WorldWideScience

Sample records for surface temperature time

  1. Time and Temperature Dependent Surface Stiffness of Poly(alpha-methylstyrene)(PAMS) through Particle Embedment

    Science.gov (United States)

    Karim, Taskin; McKenna, Gregory

    2012-02-01

    In the present work, we have used the particle embedment technique with sub-micron particles to study the time dependence surface modulus of poly(alpha-methylstyrene)(PAMS) at different temperature ranging from room temperature to 1.1Tg of PAMS. The surface was found softer at room temperature and at 1.02Tg compared to the bulk film while at 1.1Tg the surface was found stiffer compared to the macroscopic modulus measured for the same PAMS. The embedment of the particle is determined from atomic force microscope measurements and the modulus was determined using the elastic analysis of Johnson, Kendall and Roberts (JKR) with surface energy estimates of the work of adhesion as the driving force for embedment. REFERENCES 1. K. L. Johnson, K. Kendall and A. D. Roberts, P. Royal Society of Lonodon A, 324, 301-313 (1971). 2. J. H. Teichroeb and J. A. Forrest, Physical Review Letter, 91, 016104 (2003).

  2. Near surface spatially averaged air temperature and wind speed determined by acoustic travel time tomography

    Directory of Open Access Journals (Sweden)

    Armin Raabe

    2001-03-01

    Full Text Available Acoustic travel time tomography is presented as a possibility for remote monitoring of near surface airtemperature and wind fields. This technique provides line-averaged effective sound speeds changing with temporally and spatially variable air temperature and wind vector. The effective sound speed is derived from the travel times of sound signals which propagate at defined paths between different acoustic sources and receivers. Starting with the travel time data a tomographic algorithm (Simultaneous Iterative Reconstruction Technique, SIRT is used to calculate area-averaged air temperature and wind speed. The accuracy of the experimental method and the tomographic inversion algorithm is exemplarily demonstrated for one day without remarkable differences in the horizontal temperature field, determined by independent in situ measurements at different points within the measuring field. The differences between the conventionally determined air temperature (point measurement and the air temperature determined by tomography (area-averaged measurement representative for the area of the measuring field 200m x 260m were below 0.5 K for an average of 10 minutes. The differences obtained between the wind speed measured at a meteorological mast and calculated from acoustic measurements are not higher than 0.5 ms-1 for the same averaging time. The tomographically determined area-averaged distribution of air temperature (resolution 50 m x 50 m can be used to estimate the horizontal gradient of air temperature as a pre-condition to detect horizontal turbulent fluxes of sensible heat.

  3. High-resolution, real-time simultaneous 3D surface geometry and temperature measurement.

    Science.gov (United States)

    An, Yatong; Zhang, Song

    2016-06-27

    This paper presents a method to simultaneously measure three-dimensional (3D) surface geometry and temperature in real time. Specifically, we developed 1) a holistic approach to calibrate both a structured light system and a thermal camera under exactly the same world coordinate system even though these two sensors do not share the same wavelength; and 2) a computational framework to determine the sub-pixel corresponding temperature for each 3D point as well as discard those occluded points. Since the thermal 2D imaging and 3D visible imaging systems do not share the same spectrum of light, they can perform sensing simultaneously in real time: we developed a hardware system that can achieve real-time 3D geometry and temperature measurement at 26 Hz with 768 × 960 points per frame.

  4. Effect of temperature, curing time, and filler composition on surface microhardness of composite resins

    OpenAIRE

    Dimitrios Dionysopoulos; Constantinos Papadopoulos; Eugenia Koliniotou-Koumpia

    2015-01-01

    Aim: The aim of this study was to evaluate the microhardness of two composite resins when subjected to three different temperatures and three different light-curing times. Materials and Methods: Two composites were used; Filtek Z250 and Grandio. Three different temperatures (23, 37, and 55 o C) were used, utilizing a composite warmer. The heated samples were immediately injected into cylindrical molds (6 mm × 2 mm) and the top surface of the specimens was polymerized for 10, 20, and 40 se...

  5. LITERATURE REVIEW OF PUO2 CALCINATION TIME AND TEMPERATURE DATA FOR SPECIFIC SURFACE AREA

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, G.

    2012-03-06

    The literature has been reviewed in December 2011 for calcination data of plutonium oxide (PuO{sub 2}) from plutonium oxalate Pu(C{sub 2}O{sub 4}){sub 2} precipitation with respect to the PuO{sub 2} specific surface area (SSA). A summary of the literature is presented for what are believed to be the dominant factors influencing SSA, the calcination temperature and time. The PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} calcination data from this review has been regressed to better understand the influence of calcination temperature and time on SSA. Based on this literature review data set, calcination temperature has a bigger impact on SSA versus time. However, there is still some variance in this data set that may be reflecting differences in the plutonium oxalate preparation or different calcination techniques. It is evident from this review that additional calcination temperature and time data for PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} needs to be collected and evaluated to better define the relationship. The existing data set has a lot of calcination times that are about 2 hours and therefore may be underestimating the impact of heating time on SSA. SRNL recommends that more calcination temperature and time data for PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} be collected and this literature review data set be augmented to better refine the relationship between PuO{sub 2} SSA and its calcination parameters.

