich permafrost (Yedoma). The second unit consists of Holocene thermokarst (Alas) deposits. The mean bulk density of sediments from both units is ca. 1 g/cm³. The average total organic carbon (TOC) content is 2.4 wt% for Yedoma, 2.8 wt% for thermokarst deposits. The volumetric organic carbon contents of the Yedoma and thermokarst deposits are 13 ± 11 kg/m³ and 22 ± 11 kg/m³, respectively. The degree of OM degradation from both units is low (mean C/N 10, mean δ13C -26.5 ‰) because the deposits accumulated at relatively fast rates and the OM underwent only a short time of decomposition before it was incorporated into permafrost. Originating from microorganisms, archaeal lipids like archaeol can be used as a marker for methanogenic microbial communities or as a proxy for past microorganism activity. The archaeol concentrations reveal higher microbial activity in thermokarst deposits than in Yedoma deposits. The n-alkane and n-fatty acid parameters (carbon preference index

  6. Paleo-Eskimo kitchen midden preservation in permafrost under future climate conditions at Qajaa, West Greenland

    DEFF Research Database (Denmark)

    Elberling, Bo; Matthiesen, Henning; Jørgensen, Christian Juncher

    2011-01-01

    Remains from Paleo-Eskimo cultures are well-documented, but complete preservation is rare. Two kitchen middens in Greenland are known to hold extremely well-preserved organic artefacts. Here, we assess the fate of the Qajaa site in Western Greenland under future climate conditions based on site...... characteristics measured in situ and from permafrost cores. Measurements of thermal properties, heat generation, oxygen consumption and CO2 production show that the kitchen midden can be characterized as peat but produces 4–7 times more heat than natural sediment. An analytical model from permafrost research has...... been applied to assess future thawing of the midden. Results show that the preservation conditions are controlled by freezing temperatures and a high water/ice content limiting the subsurface oxygen availability. Threats to the future preservation are related to thawing followed by drainage...

  7. Circumpolar assessment of permafrost C quality and its vulnerability over time using long-term incubation data.

    Science.gov (United States)

    Schädel, Christina; Schuur, Edward A G; Bracho, Rosvel; Elberling, Bo; Knoblauch, Christian; Lee, Hanna; Luo, Yiqi; Shaver, Gaius R; Turetsky, Merritt R

    2014-02-01

    High-latitude ecosystems store approximately 1700 Pg of soil carbon (C), which is twice as much C as is currently contained in the atmosphere. Permafrost thaw and subsequent microbial decomposition of permafrost organic matter could add large amounts of C to the atmosphere, thereby influencing the global C cycle. The rates at which C is being released from the permafrost zone at different soil depths and across different physiographic regions are poorly understood but crucial in understanding future changes in permafrost C storage with climate change. We assessed the inherent decomposability of C from the permafrost zone by assembling a database of long-term (>1 year) aerobic soil incubations from 121 individual samples from 23 high-latitude ecosystems located across the northern circumpolar permafrost zone. Using a three-pool (i.e., fast, slow and passive) decomposition model, we estimated pool sizes for C fractions with different turnover times and their inherent decomposition rates using a reference temperature of 5 °C. Fast cycling C accounted for less than 5% of all C in both organic and mineral soils whereas the pool size of slow cycling C increased with C : N. Turnover time at 5 °C of fast cycling C typically was below 1 year, between 5 and 15 years for slow turning over C, and more than 500 years for passive C. We project that between 20 and 90% of the organic C could potentially be mineralized to CO2 within 50 incubation years at a constant temperature of 5 °C, with vulnerability to loss increasing in soils with higher C : N. These results demonstrate the variation in the vulnerability of C stored in permafrost soils based on inherent differences in organic matter decomposability, and point toward C : N as an index of decomposability that has the potential to be used to scale permafrost C loss across landscapes.

  8. Monitoring of permafrost condition based on longitudinal conductivity of the transition layer%基于过渡层的纵向电导率冻土特征监测

    Institute of Scientific and Technical Information of China (English)

    Vladimir N.Efremov

    2014-01-01

    实验研究结果是应用过渡层的纵向电导对多年冻土环境进行监测而获取。过渡层在地下电导率剖面位于季节融化层以下。这一层在冷冻状态下具有不同的温度值,电阻率和厚度。过渡层纵向导电的季节变化比季节融化层更重要。因此,它们可用于监测地面的建筑物和工程多年冻土地基条件,过渡层的纵向电导值可由无线电阻抗测深资料确定。%The results of experimental research of possibility to apply transition layer longitudinal con-ductivity for monitoring of permafrost condition are presented .The transition layer is a layer in subsurface conductivity section located below the seasonally thawed layer .This layer is in frozen state and has var-ying values of temperature , electrical resistivity and thickness .Seasonal variations in longitudinal con-ductivity of the transition layer are more significant than those of the seasonally thawed layer .Therefore , they can be used for monitoring the condition of permafrost foundations of buildings and engineering con -structions from the ground surface .Longitudinal conductivity values of the transition layer can be deter-mined by interpretation of radioimpedance sounding data .

  9. Biogeochemistry: Long-term effects of permafrost thaw

    Science.gov (United States)

    Zona, Donatella

    2016-09-01

    Carbon emissions from the Arctic tundra could increase drastically as global warming thaws permafrost. Clues now obtained about the long-term effects of such thawing on carbon dioxide emissions highlight the need for more data.

  10. The Lena River Delta Observatory, Arctic Siberia: a Contribution to the ESA DUE Permafrost Project

    Science.gov (United States)

    Heim, Birgit; Boike, Julia; Moritz, Langer; Annett, Bartsch; Sina, Muster; Jennifer, Sobiech; Konstanze, Piel; Günter, Stoof; Anne, Morgenstern; Mathias, Ulrich

    2010-05-01

    The major task of the ESA Data User Element DUE PERMAFROST is to develop and use Earth Observation services specifically for monitoring and modelling of permafrost. In order to setup the required information services, a target area approach with specified case study regions is used. Long-term ground data series and multidisciplinary ongoing projects make the Lena River delta (Arctic Siberia) a prime study region for evaluation and validation of the DUE PERMAFROST remote sensing products. The Lena River Delta located in the zone of continuous permafrost is a key region for Arctic system science. Since 1998, the Alfred Wegener Institute for Polar and Marine Research AWI in collaboration with the Lena Delta Reserve in Tiksi has operated the German-Russian research station Samoylov. Relevant ground-based data (air temperature, radiation, snow, albedo, soil temperature and moisture) are collected continuously. The high landscape heterogeneity (wet polygonal centres, dry polygonal rims, ponds and lakes) challenges all ground data observations. Match-up data sets of ground data and remote sensing products coincident in time and location are being built up. Exclusion and selection criteria will be based on experience, especially the knowledge on parameter variability in time and space. The main focus are the remote sensing products ‘surface temperature', ‘surface moisture', ‘albedo', ‘vegetation' and ‘water'. Statistical and contextural methods will be used for the upscaling from the plot to the meso-scale. Problems will have to be identified such as process-dependent scales and the water body ratio within the pixel.

  11. Satellite data acquisition requirements for monitoring of permafrost in polar regions

    Science.gov (United States)

    Bartsch, Annett

    2015-04-01

    Requirements for space based monitoring of permafrost features had been already defined within the IGOS Cryosphere Theme Report at the start of the IPY in 2007 (IGOS, 2007). In 2012 the Polar Space Task Group (PSTG, http://www.wmo.int/pages/prog/sat/pstg_en.php) has been established as the coordinating body of space agencies, in particular the Space Task Group (STG), for space -based observations of Polar Regions after the International Polar Year (IPY) and under the auspices of the World Meteorological Organization's (WMO) Executive Council Panel of Experts on Polar Observations Research and Services (EC-PORS). The PSTG identified the need to review the requirements for permafrost monitoring and to update these requirements as necessary in 2013. Relevant surveys with focus on satellite data are already available from the ESA DUE Permafrost User requirements survey (2009), the United States National Research Council (2014) and the ESA - CliC - IPA - GTN -P workshop in February 2014. These reports have been reviewed and specific needs discussed within the community. Acquisition requirements for monitoring of especially terrain changes (incl. rock glaciers and coastal erosion) and lakes (extent, ice properties etc.) with respect to current satellite missions have been specified. Of special interest for these applications are SAR missions. Current acquisition strategies for space borne SAR data only partially cover polar permafrost regions and some of the longterm in-situ measurement sites. Many stations are located in the proximity to coastal areas and glaciers which to some extent may allow joint usage by different cryosphere applications but requirements may deviate. The results of the discussion are presented in this paper.

  12. Impact of permafrost change on the Qinghai-Tibet Railroad engineering

    Institute of Scientific and Technical Information of China (English)

    WU; Qingbai; CHENG; Guodong

    2004-01-01

    Permafrost along the Qinghai-Tibet Railroad produces the great change under the influence of climate change, such as the decreasing of permafrost table, the rising of permafrost temperatures, etc. Climate effect on permafrost is the long-term process. Engineering action makes rapidly permafrost the large extent change. On the basis of analyzing the permafrost change under the climate change and engineering action, the thermal regime and spatial distribution of permafrost are predicted for air temperature rising 1℃ and 2℃ after 50 years in this paper. The results show that climate change results in the larger change for the thermal regime and spatial distribution of permafrost. Permafrost change will produce the great effect on the Qinghai-Tibet Railroad engineering, not only resulting in the decreasing of permafrost table beneath the roadbed, but also resulting in thawing settlement due to the thawing of ground ice near permafrost table. The idea of cooling roadbed and active protecting permafrost for the Qinghai-Tibet Railroad engineering could adjust and control the permafrost thermal state, some better methods are provided to ensure the engineering stability in the areas of warm permafrost and high ice content.

  13. Permafrost degradation risk zone assessment using simulation models

    Directory of Open Access Journals (Sweden)

    R. P. Daanen

    2011-11-01

    Full Text Available In this proof-of-concept study we focus on linking large scale climate and permafrost simulations to small scale engineering projects by bridging the gap between climate and permafrost sciences on the one hand and on the other technical recommendation for adaptation of planned infrastructures to climate change in a region generally underlain by permafrost. We present the current and future state of permafrost in Greenland as modelled numerically with the GIPL model driven by HIRHAM climate projections up to 2080. We develop a concept called Permafrost Thaw Potential (PTP, defined as the potential active layer increase due to climate warming and surface alterations. PTP is then used in a simple risk assessment procedure useful for engineering applications. The modelling shows that climate warming will result in continuing wide-spread permafrost warming and degradation in Greenland, in agreement with present observations. We provide examples of application of the risk zone assessment approach for the two towns of Sisimiut and Ilulissat, both classified with high PTP.

  14. Climatic change and permafrost. Record from surficial deposits

    Science.gov (United States)

    Carter, L. David

    1990-01-01

    The physical and chemical characteristics of surficial deposits and the floral and faunal remains they contain provide information that is useful for interpreting both paleoclimatic and past permafrost conditions. Surficial deposits thus provide a record of climatic change and permafrost history. This record suggests that initiation of permafrost in lowland areas of the Southern Arctic Archipelago and continents of the northern hemisphere may have occurred about 2,400,000 years ago during the pronounced cooling that led to the first major glaciation of late Cenozoic time. Since then, climate has been relatively cold but cyclically variable, characterized by the growth and shrinkage of large, continental ice sheets. Permafrost has expanded and contracted in response to these climatic changes, and we can expect the present permafrost conditions to change in response to future climatic changes. To predict the response of permafrost and the landscape to future climatic change we should: (1) Define relations between climate and the modern landscape; (2) establish long-term records of past climatic change and landscape response; and (3) determine the paleoenvironments of past warm periods as possible analogs for future global warming.

  15. The cooling effect of crushed rock structures on permafrost under an embankment

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the analysis and comparison of soil temperature, thermal regime and permafrost table under the experimental embankment of crushed rock structures in Beiluhe, results show that crushed rock structures provide an extensive cooling effect, which produces a rising permafrost table and decreasing soil temperatures. The rise of the permafrost table under the embankment ranges from an increase of 1.08 m to 1.67 m, with an average of 1.27 m from 2004 to 2007. Mean annual soil temperatures under the crushed rock layer embankment decreased significantly from 2005 to 2007, with average decreases of ?1.03 °C at the depth of 0.5 m, ?1.14 °C at the depth of 1.5 m, and ?0.5 °C at the depth of 5 m. During this period, mean annual soil temperatures under the crushed rock cover embankment showed a slight decrease at shallow depths, with an average decrease of ?0.2 °C at the depth of 0.5 m and 1.5 m, but a slight rise at the depth of 5 m. After the crushed rock structures were closed or crammed with sand, the cooling effect of the crushed rock layer embankment was greatly reduced and that of the crushed rock cover embankment was just slightly reduced.

  16. A statistical approach to modelling permafrost distribution in the European Alps or similar mountain ranges

    Directory of Open Access Journals (Sweden)

    L. Boeckli

    2012-01-01

    Full Text Available Estimates of permafrost distribution in mountain regions are important for the assessment of climate change effects on natural and human systems. In order to make permafrost analyses and the establishment of guidelines for e.g. construction or hazard assessment comparable and compatible between regions, one consistent and traceable model for the entire Alpine domain is required. For the calibration of statistical models, the scarcity of suitable and reliable information about the presence or absence of permafrost makes the use of large areas attractive due to the larger data base available.

    We present a strategy and method for modelling permafrost distribution of entire mountain regions and provide the results of statistical analyses and model calibration for the European Alps. Starting from an integrated model framework, two statistical sub-models are developed, one for debris-covered areas (debris model and one for steep bedrock (rock model. They are calibrated using rock glacier inventories and rock surface temperatures. To support the later generalization to surface characteristics other than those available for calibration, so-called offset terms have been introduced into the model that allow doing this in a transparent and traceable manner.

    For the debris model a generalized linear mixed-effect model (GLMM is used to predict the probability of a rock glacier being intact as opposed to relict. It is based on the explanatory variables mean annual air temperature (MAAT, potential incoming solar radiation (PISR and the mean annual sum of precipitation (PRECIP, and achieves an excellent discrimination (area under the receiver-operating characteristic, AUROC = 0.91. Surprisingly, the probability of a rock glacier being intact is positively associated with increasing PRECIP for given MAAT and PISR conditions. The rock model is based on a linear regression and was calibrated with mean annual rock surface temperatures (MARST. The

  17. Assessing hazard risk, cost of adaptation and traditional land use activities in the context of permafrost thaw in communities in Yukon and the Northwest Territories, Canada

    Science.gov (United States)

    Benkert, B.; Perrin, A.; Calmels, F.

    2015-12-01

    Together with its partners, the Northern Climate ExChange (NCE, part of the Yukon Research Centre at Yukon College) has been mapping permafrost-related hazard risk in northern communities since 2010. By integrating geoscience and climate project data, we have developed a series of community-scale hazard risk maps. The maps depict hazard risk in stoplight colours for easy interpretation, and support community-based, future-focused adaptation planning. Communities, First Nations, consultants and local regulatory agencies have used the hazard risk maps to site small-scale infrastructure projects, guide land planning processes, and assess suitability of land development applications. However, we know that assessing risk is only one step in integrating the implications of permafrost degradation in societal responses to environmental change. To build on our permafrost hazard risk maps, we are integrating economic principles and traditional land use elements. To assess economic implications of adaptation to permafrost change, we are working with geotechnical engineers to identify adaptation options (e.g., modified building techniques, permafrost thaw mitigation approaches) that suit the risks captured by our existing hazard risk maps. We layer this with an economic analysis of the costs associated with identified adaptation options, providing end-users with a more comprehensive basis upon which to make decisions related to infrastructure. NCE researchers have also integrated traditional land use activities in assessments of permafrost thaw risk, in a project led by Jean Marie River First Nation in the Northwest Territories. Here, the implications of permafrost degradation on food security and land use priorities were assessed by layering key game and gathering areas on permafrost thaw vulnerability maps. Results indicated that close to one quarter of big and small game habitats, and close to twenty percent of key furbearer and gathering areas within the First Nation

  18. Electrical and seismic mixing rules for detecting changes in ground ice content in permafrost studies

    Science.gov (United States)

    Hauck, Christian; Hilbich, Christin

    2017-04-01

    Geophysical methods are now widely used in permafrost research to detect and monitor frozen ground and potentially quantify the ground ice content in the soil. Hereby, often a combination of different methods is used to reduce the ambiguities inherent with the indirect nature of geophysical surveys. Geophysical mixing rules and petrophysical relationships originally developed by exploration industry may help to quantitatively relate geophysical variables such as the electrical resistivity or the seismic P-wave velocity to the physical properties of the subsurface. Two of these mixing rules were combined by Hauck et al. (2011) in a so-called 4-phase model to attempt to quantify the ground ice, air- and water content and their changes with time in permafrost environments (e.g. Pellet et al. 2016). However, these mixing rules are often either empirically derived (making use of a large number of borehole samples) or based on a simplified mixing model, i.e. an equal weighting of each phase component (ice, water, soil/rock, air) depending on the actual fractional content of each phase. There is thus no obvious 'best choice' model from the available geophysical approaches. Stimulated by recent theoretical work by Glover (2010), who analysed the relationships between the empirical and theory-derived mixing models, this contribution aims to analyse the applicability of various mixing models for electrical and seismic data sets in the context of detecting and monitoring permafrost degradation. Input data stem from various geophysical surveys around the world and ground truth data for validation is available from corresponding permafrost boreholes from the PERMOS and GTN-P data bases. Glover, P. W. (2010). A generalized Archie's law for n phases. Geophysics, 75(6), E247-E265. Hauck, C., Böttcher, M. and Maurer, H. (2011): A new model for estimating subsurface ice content based on combined electrical and seismic data sets. The Cryosphere, 5, 453-468. Pellet C., Hilbich C

  19. Terrestrial Permafrost Models of Martian Habitats and Inhabitants

    Science.gov (United States)

    Gilichinsky, D.

    2011-12-01

    The terrestrial permafrost is the only rich depository of viable ancient microorganisms on Earth, and can be used as a bridge to possible Martian life forms and shallow subsurface habitats where the probability of finding life is highest. Since there is a place for water, the requisite condition for life, the analogous models are more or less realistic. If life ever existed on Mars, traces might have been preserved and could be found at depth within permafrost. The age of the terrestrial isolates corresponds to the longevity of the frozen state of the embedding strata, with the oldest known dating back to the late Pliocene in Arctic and late Miocene in Antarctica. Permafrost on Earth and Mars vary in age, from a few million years on Earth to a few billion years on Mars. Such a difference in time scale would have a significant impact on the possibility of preserving life on Mars, which is why the longevity of life forms preserved within terrestrial permafrost can only be an approximate model for Mars. 1. A number of studies indicate that the Antarctic cryosphere began to develop on the Eocene-Oligocene boundary, after the isolation of the continent. Permafrost degradation is only possible if mean annual ground temperature, -28°C now, rise above freezing, i.e., a significant warming to above 25°C is required. There is no evidence of such sharp temperature increase, which indicates that the climate and geological history was favorable to persistence of pre-Pliocene permafrost. These oldest relics (~30Myr) are possibly to be found at high hypsometric levels of ice-free areas (Dry Valleys and nearby mountains). It is desirable to test the layers for the presence of viable cells. The limiting age, if one exists, within this ancient permafrost, where the viable organisms were no longer present, could be established as the limit for life preservation below 0oC. Positive results will extend the known temporal limits of life in permafrost. 2. Even in this case, the age of

  20. Can Plant Community Turnover Mitigate Permafrost Thaw Feedbacks to the Climate System?

    Science.gov (United States)

    Hough, M.; Garnello, A.; Finnell, D.; Palace, M. W.; Rich, V. I.; Saleska, S. R.

    2014-12-01

    In many parts of the Arctic, permafrost thaw due to rising temperatures results in the conversion of dry tundra to wetland bog and fen ecosystems. Such increases in anaerobic environments may have substantial feedbacks to the rate of climate change through the increased production of CH4, a greenhouse gas an order of magnitude more potent than the CO2 respired from aerobic soils. However, the total emission rates of CH4 and CO2 alone cannot predict the magnitude of feedback to the climate system since this will also depend on the ecosystem's overall carbon balance and the source of carbon (new vs old) producing the emissions. Thus, building detailed carbon budgets is essential to understanding the potential climate feedbacks of habitat changes due to permafrost thaw. We studied above-ground plant biomass and its carbon content in order to calculate the inputs of new carbon to the soil along a permafrost thaw gradient with previously well-quantified CO2 and CH4 fluxes in northern Sweden. In order to account for within-season plant community turnover, we monitored plant percent cover over the course of a growing season in three communities: areas underlain by permafrost dominated by E. vaginatum, and E. nigrum, recently thawed sphagnum dominated areas, and more established E. angustifolium dominated fen communities. Additionally, we calculated end of season biomass and percent carbon for each species and compared our findings to previously published community composition assessments from 1972/1973 and 2000. We tied our ground-based measurements to aerial remote sensing images to extrapolate biomass and percent carbon across the mire based on community type. These results allow us to calculate total carbon inputs to the mire from new above-ground biomass. By coupling these measurements with flux rates from each habitat we will be able to assess the degree to which increased biomass production might offset the increase in CH4 released from soils as a result of plant

  1. Methane dynamics regulated by microbial community response to permafrost thaw.

    Science.gov (United States)

    McCalley, Carmody K; Woodcroft, Ben J; Hodgkins, Suzanne B; Wehr, Richard A; Kim, Eun-Hae; Mondav, Rhiannon; Crill, Patrick M; Chanton, Jeffrey P; Rich, Virginia I; Tyson, Gene W; Saleska, Scott R

    2014-10-23

    Permafrost contains about 50% of the global soil carbon. It is thought that the thawing of permafrost can lead to a loss of soil carbon in the form of methane and carbon dioxide emissions. The magnitude of the resulting positive climate feedback of such greenhouse gas emissions is still unknown and may to a large extent depend on the poorly understood role of microbial community composition in regulating the metabolic processes that drive such ecosystem-scale greenhouse gas fluxes. Here we show that changes in vegetation and increasing methane emissions with permafrost thaw are associated with a switch from hydrogenotrophic to partly acetoclastic methanogenesis, resulting in a large shift in the δ(13)C signature (10-15‰) of emitted methane. We used a natural landscape gradient of permafrost thaw in northern Sweden as a model to investigate the role of microbial communities in regulating methane cycling, and to test whether a knowledge of community dynamics could improve predictions of carbon emissions under loss of permafrost. Abundance of the methanogen Candidatus 'Methanoflorens stordalenmirensis' is a key predictor of the shifts in methane isotopes, which in turn predicts the proportions of carbon emitted as methane and as carbon dioxide, an important factor for simulating the climate feedback associated with permafrost thaw in global models. By showing that the abundance of key microbial lineages can be used to predict atmospherically relevant patterns in methane isotopes and the proportion of carbon metabolized to methane during permafrost thaw, we establish a basis for scaling changing microbial communities to ecosystem isotope dynamics. Our findings indicate that microbial ecology may be important in ecosystem-scale responses to global change.

  2. Exploring Viral Mediated Carbon Cycling in Thawing Permafrost Microbial Communities

    Science.gov (United States)

    Trubl, G. G.; Solonenko, N.; Moreno, M.; Sullivan, M. B.; Rich, V. I.

    2014-12-01

    Viruses are the most abundant biological entities on Earth and their impact on carbon cycling in permafrost habitats is poorly understood. Arctic C cycling is particularly important to interpret due to the rapid climate change occurring and the large amount of C stockpiled there (~1/3 of global soil C is stored in permafrost). Viruses of microbes (i.e. phages) play central roles in C cycling in the oceans, through cellular lysis (phage drive the largest ocean C flux about 150 Gt yr-1, dwarfing all others by >5-fold), production of associated DOC, as well as transport and expression during infection (1029 transduction events day-1). C cycling in thawing permafrost systems is critical in understanding the climate trajectory and phages may be as important for C cycling here as they are in the ocean. The thawed C may become a food source for microbes, producing CO2 and potentially CH4, both potent greenhouse gases. To address the potential role of phage in C cycling in these dynamic systems, we are examining phage from an arctic permafrost thaw gradient in northern Sweden. We have developed a protocol for successfully extracting phage from peat soils and are quantifying phage in 15 peat and 2 lake sediment cores, with the goal of sequencing viromes. Preliminary data suggest that phage are present at 109 g-1 across the permafrost thaw gradient (compared to the typical marine count ~105 ml-1), implying a potentially robust phage-host interaction web in these changing environments. We are examining phage from 11 depth intervals (covering the active and permafrost layer) in the cores to assess phage-host community dynamics. Phage morphology and abundance for each layer and environment are being determined using qTEM and EFM. Understanding the phage that infect bacteria and archaea in these rapidly changing habitats will provide insight into the controls on current and future CH4 and CO2 emissions in permafrost habitats.

  3. Permafrost degradation after the 2002 wildfire in Kougarok, Seward Peninsula, Alaska

    Science.gov (United States)

    Iwahana, G.; Harada, K.; Uchida, M.; Kondo, M.; Saito, K.; Narita, K.; Kushida, K.; Hinzman, L. D.; Fukuda, M.; Tsuyuzaki, S.

    2014-12-01

    Geomorphological and thermo-hydrological changes after wildfire were investigated here to clarify the rates of permafrost degradation and impacts on the surrounding environment. Study sites are located in Kougarok on the central Seward Peninsula of northwestern Alaska. This area is classified as zones of either continuous and discontinuous permafrost. In 2002, wildfire burned a large area of this region. We selected an intact area and a burned area as research sites located close to one another and divided by a road. The surface organic layer was either combusted or reduced in thickness during the fire. It is assumed that the vegetation cover and subsurface conditions were similar between both sites before the fire. General vegetation at unburned sites was shrub-tussock tundra with more than 30 % evergreen shrubs, about 30 % deciduous shrubs and about 20 % sedges. Our studies of aerial photography and high-resolution satellite images showed that surface subsidence due to thermokarst developed differentially within some of the burned and vehicle-disturbed areas, exposing the polygonal reliefs on the surface. Within burned areas absent the thermokarst polygonal reliefs, soil moisture was higher at burned areas than unburned, and the active layer thickness was about 1.5-2.0 times deeper at the burned area during the initial stage of the study (2005-2007). In the following years, however, the difference in active layer thickness decreased, and thickness for the burned area seemed to be recovering to pre-fire status. Geophysical surveys demonstrated that there had been no detectable difference in the depth of the permafrost base between the burned and unburned areas. On the other hand, at the burned site with thermokarst polygonal reliefs, we confirmed using differential GPS that the polygonal reliefs actually coincides with depression lines along the subsurface ice wedge network. Near-surface unfrozen and frozen soil cores down to 1.6 m depth were sampled at seven and

  4. Analysis of ERT data of geoelectrical permafrost monitoring on Hoher Sonnblick (Austrian Central Alps)

    Science.gov (United States)

    Pfeiler, Stefan; Schöner, Wolfgang; Reisenhofer, Stefan; Ottowitz, David; Jochum, Birgit; Kim, Jung-Ho; Hoyer, Stefan; Supper, Robert; Heinrich, Georg

    2016-04-01

    In the Alps infrastructure facilities such as roads, routes or buildings are affected by the changes of permafrost, which often cause enormous reparation costs. Investigation on degradation of Alpine Permafrost in the last decade has increased, however, the understanding of the permafrost changes inducing its atmospheric forcing processes is still insufficient. Within the project ATMOperm the application of the geoelectrical method to estimate thawing layer thickness for mountain permafrost is investigated near the highest meteorological observatory of Austria on the Hoher Sonnblick. Therefore, it is necessary to further optimize the transformation of ERT data to thermal changes in the subsurface. Based on an innovative time lapse inversion routine for ERT data (Kim J.-H. et al 2013) a newly developed data analysis software tool developed by Kim Jung-Ho (KIGAM) in cooperation with the Geophysics group of the Geological Survey of Austria allows the statistical analysis of the entire sample set of each and every data point measured by the geoelectrical monitoring instrument. This gives on the one hand of course an enhanced opportunity to separate between „good" and „bad" data points in order to assess the quality of measurements. On the other hand, the results of the statistical analysis define the impact of every single data point on the inversion routine. The interpretation of the inversion results will be supplemented by temperature logs from selected boreholes along the ERT profile as well as climatic parameters. KIM J.-H., SUPPER R., TSOURLOS P. and YI M.-J.: Four-dimensional inversion of resistivity monitoring data through Lp norm minimizations. - Geophysical Journal International, 195(3), 1640-1656, 2013. Doi: 10.1093/gji/ggt324. (No OA) Acknowledgments: The geoelectrical monitoring on Hoher Sonnblick has been installed and is operated in the frame of the project ATMOperm (Atmosphere - permafrost relationship in the Austrian Alps - atmospheric extreme

  5. Assessing Silicate Weathering in Permafrost-Dominated Catchments Using Lithium Isotopes: The Lena River, Siberia

    Science.gov (United States)

    Murphy, M. J.; Pogge von Strandmann, P.; Porcelli, D.; Katchinoff, J. A.; Moreras Martí, A.; Hirst, C. A.; Andersson, P. S.; Maximov, T. C.

    2015-12-01

    Rising global temperatures have the potential to influence the Earth's climate feedback cycles due to permafrost thawing, altering the freshwater input and trace metal and carbon fluxes into the ocean and atmosphere. Riverine lithium isotope ratios (d7Li) are a tracer of silicate weathering processes, which are key in the removal of atmospheric CO2 over geological timescales. Despite this, little is known about the effects of permafrost thawing on d7Li variations. Strong seasonal changes in the thawed active layer thickness dictate surficial water flow paths, which may influence intra-annual riverine d7Li signatures. We present a study of the dissolved d7Li from the large permafrost-dominated watersheds of the Lena River (Siberia), which drain into the Arctic Ocean. This work comprises a temporal study during the May 2015 spring flood, from ice breakup through peak flooding, thus monitoring changes in water-rock and water-soil interaction, both processes that control weathering and hence Li isotopes. Before riverine ice started to break up, high [Li] are observed as the river signature is governed by winter base flow conditions. As the river ice breaks up, surface runoff flows over the impermeable permafrost, interacting with leaf litter, diluting the [Li]. We compare d7Li over the spring flood period with a greater spatial study conducted over two summer field seasons (2012/2013) of the main Lena River channel and its tributaries, which drain a variety of lithologies/topographies. During the summer, the thawed active layer promotes deeper water flow paths, greater water-rock interaction and enhanced secondary minerals formation which preferentially take up 6Li. Summer riverine d7Li typically fall between +14.5 ‰ to +28.5 ‰, with rivers draining the Central Siberian Plateau typically exhibiting high [Li], but similar δ7Li to rivers draining the Verkhoyansk Mountain Range. Overall, this study demonstrates how Li isotopes respond to weathering in a permafrost

  6. Collaboration in Education: International Field Class on Permafrost

    Science.gov (United States)

    Streletskiy, D. A.; Shiklomanov, N. I.; Grebenets, V. I.

    2011-12-01

    Field work is a dominant research component in the earth sciences. Understanding and proper use of field methods can enhance the quality of research, while lack of understanding in acquiring data can lead to misleading interpretation of results. Early involvement in field work helps students to bridge the gap between theoretical knowledge and practical applications and to be better prepared for future jobs. However, many University curriculums lack adequate, required field methods courses. Presented are results of collaboration between the George Washington and Moscow State Universities in organization of field courses on Arctic physical and social environments. The latest field course took place in summer 2011 in the Central Siberian region and is a part of the International Permafrost Association education and outreach effort initiated during International Polar Year. The 25 day course involved fifteen Russian and US students who traveled from Moscow to Krasnoyarsk, and then along Yenisey river to Norilsk. This route was chosen as having diversity of natural conditions and variety of economic, engineering, and demographic problems associated with development. The main goal of the class was to investigate permafrost conditions of Central Siberia; dynamics of upper permafrost due to changing climate and under anthropogenic influence; and to understand factors responsible for the diversity of permafrost conditions in the region. The students and instructors were required to make presentations on a variety of topics focusing on the region or research methods, such as climate, vegetation, hydrology, history of development, economics, remote sensing, etc. The emphasis in the field was made on understanding permafrost in relation to other components of the natural system. For example, landscape conditions (including microclimatic, biogeographic and pedologic conditions) were described at every site located in natural settings. Sites located in settlements were evaluated

  7. Permafrost and climate in Europe: monitoring and modelling thermal, geomorphological and geotechnical responses

    OpenAIRE

    2009-01-01

    We present a review of the changing state of European permafrost within a spatial zone that includes the continuous high latitude arctic permafrost of Svalbard and the discontinuous high altitude mountain permafrost of Iceland, Fennoscandia and the Alps. The paper focuses on methodological developments and data collection over the last decade or so, including research associated with the continent-scale network of instrumented permafrost boreholes established between 1998 and 2001 under the E...

  8. Permafrost in Qinghai Province:Characterization and impact on transportation construction

    Institute of Scientific and Technical Information of China (English)

    JianHong Fang; AnHua Xu

    2013-01-01

    Through a long-term summary of highway construction in the permafrost regions of Qinghai Province, the formation conditions and distribution characteristics of permafrost and their impact on transportation construction are analyzed. Research achievements on the stability of highways and urgent technical problems in the transportation construction in permafrost regions are discussed, and new development directions of highway construction in permafrost regions of Qinghai Province are introduced to provide cold regions engineering researchers with valuable references.

  9. What's down below? Current and potential future applications of geophysical techniques to identify subsurface permafrost conditions (Invited)

    Science.gov (United States)

    Douglas, T. A.; Bjella, K.; Campbell, S. W.

    2013-12-01

    can be used to delineate subsurface permafrost geomorphology. This presentation will include examples of projects in Alaska and Greenland where a combination of geophysical and other measurement techniques have been used to identify subsurface conditions. These include projects at multiple locations around Interior Alaska where a variety of ground based and standoff measurements are being used to identify subsurface conditions, and infrastructure projects at Thule, Greenland, where geophysical measurements are being used to cut costs for new construction and maintenance. The expansion of the Cold Regions Research and Engineering Laboratories' Fox Permafrost Tunnel is to provide a three dimensional test bed for geophysical measurements, and construction is aided by geophysical measurements. The array of geophysical research tools used to interrogate the subsurface in permafrost terrains can likely provide worthwhile information in non-frozen ground terrains to support sensor development and geomorphological interpretation.

  10. Microbial Carbon Cycling in Permafrost-Affected Soils

    Energy Technology Data Exchange (ETDEWEB)

    Vishnivetskaya, T. [University of Tennessee, Knoxville (UTK); Liebner, Susanne [University of Tromso, Norway; Wilhelm, Ronald [McGill University, Montreal, Quebec; Wagner, Dirk [Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany

    2011-01-01

    The Arctic plays a key role in Earth s climate system as global warming is predicted to be most pronounced at high latitudes and because one third of the global carbon pool is stored in ecosystems of the northern latitudes. In order to improve our understanding of the present and future carbon dynamics in climate sensitive permafrost ecosystems, present studies concentrate on investigations of microbial controls of greenhouse gas fluxes, on the activity and structure of the involved microbial communities, and on their response to changing environmental conditions. Permafrost-affected soils can function as both a source and a sink for carbon dioxide and methane. Under anaerobic conditions, caused by flooding of the active layer and the effect of backwater above the permafrost table, the mineralization of organic matter can only be realized stepwise by specialized microorganisms. Important intermediates of the organic matter decomposition are hydrogen, carbon dioxide and acetate, which can be further reduced to methane by methanogenic archaea. Evolution of methane fluxes across the subsurface/atmosphere boundary will thereby strongly depend on the activity of anaerobic methanogenic archaea and obligately aerobic methane oxidizing proteobacteria, which are known to be abundant and to significantly reduce methane emissions in permafrost-affected soils. Therefore current studies on methane-cycling microorganisms are the object of particular attention in permafrost studies, because of their key role in the Arctic methane cycle and consequently of their significance for the global methane budget.

  11. Organic and organo-mineral colloids in discontinuous permafrost zone

    Science.gov (United States)

    Pokrovsky, Oleg S.; Manasypov, Rinat M.; Loiko, Sergey V.; Shirokova, Liudmila S.

    2016-09-01

    On-going permafrost thaw in discontinuous permafrost regions produces significant amounts of small permafrost subsidence and depressions, while large lakes are likely to drain into streams and rivers. The intensification of permafrost thaw may alter the size distribution and chemical composition of organo-Fe-Al colloids in lakes and rivers. We used a continuum of surface water bodies, from permafrost subsidence, small depressions and thaw ponds to large lakes and rivers that drain the Western Siberia Lowland (WSL), to assess OC, major and the trace element size distribution between the 20-μm, 5-μm, 1.2-μm, 0.45-μm, 0.22-μm, 0.025-μm and 1-kDa (∼1.4 nm) size fractions. This approach allowed us to distinguish the organic and organo-ferric colloids that were responsible for the transport of trace elements in surface waters and address their evolution during possible physico-chemical and biological processes. Both conventionally dissolved (alkaline earth elements and several micronutrients (Zn, Ba, Mn, and Ni), decreased the degree of their binding to DOM along the landscape continuum, whereas the majority of insoluble TEs (Al, Fe, Co, Cd, Cu, Pb, REEs, Th, and U) remained complexed with DOM in the LMWsoil to rivers will increase.

  12. Using dissolved organic matter age and composition to detect permafrost thaw in boreal watersheds of interior Alaska

    Science.gov (United States)

    O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle Ann; Raymond, Peter A.; Butler, Kenna D.; Dornblaser, Mark M.; Heckman, Katherine

    2014-01-01

    Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting permafrost thaw in three rivers (Beaver, Birch, and Hess Creeks) within the discontinuous permafrost zone of interior Alaska. We observed strong temporal controls on Δ14C content of hydrophobic acid isolates (Δ14C-HPOA) across all rivers, with the most enriched values occurring during spring snowmelt (75 ± 8‰) and most depleted during winter flow (−21 ± 8‰). Radiocarbon ages of winter flow samples ranged from 35 to 445 yr BP, closely tracking estimated median base flow travel times for this region (335 years). During spring snowmelt, young DOM was composed of highly aromatic, high molecular-weight compounds, whereas older DOM of winter flow had lower aromaticity and molecular weight. We observed a significant correlation between Δ14C-HPOA and UV absorbance coefficient at 254 nm (α254) across all study rivers. Usingα254 as an optical indicator for Δ14C-HPOA, we also observed a long-term decline in α254 during maximum annual thaw depth over the last decade at the Hess Creek study site. These findings suggest a shift in watershed hydrology associated with increasing active layer thickness. Further development of DOM optical indicators may serve as a novel and inexpensive tool for detecting permafrost degradation in northern watersheds.

  13. Brief Communication : Future avenues for permafrost science from the perspective of early career researchers

    NARCIS (Netherlands)

    Fritz, M.; Deshpande, B. N.; Bouchard, F.; Högström, E.; Malenfant-Lepage, J.; Morgenstern, A.; Nieuwendam, A.; Oliva, M.; Paquette, M.; Rudy, A. C A; Siewert, M. B.; Sjöberg, Y.; Weege, S.

    2015-01-01

    Accelerating climate change and increased economic and environmental interests in permafrost-affected regions have resulted in an acute need for more directed permafrost research. In June 2014, 88 early career researchers convened to identify future priorities for permafrost research. This multidisc

  14. Permafrost and infrastructure in the Usa Basin (Northeast European Russia) : Possible impacts of global warming

    NARCIS (Netherlands)

    Mazhitova, G.; Karstkarel, N.; Oberman, N.; Romanovsky, V.; Kuhry, P.

    2004-01-01

    The relationship between permafrost conditions and the distribution of infrastructure in the Usa Basin, Northeast European Russia, is analyzed. About 75% of the Basin is underlain by permafrost terrain with various degrees of continuity (isolated patches to continuous permafrost). The region has a h

  15. Muon Tomography of Ice-filled Cleft Systems in Steep Bedrock Permafrost: A Proposal

    CERN Document Server

    Ihl, Matthias

    2010-01-01

    In this note, we propose a novel application of geoparticle physics, namely using a muon tomograph to study ice-filled cleft systems in steep bedrock permafrost. This research could significantly improve our understanding of high alpine permafrost in general and climate-permafrost induced rockfall in particular.

  16. Automatic testing system design and data analysis of permafrost temperature in Qinghai-Tibet Railway

    Institute of Scientific and Technical Information of China (English)

    尚迎春; 齐红元

    2008-01-01

    Aimed at the characteristics of permafrost temperature influencing the safety of Qinghai-Tibet Railway and its on-line testing system, comparing the achievement of permafrost study nationwide with those worldwide, an automatic testing system of permafrost temperature, containing a master computer and some slave computers, was designed. By choosing high-precise thermistors as temperature sensor, designing and positioning the depth and interval of testing sections, testing, keeping and sending permafrost temperature data at time over slave computers, and receiving, processing and analyzing the data of collecting permafrost temperature over master computer, the change of the permafrost temperature can be described and analyzed, which can provide information for permafrost railway engineering design. Moreover, by taking permafrost temperature testing in a certain section of Qinghai-Tibet Railway as an instance, the collected data of permafrost temperature were analyzed, and the effect of permafrost behavior was depicted under the railway, as well as, a BP model was set up to predict the permafrost characteristics. This testing system will provide information timely about the change of the permafrost to support the safety operation in Qinghai-Tibet Railway.

  17. Evidence From Hydrogen Isotopes in Meteorites for a Martian Permafrost

    Science.gov (United States)

    Usui, T.; Alexander, C. M. O'D.; Wang, J.; Simon, J. I.; Jones, J. H.