  6. Rose Island, American Samoa, 2006 Sea Surface Temperature and Meterological Standard Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site - Rose Island, American Samoa, -14.5514, -168.16018 ARGOS ID 27267 Time series data from this mooring provide high resolution sea surface temperature, surface...

  7. Developing first time-series of land surface temperature from AATSR with uncertainty estimates

    Science.gov (United States)

    Ghent, Darren; Remedios, John

    2013-04-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Earth Observation satellites provide the opportunity to obtain global coverage of LST approximately every 3 days or less. One such source of satellite retrieved LST has been the Advanced Along-Track Scanning Radiometer (AATSR); with LST retrieval being implemented in the AATSR Instrument Processing Facility in March 2004. Here we present first regional and global time-series of LST data from AATSR with estimates of uncertainty. Mean changes in temperature over the last decade will be discussed along with regional patterns. Although time-series across all three ATSR missions have previously been constructed (Kogler et al., 2012), the use of low resolution auxiliary data in the retrieval algorithm and non-optimal cloud masking resulted in time-series artefacts. As such, considerable ESA supported development has been carried out on the AATSR data to address these concerns. This includes the integration of high resolution auxiliary data into the retrieval algorithm and subsequent generation of coefficients and tuning parameters, plus the development of an improved cloud mask based on the simulation of clear sky conditions from radiance transfer modelling (Ghent et al., in prep.). Any inference on this LST record is though of limited value without the accompaniment of an uncertainty estimate; wherein the Joint Committee for Guides in Metrology quote an uncertainty as "a parameter associated with the result of a measurement that characterizes the dispersion of the values that could reasonably be attributed to the measurand that is the value of the particular quantity to be measured". Furthermore, pixel level uncertainty fields are a mandatory requirement in the on-going preparation of the LST product for the upcoming Sea and Land Surface Temperature (SLSTR) instrument on-board Sentinel-3

  8. Temperature-driven oxidation behavior on pure iron surface investigated by time-resolved EXAFS measurements

    Energy Technology Data Exchange (ETDEWEB)

    Doh, S.J.; Lee, J.M.; Je, J.H. [POSTECH, Pohang (Korea, Republic of); Noh, D.Y. [K-JIST, Kwangju (Korea, Republic of). Dept. of Materials Science and Engineering

    1998-12-31

    The surface-front oxidation mechanism of iron was investigated by time-resolved, glancing-angle Fe K-edge fluorescence EXAFS measurements at various oxidation temperatures of 200--700 C. The glancing angle was chosen according to the depth of the oxide layer, roughly 1,500--2,000 {angstrom}. The oxidation behavior under rapid heating (up to 600 C within 10 minutes) was compared with the slowly heated oxidation process using the Quick-EXAFS measurements. In the slowly heated process, Fe{sub 3}O{sub 4} was the dominating phase at a relatively low temperature (300--400 C) initially. However, at a relatively high temperature (above 600 C), the Fe{sub 2}O{sub 3} and FeO crystalline phases are gradually enriched as the successive oxidation process involving intrusive oxygen proceeded. Remarkably under a prolonged heat treatment above 600 C, the stable FeO phase that exists in a deep-lying interface structure and Fe{sub 2}O{sub 3} phase eventually dominates the thick front-surface structure. In a quickly heated process, however, Fe{sub 3}O{sub 4} phase is less dominating, which is contradictory to the commonly accepted oxidation models. The EXAFS results are discussed in conjunction with the x-ray diffraction features under the same heat treatment conditions.

  9. Long-term sea surface temperature baselines - time series, spatial covariation and implications for biological processes

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Schiedek, D.

    2007-01-01

    questions at large spatial scales, such as the response of species distributions and phenologies to climate change. In this study we investigate the spatial synchrony of long-term sea surface temperatures in the North Sea-Baltic Sea region as measured daily at four coastal sites (Marsdiep, Netherlands...... assessments of how species and ecosystems have responded to past temperature changes and how they may react to future temperature changes. (C) 2007 Elsevier B.V. All rights reserved....

  10. Pearl and Hermes, NWHI, 2004 Sea Surface Temperature and Meterological Standard Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site - Pearl and Hermes, NW Hawaiian Islands 27.85N, 175.82W, ARGOS ID 21376 Time series data from this mooring provide high resolution sea surface temperature,...

  11. nowCOAST's Map Service for NOAA NWS NDFD Forecasts of Daily Max Surface Air Temperature (deg. F) (Time Offsets)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-offsets map service provides maps depicting the NWS daily maximum surface air temperature forecasts from the National Digital...