    2014-01-01

    Fluvial landforms on Mars suggest that it was once warm enough to maintain persistent liquid water on its surface. The transition to the present cold and dry Mars is closely linked to the history of surface water, yet the evolution of surficial water is poorly constrained. We have investigated the evolution of surface water/ ice and its interaction with the atmosphere by measurements of hydrogen isotope ratios (D/H: deuterium/ hydrogen) of martian meteorites. Hydrogen is a major component of water (H2O) and its isotopes fractionate significantly during hydrological cycling between the atmosphere, surface waters, ground ice, and polar cap ice. Based on in situ ion microprobe analyses of three geochemically different shergottites, we reported that there is a water/ice reservoir with an intermediate D/H ratio (delta D = 1,000?2500 %) on Mars. Here we present the possibility that this water/ice reservoir represents a ground-ice/permafrost that has existed relatively intact over geologic time.

  18. Research on Earthquake Precursor in E-TEC: A Study on Land Surface Thermal Anomalies Using MODIS LST Product in Taiwan

    Science.gov (United States)

    Chang, W. Y.; Wu, M. C.

    2014-12-01

    Taiwan has been known as an excellent natural laboratory characterized by rapid active tectonic rate and high dense seismicity. The Eastern Taiwan Earthquake Research Center (E-TEC) is established on 2013/09/24 in National Dong Hwa University and collaborates with Central Weather Bureau (CWB), National Center for Research on Earthquake Engineering (NCREE), National Science and Technology Center for Disaster Reduction (NCDR), Institute of Earth Science of Academia Sinica (IES, AS) and other institutions (NCU, NTU, CCU) and aims to provide an integrated platform for researchers to conduct the new advances on earthquake precursors and early warning for seismic disaster prevention in the eastern Taiwan, as frequent temblors are most common in the East Taiwan rift valley. E-TEC intends to integrate the multi-disciplinary observations and is equipped with stations to monitor a wide array of factors of quake precursors, including seismicity, GPS, strain-meter, ground water, geochemistry, gravity, electromagnetic, ionospheric density, thermal infrared remote sensing, gamma radiation etc, and will maximize the value of the data for researches with the range of monitoring equipment that enable to predict where and when the next devastated earthquake will strike Taiwan and develop reliable earthquake prediction models. A preliminary study on earthquake precursor using monthly Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) data before 2013/03/27 Mw6.2 Nantou earthquake in Taiwan is presented. Using the statistical analysis, the result shows the peak of the anomalous LST that exceeds a standard deviation of LST appeared on 2013/03/09 and became less or none anomalies observed on 2013/03/16 before the main-shock, which is in consist with the phenomenon observed by other researchers. This preliminary experimental result shows that the thermal anomalies reveal the possibility to associate surface thermal phenomena before the strong earthquakes.

  19. Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009

    Science.gov (United States)

    McGuire, A. David; Koven, Charles; Lawrence, David M.; Clein, Joy S.; Xia, Jiangyang; Beer, Christian; Burke, Eleanor; Chen, Guangsheng; Chen, Xiaodong; Delire, Christine; Jafarov, Elchin; MacDougall, Andrew H.; Marchenko, Sergey; Nicolsky, Dmitry; Peng, Shushi; Rinke, Annette; Saito, Kazuyuki; Zhang, Wenxin; Alkama, Ramdane; Bohn, Theodore J.; Ciais, Philippe; Decharme, Bertrand; Ekici, Altug; Gouttevin, Isabelle; Hajima, Tomohiro; Hayes, Daniel J.; Ji, Duoying; Krinner, Gerhard; Lettenmaier, Dennis P.; Luo, Yiqi; Miller, Paul A.; Moore, John C.; Romanovsky, Vladimir; Schädel, Christina; Schaefer, Kevin; Schuur, Edward A. G.; Smith, Benjamin; Sueyoshi, Tetsuo; Zhuang, Qianlai

    2016-07-01

    A significant portion of the large amount of carbon (C) currently stored in soils of the permafrost region in the Northern Hemisphere has the potential to be emitted as the greenhouse gases CO2 and CH4 under a warmer climate. In this study we evaluated the variability in the sensitivity of permafrost and C in recent decades among land surface model simulations over the permafrost region between 1960 and 2009. The 15 model simulations all predict a loss of near-surface permafrost (within 3 m) area over the region, but there are large differences in the magnitude of the simulated rates of loss among the models (0.2 to 58.8 × 103 km2 yr-1). Sensitivity simulations indicated that changes in air temperature largely explained changes in permafrost area, although interactions among changes in other environmental variables also played a role. All of the models indicate that both vegetation and soil C storage together have increased by 156 to 954 Tg C yr-1 between 1960 and 2009 over the permafrost region even though model analyses indicate that warming alone would decrease soil C storage. Increases in gross primary production (GPP) largely explain the simulated increases in vegetation and soil C. The sensitivity of GPP to increases in atmospheric CO2 was the dominant cause of increases in GPP across the models, but comparison of simulated GPP trends across the 1982-2009 period with that of a global GPP data set indicates that all of the models overestimate the trend in GPP. Disturbance also appears to be an important factor affecting C storage, as models that consider disturbance had lower increases in C storage than models that did not consider disturbance. To improve the modeling of C in the permafrost region, there is the need for the modeling community to standardize structural representation of permafrost and carbon dynamics among models that are used to evaluate the permafrost C feedback and for the modeling and observational communities to jointly develop data sets

  20. GAPHAZ: improving knowledge management of glacier and permafrost hazards and risks in mountains

    Science.gov (United States)

    Huggel, Christian; Burn, Chris; Clague, John J.; Hewitt, Ken; Kääb, Andreas; Krautblatter, Michael; Kargel, Jeffrey S.; Reynolds, John; Sokratov, Sergey

    2014-05-01

    -researched and monitored regions to the more extensive and diverse regions needs to be addressed.. Standards are required to ensure an adequate level of quality and to avoid incorrect assessments with potentially adverse consequences, as experiences in the past have shown. Concepts and terminologies related to hazard and risk assessments must follow recently issued consensus statements, such as those of UN-ISDR and IPCC. Hazard assessments must be undertaken routinely and regularly, combined with appropriate ground-based and remote sensing monitoring. Assessments need to adequately consider the physical processes and their interactions. Integrative risk assessments should be achieved by interdisciplinary cooperation. There is still a lack of integration of physical/engineering and social aspects of glacier and permafrost hazards; therefore communication and exchange between natural and social science experts must be strengthened. In the design and implementation of risk reduction and adaptation measures, a close collaboration among scientists, policy makers, and local populations is necessary. Recognizing different perceptions of risks among actors are particularly important if risk reduction efforts are to be successful. Measures should generally be adapted to the local social, cultural, economic, political, and institutional context. Early warning systems are becoming increasingly important, and a growing number of experiences are available also for high-mountain environments. A systematic analysis and exchange of experiences using dedicated expert networks will be fostered by GAPHAZ in collaboration with other initiatives and actors.

  1. Permafrost and geotechnical investigations in Nalaikh Depression of Mongolia

    Institute of Scientific and Technical Information of China (English)

    Dashjamts Dalai; Batsaikhan Anand; Dugersuren Enkhbaatar

    2015-01-01

    Mongolia is a land-locked country in Central Asia, located between Russia and China. The country's high altitude results in cold, dry, and harsh climatic conditions with permafrost being widespread through the territory. Although the capital city Ulaanbaatar is situated in an area with discontinuous permafrost, the downtown section has recently seen a disappearance of permafrost due to an underground central heating system. During the last decade, expansion of the suburbs toward the Nalaikh Depression has resulted in construction of a new residential complex (Urgakh Naran), construction materials trading center, cement factory and agricultural products market. In the next 10 years, projects such as a university campus, logistics center, residential complex, railway and highway extensions connecting Russia and China have been planned. Engineer-ing-geological and geotechnical investigations have been conducted for these construction projects. This paper presents some of the results determining the engineering geocryological conditions of Nalaikh district and offers foundation design options.

  2. The convection cooling system of the Yakutsk permafrost seed repository

    Institute of Scientific and Technical Information of China (English)

    Vladimir N.Panin; Georgii P.Kuzmin

    2014-01-01

    Temperature is critical to maintaining seed viability under long term storage conditions. It has been common practice to use refrigeration systems to maintain required storage temperatures. A seed repository constructed in permafrost in Ya kutsk, Russia is the first seed storage facility that relies solely on natural cold. This paper describes the design and per formance of the cooling system of the repository. An innovative aspect of the cooling system is that it utilizes the patterns of temperature wave propagation in permafrost. Predicted and measured ground temperatures for the first year of operation are presented and analyzed. Results indicate that convection air cooling systems can be used to control the temperature regime in underground facilities in permafrost.

  3. The Ecological Situation in the Russian Arctic Permafrost Zone

    Directory of Open Access Journals (Sweden)

    Petrov Sergei

    2016-01-01

    Full Text Available The paper describes innovative approaches to ensure environmental safety in the production of hydrocarbon material in a permafrost zone. Studies the anthropogenic environmental factors, climatic and geographical and geological conditions of Purovskiy district of Yamalo-Nenets Autonomous Area (YaNAO. We consider the chemical characteristics of wastewater discharged into surface water objects, polluting emissions into the atmosphere. The conclusions of the environmental situation in Purovskiy and Ustpurovsk-Tazovskiy permafrost areas. Calculate the concentration of pollutants in the control section of the water object and the maximum ground-level concentrations of pollutants in the atmospheric air. The conclusions about the exceeding the maximum permissible concentration (MPC in the atmospheric air for solids, carbon monoxide, nitrogen dioxide. Was examined the climatic conditions of the Far North. Correlational analysis was performed between human factors and temperature conditions of the northern territories, as well as between the climate and natural features cryological and disturbed permafrost soils.

  4. Expert assessment of vulnerability of permafrost carbon to climate change

    Science.gov (United States)

    Schuur, E.A.G.; Abbott, B.W.; Bowden, W.B.; Brovkin, V.; Camill, P.; Canadell, J.G.; Chanton, J.P.; Chapin, F. S.; Christensen, T.R.; Ciais, P.; Crosby, B.T.; Czimczik, C.I.; Grosse, G.; Harden, J.; Hayes, D.J.; Hugelius, G.; Jastrow, J.D.; Jones, J.B.; Kleinen, T.; Koven, C.D.; Krinner, G.; Kuhry, P.; Lawrence, D.M.; McGuire, A.D.; Natali, Susan M.; O'Donnell, J. A.; Ping, C.-L.; Riley, W.J.; Rinke, A.; Romanovsky, V.E.; Sannel, A.B.K.; Schädel, C.; Schaefer, K.; Sky, J.; Subin, Z.M.; Tarnocai, C.; Turetsky, M.R.; Waldrop, M.P.; Anthony, K.M. Walter; Wickland, K.P.; Wilson, C.J.; Zimov, S.A.

    2013-01-01

    Approximately 1700 Pg of soil carbon (C) are stored in the northern circumpolar permafrost zone, more than twice as much C than in the atmosphere. The overall amount, rate, and form of C released to the atmosphere in a warmer world will influence the strength of the permafrost C feedback to climate change. We used a survey to quantify variability in the perception of the vulnerability of permafrost C to climate change. Experts were asked to provide quantitative estimates of permafrost change in response to four scenarios of warming. For the highest warming scenario (RCP 8.5), experts hypothesized that C release from permafrost zone soils could be 19–45 Pg C by 2040, 162–288 Pg C by 2100, and 381–616 Pg C by 2300 in CO2 equivalent using 100-year CH4 global warming potential (GWP). These values become 50 % larger using 20-year CH4 GWP, with a third to a half of expected climate forcing coming from CH4 even though CH4 was only 2.3 % of the expected C release. Experts projected that two-thirds of this release could be avoided under the lowest warming scenario (RCP 2.6). These results highlight the potential risk from permafrost thaw and serve to frame a hypothesis about the magnitude of this feedback to climate change. However, the level of emissions proposed here are unlikely to overshadow the impact of fossil fuel burning, which will continue to be the main source of C emissions and climate forcing.

  5. Permafrost in Space: first results of experiment "EXOBIOFROST"

    Science.gov (United States)

    Spirina, Elena; Rivkina, Elizaveta; Shmakova, Lubov; Mironov, Vasiliy; Shatilovich, Anastasiya

    Experiment "EXOBIOFROST" was conducted as part of BION-M project of Russian Space Agency. We investigated a response of microbial complexes, including the pure cultures of microorganisms isolated from permafrost and the initial permafrost samples of different origin and age on space conditions. Duration of experiment was 1 month, from April, 19 to May, 19, 2013. All samples were investigated before and after the space flight. For the experiment we selected five samples of permafrost soil from Kolyma-Indigirka Lowland and Antarctica, and also the cultures of microorganisms: Exiguobacterium sibiricum - gram negative bacteria; Colpoda Steinii and Exocolpoda augustini — ciliates, and two strains of Acanthamoeba castelliane. Studies have revealed differences in structure and composition of microbial communities in control and in post-flight samples. All Arctic samples were characterized by a significant, 3-5 orders of magnitude, increase in the number of microorganisms compared to the control samples. However, there is a marked reduction in the amount of extracted DNA in post-flight permafrost samples. Post-flight analysis of ciliates, Colpoda Steinii and Exocolpoda augustini, revealed that 70-97% of cysts are damaged. In general, the primary post-flight analysis and a comparison with the control samples showed that the modern tundra colpoda more resistant to space conditions than they from the ancient permafrost sediments and strain of Colpoda steinii more resistant than the strain Exocolpoda augustini. Post-flight analysis of Acanthamoeba castelliane showed presence of viable cysts capable of excystation. Thus, we can conclude that the experiment "EXOBIOFROST" conducted in open space on the apparatus BION-M №1 does not prove fatal to permafrost microorganisms.

  6. Aliphatic side chains of proteins as potential geomarkers of NOM liberated from the melting permafrost and discharged to the Arctic Ocean by the Kolyma River run off

    Science.gov (United States)

    Dubinenkov, I. V.; Perminova, I.; Kononikhin, A.; Nikolaev, E.; Hertkorn, N.; Bulygina, E. B.; Holmes, R. M.

    2011-12-01

    , etc). Mobilization of much more bioavailable pool of organic compounds such as peptides, which were found in the permafrost samples might affect substantially carbon cycling in the region and in the Arctic Ocean. Further understanding of carbon turnover in the Arctic region on the molecular level is needed to predict the possible consequences of massive permafrost thaw for the global climate change and reveal the reliable geomarkers of this process. This can be achieved with a combined use of NMR and FTICRMS spectroscopic techniques possessing unprecedented resolution power for investigation of complex mixtures.. Acknowledgement. This study is part of the Polaris Project, an NSF-funded undergraduate field program based out of the Northeast Science Station in Cherskiy, Northeast Siberia (www.thepolarisproject.org). The research was supported by CRDF-RFBR Grant 09-03-92500 and Travel Grant of IHSS allocated in 2011 to Ivan Dubinenkov.

  7. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated

  8. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-07-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope drilled and cored a well The HOT ICE No.1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report.

  9. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-06-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope drilled and cored a well The HOT ICE No.1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report.

  10. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the second year of a three-year endeavor being sponsored by Maurer Technology, Noble, and Anadarko Petroleum, in partnership with the DOE. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition. We plan to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. We also plan to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope is to drill and core a well on Anadarko leases in FY 2003 and 2004. We are also using an on-site core analysis laboratory to determine some of the physical characteristics of the hydrates and surrounding rock. The well is being drilled from a new Anadarko Arctic Platform that will have minimal footprint and environmental impact. We hope to correlate geology, geophysics, logs, and drilling and production data to allow reservoir models to be calibrated. Ultimately, our goal is to form an objective technical and economic evaluation of reservoir potential in Alaska.

  11. Relationship between Methane Content in Siberian Permafrost and Soil Properties

    Science.gov (United States)

    Brouchkov, A.; Fukuda, M.

    2004-05-01

    Methane is one of the greenhouse gases among other gases, and it is important to identify sources of methane. Permafrost deposits in Siberia contain large amounts of methane in air bubbles, and there is a high possibility of permafrost thawing due to climatic warming. However, distribution of methane in frozen deposits is still poorly known. It should be related to soil content and properties. Therefore, present knowledge of permafrost soils collected by a number of studies can be a key to understanding of methane distribution; the subject was never discussed before. Air bubbles from frozen soil and ice were sampled at the uppermost layers of permafrost from the depth up to 5 and more m in Eastern Siberia. The major study site was located in valley of Lena River. The permafrost samples were obtained by shallow borehole drilling. Soil composition, density and water content were also measured as well as the concentration of gases in the air bubbles. Total number of air samples was about 200. Air from soils was analyzed by gas chromatograph. No certain relationship between methane concentration and depth was found. Highly concentrated methane occurs in permafrost at different depths. Ice wedges contain less methane than frozen soils in general. There no obvious tendencies between water contents and values of concentrations of both methane and carbon dioxide were found. Methane content increases in general with water content increase, and carbon dioxide content becomes lower; however, in some cases the tendency is opposite, if the concentration is high (up to 70 ppt). Data collected on ion (salt) content is limited, but methane content rises with salinization increase. Low methane content and low salinization in the same time could be connected to possible thawing of permafrost when soil could be washed. Frozen soils containing large amounts of methane and being thawed have average pH about 7-9. The more density and age of frozen soil the more methane content; it could

  12. Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway

    Institute of Scientific and Technical Information of China (English)

    JIN; Huijun; ZHAO; Lin; WANG; Shaoling

    2006-01-01

    Permafrost on the Qinghai-Tibet Plateau (QTP) is widespread, thin, and thermally unstable. Under a warming climate during the past few decades, it has been degrading extensively with generally rising ground temperatures, the deepening of the maximum summer thaw, and with lessening of the winter frost penetration. The permafrost has degraded downward, upward and laterally.Permafrost has thinned or, in some areas, has totally disappeared. The modes of permafrost degradation have great significance in geocryology, in cold regions engineering and in cold regions environmental management. Permafrost in the interior of the QTP is well represented along the Qing-hal-Tibet Highway (QTH), which crosses the Plateau through north to south and traverses 560 km of permafrost-impacted ground. Horizontally, the degradation of permafrost occurs more visibly in the sporadic permafrost zone in the vicinity of the lower limit of permafrost (LLP), along the margins of taliks, and around permafrost islands. Downward degradation develops when the maximum depth of seasonal thaw exceeds the maximum depth of seasonal frost, and it generally results in the formation of a layered talik disconnecting the permafrost from the seasonal frost layer. The downward degradation is divided into four stages: 1) initial degradation, 2) accelerated degradation, 3) layered talik and 4)finally the conversion of permafrost to seasonally frozen ground (SFG). The upward degradation occurs when the geothermal gradient in permafrost drops to less than the geothermal gradients in the underlying thawed soil layers. Three types of permafrost temperature curves (stable, degrading, and phase-changing transitory permafrost) illustrate these modes. Although strong differentiations in local conditions and permafrost types exist, the various combinations of the three degradation modes will ultimately transform permafrost into SFG. Along the QTH, the downward degradation has been proceeding at annual rates of 6 to 25 cm

  13. Great challenges of and innovative solutions to the unstable permafrost in Central and High Asia under a warming climate-the first Asian Conference on Permafrost

    Institute of Scientific and Technical Information of China (English)

    Huijun Jin; Jerry Brown

    2007-01-01

    @@ The first Asian Conference on Permafrost (ACOP) was co-sponsored by the State Key Laboratory of Frozen Soils Engineering(SKLFSE) of the Cold and Arid Regions Environmental and Engineering Research Institute (CAREERI), the Geographical Society of China (GSA), and the Intema-tional Permafrost Association (IPA), and cochaired by Academician Guodong Cheng,President of the Chinese Academy of Sci-ences Lanzhou Branch, and Professor Jerry Brown, President, International Permafrost Association.

  14. Satellite-derived NDVI, LST, and climatic factors driving the distribution and abundance of Anopheles mosquitoes in a former malarious area in northwest Argentina.

    Science.gov (United States)

    Dantur Juri, María Julia; Estallo, Elizabet; Almirón, Walter; Santana, Mirta; Sartor, Paolo; Lamfri, Mario; Zaidenberg, Mario

    2015-06-01

    Distribution and abundance of disease vectors are directly related to climatic conditions and environmental changes. Remote sensing data have been used for monitoring environmental conditions influencing spatial patterns of vector-borne diseases. The aim of this study was to analyze the effect of the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and climatic factors (temperature, humidity, wind velocity, and accumulated rainfall) on the distribution and abundance of Anopheles species in northwestern Argentina using Poisson regression analyses. Samples were collected from December, 2001 to December, 2005 at three localities, Aguas Blancas, El Oculto and San Ramón de la Nueva Orán. We collected 11,206 adult Anopheles species, with the major abundance observed at El Oculto (59.11%), followed by Aguas Blancas (22.10%) and San Ramón de la Nueva Orán (18.79%). Anopheles pseudopunctipennis was the most abundant species at El Oculto, Anopheles argyritarsis predominated in Aguas Blancas, and Anopheles strodei in San Ramón de la Nueva Orán. Samples were collected throughout the sampling period, with the highest peaks during the spring seasons. LST and mean temperature appear to be the most important variables determining the distribution patterns and major abundance of An. pseudopunctipennis and An. argyritarsis within malarious areas. © 2015 The Society for Vector Ecology.

  15. Review and synthesis: Changing permafrost in a warming world and feedbacks to the Earth System

    Science.gov (United States)

    Grosse, Guido; Goetz, Scott; McGuire, Anthony; Romanovsky, Vladimir E.; Schuur, Edward A.G.

    2016-01-01

    The permafrost component of the cryosphere is changing dramatically, but the permafrost region is not well monitored and the consequences of change are not well understood. Changing permafrost interacts with ecosystems and climate on various spatial and temporal scales. The feedbacks resulting from these interactions range from local impacts on topography, hydrology, and biology to complex influences on global scale biogeochemical cycling. This review contributes to this focus issue by synthesizing its 28 multidisciplinary studies which provide field evidence, remote sensing observations, and modeling results on various scales. We synthesize study results from a diverse range of permafrost landscapes and ecosystems by reporting key observations and modeling outcomes for permafrost thaw dynamics, identifying feedbacks between permafrost and ecosystem processes, and highlighting biogeochemical feedbacks from permafrost thaw. We complete our synthesis by discussing the progress made, stressing remaining challenges and knowledge gaps, and providing an outlook on future needs and research opportunities in the study of permafrost–ecosystem–climate interactions.

  16. New permafrost is forming around shrinking Arctic lakes, but will it last?

    Science.gov (United States)

    Briggs, Martin A.; Walvoord, Michelle A.; McKenzie, Jeffrey M.; Voss, Clifford I.; Day-Lewis, Frederick D.; Lane, Jr., John W.

    2014-01-01

    Widespread lake shrinkage in cold regions has been linked to climate warming and permafrost thaw. Permafrost aggradation, however, has been observed within the margins of recently receded lakes, in seeming contradiction of climate warming. Here permafrost aggradation dynamics are examined at Twelvemile Lake, a retreating lake in interior Alaska. Observations reveal patches of recently formed permafrost within the dried lake margin, colocated with discrete bands of willow shrub. We test ecological succession, which alters shading, infiltration, and heat transport, as the driver of aggradation using numerical simulation of variably saturated groundwater flow and heat transport with phase change (i.e., freeze-thaw). Simulations support permafrost development under current climatic conditions, but only when net effects of vegetation on soil conditions are incorporated, thus pointing to the role of ecological succession. Furthermore, model results indicate that permafrost aggradation is transitory with further climate warming, as new permafrost thaws within seven decades.

  17. Hydrological and Biogeochemical Trajectories Change in Response to Permafrost Thaw in Arctic and Subarctic Regions

    Science.gov (United States)

    Striegl, R. G.; Walvoord, M. A.

    2012-12-01

    High latitude regions are particularly susceptible to changes in hydrology, carbon and nutrient biogeochemistry, and ecosystem dynamics in response to climate warming. However, these regions are vast, have few historical data, and are difficult to study because of their remoteness. Large-scale studies of water and materials exports by river systems inform on changes that are occurring on the basin scale, but provide limited process level information. Conversely, process studies in small watersheds and catchments provide bounds on responses to environmental change, but have limited value in scaling to larger systems, unless the variability of controlling conditions has been adequately captured and the distribution of these conditions is known. Regional process-based models that accurately account for spatial and temporal variability can inform on the potential location and intensity of change in a basin or region. We use the Yukon River basin of Alaska USA and NW Canada as a model for understanding the trajectories of hydrologic and carbon cycle changes in permafrost-dominated landscapes. Early measurements of carbon exports by the Yukon River suggested that recent changes in hydrology were affecting C exports; this was confirmed by historical analyses of change in groundwater contributions to river flow. Since all carbon cycling processes are directly linked to water distribution, availability, and movement, we recognized the need for implementing hydrologic models to quantify the role of permafrost on water flow and distribution and to accurately project hydrologic conditions, based on historical hydrologic information, current and projected land surface and subsurface information, and current and projected climatic information. Coupling of hydrologic projections with source, sink, and other process understanding of carbon biogeochemistry resulted in improved basin scale understanding of current and future carbon dynamics in permafrost-dominated landscapes.

  18. PYRN-Bib: The Permafrost Young Researchers Network Bibliography of Permafrost-Related Degree-Earning Theses

    Science.gov (United States)

    Grosse, Guido; Lantuit, Hugues; Gärtner-Roer, Isabelle

    2010-05-01

    PYRN-Bib is an international bibliographical database aiming at collecting and distributing information on all theses submitted for earning a scientific degree in permafrost-related research. PYRN-Bib is hosted by the Permafrost Young Researchers Network (PYRN, http://pyrn.ways.org), an international network of early career students and young scientists in permafrost related research with currently more than 750 members. The fully educational, non-profit project PYRN-Bib is published under the patronage of the International Permafrost Association (IPA). The bibliography covers all theses as long as they clearly treat aspects of permafrost research from such diverse fields as: Geophysics, Geology, Cryolithology, Biology, Biogeochemistry, Microbiology, Astrobiology, Chemistry, Engineering, Geomorphology, Remote Sensing, Modeling, Mineral and Hydrocarbon Exploration, and Science History and Education. The specific goals of PYRN-Bib are (1) to generate a comprehensive database that includes all degree-earning theses (e.g. Diploma, Ph.D., Master, etc.), coming from any country and any scientific field, under the single condition that the thesis is strongly related to research on permafrost and/or periglacial processes; (2) to reference unique but buried sources of information including theses published in languages other than English; (3) to make the database widely available to the scientific community and the general public; (4) to solicit PYRN membership; and (5) to provide a mean to map the evolution of permafrost research over the last decades, including regional trends, shifts in research direction, and/or the place of permafrost research in society. PYRN-Bib is available online and maintained by PYRN. The complete bibliography can be downloaded at no cost and is offered in different file formats: tagged Endnote library, XML, BibTex, and PDF. New entries are continuously provided by PYRN members and the scientific community. PYRN-Bib currently contains more than

  19. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and

  20. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2004-11-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored a well (the Hot Ice No. 1) on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained

  1. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored a well (the Hot Ice No. 1) on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained

  2. Changing Permafrost in the Arctic and its Global Effects in the 21st Century (PAGE21): A very large international and integrated project to measure the impact of permafrost degradation on the climate system

    Science.gov (United States)

    Lantuit, Hugues; Boike, Julia; Dahms, Melanie; Hubberten, Hans-Wolfgang

    2013-04-01

    climate-change mitigation. The concept of PAGE21 is to directly address these questions through a close interaction between monitoring activities, proc-ess studies and modeling on the pertinent temporal and spatial scales. Field sites have been selected to cover a wide range of environmental conditions for the validation of large scale mod-els, the development of permafrost monitoring capabilities, the study of permafrost processes, and for overlap with existing monitoring programs. PAGE21 will contribute to upgrading the project sites with the objective of providing a measurement baseline, both for process studies and for modeling programs. PAGE21 is determined to break down the traditional barriers in permafrost sciences between observational and model-supported site studies and large-scale climate modeling. Our concept for the interaction between site-scale studies and large-scale modeling is to establish and maintain a direct link be-tween these two areas for developing and evaluating, on all spatial scales, the land-surface modules of leading European global climate models taking part in the Coupled Model Inter-comparison Project Phase 5 (CMIP5), designed to inform the IPCC process. The timing of this project is such that the main scientific results from PAGE21, and in particular the model-based assessments will build entirely on new outputs and results from the CMIP5 Climate Model Intercomparison Project designed to inform the IPCC Fifth Assessment Report. However, PAGE21 is designed to leave a legacy that will en-dure beyond the lifetime of the projections that it produces. This legacy will comprise • an improved understanding of the key processes and parameters that determine the vulnerability of arctic permafrost to climate change, • the production of a suite of major European coupled climate models including detailed and validated repre-sentations of permafrost-related processes, that will reduce uncertainties in future climate projections pro-duced well

  3. Permafrost in Marine Deposits at Ilulissat Airport in Greenland, Revisited

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Ingeman-Nielsen, Thomas

    2008-01-01

    residual salt content in the porewater. However, in the less saline top zone massive ice layers was found constituting up to 30 volume%. These formations representing a type example of saline permafrost caused the planned position of the runway to be shifted towards northwest and a removal of the layers...

  4. Relict gas hydrates as possible reason of gas emission from shallow permafrost at the northern part of West Siberia

    Science.gov (United States)

    Chuvilin, Evgeny; Bukhanov, Boris; Tumskoy, Vladimir; Istomin, Vladimir; Tipenko, Gennady

    2017-04-01

    zone) permafrost horizons. The results show that all investigated frozen hydrate-bearing sandy and silty sand samples in the temperature range from -16 °C to -2 °C are characterized by not complete decomposition of pore hydrate at relieving pressure below the equilibrium. It was observed that at typical north Western Siberian permafrost temperature of -6 ° C the safety of pore hydrate in frozen samples can reach 60% at the pressure reducing below the equilibrium. In was found that with increasing temperature and particle size (dispersity) the efficiency of pore hydrate self-preservation is decreased, but even at the temperature of -2 °C there is residual pore methane hydrate content in non-saline sandy samples. All this suggests about high preservation of methane hydrates in frozen sediments at non-equilibrium thermobaric conditions, close to reservoir conditions. Based on the results of mathematical and experimental simulations about the possibility of relic gas hydrates existence on permafrost depth up to 200 m in the northern part of Western Siberia on the less than 200 m due to geological manifestation of the self-preservation effect of gas hydrates. References. 1.Chuvilin EM, Yakushev VS, Perlova EV. Gas and gas hydrates in the permafrost of Bovanenkovo gas field, Yamal Peninsula, West Siberia. // Polarforschung 68: 215-219, 1998. (erschienen 2000). 2.Yakushev V.S., Chuvilin E.M. 2000. Natural gas and hydrate accumulation within permafrost in Russia. Cold Regions Science and Technology. 31: 189-197. These researches are supported by grant RSF №16-17-00051.

  5. Carbon and Nitrogen cycling in a permafrost soil profile

    Science.gov (United States)

    Salmon, V. G.; Schaedel, C.; Mack, M. C.; Schuur, E.

    2015-12-01

    In high latitude ecosystems, active layer soils thaw during the growing season and are situated on top of perennially frozen soils (permafrost). Permafrost affected soil profiles currently store a globally important pool of carbon (1330-1580 PgC) due to cold temperatures constraining the decomposition of soil organic matter. With global warming, however, seasonal thaw is expected to increase in speed and extend to deeper portions of the soil profile. As permafrost soils become part of the active layer, carbon (C) and nitrogen (N) previously stored in soil organic matter will be released via decomposition. In this experiment, the dynamic relationship between N mineralization, C mineralization, and C quality was investigated in moist acidic tundra soils. Soils from the active layer surface down through the permafrost (80cm) were incubated aerobically at 15°C for 225 days. Carbon dioxide fluxes were fit with a two pool exponential decay model so that the size and turnover of both the quickly decomposing C pool (Cfast) and the slowly decomposing C pool (Cslow) could be assessed. Soil extractions with 2M KCl were performed at six time points throughout the incubation so that dissolve inorganic N (DIN) and dissolved organic C (DOC) could be measured. DIN was readily extractable from deep permafrost soils throughout the incubation (0.05 mgN/g dry soil) but in active layer soils DIN was only produced after Cfast had been depleted. In contrast, active layer soils had high levels of DOC (0.65 mgC/g dry soil) throughout the incubation but in permafrost soils, DOC became depleted as Cfast reduced in size. The strong contrasts between the C and N cycling in active layer soils versus permafrost soils suggest that the deeper thaw will dramatically increase N availability in these soil profiles. Plants and soil microbes in the tundra are currently N limited so our findings imply that deepening thaw will 1) provide N necessary for increased plant growth and 2) stimulate losses of

  6. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment

    OpenAIRE

    2016-01-01

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are ...

  7. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire:an expert assessment

    OpenAIRE

    2016-01-01

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are ...

  8. 应用等效纬度-海拔模型进行地温及多年冻土制图%Ground Temperature and Permafrost Mapping Using an Equivalent Latitude/Elevation Model

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This research presents a method for permafrost mapping in discontinuous permafrost regions based on equivalent latitude/elevation concept in interior Alaska. In winter months, study site has a strong temperature inversion in air up to 700 m elevation. Air temperature data and the effects of slope, aspect and elevation were used to create an equivalent latitude/elevation model. This model was well correlated with mean annual surface temperature (0.79). In this watershed, the thawing index (It≈1 400 ℃*days) at the ground surface and snow depth do not vary greatly from south facing to north facing slopes. The primary controlled factor that determines the mean annual surface temperature was the winter surface temperature. The permafrost stability is effectively controlled by the freezing index. We determined 37.5% of Caribou-Poker Creeks Research Watershed has unstable or thawing permafrost. At least 2.1% of the permafrost in this watershed may have disappeared in the last 90 years due to climate warming. This method makes it possible to evaluate the permafrost stability in the present, past and future.

  9. Growth of trees on permafrost: habitat driven response to climate

    Science.gov (United States)

    Bryukhanova, Marina; Fonti, Patrick; Kirdyanov, Alexander; Saurer, Matthias; Siegwolf, Rolf; Pochebit, Natalia; Sidorova, Olga; Prokushkin, Anatoly

    2013-04-01

    Global change is expected to alter boreal forest conditions with far reaching consequences for tree growth in these ecosystems. Within this study we aimed at determining which limiting factors control tree-growth on permafrost under different site conditions. A tree-ring multi-proxy characterisation of mature Larix gmelinii (Rupr.) Rupr. from a continuous permafrost zone of Siberia (Russia, 64°18' N, 100°11' E) was used to identify the physiological principle of responses related to the plant-soil system. Tree-ring width (1975-2009), carbon and oxygen stable isotopes, and xylem structural characteristics (2000-2009) indicated that an increased depth of the soil active layer favors a better exploitation of the available resources. Our study used a mechanistic description of expected soil thermo-hydrological changes associated with a detailed comparison of tree growth responses, and supplied possible scenarios of northern larch stands development under projected climate change and permafrost degradation. By using a "space for time" approach along a 100 m long transect characterized by distinct permafrost regimes combined with measurements of physiological and structural tree responses, it become possible to propose a mechanism responsible for the differing climatic-growth responses. The results obtained indicate global warming to promote large increases in tree productivity of permafrost larch stands with a shift from a cold to a water limited environment. This work was supported by the SNSF (VG IZ76Z0_141967/1, SCOPES IZ73Z0_128035) and grant form the President of the Russian Federation for young scientists 5498.2012.4.

  10. Potential Arctic tundra vegetation shifts in response to changing temperature, precipitation and permafrost thaw

    Science.gov (United States)

    van der Kolk, Henk-Jan; Heijmans, Monique M. P. D.; van Huissteden, Jacobus; Pullens, Jeroen W. M.; Berendse, Frank

    2016-11-01

    Over the past decades, vegetation and climate have changed significantly in the Arctic. Deciduous shrub cover is often assumed to expand in tundra landscapes, but more frequent abrupt permafrost thaw resulting in formation of thaw ponds could lead to vegetation shifts towards graminoid-dominated wetland. Which factors drive vegetation changes in the tundra ecosystem are still not sufficiently clear. In this study, the dynamic tundra vegetation model, NUCOM-tundra (NUtrient and COMpetition), was used to evaluate the consequences of climate change scenarios of warming and increasing precipitation for future tundra vegetation change. The model includes three plant functional types (moss, graminoids and shrubs), carbon and nitrogen cycling, water and permafrost dynamics and a simple thaw pond module. Climate scenario simulations were performed for 16 combinations of temperature and precipitation increases in five vegetation types representing a gradient from dry shrub-dominated to moist mixed and wet graminoid-dominated sites. Vegetation composition dynamics in currently mixed vegetation sites were dependent on both temperature and precipitation changes, with warming favouring shrub dominance and increased precipitation favouring graminoid abundance. Climate change simulations based on greenhouse gas emission scenarios in which temperature and precipitation increases were combined showed increases in biomass of both graminoids and shrubs, with graminoids increasing in abundance. The simulations suggest that shrub growth can be limited by very wet soil conditions and low nutrient supply, whereas graminoids have the advantage of being able to grow in a wide range of soil moisture conditions and have access to nutrients in deeper soil layers. Abrupt permafrost thaw initiating thaw pond formation led to complete domination of graminoids. However, due to increased drainage, shrubs could profit from such changes in adjacent areas. Both climate and thaw pond formation

  11. Warming permafrost and active layer variability at Cime Bianche, Western Alps

    Directory of Open Access Journals (Sweden)

    P. Pogliotti

    2014-07-01

    Full Text Available The objective of this paper is to provide a first synthesis on the state and recent evolution of permafrost at the monitoring site of Cime Bianche (3100 m a.s.l.. The analysis is based on seven years of ground temperatures observations in two boreholes and seven surface points. The analysis aims to quantify the spatial and temporal variability of ground surface temperatures in relation to snow cover, the small scale spatial variability of the active layer thickness and the warming trends on deep permafrost temperatures. Results show that the heterogeneity of snow cover thickness, both in space and time, is the main factor controlling ground surface temperatures and leads to a mean range of spatial variability (2.5±0.15°C which far exceeds the mean range of observed inter-annual variability (1.6±0.12°C. The active layer thickness measured in two boreholes 30 m apart, shows a mean difference of 2.03±0.15 m with the active layer of one borehole consistently lower. As revealed by temperature analysis and geophysical soundings, such a difference is mainly driven by the ice/water content in the sub-surface and not by the snow cover regimes. The analysis of deep temperature time series reveals that permafrost is warming. The detected linear trends are statistically significant starting from depth below 8 m, span the range 0.1–0.01°C year−1 and decrease exponentially with depth. Our findings are discussed in the context of the existing literature.

  12. The state of permafrost surrounding "Gabriel de Castilla" Spanish Antarctic Station (Deception Island, Antarctica): Studying the possible degradation due to the infrastructures heating effect.

    Science.gov (United States)

    Recio, Cayetana; Ángel de Pablo, MIguel; Ramos, MIguel; Molina, Antonio

    2015-04-01

    Permafrost degradation is one of the effects of the global warming. Many studies reveal the increase of active layer and reduction on permafrost table thickness, also in Antarctica. However, these trends on permafrost can be accelerated by the human activities, as the heating produced by the Antarctic stations infrastructures when they are not properly isolated from the ground. In Deception island, South Shetland Archipelago, we started 3 years ago a monitoring program at the 26 years old "Gabriel de Castilla" Spanish Antarctic Station (SAS), It is focused on charactering the state of permafrost, since in the coastal scarps at tens of meters from the station an increase on erosion had been detected. Although the main cause of the erosion of this coastal volcanoclastic materials is the 2 meters thick icefield which forms during the winter in the inner sea of this volcanic island, we want to detect any possible contribution to the coastal erosion caused by the permafrost degradation related to the SAS presence. We present our preliminary analysis based on three years of continuous ground temperature data, monitored at a shallow borehole (70 cm deep) in the SAS edge, together with the active layer thickness measured around the station and their vicinities in two thawing seasons. We complete this study with the analysis of the continuous temperature data taken inside the SAS and the air and ground temperatures below the station, acquired during the last Antarctic Campaign (December 2014-February 2015). These preliminary results are fundamental 1) to discard any contribution from the SAS presence, and to help to improve its thermal isolation, 2) to help improve our knowledge about the thermal state of permafrost in the area, and 3) to help to understand the causes of the coastal erosion in the volcanic Deception Island.

  13. The Importance of Permafrost Thaw, Fire and Logging Disturbances as Driving Factors of Historical and Projected Carbon Dynamics in Alaskan Ecosystems

    Science.gov (United States)

    Genet, H.; Zhang, Y.; McGuire, A. D.; He, Y.; Johnson, K. D.; D'Amore, D. V.; Zhou, X.; Bennett, A.; Breen, A. L.; Biles, F. E.; Bliss, N. B.; Euskirchen, E. S.; Kurkowski, T. A.; Pastick, N.; Rupp, S. T.; Wylie, B. K.; Zhu, Z.; Zhuang, Q.