  12. nowCOAST's Map Service for NOAA NWS NDFD Forecasts of Daily Min Surface Air Temperature (deg. F) (Time Offsets)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-offsets map service provides maps depicting the NWS daily minimum surface air temperature forecasts from the National Digital...

  13. Kure Atoll, NWHI, 2004 Sea Surface Temperature and Meterological Standard Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site - Kure Atoll, NW Hawaiian Islands (28.41858, -178.34333 ) ARGOS ID 21392 Time series data from this mooring provide high resolution sea surface temperature,...

  14. Maro Reef, NWHI 2004 Sea Surface Temperature and Meterological Standard Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site - Maro Reef, NW Hawaiian Islands (25.44643, -170.63366 ) ARGOS ID 21531 Time series data from this mooring provide high resolution sea surface temperature,...

  15. Palmyra Atoll, 2006 Sea Surface Temperature and Meteorological Enhanced Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site Palmyra Atoll, (5.88467, -162.10281 ) ARGOS ID 307-001. Time series data from this mooring provide high resolution sea surface temperature and conductivity, and...

  16. Effect of temperature and time on microstructure and surface functional groups of activated carbon fibers prepared from liquefied wood

    Directory of Open Access Journals (Sweden)

    Wenjing Liu

    2012-11-01

    Full Text Available Activated carbon fibers were prepared from liquefied wood through stream activation. The effects of activation temperature and time on the microstructure and surface functional groups of the liquefied wood activated carbon fibers (LWACFs were studied using analysis of burning behavior, X-ray diffraction, nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and SEM. The results showed that the burn-off value of the LWACFs increased gradually with the increase in temperature or time. All the LWACFs were far from being structurally graphitized, and in general, as temperature or time increased, the degree of graphitization and thickness of crystal structure increased. In addition, the LWACFs possessed rich micropores, and their specific surface area, pore volume, micropore size, and mesopore quantity were directly related to the activation temperature or time. The maximum specific surface area was found to be 2641 m2/g. The fractal dimension values of all samples were close to 3, indicating that their surfaces were very rough. Furthermore, with an increase in temperature or time, the elemental content of carbon increased, while that of oxygen decreased. Meanwhile, as the temperature or time increased, the relative content of graphitic carbon decreased, whereas that of carbon bonded to oxygen-containing functions increased. The surface of samples prepared at higher temperature or with longer time formed a considerable amount of holes.

  17. Relationship between the Arctic oscillation and surface air temperature in multi-decadal time-scale

    Science.gov (United States)

    Tanaka, Hiroshi L.; Tamura, Mina

    2016-09-01

    In this study, a simple energy balance model (EBM) was integrated in time, considering a hypothetical long-term variability in ice-albedo feedback mimicking the observed multi-decadal temperature variability. A natural variability was superimposed on a linear warming trend due to the increasing radiative forcing of CO2. The result demonstrates that the superposition of the natural variability and the background linear trend can offset with each other to show the warming hiatus for some period. It is also stressed that the rapid warming during 1970-2000 can be explained by the superposition of the natural variability and the background linear trend at least within the simple model. The key process of the fluctuating planetary albedo in multi-decadal time scale is investigated using the JRA-55 reanalysis data. It is found that the planetary albedo increased for 1958-1970, decreased for 1970-2000, and increased for 2000-2012, as expected by the simple EBM experiments. The multi-decadal variability in the planetary albedo is compared with the time series of the AO mode and Barents Sea mode of surface air temperature. It is shown that the recent AO negative pattern showing warm Arctic and cold mid-latitudes is in good agreement with planetary albedo change indicating negative anomaly in high latitudes and positive anomaly in mid-latitudes. Moreover, the Barents Sea mode with the warm Barents Sea and cold mid-latitudes shows long-term variability similar to planetary albedo change. Although further studies are needed, the natural variabilities of both the AO mode and Barents Sea mode indicate some possible link to the planetary albedo as suggested by the simple EBM to cause the warming hiatus in recent years.

  18. Lake Surface Water Temperature of European Lakes retrieved from AVHRR Data - Time Series and Quality Assessment

    Science.gov (United States)

    Wunderle, S.; Lieberherr, G.; Riffler, M.

    2016-12-01

    Data analysis of the recent years showed an increase of lake surface water temperature for many lakes around the world. But due to sparse in-situ measurements, which are often not well documented, only satellite data can provide the needed information of the last decades. The importance of lakes for climate research was also highlighted by the Global Climate Observing System (GCOS) defining lakes as Essential Climate Variables (ECVs). Within the frame of a research project funded by the Swiss National Science Foundation a procedure was developed to retrieve lake surface water temperature with high accuracy based on our archived AVHRR data at the University of Bern, Switzerland. The data archive starts in 1985 and is continuously filled with NOAA-/MetOp-AVHRR data received by our antenna resulting in a time series of more than 30 years (WMO definition of a climate period). The data set covering Europe is also used by other teams for climate related studies resulting in improved pre-processing to guarantee precise calibration and geocoding. The first part of our presentation will be dedicated to the quality of the LSWT retrieval comparing various in-situ measurements from lakes in Switzerland with varying sizes (150km2 - 9km2). The quality of the used split-window approach is sensitive to the derived split-window coefficients. The influence of water vapor, view angle, temporal and spatial validity and day vs. night data will be shown. In addition, some information will be presented about the influence of topography and climatic regions (e.g. Scandinavia vs. Greece) on the quality of the LSWT product. Based on these findings compiling time series for different lakes in Europe will be the focus of the second part of our presentation with details of the applied quality assessment to avoid erroneous signals. Hence, some information is given about hierarchical quality checks which are needed to guarantee a dataset without artefacts. Finally, some results of time series

  19. Use of postmortem temperature decay response surface plots of heat transport in the human eye to predict time of death.

    Science.gov (United States)

    Smart, Jimmy L

    2014-03-01

    A finite element heat transfer model of the human eye was previously constructed and applied to experimental postmortem temperature decay curves collected in eyeballs of ten human bodies. The model was applied in the early postmortem period of 0–24 h under conditions of natural convection–radiation. Based upon this previous model, response surfaces for postmortem temperature decay were constructed based upon variable ranges of the natural convective–radiation heat transfer coefficient from 7–13 W/m2 K, ambient temperatures of 10–33°C, and times of 0–24 h. Mathematical equations to describe these response surfaces have been developed. This response surface method is demonstrated for use by coroners/medical personnel to estimate time of death from recorded field temperature data collected over a 30-min period. Sensitivity of the model to small changes in the key variable of ambient temperature is explored. The response surface model is applied to two cases of previously collected experimental eyeball temperature data. This response surface model method is only valid for constant surrounding temperatures, conditions of natural convection, no radiation effects, and postmortem times of 0–24 h.

  20. Global Sea Surface Temperature and Sea Level Rise Estimation with Optimal Historical Time Lag Data

    Directory of Open Access Journals (Sweden)

    Mustafa M. Aral

    2016-11-01

    Full Text Available Prediction of global temperatures and sea level rise (SLR is important for sustainable development planning of coastal regions of the world and the health and safety of communities living in these regions. In this study, climate change effects on sea level rise is investigated using a dynamic system model (DSM with time lag on historical input data. A time-invariant (TI-DSM and time-variant dynamic system model (TV-DSM with time lag is developed to predict global temperatures and SLR in the 21st century. The proposed model is an extension of the DSM developed by the authors. The proposed model includes the effect of temperature and sea level states of several previous years on the current temperature and sea level over stationary and also moving scale time periods. The optimal time lag period used in the model is determined by minimizing a synthetic performance index comprised of the root mean square error and coefficient of determination which is a measure for the reliability of the predictions. Historical records of global temperature and sea level from 1880 to 2001 are used to calibrate the model. The optimal time lag is determined to be eight years, based on the performance measures. The calibrated model was then used to predict the global temperature and sea levels in the 21st century using a fixed time lag period and moving scale time lag periods. To evaluate the adverse effect of greenhouse gas emissions on SLR, the proposed model was also uncoupled to project the SLR based on global temperatures that are obtained from the Intergovernmental Panel on Climate Change (IPCC emission scenarios. The projected SLR estimates for the 21st century are presented comparatively with the predictions made in previous studies.

  1. nowCOAST's Map Service for NOAA NWS NCEP Real-Time Global and NASA SPoRT Sea Surface Temperature Analyses (Time Enabled)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST time-enabled map service provides a map depicting the latest daily sea surface temperature analyses from both the NOAA/NWS/NCEP...

  2. Surface Temperature Variation Prediction Model Using Real-Time Weather Forecasts

    Science.gov (United States)

    Karimi, M.; Vant-Hull, B.; Nazari, R.; Khanbilvardi, R.

    2015-12-01

    Combination of climate change and urbanization are heating up cities and putting the lives of millions of people in danger. More than half of the world's total population resides in cities and urban centers. Cities are experiencing urban Heat Island (UHI) effect. Hotter days are associated with serious health impacts, heart attaches and respiratory and cardiovascular diseases. Densely populated cities like Manhattan, New York can be affected by UHI impact much more than less populated cities. Even though many studies have been focused on the impact of UHI and temperature changes between urban and rural air temperature, not many look at the temperature variations within a city. These studies mostly use remote sensing data or typical measurements collected by local meteorological station networks. Local meteorological measurements only have local coverage and cannot be used to study the impact of UHI in a city and remote sensing data such as MODIS, LANDSAT and ASTER have with very low resolution which cannot be used for the purpose of this study. Therefore, predicting surface temperature in urban cities using weather data can be useful.Three months of Field campaign in Manhattan were used to measure spatial and temporal temperature variations within an urban setting by placing 10 fixed sensors deployed to measure temperature, relative humidity and sunlight. Fixed instrument shelters containing relative humidity, temperature and illumination sensors were mounted on lampposts in ten different locations in Manhattan (Vant-Hull et al, 2014). The shelters were fixed 3-4 meters above the ground for the period of three months from June 23 to September 20th of 2013 making measurements with the interval of 3 minutes. These high resolution temperature measurements and three months of weather data were used to predict temperature variability from weather forecasts. This study shows that the amplitude of spatial and temporal variation in temperature for each day can be predicted