    2014-12-01

    Carbon dynamics of natural ecosystems are influenced by disturbance regimes of various frequencies and magnitudes. With global change, these disturbances are projected to increase in frequency and/or magnitude and may have significant effects on future net carbon balance, especially in high latitude ecosystems where carbon stocks are among the largest on Earth and climate change is substantial. In Alaska, permafrost degradation and fire in the boreal and arctic regions and logging in the southern coastal region are the main disturbances that affect ecosystems. Large uncertainties related to the effects of these disturbances on the capacity of these regions to store carbon still exist mainly due to difficulty in representing permafrost degradation in current ecosystem models. We ran the Terrestrial Ecosystem Model (TEM), which explicitly simulates the carbon cycle and permafrost dynamics, coupled with a disturbance model (the Alaska Frame Based Ecosystem Code, ALFRESCO) to assess the relative importance of permafrost thaw, wildfire, and forest management on historical and projected carbon balance and carbon stocks in Alaska, from 1950 to 2100, at a 1-km resolution. Our simulations showed that the increase in plant productivity in response to warming in boreal and arctic regions is offset by soil carbon loss due to permafrost degradation and wildfire combustion during both historical and future simulations. Fire disturbances act as a catalyst accelerating permafrost degradation and associated soil carbon loss. In addition, our preliminary results for south coastal regions of Alaska indicate that logging of second growth forests could influence carbon dynamics in that region. Overall, these results have implications for land management strategies and illustrate the importance of taking into account multiple types of disturbance regimes in ecosystem models for Alaska.

  14. The use of electromagnetic induction methods for establishing quantitative permafrost models in West Greenland

    Science.gov (United States)

    Ingeman-Nielsen, Thomas; Brandt, Inooraq

    2010-05-01

    permafrozen sediments is generally not available in Greenland, and mobilization costs are therefore considerable thus limiting the use of geotechnical borings to larger infrastructure and construction projects. To overcome these problems, we have tested the use of shallow Transient ElectroMagnetic (TEM) measurements, to provide constraints in terms of depth to and resistivity of the conductive saline layer. We have tested such a setup at two field sites in the Ilulissat area (mid-west Greenland), one with available borehole information (site A), the second without (site C). VES and TEM soundings were collected at each site and the respective data sets subsequently inverted using a mutually constrained inversion scheme. At site A, the TEM measurements (20x20m square loop, in-loop configuration) show substantial and repeatable negative amplitude segments, and therefore it has not presently been possible to provide a quantitative interpretation for this location. Negative segments are typically a sign of Induced Polarization or cultural effects. Forward modeling based on inversion of the VES data constrained with borehole information has indicated that IP effects could indeed be the cause of the observed anomaly, although such effects are not normally expected in permafrost or saline deposits. Data from site C has shown that jointly inverting the TEM and VES measurements does provide well determined estimates for all layer parameters except the thickness of the active layer and resistivity of the bedrock. The active layer thickness may be easily probed to provide prior information on this parameter, and the bedrock resistivity is of limited interest in technical applications. Although no confirming borehole information is available at this site, these results indicate that joint or mutually constrained inversion of TEM and VES data is feasible and that this setup may provide a fast and cost effective method for establishing quantitative interpretations of permafrost structure in

  15. Buried glacier ice in permafrost, a window to the past: examples from Bylot Island, Canadian Arctic

    Science.gov (United States)

    Fortier, D.; Coulombe, S.; Kanevskiy, M. Z.; Paquette, M.; Shur, Y.; Stephani, E.

    2011-12-01

    Bylot Island is located north of Baffin Island (73°N, 80°W) and is extensively covered by an ice cap and its outlet glaciers flowing towards the arctic lowland of the Lancaster formation. During summers of 2009 and 2011 several active-layer detachment slides exposed large massive ice bodies and other types of debris-rich ice that were interpreted as buried glacier ice. The upper part of the massive ice and debris-rich ice were usually in contact with various types of ice-contact or glacio-fluvial sediments and in some cases they were covered by mass wasting/colluvial deposits. This suggests that their preservation was likely related to burial of the ice and refreezing of the overlying sediments following permafrost aggradation. A preliminary analysis of the ice facies and ice crystals revealed the presence of four distinct types of ice: 1) clear-ice bodies with very few sediment and no organic inclusions. The ice crystals were large (cm), randomly oriented and air bubbles were observed at the junction of crystals. These characteristics could potentially indicate an englacial (snow-neve metamorphism) origin for these clear ice bodies; 2) large, meter thick, clear ice layers with no sediment, nor organics. The ice crystals were large (cm), several cm long, oriented in the same direction, and vertically aligned. These characteristics could potentially point to water that refroze in a tunnel incised in englacial ice; 3) Successive, mm to cm thick, ice layers, separated by undulating sand and gravel bands also containing cobles to boulder size rock fragments. These characteristics could potentially represent regelation ice formed at the base of glaciers and incorporated to the glacier sole; 4) mm to cm suspended aggregate of fine-grained sediments in clear ice. These micro-suspended and suspended cryostructures were sometimes deformed and aligned in the form of thin (mm) undulating layers. These micro-structures were very similar to basal ice facies, presumably

  16. Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils

    Science.gov (United States)

    Treat, C.C.; Jones, Miriam C.; Camill, P.; Gallego-Sala, A.; Garneau, M.; Harden, Jennifer W.; Hugelius, G.; Klein, E.S.; Kokfelt, U.; Kuhry, P.; Loisel, J.; Mathijssen, J.H.; O'Donnell, J.A.; Oksanen, P.O.; Ronkainen, T.M.; Sannel, A.B.K.; Talbot, J. J.; Tarnocal, C.M.; Valiranta, M.

    2016-01-01

    Permafrost dynamics play an important role in high-latitude peatland carbon balance and are key to understanding the future response of soil carbon stocks. Permafrost aggradation can control the magnitude of the carbon feedback in peatlands through effects on peat properties. We compiled peatland plant macrofossil records for the northern permafrost zone (515 cores from 280 sites) and classified samples by vegetation type and environmental class (fen, bog, tundra and boreal permafrost, and thawed permafrost). We examined differences in peat properties (bulk density, carbon (C), nitrogen (N) and organic matter content, and C/N ratio) and C accumulation rates among vegetation types and environmental classes. Consequences of permafrost aggradation differed between boreal and tundra biomes, including differences in vegetation composition, C/N ratios, and N content. The vegetation composition of tundra permafrost peatlands was similar to permafrost-free fens, while boreal permafrost peatlands more closely resembled permafrost-free bogs. Nitrogen content in boreal permafrost and thawed permafrost peatlands was significantly lower than in permafrost-free bogs despite similar vegetation types (0.9% versus 1.5% N). Median long-term C accumulation rates were higher in fens (23 g C m−2 yr−1) than in permafrost-free bogs (18 g C m−2 yr−1) and were lowest in boreal permafrost peatlands (14 g C m−2 yr−1). The plant macrofossil record demonstrated transitions from fens to bogs to permafrost peatlands, bogs to fens, permafrost aggradation within fens, and permafrost thaw and reaggradation. Using data synthesis, we have identified predominant peatland successional pathways, changes in vegetation type, peat properties, and C accumulation rates associated with permafrost aggradation.

  17. Influence of urbanization on permafrost: a case study from Mohe County, northernmost China

    Directory of Open Access Journals (Sweden)

    W. B. Yu

    2014-08-01

    Full Text Available Mohe County, northernmost China, is one of the densely populated areas in permafrost regions. The urban population has grown from about 25 000 residents in 1992 to more than 41 000 in 2011. Resident's life is closely related to permafrost environment. This paper adopted drilling, ground penetration radar, and ground temperature monitoring to investigate the permafrost in the urban area of Mohe County. The results show that the permafrost table is much lower in the urban area of Mohe County because of the urban heat island, surface disturbance of construction, space heating in winter etc. The permafrost table is 2.63–3.70 m on the edge of the urban area; the mean annual ground temperature is −1.0 to −1.33 °C. In the urban area, the maximum depth of permafrost has exceeded 15 m. The permafrost in the undisturbed area is 1.65–2.0 m, with much lower ground temperature −2.75 °C. Evidences outline a clear distribution rule that, from the edge to the center of the urban area of Mohe County, the permafrost table goes deeper and deeper, which states that the urbanization has significant influence on permafrost degradation. The degradation of permafrost in the urban area in turn has been affecting the residents' lives, such as water supply and stability of buildings.

  18. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Donn McGuire; Thomas Williams; Bjorn Paulsson; Alexander Goertz

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a drilling hazard by the oil and gas industry for years. Drilling engineers working in Russia, Canada and the USA have documented numerous problems, including drilling kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates as a potential energy source agree that the resource potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained from physical samples taken from actual hydrate-bearing rocks. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The project team drilled and continuously cored the Hot Ice No. 1 well on Anadarko-leased acreage beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and used for determining physical characteristics of hydrates and surrounding rock. After the well was logged, a 3D vertical seismic profile (VSP) was recorded to calibrate the shallow geologic section with seismic data and to investigate techniques to better resolve lateral subsurface variations of potential hydrate-bearing strata. Paulsson Geophysical Services, Inc. deployed their 80 level 3C clamped borehole seismic receiver array in the wellbore to record samples every 25 ft. Seismic vibrators were successively positioned at 1185 different surface positions in a circular pattern around the wellbore. This technique generated a 3D image of the subsurface. Correlations were

  19. Mutations in the Arabidopsis Lst8 and Raptor genes encoding partners of the TOR complex, or inhibition of TOR activity decrease abscisic acid (ABA) synthesis.

    Science.gov (United States)

    Kravchenko, Alena; Citerne, Sylvie; Jéhanno, Isabelle; Bersimbaev, Rakhmetkazhi I; Veit, Bruce; Meyer, Christian; Leprince, Anne-Sophie

    2015-11-27

    The Target of Rapamycin (TOR) kinase regulates essential processes in plant growth and development by modulation of metabolism and translation in response to environmental signals. In this study, we show that abscisic acid (ABA) metabolism is also regulated by the TOR kinase. Indeed ABA hormone level strongly decreases in Lst8-1 and Raptor3g mutant lines as well as in wild-type (WT) Arabidopsis plants treated with AZD-8055, a TOR inhibitor. However the growth and germination of these lines are more sensitive to exogenous ABA. The diminished ABA hormone accumulation is correlated with lower transcript levels of ZEP, NCED3 and AAO3 biosynthetic enzymes, and higher transcript amount of the CYP707A2 gene encoding a key-enzyme in abscisic acid catabolism. These results suggest that the TOR signaling pathway is implicated in the regulation of ABA accumulation in Arabidopsis.

  20. Implementation of a satellite data based permafrost information system - the DUE permafrost project

    NARCIS (Netherlands)

    Bartsch, A.; Wiesmann, A.; Strozzi, T.; Schmullius, C.; Hese, S.; Duguay, C.; Heim, B.; Boike, J.; Herold, M.

    2010-01-01

    directly measured with remotely sensed data. However, many parameters which influence the ground thermal regime and surface indicators can be captured with satellite data in an operational manner. Those are e.g. land surface temperature, land cover and snow parameters, soil moisture and terrain chan

  1. Does mountain permafrost in Mongolia control water availability?

    Science.gov (United States)

    Menzel, Lucas; Kopp, Benjamin; Munkhjargal, Munkhdavaa

    2016-04-01

    In semi-arid Mongolia, continuous and discontinuous permafrost covers wide parts of the mountains, especially in the northwest of the country. Long-term analysis of annual discharge from rivers draining the mountainous parts shows high temporal variability, with some evidence of decreasing trends, accompanied by decreased intra-annual variability. Investigations show that annual precipitation features small changes while annual air temperature significantly increased over the last decades, with warming rates clearly outranging the global average. Widespread and drastic changes in land cover through forest fires in northern Mongolia might have an additional impact on water retention and the stability of permafrost. Hence, there is concern about an increased degradation of mountain permafrost and a possible impact on river discharge and water availability. Decreased water availability from the mountains would have strong socio-economic implications for the population living in the steppe belt downstream the mountains. Therefore, a monitoring program has been conducted in northern Mongolia that aims to improve the understanding of how climate change and forest fires are influencing mountain permafrost and water resources. The study region, Sugnugur valley, is located about 100 km north of Ulaanbaatar and includes the transition belt between the steppe, the boreal zone and the alpine tundra of the Khentii Mountains. Extensive measurements of soil temperatures, soil moisture, discharge and climatic parameters have been carried out along transects which stretch across the Sugnugur river valley and include steppe, boreal forest as well as burnt forest. First results indicate that the environmental conditions show drastic changes after forest fire, with reduced water retention in the headwaters. After forest fires, changing runoff processes above the permafrost table have been observed, where water drains rapidly along preferential flow paths. This eventually leads to

  2. ADAPT: building conceptual models of the physical and biological processes across permafrost landscapes

    Science.gov (United States)

    Allard, M.; Vincent, W. F.; Lemay, M.

    2012-12-01

    Fundamental and applied permafrost research is called upon in Canada in support of environmental protection, economic development and for contributing to the international efforts in understanding climatic and ecological feedbacks of permafrost thawing under a warming climate. The five year "Arctic Development and Adaptation to Permafrost in Transition" program (ADAPT) funded by NSERC brings together 14 scientists from 10 Canadian universities and involves numerous collaborators from academia, territorial and provincial governments, Inuit communities and industry. The geographical coverage of the program encompasses all of the permafrost regions of Canada. Field research at a series of sites across the country is being coordinated. A common protocol for measuring ground thermal and moisture regime, characterizing terrain conditions (vegetation, topography, surface water regime and soil organic matter contents) is being applied in order to provide inputs for designing a general model to provide an understanding of transfers of energy and matter in permafrost terrain, and the implications for biological and human systems. The ADAPT mission is to produce an 'Integrated Permafrost Systems Science' framework that will be used to help generate sustainable development and adaptation strategies for the North in the context of rapid socio-economic and climate change. ADAPT has three major objectives: to examine how changing precipitation and warming temperatures affect permafrost geosystems and ecosystems, specifically by testing hypotheses concerning the influence of the snowpack, the effects of water as a conveyor of heat, sediments, and carbon in warming permafrost terrain and the processes of permafrost decay; to interact directly with Inuit communities, the public sector and the private sector for development and adaptation to changes in permafrost environments; and to train the new generation of experts and scientists in this critical domain of research in Canada

  3. The long-term fate of permafrost peatlands under rapid climate warming

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal

    2015-01-01

    Permafrost peatlands contain globally important amounts of soil organic carbon, owing to cold conditions which suppress anaerobic decomposition. However, climate warming and permafrost thaw threaten the stability of this carbon store. The ultimate fate of permafrost peatlands and their carbon...... stores is unclear because of complex feedbacks between peat accumulation, hydrology and vegetation. Field monitoring campaigns only span the last few decades and therefore provide an incomplete picture of permafrost peatland response to recent rapid warming. Here we use a high-resolution palaeoecological...... approach to understand the longer-term response of peatlands in contrasting states of permafrost degradation to recent rapid warming. At all sites we identify a drying trend until the late-twentieth century; however, two sites subsequently experienced a rapid shift to wetter conditions as permafrost thawed...

  4. The long-term fate of permafrost peatlands under rapid climate warming

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal;

    2015-01-01

    Permafrost peatlands contain globally important amounts of soil organic carbon, owing to cold conditions which suppress anaerobic decomposition. However, climate warming and permafrost thaw threaten the stability of this carbon store. The ultimate fate of permafrost peatlands and their carbon...... stores is unclear because of complex feedbacks between peat accumulation, hydrology and vegetation. Field monitoring campaigns only span the last few decades and therefore provide an incomplete picture of permafrost peatland response to recent rapid warming. Here we use a high-resolution palaeoecological...... approach to understand the longer-term response of peatlands in contrasting states of permafrost degradation to recent rapid warming. At all sites we identify a drying trend until the late-twentieth century; however, two sites subsequently experienced a rapid shift to wetter conditions as permafrost thawed...

  5. The research station "Vaskiny Dachi", Central Yamal, West Siberia, Russia – a review of 25 years of permafrost studies

    Directory of Open Access Journals (Sweden)

    Marina O. Leibman

    2015-03-01

    Full Text Available The research station "Vaskiny Dachi" on the Yamal Peninsula was established in 1988. Activities aimed at monitoring of permafrost and related environmental features under a relatively low level of nature disturbances caused by gas field development. Cryogenic processes that may affect the environment and their structures have been of primary interest. Landslides are the most common cryogenic processes in Central Yamal in general and also in the proximity of the station. Field surveys of numerous landslides, analysis of their dependence on climatic parameters and their fluctuations resulted in novel classification of cryogenic landslides based on mechanisms of their development. Dating by radiocarbon and dendrochronology allows the separation of cycles of landslide activation. Cryogenic landslides control the development of other processes, such as thermal erosion, river channel erosion and thermokarst. It also affects topography, vegetation pattern, geochemistry of vegetation, ground water and soils. As a result, permafrost parameters, specifically active layer depth and ground temperature, moisture and ice content in the active layer, depend indirectly on landsliding. Monitoring within the framework of the main programs of the International Permafrost Association, such as Circumarctic Active Layer Monitoring (CALM, since 1993 and Thermal State of Permafrost (TSP, since 2011, play an important role among the research activities. From the collected data one can conclude that ground temperature increased on average by about 1 °C since the 1990s. At the same time, active layer fluctuations do not exactly follow the air temperature changes. Spatial changes in ground temperature are controlled by the redistribution of snow which is resulting from strong winds characteristic for tundra environments and the highly dissected relief of Central Yamal. Temporal variations rather depend on air temperature fluctuations but the rate differs in various

  6. Thousands of Viral Populations Recovered from Peatland Soil Metagenomes Reveal Viral Impacts on Carbon Cycling in Thawing Permafrost

    Science.gov (United States)

    Emerson, J. B.; Brum, J. R.; Roux, S.; Bolduc, B.; Woodcroft, B. J.; Singleton, C. M.; Boyd, J. A.; Hodgkins, S. B.; Wilson, R.; Trubl, G. G.; Jang, H. B.; Crill, P. M.; Chanton, J.; Saleska, S. R.; Rich, V. I.; Tyson, G. W.; Sullivan, M. B.

    2016-12-01

    Methane and carbon dioxide emissions, which are under significant microbial control, provide positive feedbacks to climate change in thawing permafrost peatlands. Although viruses in marine systems have been shown to impact microbial ecology and biogeochemical cycling through host cell lysis, horizontal gene transfer, and auxiliary metabolic gene expression, viral ecology in permafrost and other soils remains virtually unstudied due to methodological challenges. Here, we identified viral sequences in 208 assembled bulk soil metagenomes derived from a permafrost thaw gradient in Stordalen Mire, northern Sweden, from 2010-2012. 2,048 viral populations were recovered, which genome- and network-based classification revealed to be largely novel, increasing known viral genera globally by 40%. Ecologically, viral communities differed significantly across the thaw gradient and by soil depth. Co-occurring microbial community composition, soil moisture, and pH were predictors of viral community composition, indicative of biological and biogeochemical feedbacks as permafrost thaws. Host prediction—achieved through clustered regularly interspaced short palindromic repeats (CRISPRs), tetranucleotide frequency patterns, and other sequence similarities to binned microbial population genomes—was able to link 38% of the viral populations to a microbial host. 5% of the implicated hosts were archaea, predominantly methanogens and ammonia-oxidizing Nitrososphaera, 45% were Acidobacteria or Verrucomicrobia (mostly predicted heterotrophic complex carbon degraders), and 21% were Proteobacteria, including methane oxidizers. Recovered viral genome fragments also contained auxiliary metabolic genes involved in carbon and nitrogen cycling. Together, these data reveal multiple levels of previously unknown viral contributions to biogeochemical cycling, including to carbon gas emissions, in peatland soils undergoing and contributing to climate change. This work represents a significant step

  7. The applicability of ERA-Interim land surface temperature dataset to map the permafrost distribution over the Tibetan Plateau%ERA-Interim地表温度数据集在青藏高原冻土分布制图应用的适用性评估

    Institute of Scientific and Technical Information of China (English)

    秦艳慧; 吴通华; 李韧; 谢昌卫; 邹德富; 张乐乐; 王田野; 余文君; 王蔚华

    2015-01-01

    Land surface temperature (LST)reflects the impact of local factors,such as vegetation,soil and the atmosphere of a region,on the ground thermal regime.LST is the boundary condition of many permafrost distri-bution models and land surface models in the cold regions.It is of great significance for mapping permafrost and estimating the active layer thickness as well.In order to assess the applicability of the ERA-Interim LST on the Tibetan Plateau,observations from 69 meteorological stations at the altitude more than 2 000 m a.s.l.,were compared with the ERA-Interim LST from 1981 to 2013.The difference between the two datasets and the spatial distribution of their differences were analyzed.The results showed that the changing trends of ERA-Interim LST and of observation were consistent,but numerically the former was significantly lower than the latter,with an av-erage bias of 7 .4 ℃.The great bias could be due to the difference between the elevation of ERA-Interim reanal-ysis data grid and the altitude of meteorological stations.According to the elevation difference,simulation of the ERA-Interim LST was rerun.Thus,most of ERA-Interim LST fitted well with the observation,with an average bias of 0.4 ℃.Although there is still some bias between the two,it is useful to apply the reanalysis dataset in the west of the Tibetan Plateau,where few observation records are available.Finally,the simulated ERA-Interim LST was used as an input parameter to the permafrost distribution model.The modeling results show that the per-mafrost area on the plateau is 1 .14 ×106 km2 approximately and the area of seasonal frozen soil is 1 .43 ×106 km2 .%地表温度综合反映了大气、植被和土壤等因素的能量交换状况,是冻土分布模型和一些寒区陆面过程模式的上边界条件,对多年冻土分布制图和活动层厚度估算有重要意义.为了评估 ERA-Interim地表温度产品在青藏高原地区的适用性,综合比较了青藏高原69

  8. Mechanistic modeling of microbial interactions at pore to profile scale resolve methane emission dynamics from permafrost soil

    Science.gov (United States)

    Ebrahimi, Ali; Or, Dani

    2017-05-01

    The sensitivity of polar regions to raising global temperatures is reflected in rapidly changing hydrological processes associated with pronounced seasonal thawing of permafrost soil and increased biological activity. Of particular concern is the potential release of large amounts of soil carbon and stimulation of other soil-borne greenhouse gas emissions such as methane. Soil methanotrophic and methanogenic microbial communities rapidly adjust their activity and spatial organization in response to permafrost thawing and other environmental factors. Soil structural elements such as aggregates and layering affect oxygen and nutrient diffusion processes thereby contributing to methanogenic activity within temporal anoxic niches (hot spots). We developed a mechanistic individual-based model to quantify microbial activity dynamics in soil pore networks considering transport processes and enzymatic activity associated with methane production in soil. The model was upscaled from single aggregates to the soil profile where freezing/thawing provides macroscopic boundary conditions for microbial activity at different soil depths. The model distinguishes microbial activity in aerate bulk soil from aggregates (or submerged profile) for resolving methane production and oxidation rates. Methane transport pathways by diffusion and ebullition of bubbles vary with hydration dynamics. The model links seasonal thermal and hydrologic dynamics with evolution of microbial community composition and function affecting net methane emissions in good agreement with experimental data. The mechanistic model enables systematic evaluation of key controlling factors in thawing permafrost and microbial response (e.g., nutrient availability and enzyme activity) on long-term methane emissions and carbon decomposition rates in the rapidly changing polar regions.