  3. On the time-varying trend in global-mean surface temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhaohua [Florida State University, Department of Meteorology and Center for Ocean-Atmospheric Prediction Studies, Tallahassee, FL (United States); Huang, Norden E. [National Central University, Research Center for Adaptive Data Analysis Center, Chungli (China); Wallace, John M.; Smoliak, Brian V. [University of Washington, Department of Atmospheric Sciences, Seattle, WA (United States); Chen, Xianyao [State Oceanic Administration, The First Institute of Oceanography, Qingdao (China)

    2011-08-15

    The Earth has warmed at an unprecedented pace in the decades of the 1980s and 1990s (IPCC in Climate change 2007: the scientific basis, Cambridge University Press, Cambridge, 2007). In Wu et al. (Proc Natl Acad Sci USA 104:14889-14894, 2007) we showed that the rapidity of the warming in the late twentieth century was a result of concurrence of a secular warming trend and the warming phase of a multidecadal ({proportional_to}65-year period) oscillatory variation and we estimated the contribution of the former to be about 0.08 C per decade since {proportional_to}1980. Here we demonstrate the robustness of those results and discuss their physical links, considering in particular the shape of the secular trend and the spatial patterns associated with the secular trend and the multidecadal variability. The shape of the secular trend and rather globally-uniform spatial pattern associated with it are both suggestive of a response to the buildup of well-mixed greenhouse gases. In contrast, the multidecadal variability tends to be concentrated over the extratropical Northern Hemisphere and particularly over the North Atlantic, suggestive of a possible link to low frequency variations in the strength of the thermohaline circulation. Depending upon the assumed importance of the contributions of ocean dynamics and the time-varying aerosol emissions to the observed trends in global-mean surface temperature, we estimate that up to one third of the late twentieth century warming could have been a consequence of natural variability. (orig.)

  4. Long spatial coherence times a few micro-meters from a room temperature surface

    CERN Document Server

    Zhou, Shuyu; Keil, Mark; Japha, Yonathan; Folman, Ron

    2015-01-01

    The search for quantum coherence based on isolated atoms integrated with a room temperature solid state device (so-called atomchip [1-3]) has been intensifying in the last decade, with advances being made towards applications such as clocks, quantum information processing, surface probing and acceleration and gravitational field sensors. Such a device will also enable (and to some extent has already enabled) novel experiments in fundamental physics (e.g., [4-7]). Here we report on the trapping and maintenance of spatial coherence of atoms (in a Bose-Einstein Condensate -- BEC) about 5$\\mu$m from a room temperature surface, reducing significantly the distance previously achieved between the spatially coherent atoms and their classical environment [8-12], and most importantly entering the regime where atomic circuits are enabled. In addition, we enter the interesting regime in which the distance to the surface is much smaller than the probed coherence length, a regime in which the spatial dephasing reaches its ...

  5. How Much Global Burned Area Can Be Forecast on Seasonal Time Scales Using Sea Surface Temperatures?

    Science.gov (United States)

    Chen, Yang; Morton, Douglas C.; Andela, Niels; Giglio, Louis; Randerson, James T.

    2016-01-01

    Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual burned area from the Global Fire Emissions Database version 4 with small fires (GFED4s) can be predicted using SSTs from 14 different ocean regions. We found that about 48 of global burned area can be forecast with a correlation coefficient that is significant at a p forecasts may be possible with the aim of improving ecosystem management.

  6. Two decades of temperature-time monitoring experiment: air - ground surface - shallow subsurface interactions

    Science.gov (United States)

    Cermak, Vladimir; Dedecek, Petr; Safanda, Jan; Kresl, Milan

    2014-05-01

    Long-term observations (1994-2013) of air and shallow ground temperatures at borehole Prague-Sporilov (50º02'28.5"E, 14º28'40.2"N, 274 m a.s.l.) have been thoroughly analyzed to understand the relationship between these quantities and to describe the mechanism of heat transport at the land-atmosphere boundary layer. Data provided a surprisingly small mean ground-air temperature offset of only 0.31 K with no clear annual course and with the offset value changing irregularly even on a daily scale. Such value is substantially lower than similar values (1-2 K and more) found elsewhere, but may well characterize a mild temperate zone, when all so far available information referred rather to southern locations. Borehole data were correlated with similar observations in a polygon-site under four types of surface conditions (grass, soil, sand and asphalt) completed with registration of meteorological variables (wind direction & velocity, air & soil humidity, direct & reflected solar radiation, precipitation and snow cover). The "thermal orbits" technique proved to be an effective tool for the fast qualitative diagnostics of the thermal regime in the subsurface (conductive versus non-conductive).

  7. Application limits of the interpretation of near-surface temperature time series to assess groundwater recharge

    Science.gov (United States)

    Gosselin, J. S.; Rivard, C.; Martel, R.; Lefebvre, R.

    2016-07-01

    The main objective of this study was to test the application limits of a groundwater recharge assessment technique based on the inversion of a vertical one-dimensional numerical model of advective-conductive heat transport, using temperature time series at three different depths (1, 3, 5 m) in the unsaturated zone. For this purpose, several synthetic hourly datasets of subsurface temperatures, representing various weather, ground cover, and soil texture conditions, thus covering a wide range of groundwater recharge values, were produced with the vertical one-dimensional coupled heat and moisture transport simulator SHAW (Simultaneous Heat and Water model). Estimates of the vertical flux of water in the soil were then retrieved from these realistic temperature profiles using a simple one-dimensional numerical simulator of advective and conductive heat transport in the unsaturated zone that was developed as part of this study. The water flux was assumed constant on a weekly, monthly, semiannual, and annual basis. From these vertical water flux estimates, annual (potential) groundwater recharge rates were then computed and results were compared to those calculated previously with SHAW to assess the accuracy of the method. Results showed that, under ideal conditions, it would be possible to estimate annual recharge rates that are above 200 mm/y, with an acceptable error of less than 20%. These "ideal" conditions include the resolution of the water flux on a weekly basis, error-free temperature measurements below the soil freezing zone, and model parameter values (thermal conductivity and heat capacity of the soil) known a priori with no uncertainty. However, this work demonstrates that the accuracy of the method is highly sensitive to the uncertainty of the input model parameters of the numerical model used to carry out the inversion and to measurement errors of temperature time series. For the conditions represented in this study, these findings suggest that, despite

  8. Spatial Correlations of Anomaly Time Series of AIRS Version-6 Land Surface Skin Temperatures with the Nino-4 Index

    Science.gov (United States)

    Susskind, Joel; Lee, Jae N.; Iredell, Lena

    2013-01-01

    The AIRS Science Team Version-6 data set is a valuable resource for meteorological studies. Quality Controlled earth's surface skin temperatures are produced on a 45 km x 45 km spatial scale under most cloud cover conditions. The same retrieval algorithm is used for all surface types under all conditions. This study used eleven years of AIRS monthly mean surface skin temperature and cloud cover products to show that land surface skin temperatures have decreased significantly in some areas and increased significantly in other areas over the period September 2002 through August 2013. These changes occurred primarily at 1:30 PM but not at 1:30 AM. Cooling land areas contained corresponding increases in cloud cover over this time period, with the reverse being true for warming land areas. The cloud cover anomaly patterns for a given month are affected significantly by El Nino/La Nina activity, and anomalies in cloud cover are a driving force behind anomalies in land surface skin temperature.

  9. Real-Time Two-Dimensional Mapping of Relative Local Surface Temperatures with a Thin-Film Sensor Array

    Directory of Open Access Journals (Sweden)

    Gang Li

    2016-06-01

    Full Text Available Dynamic mapping of an object’s local temperature distribution may offer valuable information for failure analysis, system control and improvement. In this letter we present a computerized measurement system which is equipped with a hybrid, low-noise mechanical-electrical multiplexer for real-time two-dimensional (2D mapping of surface temperatures. We demonstrate the performance of the system on a device embedded with 32 pieces of built-in Cr-Pt thin-film thermocouples arranged in a 4 × 8 matrix. The system can display a continuous 2D mapping movie of relative temperatures with a time interval around 1 s. This technique may find applications in a variety of practical devices and systems.

  10. How much global burned area can be forecast on seasonal time scales using sea surface temperatures?

    Science.gov (United States)

    Chen, Yang; Morton, Douglas C.; Andela, Niels; Giglio, Louis; Randerson, James T.

    2016-04-01

    Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual burned area from the Global Fire Emissions Database version 4 with small fires (GFED4s) can be predicted using SSTs from 14 different ocean regions. We found that about 48% of global burned area can be forecast with a correlation coefficient that is significant at a p climate index (OCI) 3 or more months prior to the month of peak burning. Continental regions where burned area had a higher degree of predictability included equatorial Asia, where 92% of the burned area exceeded the correlation threshold, and Central America, where 86% of the burned area exceeded this threshold. Pacific Ocean indices describing the El Niño-Southern Oscillation were more important than indices from other ocean basins, accounting for about 1/3 of the total predictable global burned area. A model that combined two indices from different oceans considerably improved model performance, suggesting that fires in many regions respond to forcing from more than one ocean basin. Using OCI—burned area relationships and a clustering algorithm, we identified 12 hotspot regions in which fires had a consistent response to SST patterns. Annual burned area in these regions can be predicted with moderate confidence levels, suggesting operational forecasts may be possible with the aim of improving ecosystem management.