  9. Ground-temperature controlling effects of duct-ventilated railway embankment in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    NIU; Fujun; CHENG; Guodong

    2004-01-01

    Based on observed data from field-testing embankment of the Qinghai-Tibet Railway, ground-temperature controlling effect of duct-ventilated embankment is studied in this paper.The results show that ventilation ducts can effectively cool the soils surrounding the ducts of the embankment, and the heat budget of the ambient soils in a year shows as heat release. Temperature status of the permafrost below the embankment with ducts buried in the relatively high position is similar to that of the common embankment. The permafrost processes warming all along in the two freezing-thawing cycles when the embankment was constructed. However, the temperature of the frozen soils below the embankment, in which the ducts buried in the relatively low position, rises a little in the initial stage. After that, it cools down gradually. At the same time,ventilation ducts can effectively reduce the thermal disturbance caused by the filled soils. The frozen soils below the common embankment and that with high-posited ducts absorb heat all along in the initial two cycles. While the soils below the embankment with low-posited ducts begin to release heat in the second cycle. This phenomenon proves that the ventilation embankment with low-posited ducts shows efficient temperature-controlling effect. Such embankment can actively cool the subgrade soils and therefore keeps the roadbed thermally stable.

  10. The influence of surface characteristics, topography, and continentality on mountain permafrost in British Columbia

    Directory of Open Access Journals (Sweden)

    A. Hasler

    2014-09-01

    Full Text Available Thermal offset and surface offset are terms that describe the deviation of the mean annual ground temperature from the mean annual air temperature. These offsets are controlled by surface characteristics and topo-climatic factors on a micro- and meso-scales. Macro-climatic conditions may, however, influence the effectiveness of the responsible processes. Existing knowledge on surface- and topography-specific offsets is not easily transferable and limits the applicability of empirical permafrost distribution models over large areas with macro-climatic gradients. In this paper we describe surface and thermal offsets derived from distributed measurements at seven field sites in British Columbia. Key findings are (i a surprisingly small variation of the surface offsets between different surface types and small thermal offsets in general (excluding wetlands and peat, (ii a clear influence of the micro-topography at wind exposed sites (snow cover erosion, (iii a north–south difference of the surface offset of 4 °C in near-vertical bedrock and of 1.5–3 °C on open (no canopy gentle slopes, (iv only small macro-climatic differences caused by the reverse influence of snow cover thickness and annual air temperature amplitude. These findings suggest, that empirical permafrost models based on topo-climatic variables may be applicable across regions with significant macro-climatic differences.

  11. Vejbygning i områder med permafrost

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr

    2009-01-01

    Siden begyndelsen af 1990’erne er der registreret en markant stigning i den årlige middeltemperatur i Nunavik, Québec Canada. Dette har ført til en reduktion i udbredelsen af permafrost, hvilket truer stabiliteten af lufthavne og veje i området. I sommeren 2007 blev en teststrækning opført i...... Tasiujaq Lufthavn for at studere effekten af tre forskellige metoder, som skal være med til at reducere optøningen af permafrost under landingsbanen. De tre metoder, som er blevet undersøgt, er konvektionskøling (air convection embankment), varmeudtrækning (heat drain) samt et forsøg med ændring af...

  12. Priming-induced Changes in Permafrost Soil Organic Matter Decomposition

    Science.gov (United States)

    Pegoraro, E.; Schuur, E.; Bracho, R. G.

    2015-12-01

    Warming of tundra ecosystems due to climate change is predicted to thaw permafrost and increase plant biomass and litter input to soil. Additional input of easily decomposable carbon can alter microbial activity by providing a much needed energy source, thereby accelerating soil organic matter decomposition. This phenomenon, known as the priming effect, can increase CO2 flux from soil to the atmosphere. However, the extent to which this mechanism can decrease soil carbon stocks in the Arctic is unknown. This project assessed priming effects on permafrost soil collected from a moist acidic tundra site in Healy, Alaska. We hypothesized that priming would increase microbial activity by providing microbes with a fresh source of carbon, thereby increasing decomposition of old and slowly decomposing carbon. Soil from surface and deep layers were amended with multiple pulses of uniformly 13C labeled glucose and cellulose, and samples were incubated at 15° C to quantify whether labile substrate addition increased carbon mineralization. We quantified the proportion of old carbon mineralization by measuring 14CO2. Data shows that substrate addition resulted in higher respiration rates in amended soils; however, priming was only observed in deep layers, where 30% more soil-derived carbon was respired compared to control samples. This suggests that microbes in deep layers are limited in energy, and the addition of labile carbon increases native soil organic matter decomposition, especially in soil with greater fractions of slowly decomposing carbon. Priming in permafrost could exacerbate the effects of climate change by increasing mineralization rates of carbon accumulated over the long-term in deep layers. Therefore, quantifying priming effect in permafrost soils is imperative to understanding the dynamics of carbon turnover in a warmer world.

  13. Symbiosis of Marshes and Permafrost in Da and Xiao Hinggan Mountains in Northeastern China

    Institute of Scientific and Technical Information of China (English)

    JIN Huijun; SUN Guangyou; YU Shaopeng; JIN Rui; HE Ruixia

    2008-01-01

    Recently, the degradation of permafrost and marsh environments in the Da and Xiao Hinggan Mountainshas become a great concern as more human activities and pronounced climate warming were observed during the past30 years and projected for the near future. The distribution patterns and development mechanisms of the permafrostand marshes have been examined both in theories and in field observations, in order to better understand the symbiosisof permafrost and marshes. The permafrost and marshes in the Da and Xiao Hinggan Mountains display discerniblezonations in latitude and elevation. The marsh vegetation canopy, litter and peat soil have good thermal insulationproperties for the underlying permafrost, resulting in a thermal offset of 3℃ to 4℃ and subsequently suppressing soiltemperature, In addition, the much higher thermal conductivity of frozen and ice-rich peat in the active layer is condu-cive to the development or in favor of the protection of permafrost due to the semi-conductor properties of the soilsoverlying the permafrost. On the other hand, because permafrost is almost impervious, the osmosis of water in marshsoils can be effectively reduced, timely providing water supplies for helophytes growth or germination in spring. In theDa and Xiao Hinggan Mountains, the permafrost degradation has been accelerating due to the marked climate warming,ever increasing human activities, and the resultant eco-environmental changes. Since the permafrost and marsh envi-ronments are symbiotic and interdependent, they need to be managed or protected in a well-coordinated and integratedway.

  14. Presence of rapidly degrading permafrost plateaus in south-central Alaska

    Science.gov (United States)

    Jones, Benjamin M.; Baughman, Carson A.; Romanovsky, Vladimir E.; Parsekian, Andrew D.; Babcock, Esther L.; Stephani, Eva; Jones, Miriam C.; Grosse, Guido; Berg, Edward E.

    2016-11-01

    Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0 °C. In this study, we document the presence of residual permafrost plateaus in the western Kenai Peninsula lowlands of south-central Alaska, a region with a MAAT of 1.5 ± 1 °C (1981-2010). Continuous ground temperature measurements between 16 September 2012 and 15 September 2015, using calibrated thermistor strings, documented the presence of warm permafrost (-0.04 to -0.08 °C). Field measurements (probing) on several plateau features during the fall of 2015 showed that the depth to the permafrost table averaged 1.48 m but at some locations was as shallow as 0.53 m. Late winter surveys (augering, coring, and GPR) in 2016 showed that the average seasonally frozen ground thickness was 0.45 m, overlying a talik above the permafrost table. Measured permafrost thickness ranged from 0.33 to > 6.90 m. Manual interpretation of historic aerial photography acquired in 1950 indicates that residual permafrost plateaus covered 920 ha as mapped across portions of four wetland complexes encompassing 4810 ha. However, between 1950 and ca. 2010, permafrost plateau extent decreased by 60.0 %, with lateral feature degradation accounting for 85.0 % of the reduction in area. Permafrost loss on the Kenai Peninsula is likely associated with a warming climate, wildfires that remove the protective forest and organic layer cover, groundwater flow at depth, and lateral heat transfer from wetland surface waters in the summer. Better understanding the resilience and vulnerability of ecosystem-protected permafrost is critical for mapping and predicting future permafrost extent and degradation across all permafrost regions that are currently warming. Further work should focus on reconstructing

  15. Spatial variability and landscape controls of near-surface permafrost within the Alaskan Yukon River Basin

    Science.gov (United States)

    Pastick, Neal J.; Jorgenson, M. Torre; Wylie, Bruce K.; Rose, Joshua R.; Rigge, Matthew; Walvoord, Michelle A.

    2014-01-01

    The distribution of permafrost is important to understand because of permafrost's influence on high-latitude ecosystem structure and functions. Moreover, near-surface (defined here as within 1 m of the Earth's surface) permafrost is particularly susceptible to a warming climate and is generally poorly mapped at regional scales. Subsequently, our objectives were to (1) develop the first-known binary and probabilistic maps of near-surface permafrost distributions at a 30 m resolution in the Alaskan Yukon River Basin by employing decision tree models, field measurements, and remotely sensed and mapped biophysical data; (2) evaluate the relative contribution of 39 biophysical variables used in the models; and (3) assess the landscape-scale factors controlling spatial variations in permafrost extent. Areas estimated to be present and absent of near-surface permafrost occupy approximately 46% and 45% of the Alaskan Yukon River Basin, respectively; masked areas (e.g., water and developed) account for the remaining 9% of the landscape. Strong predictors of near-surface permafrost include climatic indices, land cover, topography, and Landsat 7 Enhanced Thematic Mapper Plus spectral information. Our quantitative modeling approach enabled us to generate regional near-surface permafrost maps and provide essential information for resource managers and modelers to better understand near-surface permafrost distribution and how it relates to environmental factors and conditions.

  16. Integrated geophysical surveys on railroads in permafrost areas

    Institute of Scientific and Technical Information of China (English)

    A Ivanov; S Klepikova; M Shirobokov; A Urusova; A Savin

    2013-01-01

    The zones of thawed ground in the permafrost area are most dangerous from engineer-geologist effect point of view. Detection of such zones, as making forecast of their movement is the main task of engineer-geologist survey been held in railway industry. This paper presents general issues concerning railway construction and operation in permafrost areas. Comprehensive geophysical methods to monitor the development of thawed soils are considered in detail. The main physical parameters which help define permafrost and thawed soil patches are described. Author of current paper pointed out main factors, allowing predicting potential areas of development of thawed grounds. They offered set non-destructive methods:GPR investigations, seismic survey and elec-tric exploration. Whole sets of geophysical data:electric resistivity, velocity of S-wave and P-wave (and their correlation), allow us with high confidence specify characteristics and state of soil either under the line of road, or near it. At the same time the meth-od allows to predict direction of further development of thawed ground area.

  17. The cryosphere and glacial permafrost as its integral component

    Science.gov (United States)

    Dobiński, Wojciech

    2012-12-01

    Since Earth sciences have undertaken studies of other celestial bodies, its various fields have moved beyond the scope of study assigned to them by name. Interest in space makes it necessary to abandon research geocentrism and reverse relations when comparing the structure of the Earth with other celestial bodies. As an exceptional place in the universe, it should not be the Earth which constitutes a reference point, especially in cryospheric research, but rather the other celestial bodies of our planetary system. This approach, referred to as "Spatial Uniformitarianism," is the basis for determining the place of ice in the environment and for assigning it to the lithosphere. Ice can be penetrated by frost just as other minerals and rocks, so the occurrence of permafrost may yet be attributed to glaciers and ice-caps. In the article, the occurrence of glacial permafrost has been worked out on the basis of a thermal classification of glaciers with a thorough understanding of the phenomenon. This allows us to specify permafrost's presence beneath glaciers and ice-caps, a concept which had been needlessly vague. Further, by considering rock glaciers as a mixture of two types of rocks, and by understanding the importance of movement in their evolution, we are now closer to fruitfully determining their role in the environment, their geomorphological significance.

  18. Environmental selection of planktonic methanogens in permafrost thaw ponds

    Science.gov (United States)

    Crevecoeur, Sophie; Vincent, Warwick F.; Lovejoy, Connie

    2016-08-01

    The warming and thermal erosion of ice-containing permafrost results in thaw ponds that are strong emitters of methane to the atmosphere. Here we examined methanogens and other Archaea, in two types of thaw ponds that are formed by the collapse of either permafrost peat mounds (palsas) or mineral soil mounds (lithalsas) in subarctic Quebec, Canada. Using high-throughput sequencing of a hypervariable region of 16S rRNA, we determined the taxonomic structure and diversity of archaeal communities in near-bottom water samples, and analyzed the mcrA gene transcripts from two sites. The ponds at all sites were well stratified, with hypoxic or anoxic bottom waters. Their archaeal communities were dominated by Euryarchaeota, specifically taxa in the methanogenic orders Methanomicrobiales and Methanosarcinales, indicating a potentially active community of planktonic methanogens. The order Methanomicrobiales accounted for most of the mcrA transcripts in the two ponds. The Archaeal communities differed significantly between the lithalsa and palsa ponds, with higher alpha diversity in the organic-rich palsa ponds, and pronounced differences in community structure. These results indicate the widespread occurrence of planktonic, methane-producing Archaea in thaw ponds, with environmental selection of taxa according to permafrost landscape type.

  19. Metagenomic analysis of permafrost microbial community response to thaw

    Energy Technology Data Exchange (ETDEWEB)

    Mackelprang, R.; Waldrop, M.P.; DeAngelis, K.M.; David, M.M.; Chavarria, K.L.; Blazewicz, S.J.; Rubin, E.M.; Jansson, J.K.

    2011-07-01

    We employed deep metagenomic sequencing to determine the impact of thaw on microbial phylogenetic and functional genes and related this data to measurements of methane emissions. Metagenomics, the direct sequencing of DNA from the environment, allows for the examination of whole biochemical pathways and associated processes, as opposed to individual pieces of the metabolic puzzle. Our metagenome analyses revealed that during transition from a frozen to a thawed state there were rapid shifts in many microbial, phylogenetic and functional gene abundances and pathways. After one week of incubation at 5°C, permafrost metagenomes converged to be more similar to each other than while they were frozen. We found that multiple genes involved in cycling of C and nitrogen shifted rapidly during thaw. We also constructed the first draft genome from a complex soil metagenome, which corresponded to a novel methanogen. Methane previously accumulated in permafrost was released during thaw and subsequently consumed by methanotrophic bacteria. Together these data point towards the importance of rapid cycling of methane and nitrogen in thawing permafrost.

  20. A rock-/ice mechanical model for the destabilisation of permafrost rocks

    Science.gov (United States)

    Krautblatter, Michael; Funk, Daniel

    2010-05-01

    The destabilisation of permafrost rocks is commonly attributed to changes in ice-mechanical properties (Davies et al. 2001). The effect of low temperatures on intact rock strength and its mechanical relevance for shear strength and brittle fracture propagation has not been considered yet. But this effect is significant since compressive and tensile strength are reduced by up to 50% and more when rock thaws (Mellor, 1973). Here we show, that the reduction of the shear resistance of rock-rock contacts in joints plays a key role for the onset of larger instabilities in thawing permafrost rocks. Based on a Mohr-Coulomb assumption, we defined a failure criterion of an ice-filled rock cleft, with cohesive rock bridges, contact of rough fracture surfaces, ductile creep of ice and with a representation of rock-ice "failure" mechanisms along the surface and inside the ice body. The synoptic models are based on the principle of superposition, i.e. that shear stress "absorbed" by one component reduces the amount of shear stress applied to the other components. Failure along existing sliding planes can be explained by the impact of temperature on shear stress uptake by creep deformation of ice, the propensity of failure along rock-ice fractures and reduced total friction along rough rock-rock contacts. This model may account for the rapid response of rockslides to warming (reaction time). In the long term, brittle fracture propagation is initialised. Warming reduces the shear stress uptake by total friction and decreases the critical fracture toughness along rock bridges. The latter model accounts for slow subcritical destabilisation of whole rock slopes over decades to millennia, subsequent to the warming impulse (relaxation time). To test the importance of reduced friction, we conducted shearing tests on homogeneous fine-grained limestone specimen taken from a permafrost site (Zugspitze, Germany). In a temperature-controlled shearing box, we repeatedly tested mechanical

  1. Simulation of hydrodynamic effects of salt rejection due to permafrost. Hydrogeological numerical model of density-driven mixing, at a regional scale, due to a high salinity pulse

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik [BERGAB, Goeteborg (Sweden); Svensson, Urban [CFE AB, Norrkoeping (Sweden); Follin, Sven [SF GeoLogic AB, Taeby (Sweden)

    2006-10-15

    The main objective of this study is to support the safety assessment of the investigated candidate sites concerning hydrogeological and hydrogeochemical issues related to permafrost. However, a more specific objective of the study is to improve the assessment of processes in relation to permafrost scenarios. The model is based on a mathematical model that includes Darcy velocities, mass conservation, matrix diffusion, and salinity distribution. Gravitational effects are thus fully accounted for. A regional groundwater flow model (POM v1.1, Simpevarp) was used as basis for the simulations. The main results of the model include salinity distributions in time. The general conclusion is that density-driven mixing processes are contained within more permeable deformation zones and that these processes are fast as compared with preliminary permafrost growth rates. The results of the simulation suggest that a repository volume in the rock mass in-between the deterministic deformation zones, approximately 150 m below the permafrost will not experience a high salinity situation due to the salt rejection process.

  2. Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas.

    Science.gov (United States)

    Wang, Zhiwei; Wang, Qian; Wu, Xiaodong; Zhao, Lin; Yue, Guangyang; Nan, Zhuotong; Wang, Puchang; Yi, Shuhua; Zou, Defu; Qin, Yu; Wu, Tonghua; Shi, Jianzong

    2017-01-01

    The Qinghai-Tibetan Plateau (QTP) contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) product based on turning points (TPs), which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI) and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost regions than the

  3. A Laboratory Seismoelectric Measurement for the Permafrost Model with a Frozen-unfrozen Interface

    Science.gov (United States)

    Liu, Z.