  11. Analysis of temperature time series to estimate direction and magnitude of water fluxes in near-surface sediments

    Science.gov (United States)

    Munz, Matthias; Oswald, Sascha E.; Schmidt, Christian

    2017-04-01

    The application of heat as a hydrological tracer has become a standard method for quantifying water fluxes between groundwater and surface water. Typically, time series of temperatures in the surface water and in the sediment are observed and are subsequently evaluated by a vertical 1D representation of heat transport by advection and dispersion. Several analytical solutions as well as their implementation into user-friendly software exist in order to estimate water fluxes from the observed temperatures. The underlying assumption of a stationary, one-dimensional vertical flow field is frequently violated in natural systems. Here subsurface water flow often has a significant horizontal component. We developed a methodology for identifying the geometry of the subsurface flow field based on the variations of diurnal temperature amplitudes with depths. For instance: Purely vertical heat transport is characterized by an exponential decline of temperature amplitudes with increasing depth. Pure horizontal flow would be indicated by a constant, depth independent vertical amplitude profile. The decline of temperature amplitudes with depths could be fitted by polynomials of different order whereby the best fit was defined by the highest Akaike Information Criterion. The stepwise model optimization and selection, evaluating the shape of vertical amplitude ratio profiles was used to determine the predominant subsurface flow field, which could be systematically categorized in purely vertical and horizontal (hyporheic, parafluvial) components. Analytical solutions to estimate water fluxes from the observed temperatures are restricted to specific boundary conditions such as a sinusoidal upper temperature boundary. In contrast numerical solutions offer higher flexibility and can handle temperature data which is characterized by irregular variations such as storm-event induced temperature changes and thus cannot readily be incorporated in analytical solutions. There are several

  12. Optimization of extraction time and temperature on antioxidant activity of Schizophyllum commune aqueous extract using response surface methodology.

    Science.gov (United States)

    Yim, Hip Seng; Chye, Fook Yee; Rao, Vigneswara; Low, Jia Yin; Matanjun, Patricia; How, Siew Eng; Ho, Chun Wai

    2013-04-01

    Central composite design of response surface methodology (RSM) was employed to optimize the extraction time (X 1 : 99.5-290.5 min) and temperature (X 2 : 30.1-54.9 °C) of Schizophyllum commune aqueous extract with high antioxidant activities and total phenolic content (TPC). Results indicated that the data were adequately fitted into four second-order polynomial models. The extraction time and temperature were found to have significant linear, quadratic and interaction effects on antioxidant activities and TPC. The optimal extraction time and temperature were: 290.5 min and 35.7 °C (DPPH(•) scavenging ability); 180.7 min and 41.7 °C (ABTS(•+) inhibition ability); 185.2 min and 42.4 °C (ferric reducing antioxidant power, FRAP); 290.5 min and 40.3 °C (TPC). These optimum conditions yielded 85.10%; 94.31%; 0.74 mM Fe(2+) equivalent/100 g; 635.76 mg gallic acid equivalent/100 g, respectively. The yields of antioxidant activities and TPC obtained experimentally were close to its predicted values. The establishment of such model provides a good experimental basis employing RSM for optimizing the extraction time and temperature on antioxidants from S. commune aqueous extract.

  13. Reconstructing synthetic hourly time series of near-surface air temperatures in a mountainous region of the tropical Andes

    Science.gov (United States)

    Angel, E.; Ortega, S.; Gonzalez-Duque, D.; Alvarez-Villa, O. D.; Ruiz-Carrascal, D.

    2016-12-01

    There is a need to quantify near-surface air temperatures in areas of ongoing and projected faster upper-tropospheric warming. Twenty-two high-resolution data loggers were deployed along a steep altitudinal gradient in the Colombian Central Cordillera. Digital sensors were distributed in the range [4,891-1,611 m] and are collecting hourly near-surface temperature, relative humidity and dew point data. To date, records of the oldest data loggers span back to mid Dec 2008. A reconstruction methodology was used to generate long term temperature series at an hourly resolution. The approach included spatio-temporal interpolations where there was sufficient information from data-loggers, but relied on the typical behavior of the diurnal cycle when there was not hourly information to interpolate from. The typical diurnal cycle for each month was described using a "characteristic curve," created from hourly data-logger records. This characteristic curves allow to generate hourly data using daily temperatures. It is worth noticing that the ENSO signal is included in the synthetic series as it is already captured by daily temperature records. Comparisons with actual temperature records yield monthly mean errors of -0.38°C, and Pearson and Spearman correlations reaching values above 0.910. Synthetic hourly time series are also reconstructed through the analysis of the vertical profiles of reanalysis and ground-truth data. In this case, mean errors increase to -0.98°C and the lowest correlations decrease to 0.784. The tropical altitudinal transect is already providing numerous insights to understand convective processes in a site where large vertical temperature gradients exist, and that is projected to warm up faster that the surrounding lowlands.