    2007-12-01

    For the Qing-Cang railway line located in the permafrost region, the freeze-thaw cycling with the seasons and spring-thaw of the permafrost are main factors to weaken the railway bed. Therefore, the determination of the frozen-unfrozen interface depth below the railway bed is important for the railway operation, and moreover, it can contribute to the evaluation of the permafrost environment effected by the railway. Since the frozen-unfrozen interface is a contact of two media with various porosity and saturation, an electric double-layer can be formed at the interface by the absorption of electrical charge to it. When a seismic wave is incident at the interface, a relative motion of the charges in the electric double-layer would induce an electromagnetic (EM) wave, or a seismoeletric conversion signal that can be measured remotely, which is potential for determining the frost depth. A simple permafrost model with a frozen-unfrozen interface was built mainly by two parts: the upper part was a frozen sand block with a 7cm thickness and the lower one with the same material was in an unfrozen state saturated with water. And the contact of the two parts simulated the frozen-unfrozen interface. The interface model was placed in a freezer, while it was heated from the bottom with a heating sheet made by the electric heating wires laid under the unfrozen part. A P-wave source transducer with 48 kHz narrow band frequency was set on the top the frozen part and driven by a square electric pulse. The six electrodes with a 1 cm even interval were fixed inside the frozen part with 1 cm vertical distance to the interface. In the experiment, all the analog signals acquired from the temperature sensors, acoustic transducers, and electrodes were sent through preamplifiers and recorded digitally by computer-based virtual instruments (VIs). At the beginning of the experiment, the first arrivals of the seismoeletric signals observed from the six electrodes with minimum offset set to be

  4. Storage and transformation of organic matter fractions in cryoturbated permafrost soils across the Siberian Arctic

    Directory of Open Access Journals (Sweden)

    N. Gentsch

    2015-02-01

    Full Text Available In permafrost soils, the temperature regime and the resulting cryogenic processes are decisive for the storage of organic carbon (OC and its small-scale spatial variability. For cryoturbated soils there is a lack in the assessment of pedon-scale heterogeneity in OC stocks and the transformation of functionally different organic matter (OM fractions such as particulate and mineral-associated OM. Therefore, pedons of 28 Turbels across the Siberian Arctic were sampled in five meter wide soil trenches in order to calculate OC and total nitrogen (TN stocks within the active layer and the upper permafrost based on digital profile mapping. Density fractionation of soil samples was performed to distinguish particulate OM (light fraction, LF, −3, mineral associated OM (heavy fraction, HF, >1.6 g cm−3, and a mobilizable dissolved pool (mobilizable fraction, MoF. Mineral-organic associations were characterized by selective extraction of pedogenic Fe and Al oxides and the clay composition was analyzed by X-ray diffraction. Organic matter transformation in bulk soil and density fractions was assessed by the stable carbon isotope ratio (δ13C and element contents (C and N. Across all investigated soil profiles, total OC stocks were calculated to 20.2 ± 8.0 kg m−2 (mean ± SD to 100 cm soil depth. Of this average, 54% of the OC was located in active layer horizons (annual summer thawing layer showing evidence of cryoturbation, and another 35% was present in the permafrost. The HF-OC dominated the overall OC stocks (55% followed by LF-OC (19% in mineral and 13% in organic horizons. During fractionation about 13% of the OC was released as MoF, which likely represents the most bioavailable OM pool. Cryogenic activity combined with an impaired biodegradation in topsoil horizons (O and A horizons were the principle mechanisms to sequester large OC stocks in the subsoil (16.4 ± 8.1 kg m−2; all mineral B, C, and permafrost horizons. About 22% of the subsoil

  5. Forests on thawing permafrost: fragmentation, edge effects, and net forest loss.

    Science.gov (United States)

    Baltzer, Jennifer L; Veness, Tyler; Chasmer, Laura E; Sniderhan, Anastasia E; Quinton, William L

    2014-03-01

    Much of the world's boreal forest occurs on permafrost (perennially cryotic ground). As such, changes in permafrost conditions have implications for forest function and, within the zone of discontinuous permafrost (30-80% permafrost in areal extent), distribution. Here, forested peat plateaus underlain by permafrost are elevated above the surrounding permafrost-free wetlands; as permafrost thaws, ground surface subsidence leads to waterlogging at forest margins. Within the North American subarctic, recent warming has produced rapid, widespread permafrost thaw and corresponding forest loss. Although permafrost thaw-induced forest loss provides a natural analogue to deforestation occurring in more southerly locations, we know little about how fragmentation relates to subsequent permafrost thaw and forest loss or the role of changing conditions at the edges of forested plateaus. We address these knowledge gaps by (i) examining the relationship of forest loss to the degree of fragmentation in a boreal peatland in the Northwest Territories, Canada; and (ii) quantifying associated biotic and abiotic changes occurring across forest-wetland transitions and extending into the forested plateaus (i.e., edge effects). We demonstrate that the rate of forest loss correlates positively with the degree of fragmentation as quantified by perimeter to area ratio of peat plateaus (edge : area). Changes in depth of seasonal thaw, soil moisture, and effective leaf area index (LAIe ) penetrated the plateau forests by 3-15 m. Water uptake by trees was sevenfold greater in the plateau interior than at the edges with direct implications for tree radial growth. A negative relationship existed between LAIe and soil moisture, suggesting that changes in vegetation physiological function may contribute to changing edge conditions while simultaneously being affected by these changes. Enhancing our understanding of mechanisms contributing to differential rates of permafrost thaw and associated

  6. Variations in Growing-Season NDVI and Its Response to Permafrost Degradation in Northeast China

    Directory of Open Access Journals (Sweden)

    Jinting Guo

    2017-04-01

    Full Text Available Permafrost is extremely sensitive to climate change. The degradation of permafrost has strong and profound effects on vegetation. The permafrost zone of northeastern China is the second largest region of permafrost in China and lies on the south edge of the Eurasian cryolithozone. This study analyzed the spatiotemporal variations of the growing-season Normalization Difference Vegetation Index (NDVI in the permafrost zone of northeastern China and analyzed the correlation between NDVI and ground surface temperatures (GST during the years 1981–2014. Mean growing-season NDVI (MGS-NDVI experienced a marked increase of 0.003 year−1 across the entire permafrost zone. The spatial dynamics of vegetation cover had a high degree of heterogeneity on a per pixel scale. The MGS-NDVI value increased significantly (5% significance level in 80.57%, and this increase was mostly distributed in permafrost zone except for the western steppe region. Only 7.72% experienced a significant decrease in NDVI, mainly in the cultivated and steppe portions. In addition, MGS-NDVI increased significantly with increasing growing-season mean ground surface temperature (GS-MGST. Our results suggest that a warming of GS-MGST (permafrost degradation in the permafrost region of northeastern China played a positive role in increasing plant growth and activities. Although increasing ground surface temperature resulted in increased vegetation cover and growth in the short time of permafrost degradation, from the long term point of view, permafrost degradation or disappearance may weaken or even hinder vegetation activities.

  7. Increasing risks related to landslides from degrading permafrost into new lakes in de-glaciating mountain ranges

    Science.gov (United States)

    Haeberli, Wilfried; Schaub, Yvonne; Huggel, Christian

    2017-09-01

    While glacier volumes in most cold mountain ranges rapidly decrease due to continued global warming, degradation of permafrost at altitudes above and below glaciers is much slower. As a consequence, many still existing glacier and permafrost landscapes probably transform within decades into new landscapes of bare bedrock, loose debris, sparse vegetation, numerous new lakes and steep slopes with slowly degrading permafrost. These new landscapes are likely to persist for centuries if not millennia to come. During variable but mostly extended future time periods, such new landscapes will be characterized by pronounced disequilibria within their geo- and ecosystems. This especially involves long-term stability reduction of steep/icy mountain slopes as a slow and delayed reaction to stress redistribution following de-buttressing by vanishing glaciers and to changes in mechanical strength and hydraulic permeability caused by permafrost degradation. Thereby, the probability of far-reaching flood waves from large mass movements into lakes systematically increases with the formation of many new lakes and systems of lakes in close neighborhood to, or even directly at the foot of, so-affected slopes. Results of recent studies in the Swiss Alps are reviewed and complemented with examples from the Cordillera Blanca in Peru and the Mount Everest region in Nepal. Hot spots of future hazards from potential flood waves caused by large rock falls into new lakes can already now be recognized. To this end, integrated spatial information on glacier/permafrost evolution and lake formation can be used together with scenario-based models for rapid mass movements, impact waves and flood propagation. The resulting information must then be combined with exposure and vulnerability considerations related to settlements and infrastructure. This enables timely planning of risk reduction options. Such risk reduction options consist of two components: Mitigation of hazards, which in the present

  8. Ideas and perspectives: Holocene thermokarst sediments of the Yedoma permafrost region do not increase the northern peatland carbon pool

    Science.gov (United States)

    Hugelius, Gustaf; Kuhry, Peter; Tarnocai, Charles

    2016-04-01

    Permafrost deposits in the Beringian Yedoma region store large amounts of organic carbon (OC). Walter Anthony et al. (2014) describe a previously unrecognized pool of 159 Pg OC accumulated in Holocene thermokarst sediments deposited in Yedoma region alases (thermokarst depressions). They claim that these alas sediments increase the previously recognized circumpolar permafrost peat OC pool by 50 %. It is stated that previous integrated studies of the permafrost OC pool have failed to account for these deposits because the Northern Circumpolar Soil Carbon Database (NCSCD) is biased towards non-alas field sites and that the soil maps used in the NCSCD underestimate coverage of organic permafrost soils. Here we evaluate these statements against a brief literature review, existing data sets on Yedoma region soil OC storage and independent field-based and geospatial data sets of peat soil distribution in the Siberian Yedoma region. Our findings are summarized in three main points. Firstly, the sediments described by Walter Anthony et al. (2014) are primarily mineral lake sediments and do not match widely used international scientific definitions of peat or organic soils. They can therefore not be considered an addition to the circumpolar peat carbon pool. We also emphasize that a clear distinction between mineral and organic soil types is important since they show very different vulnerability trajectories under climate change. Secondly, independent field data and geospatial analyses show that the Siberian Yedoma region is dominated by mineral soils, not peatlands. Thus, there is no evidence to suggest any systematic bias in the NCSCD field data or maps. Thirdly, there is spatial overlap between these Holocene thermokarst sediments and previous estimates of permafrost soil and sediment OC stocks. These carbon stocks were already accounted for by previous studies and they do not significantly increase the known circumpolar OC pool. We suggest that these inaccurate

  9. Effects of Experimental Warming of the Deep Soil and Permafrost on Ecosystem Carbon Balance in Alaskan Tundra (Invited)

    Science.gov (United States)

    Schuur, E. A.; Natali, S.; Trucco, C.; Hicks, C. E.; Crummer, K. G.; Baron Lopez, A. F.

    2010-12-01

    Approximately 1670 Pg (billion tons) of soil carbon are stored in the northern circumpolar permafrost zone, more than twice as much carbon than currently contained in the atmosphere. Permafrost thaw, and the microbial decomposition of previously frozen organic carbon, is considered one of the most likely positive feedbacks from terrestrial ecosystems to the atmosphere in a warmer world. Yet, the rate and form of release is highly uncertain but crucial for predicting the strength and timing of this carbon cycle feedback this century and beyond. Here we report results from a new ecosystem warming manipulation —the Carbon in Permafrost Experimental Heating Research (CiPEHR) project—where we increased air and soil temperature, and degraded the surface permafrost. We used snow fences coupled with spring snow removal to increase deep soil temperatures and thaw depth (winter warming) and open top chambers to increase growing season air temperatures (summer warming). Winter warming increased depth-integrated soil temperature by 1.5 degrees C, which resulted in a 10% increase thaw depth that persisted into the following winter. Surprisingly, the 2 kg C m-2 contained in the additional thawed soil in the winter warming plots did not result in significant changes in cumulative growing season respiration, which may have been inhibited by soil saturation at the base of the active layer. However, the limited effect of deep soil warming during the growing season contrasted with the large increase in winter respiration, which in sum doubled the net loss of carbon dioxide to the atmosphere on an annual basis. While most changes to the abiotic environment at CiPEHR were driven by winter warming, summer warming (mainly air) effects on plant and soil processes resulted in 20 percent increases in both gross primary productivity and growing season ecosystem respiration and significantly altered the age and sources of carbon dioxide respired from this ecosystem. These results

  10. 黄河源区冻土分布制图及其热稳定性特征模拟%Mapping Frozen Soil Distribution and Modeling Permafrost Stability in the Source Area of the Yellow River

    Institute of Scientific and Technical Information of China (English)

    李静; 盛煜; 吴吉春; 冯子亮; 宁作君; 胡晓莹; 张秀敏

    2016-01-01

    The source area of the Yellow River (SAYR) is located in the eastern-to-medium part of the Qing-hai-Tibet Plateau. Permafrost in the SAYR experienced remarkable degradation in the past. Taking distribution patterns of frozen soil and permafrost stability as research object, the characteristics of permafrost development and distribution patterns at various terrains and land covers were analyzed based on a large amount of field in-vestigations and the measurements. In addition, thermal features of permafrost were analyzed based on the mea-sured ground temperatures at various depths. The effects of the geological and geographic factors on permafrost distribution and thermal stability were discussed. It was indicated that:1) Permafrost was occasionally devel-oped in the various fluvial and proluvial plains with elevation generally lower than 4300 m;2) Permafrost was widely distributed in the mountains higher than 4350 m except for the sunny slope terrain, where local terrain played an important role in permafrost development and distribution;3) The combinations of local terrain, surfi-cial vegetation, soil wetness and moisture conditions all contributed to the formation and distribution of perma-frost in the low hills and mountains where elevation ranged in 4300-4350 m.Taking the annual mean ground temperature (MAGT) as the basis, an experiential-statistical MAGT-based model was constructed, of which lati-tude, longitude and elevation were set up as independent variables. Together with DEM data, permafrost MAGTs were primarily modeled using the statistically regression model. And then, the modeled results in the south-facing areas were slightly adjusted, and a secondly model was constructed to model permafrost distribu-tion in the shady areas. Thirdly, the combined modeling results were locally adjusted using the measurements. The frozen soil map in the SAYR was thus compiled. Taking 0oC as the boundary between permafrost and sea-sonally frozen soil, it was indicated

  11. The HOLOANTAR project: Holocene environmental change in the Maritime Antarctic. Interactions between permafrost and the lacustrine environment

    Science.gov (United States)

    Oliva, Marc; Vieira, Gonçalo; Mora, Carla; Trindade, Alexandre; Agrela, Joao; Batista, Vanessa; Correia, António; Schaefer, Carlos; Simas, Felipe; Ramos, Miguel; De Pablo, Miguel Angel; Toro, Manuel; Antoniades, Dermot; Galan, Luis; Giralt, Santiago; Granados, Ignacio; Pla, Sergi; Serrano, Enrique

    2013-04-01

    The objective of this abstract is to present the HOLOANTAR project, a multidisciplinary research funded by the Portuguese Government. The project integrates 16 researchers from different international institutions (Portugal, Spain, Brazil and Uruguay).. The main purpose of HOLOANTAR is to infer the palaeoenvironmental evolution and associated climate variability occurred over the last millennia in ice-free areas of the Maritime Antarctica based on the study of lake sediments. The South Shetland Islands (SSI) are located in the northwestern tip of the Antarctic Peninsula, one of the Earth's regions that have experienced a stronger warming signal during the second half of the 20th century. In the ice-free areas of this archipelago the terrestrial ecosystem is supported by permafrost, though its reaction to climate change is still poorly known. However, in the recent years a very important effort took place to monitor the thermal state and characteristics of permafrost in order to study its response to the recent warming trend. Many international teams are involved on several of these long-term monitoring projects, but HOLOANTAR, in addition, pretends to offer a new integrated approach aiming to bridge the gap between contemporary and past changes in permafrost environments. HOLOANTAR project is based on two main hypotheses: a) A multi-proxy analysis of lake sediments will allow reconstructing the palaeoecological evolution in the Maritime Antarctic and the role played in it by permafrost and active layer dynamics, b) The detection of activity rates, spatial patterns and geographical controls of contemporary key-geomorphic processes and permafrost distribution, will allow defining their limiting climatic conditions that will be used to interpret the sedimentary record. This approach is innovative since it will focus on both present and past geomorphodynamics as keys for understanding the landscape evolution. In Byers Peninsula (Livingston), the largest ice-free area

  12. A conceptual model of the controlling factors of soil organic carbon and nitrogen densities in a permafrost-affected region on the eastern Qinghai-Tibetan Plateau

    Science.gov (United States)

    Wu, Xiaodong; Fang, Hongbing; Zhao, Yonghua; Smoak, Joseph M.; Li, Wangping; Shi, Wei; Sheng, Yu; Zhao, Lin; Ding, Yongjian

    2017-07-01

    Many investigations of the preservation of soil organic carbon (SOC) in permafrost regions have examined roles of geomorphology, pedogenesis, vegetation cover, and permafrost within particular regions. However, it is difficult to disentangle the effects of multiple factors on the SOC in permafrost regions due to the heterogeneity in environmental conditions. Based on data from 73 soil study sites in permafrost regions of the eastern Qinghai-Tibetan Plateau, we developed a simple conceptual model, which relates SOC to topography, vegetation, and pedogenesis. We summarized the dominant factors and their controls on SOC using 31 measured soil physiochemical variables. Soil texture explains approximately 60% of the variations in the SOC stocks for the upper 0-2 m soil. Soil particle size closely correlates to soil moisture, which is an important determinant of SOC. Soil salinity and cations are important factors as well and can explain about 10% of the variations in SOC. The SOC and total nitrogen (TN) stocks for the 1-2 m depths have larger uncertainties than those of upper 1 m soil layer. The vegetation, pH, and bulk density mainly affects SOC and TN stocks for the upper 1 m soil layers, while the active layer thickness and soil particle size have greater influence on SOC and TN stocks for the 1-2 m soils. Our results suggest that the soil particle size is the most important controller of SOC pools, and the stocks of SOC and TN are strongly effected by soil development processes in the permafrost regions of the eastern Qinghai-Tibetan Plateau.

  13. Assessment of permafrost distribution maps in the Hindu Kush Himalayan region using rock glaciers mapped in Google Earth

    NARCIS (Netherlands)

    Schmid, M.O.; Baral, P.; Gruber, S.; Shahi, S.; Shrestha, T.; Stumm, D.; Wester, P.

    2015-01-01

    The extent and distribution of permafrost in the mountainous parts of the Hindu Kush Himalayan (HKH) region are largely unknown. A long tradition of permafrost research, predominantly on rather gentle relief, exists only on the Tibetan Plateau. Two permafrost maps are available digitally that cov

  14. A radiance-based method for estimating uncertainties in the Atmospheric Infrared Sounder (AIRS) land surface temperature product

    Science.gov (United States)

    Hulley, Glynn C.; Hook, Simon J.

    2012-10-01

    Land Surface Temperature (LST) has been identified by NASA and other international organizations as an important Earth System Data Record (ESDR). An ESDR is defined as a long-term, well calibrated and validated data set. Identifying uncertainties in LST products with coarse spatial resolutions (>10 km) such as those from hyperspectral infrared sounders is notoriously difficult due to the challenges of making reliable in situ measurements representative of the spatial scales of the output products. In this study we utilize a Radiance-based (R-based) LST method for estimating uncertainties in the Atmospheric Infrared Sounder (AIRS) v5 LST product. The R-based method provides estimates of the true LST using a radiative closure simulation without the need for in situ measurements, and requires input air temperature, relative humidity profiles and emissivity data. The R-based method was employed at three validation sites over the Namib Desert, Gran Desierto, and Redwood National Park for all AIRS observations from 2002 to 2010. Results showed daytime LST root-mean square errors (RMSE) of 2-3 K at the Namib and Desierto sites, and 1.5 K at the Redwood site. Nighttime LST RMSEs at the two desert sites were a factor of two less when compared to daytime results. Positive daytime LST biases were found at each site due to an underestimation of the daytime AIRS v5 longwave spectral emissivity, while the reverse occurred at nighttime. In the AIRS v6 product (release 2012), LST biases and RMSEs will be reduced significantly due to improved methodologies for the surface retrieval and emissivity first guess.

  15. Authigenic mineral formation in fluid permeability zones in the West Siberia Permafrost

    Science.gov (United States)

    Kurchatova, A. N.; Melnikov, V. P.; Rogov, V. V.; Slagoda, E. A.

    2016-06-01

    Basic chemical and mineralogical anomalies in permafrost caused by hydrocarbon migration are considered. Direct evidence for bacterial oxidation of light hydrocarbons, primarily methane, were first obtained in fluid permeability zones in the permafrost as a stepwise formation of authigenic minerals such as iron sulfides and oxides, carbonates, silicates, and gypsum.

  16. Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw

    NARCIS (Netherlands)

    Vonk, J. E.; Mann, P. J.; Dowdy, K. L.; Davydova, A.; Davydov, S. P.; Zimov, N.; Spencer, R. G. M.; Bulygina, E. B.; Eglinton, T. I.; Holmes, R. M.

    2013-01-01

    Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic permafrost and is characterized by the presence of massive ice wedges. Due to its rapid formation by sediment accumulation and subsequent frozen storage, Yedoma OM is relatively well preserved an

  17. Reviews and syntheses : Effects of permafrost thaw on Arctic aquatic ecosystems

    NARCIS (Netherlands)

    Vonk, J. E.; Tank, S. E.; Bowden, W. B.; Laurion, I.; Vincent, W. F.; Alekseychik, P.; Amyot, M.; Billet, M. F.; Canário, J.; Cory, R. M.; Deshpande, B. N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; Macmillan, G.; Rautio, M.; Walter Anthony, K. M.; Wickland, K. P.

    2015-01-01

    The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current st

  18. Microbes in thawing permafrost: the unknown variable in the climate change equation

    Energy Technology Data Exchange (ETDEWEB)

    Graham, David E [ORNL; Wallenstein, Matthew D [Colorado State University, Fort Collins; Vishnivetskaya, T. [University of Tennessee, Knoxville (UTK); Waldrop, Mark P. [U.S. Geological Survey, Menlo Park, CA; Phelps, Tommy Joe [ORNL; Pfiffner, Susan M. [University of Tennessee, Knoxville (UTK); Onstott, T. C. [Princeton University; Whyte, Lyle [McGill University, Montreal, Quebec; Rivkina, Elizaveta [Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences; Gilichinsky, David A [Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences; Elias, Dwayne A [ORNL; Mackelprang, Rachel [U.S. Department of Energy, Joint Genome Institute; Verberkmoes, Nathan C [ORNL; Hettich, Robert {Bob} L [ORNL; Wagner, Dirk [Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany; Wullschleger, Stan D [ORNL; Jansson, Janet [Lawrence Berkeley National Laboratory (LBNL)

    2012-01-01

    Considering that 25% of Earth s terrestrial surface is underlain by permafrost (ground that has been continuously frozen for at least 2 years), our understanding of the diversity of microbial life in this extreme habitat is surprisingly limited. Taking into account the total mass of perennially frozen sediment (up to several hundred meters deep), permafrost contains a huge amount of buried, ancient organic carbon (Tarnocai et al., 2009). In addition, permafrost is warming rapidly in response to global climate change (Romanovsky et al., 2010), potentially leading to widespread thaw and a larger, seasonally thawed soil active layer. This concern has prompted the question: will permafrost thawing lead to the release of massive amounts of carbon dioxide (CO2) and methane (CH4) into the atmosphere? This question can only be answered by understanding how the microbes residing in permafrost will respond to thaw, through processes such as respiration, fermentation, methanogenesis and CH4 oxidation (Schuur et al., 2009). Predicting future carbon fluxes is complicated by the diversity of permafrost environments, ranging from high mountains, southern boreal forests, frozen peatlands and Pleistocene ice complexes (yedoma) up to several hundred meters deep, which vary widely in soil composition, soil organic matter (SOM) quality, hydrology and thermal regimes (Figure 1). Permafrost degradation can occur in many forms: thaw can progress downward from seasonally-thawed active layer soils in warming climates or laterally because of changes in surface or groundwater flow paths (Grosse et al., 2011). Permafrost degradation can sometimes lead to dramatic changes in ecosystem structure and function

  19. Evaluation of the permafrost stability degradation from 1980 to 2010 in China

    Institute of Scientific and Technical Information of China (English)

    YouHua Ran; Xin Li

    2016-01-01

    The degradation of permafrost stability in China over the past 30 years is evaluated using a new, high-resolution near-surface air temperature reanalysis dataset. Results show that the permafrost extent clearly decreased by 22%from 1980 to 2010, that is, a loss of 12.68×104 km2. The degradation occurred not only in the transition regions between per-mafrost and seasonally frozen ground, but also and more importantly, in the interior of the permafrost regions. The deg-radation in the interior of permafrost regions accounted for 87%of the total degraded areas. The degradation occurred mainly during the 1980s to 1990s in the northeast permafrost area and the Qilian Mountains, and during the 1990s to 2000s in most areas of the Qinghai-Tibet Plateau (QTP). This degradation will have systemic impacts on engineered infra-structures in permafrost regions, the water balance, and the global carbon budget. A more robust physical model should be used to evaluate the permafrost thermal stability at finer resolution in the future.

  20. Chemical indicators of cryoturbation and microbial processing throughout an alaskan permafrost soil depth profile

    Science.gov (United States)

    Although permafrost soils contain vast stores of carbon, we know relatively little about the chemical composition of their constituent organic matter. Soil organic matter chemistry is an important predictor of decomposition rates, especially in the initial stages of decomposition. Permafrost, organi...

  1. Vulnerability of Permafrost Soil Carbon to Climate Warming: Evaluating Controls on Microbial Community Composition

    Science.gov (United States)

    Abstract: Despite the fact that permafrost soils contain up to half of the carbon (C) in terrestrial pools, we have a poor understanding of the controls on decomposition in thawed permafrost. Global climate models assume that decomposition increases linearly with temperature, yet decomposition in th...

  2. Field training for permafrost students in the cold-climate conditions

    Science.gov (United States)

    Leibman, M.

    2009-04-01

    We all know how complicated is organizing expeditions to the Arctic, especially to the remote areas with continuous permafrost, tundra landscapes, expensive helicopters, and extreme living conditions. But this cannot be the reason to deprive students of studying the nature. There is a serious problem with computer modeling becoming a main research instrument. Often young people involved in such modeling have never seen the object of their modeling. Some of us are "remnants" of the epoch before computer and satellite technologies when field data was the main source of mapping information, small-scale maps were based on field mapping. This knowledge is getting lost with the experts getting retired. This is the reason for involving students into field research as much and as soon as possible. Arctic expeditions often mean absence of usual amenities in living conditions, exposure to weather extremes, bugs and simple meal. These complications make each bit of field data be of high-hourly-rate. That is why teaching the methods of field study is very important, to make each trip most effective and reduce costs of each bit of information. These methods include both science and logistic issues. There are two more aspects in field training: (1) students and teachers from different countries meeting in field learn to identify natural objects and conciliate positions and terminology; and (2) students and teachers from different disciplines learn to conciliate understanding of each others study subjects. Examples of field research stations in Russian Arctic where interdisciplinary studies are ongoing for many years with participation of graduate and postgraduate students show the effectiveness of the above mentioned approach. In the north of West Siberia there are four polygons serving as a base for associated research of permafrost geologists, geographers, biologists, geochemists and more. The system is built in which basic role is shifting from one subject to the other

  3. Towards improved parameterization of a macroscale hydrologic model in a discontinuous permafrost boreal forest ecosystem

    Directory of Open Access Journals (Sweden)

    A. Endalamaw

    2017-09-01

    Full Text Available Modeling hydrological processes in the Alaskan sub-arctic is challenging because of the extreme spatial heterogeneity in soil properties and vegetation communities. Nevertheless, modeling and predicting hydrological processes is critical in this region due to its vulnerability to the effects of climate change. Coarse-spatial-resolution datasets used in land surface modeling pose a new challenge in simulating the spatially distributed and basin-integrated processes since these datasets do not adequately represent the small-scale hydrological, thermal, and ecological heterogeneity. The goal of this study is to improve the prediction capacity of mesoscale to large-scale hydrological models by introducing a small-scale parameterization scheme, which better represents the spatial heterogeneity of soil properties and vegetation cover in the Alaskan sub-arctic. The small-scale parameterization schemes are derived from observations and a sub-grid parameterization method in the two contrasting sub-basins of the Caribou Poker Creek Research Watershed (CPCRW in Interior Alaska: one nearly permafrost-free (LowP sub-basin and one permafrost-dominated (HighP sub-basin. The sub-grid parameterization method used in the small-scale parameterization scheme is derived from the watershed topography. We found that observed soil thermal and hydraulic properties – including the distribution of permafrost and vegetation cover heterogeneity – are better represented in the sub-grid parameterization method than the coarse-resolution datasets. Parameters derived from the coarse-resolution datasets and from the sub-grid parameterization method are implemented into the variable infiltration capacity (VIC mesoscale hydrological model to simulate runoff, evapotranspiration (ET, and soil moisture in the two sub-basins of the CPCRW. Simulated hydrographs based on the small-scale parameterization capture most of the peak and low flows, with similar accuracy in both sub

  4. Towards improved parameterization of a macroscale hydrologic model in a discontinuous permafrost boreal forest ecosystem

    Science.gov (United States)

    Endalamaw, Abraham; Bolton, W. Robert; Young-Robertson, Jessica M.; Morton, Don; Hinzman, Larry; Nijssen, Bart

    2017-09-01

    Modeling hydrological processes in the Alaskan sub-arctic is challenging because of the extreme spatial heterogeneity in soil properties and vegetation communities. Nevertheless, modeling and predicting hydrological processes is critical in this region due to its vulnerability to the effects of climate change. Coarse-spatial-resolution datasets used in land surface modeling pose a new challenge in simulating the spatially distributed and basin-integrated processes since these datasets do not adequately represent the small-scale hydrological, thermal, and ecological heterogeneity. The goal of this study is to improve the prediction capacity of mesoscale to large-scale hydrological models by introducing a small-scale parameterization scheme, which better represents the spatial heterogeneity of soil properties and vegetation cover in the Alaskan sub-arctic. The small-scale parameterization schemes are derived from observations and a sub-grid parameterization method in the two contrasting sub-basins of the Caribou Poker Creek Research Watershed (CPCRW) in Interior Alaska: one nearly permafrost-free (LowP) sub-basin and one permafrost-dominated (HighP) sub-basin. The sub-grid parameterization method used in the small-scale parameterization scheme is derived from the watershed topography. We found that observed soil thermal and hydraulic properties - including the distribution of permafrost and vegetation cover heterogeneity - are better represented in the sub-grid parameterization method than the coarse-resolution datasets. Parameters derived from the coarse-resolution datasets and from the sub-grid parameterization method are implemented into the variable infiltration capacity (VIC) mesoscale hydrological model to simulate runoff, evapotranspiration (ET), and soil moisture in the two sub-basins of the CPCRW. Simulated hydrographs based on the small-scale parameterization capture most of the peak and low flows, with similar accuracy in both sub-basins, compared to

  5. LGM permafrost distribution: how well can the latest PMIP multi-model ensembles perform reconstruction?

    Directory of Open Access Journals (Sweden)

    K. Saito

    2013-08-01

    Full Text Available Here, global-scale frozen ground distribution from the Last Glacial Maximum (LGM has been reconstructed using multi-model ensembles of global climate models, and then compared with evidence-based knowledge and earlier numerical results. Modeled soil temperatures, taken from Paleoclimate Modelling Intercomparison Project phase III (PMIP3 simulations, were used to diagnose the subsurface thermal regime and determine underlying frozen ground types for the present day (pre-industrial; 0 kya and the LGM (21 kya. This direct method was then compared to an earlier indirect method, which categorizes underlying frozen ground type from surface air temperature, applying to both the PMIP2 (phase II and PMIP3 products. Both direct and indirect diagnoses for 0 kya showed strong agreement with the present-day observation-based map. The soil temperature ensemble showed a higher diversity around the border between permafrost and seasonally frozen ground among the models, partly due to varying subsurface processes, implementation, and settings. The area of continuous permafrost estimated by the PMIP3 multi-model analysis through the direct (indirect method was 26.0 (17.7 million km2 for LGM, in contrast to 15.1 (11.2 million km2 for the pre-industrial control, whereas seasonally frozen ground decreased from 34.5 (26.6 million km2 to 18.1 (16.0 million km2. These changes in area resulted mainly from a cooler climate at LGM, but from other factors as well, such as the presence of huge land ice sheets and the consequent expansion of total land area due to sea-level change. LGM permafrost boundaries modeled by the PMIP3 ensemble – improved over those of the PMIP2 due to higher spatial resolutions and improved climatology – also compared better to previous knowledge derived from geomorphological and geocryological evidence. Combinatorial applications of coupled climate models and detailed stand-alone physical-ecological models for the cold-region terrestrial

  6. Development of highway constructing technology in the permafrost region on the Qinghai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surroundings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2―0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate, and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engineering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road

  7. Development of highway constructing technology in the permafrost region on the Qinshai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    WANG ShuangJie; CHEN JianBing; ZHANG JinZhao; LI ZhuLong

    2009-01-01

    The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surround-ings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2-0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate,and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engi- neering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road

  8. Microbial populations in Antarctic permafrost: biodiversity, state, age, and implication for astrobiology.

    Science.gov (United States)

    Gilichinsky, D A; Wilson, G S; Friedmann, E I; McKay, C P; Sletten, R S; Rivkina, E M; Vishnivetskaya, T A; Erokhina, L G; Ivanushkina, N E; Kochkina, G A; Shcherbakova, V A; Soina, V S; Spirina, E V; Vorobyova, E A; Fyodorov-Davydov, D G; Hallet, B; Ozerskaya, S M; Sorokovikov, V A; Laurinavichyus, K S; Shatilovich, A V; Chanton, J P; Ostroumov, V E; Tiedje, J M

    2007-04-01

    Antarctic permafrost soils have not received as much geocryological and biological study as has been devoted to the ice sheet, though the permafrost is more stable and older and inhabited by more microbes. This makes these soils potentially more informative and a more significant microbial repository than ice sheets. Due to the stability of the subsurface physicochemical regime, Antarctic permafrost is not an extreme environment but a balanced natural one. Up to 10(4) viable cells/g, whose age presumably corresponds to the longevity of the permanently frozen state of the sediments, have been isolated from Antarctic permafrost. Along with the microbes, metabolic by-products are preserved. This presumed natural cryopreservation makes it possible to observe what may be the oldest microbial communities on Earth. Here, we describe the Antarctic permafrost habitat and biodiversity and provide a model for martian ecosystems.

  9. Experimental Study on Settlement of Embankment over Permafrost along Qinghai-Tibetan Railway%青藏铁路冻土路基沉降变形现场试验研究

    Institute of Scientific and Technical Information of China (English)

    张建明; 张明义; 朱元林; 蒋观利

    2004-01-01

    Based on the field data of ground temperature and roadway settlement observed during the construction of the experimental embankments over permafrost along the Qinghai-Tibetan Railway, this paper discusses the differences of frost process on the roadway surface from that on the natural ground surface, the changes of permafrost table under the roadway embankment, and the peculiarities of roadway settlement. Analyses of the test results show : 1) The differences of the freezing indexes between the roadway surfaces and the natural ground surfaces are less than those of the thawing indexes for all the test sections; 2) Since the measures of permafrost protection were taken, the permafrost tables under the embankments have raised after the roadway was constructed. The minimum is about 0.4 m and the maximum is 1.2 m; 3) the settlements of the roadway are mainly from the compression and creep of the icerich frozen soils under the original permafrost tables and the maximum has reached 6 ~ 8 cm during the first year after the embankments were constructed. Moreover, concerning the processes of roadway settlement, the deformation of the embankments has no obvious trend of attenuation at present. Especially,for the roadway with high embankments, the settlement may reach a remarkable value and much consideration must be given for this problem.

  10. Subsurface fate of spilled petroleum hydrocarbons in continuous permafrost

    Science.gov (United States)

    McCarthy, K.; Walker, L.; Vigoren, L.

    2004-01-01

    Accidental releases of approximately 2000 m3 of fuel have resulted in subsurface contamination adjacent to Imikpuk Lake, a drinking-water source near Barrow, AK. This paper presents a conceptual model of the distribution and transport of subsurface free-phase hydrocarbons at this site. The mean annual temperature in Barrow is -13 ??C, and average monthly temperatures exceed 0 ??C only during the months of June, July, and August. As a result, the region is underlain by areally continuous permafrost that extends to depths of up to 300 m and constrains subsurface hydrologic processes to a shallow zone that temporarily thaws each summer. During the 1993 and 1994 thaw seasons, the measured depth of thaw varied across the site from approximately 0.5 to 2 m. However, exploratory borings in 1995 showed that free-phase hydrocarbons were present at depths greater than 3 m, indicating that permafrost at this site is not a barrier to the vertical migration of nonaqueous-phase liquids. In 1996, a subsurface containment barrier was installed to prevent lateral movement of contaminated water to Imikpuk Lake, and a recovery trench was excavated upgradient of the barrier to facilitate removal of free-phase hydrocarbons. Free-phase hydrocarbons were recovered from the trench during 1996, 1997, and 1998. Recovery rates diminished over this time, and in 1999, no further product was recovered and the recovery operation was halted. Subsequent exploratory borings in 2001 and 2002 have revealed that some product remains in the subsurface. Data indicate that this remaining product exists in small discrete pockets or very thin layers of hydrocarbon floating on brine. These small reservoirs appear to be isolated from one another by relatively impermeable permafrost. Published by Elsevier B.V.

  11. Weichselian permafrost depth in the Netherlands: a comprehensive uncertainty and sensitivity analysis

    Science.gov (United States)

    Govaerts, Joan; Beerten, Koen; ten Veen, Johan

    2016-11-01

    The Rupelian clay in the Netherlands is currently the subject of a feasibility study with respect to the storage of radioactive waste in the Netherlands (OPERA-project). Many features need to be considered in the assessment of the long-term evolution of the natural environment surrounding a geological waste disposal facility. One of these is permafrost development as it may have an impact on various components of the disposal system, including the natural environment (hydrogeology), the natural barrier (clay) and the engineered barrier. Determining how deep permafrost might develop in the future is desirable in order to properly address the possible impact on the various components. It is expected that periglacial conditions will reappear at some point during the next several hundred thousands of years, a typical time frame considered in geological waste disposal feasibility studies. In this study, the Weichselian glaciation is used as an analogue for future permafrost development. Permafrost depth modelling using a best estimate temperature curve of the Weichselian indicates that permafrost would reach depths between 155 and 195 m. Without imposing a climatic gradient over the country, deepest permafrost is expected in the south due to the lower geothermal heat flux and higher average sand content of the post-Rupelian overburden. Accounting for various sources of uncertainty, such as type and impact of vegetation, snow cover, surface temperature gradients across the country, possible errors in palaeoclimate reconstructions, porosity, lithology and geothermal heat flux, stochastic calculations point out that permafrost depth during the coldest stages of a glacial cycle such as the Weichselian, for any location in the Netherlands, would be 130-210 m at the 2σ level. In any case, permafrost would not reach depths greater than 270 m. The most sensitive parameters in permafrost development are the mean annual air temperatures and porosity, while the geothermal heat

  12. Merging Field Measurements and High Resolution Modeling to Predict Possible Societal Impacts of Permafrost Degradation

    Science.gov (United States)

    Romanovsky, V. E.; Nicolsky, D.; Marchenko, S. S.; Cable, W.; Panda, S. K.

    2015-12-01

    A general warming trend in permafrost temperatures has triggered permafrost degradation in Alaska, especially at locations influenced by human activities. Various phenomena related to permafrost degradation are already commonly observed, including increased rates of coastal and riverbank erosion, increased occurrences of retrogressive thaw slumps and active layer detachment slides, and the disappearance of tundra lakes. The combination of thawing permafrost and erosion is damaging local community infrastructure such as buildings, roads, airports, pipelines, water and sanitation facilities, and communication systems. The potential scale of direct ecological and economical damage due to degrading permafrost has just begun to be recognized. While the projected changes in permafrost are generally available on global and regional scales, these projections cannot be effectively employed to estimate the societal impacts because of their coarse resolution. Intrinsic problems with the classical "spatial grid" approach in spatially distributed modeling applications preclude the use of this modeling approach to solve the above stated problem. Two types of models can be used to study permafrost dynamics in this case. One approach is a site-specific application of the GIPL2.0 permafrost model and another is a very high (tens to hundred meter) resolution spatially distributed version of the same model. The results of properly organized field measurements are also needed to calibrate and validate these models for specific locations and areas of interest. We are currently developing a "landscape unit" approach that allows practically unlimited spatial resolution of the modeling products. Classification of the study area into particular "landscape units" should be performed in accordance with the main factors controlling the expression of climate on permafrost in the study area, typically things such as vegetation, hydrology, soil properties, topography, etc. In areas with little

  13. Uav Photogrammetry for Mapping and Monitoring of Northern Permafrost Landscapes

    Science.gov (United States)

    Fraser, R. H.; Olthof, I.; Maloley, M.; Fernandes, R.; Prevost, C.; van der Sluijs, J.

    2015-08-01

    Northern environments are changing in response to recent climate warming, resource development, and natural disturbances. The Arctic climate has warmed by 2-3°C since the 1950's, causing a range of cryospheric changes including declines in sea ice extent, snow cover duration, and glacier mass, and warming permafrost. The terrestrial Arctic has also undergone significant temperature-driven changes in the form of increased thermokarst, larger tundra fires, and enhanced shrub growth. Monitoring these changes to inform land managers and decision makers is challenging due to the vast spatial extents involved and difficult access. Environmental monitoring in Canada's North is often based on local-scale measurements derived from aerial reconnaissance and photography, and ecological, hydrologic, and geologic sampling and surveying. Satellite remote sensing can provide a complementary tool for more spatially comprehensive monitoring but at coarser spatial resolutions. Satellite remote sensing has been used to map Arctic landscape changes related to vegetation productivity, lake expansion and drainage, glacier retreat, thermokarst, and wildfire activity. However, a current limitation with existing satellite-based techniques is the measurement gap between field measurements and high resolution satellite imagery. Bridging this gap is important for scaling up field measurements to landscape levels, and validating and calibrating satellite-based analyses. This gap can be filled to a certain extent using helicopter or fixed-wing aerial surveys, but at a cost that is often prohibitive. Unmanned aerial vehicle (UAV) technology has only recently progressed to the point where it can provide an inexpensive and efficient means of capturing imagery at this middle scale of measurement with detail that is adequate to interpret Arctic vegetation (i.e. 1-5 cm) and coverage that can be directly related to satellite imagery (1-10 km2). Unlike satellite measure