  14. Influence of Surface Resistivity and Temperature on Variation with Time of Current Pulses in Air at Optimum Pressure

    Directory of Open Access Journals (Sweden)

    S.G. Pimpale

    1977-04-01

    Full Text Available The variation of discharge current pulses with the surface nature of electrodes has been investigated by producing discharge in the intense ionizing zone of two ozonizers (A&B containing pure, dry air at a pressure of 4 & 10mm of mercury respectively. The course of reaction in the tube A showed that the periodic rise and fall of discharge counts through a series of recurrences whose amplitude varied randomly. During this reaction, steady potential, temperature of the electrolytic bath, counting time and pulse height were kept fixed. The phenomenon obtained for both the tubes is produced within a critical range of conditions. The results have been interpreted on the basis of activated adsorption at a temperature of 90 degree and 100 degree Centigrade and discussed on the theoretical grounds of change of surface resistivity upon the glass walls. Use of different coatings on annular surface in the same system with appropriate levels of electrolytic solution for a definite value of height-pulses and temperature, etc. shows significant variations in the discharge counts.

  15. A Time Series of Mean Global Sea Surface Temperature from the Along-Track Scanning Radiometers

    Science.gov (United States)

    Veal, Karen L.; Corlett, Gary; Remedios, John; Llewellyn-Jones, David

    2010-12-01

    A climate data set requires a long time series of consistently processed data with suitably long periods of overlap of different instruments which allows characterization of any inter-instrument biases. The data obtained from ESA's three Along-Track Scanning Radiometers (ATSRs) together comprise an 18 year record of SST with overlap periods of at least 6 months. The data from all three ATSRs has been consistently processed. These factors together with the stability of the instruments and the precision of the derived SST makes this data set eminently suitable for the construction of a time series of SST that complies with many of the GCOS requirements for a climate data set. A time series of global and regional average SST anomalies has been constructed from the ATSR version 2 data set. An analysis of the overlap periods of successive instruments was used to remove intra-series biases and align the series to a common reference. An ATSR climatology has been developed and has been used to calculate the SST anomalies. The ATSR-1 time series and the AATSR time series have been aligned to ATSR-2. The largest adjustment is ~0.2 K between ATSR-2 and AATSR which is suspected to be due to a shift of the 12 μm filter function for AATSR. An uncertainty of 0.06 K is assigned to the relative anomaly record that is derived from the dual three-channel night-time data. A relative uncertainty of 0.07 K is assigned to the dual night-time two-channel record, except in the ATSR-1 period (1994-1996) where it is larger.

  16. Surface Temperature Data Analysis

    Science.gov (United States)

    Hansen, James; Ruedy, Reto

    2012-01-01

    Small global mean temperature changes may have significant to disastrous consequences for the Earth's climate if they persist for an extended period. Obtaining global means from local weather reports is hampered by the uneven spatial distribution of the reliably reporting weather stations. Methods had to be developed that minimize as far as possible the impact of that situation. This software is a method of combining temperature data of individual stations to obtain a global mean trend, overcoming/estimating the uncertainty introduced by the spatial and temporal gaps in the available data. Useful estimates were obtained by the introduction of a special grid, subdividing the Earth's surface into 8,000 equal-area boxes, using the existing data to create virtual stations at the center of each of these boxes, and combining temperature anomalies (after assessing the radius of high correlation) rather than temperatures.

  17. Delineation of Surface-Groundwater Interactions Using Statistical Analysis of Temperature Time-Series and Resistivity Methods

    Science.gov (United States)

    Scotch, C. G.; Murgulet, D.; Hay, R.

    2013-12-01

    Although surface-water and groundwater are often referred to as separate domains, they are intimately related as a change in one domain can ultimately affect the other domain. Since the two domains act as linked pathways for contaminant transport in the hydrologic cycle a comprehensive understanding of this relationship is essential for improved SW-GW management practices. The main objective of this study is to develop new statistical methods to better identify and characterize the advective component or water movement between SW-GW in a coastal area along the South Texas coast, adjacent to the Gulf of Mexico (GOM) margin, characterized by low gradients and low-conductivity stream beds. Identifying advection zones using temperature data in regions with low topographic relief and numerous small-scale flow paths is difficult. To overcome this challenge this study proposes the use of seasonal-trend decomposition (STL) of time series temperature data to analyze exchanges in this type of environment. Seasonal decomposition analysis was used to remove the daily and annual cyclic components leaving the random or non-cyclic component. It can be inferred that high variances of the random component indicate periods of advection. This statistically-derived advective component correlates well with advection periods identified from the conventional time-series temperature profile analysis. This correlation is a good validation of the statistical approach as means of identifying periods of advection and SW-GW interaction. Electrical resistivity imaging will be used for validation of the statistical model.

  18. Time series decomposition of remotely sensed land surface temperature and investigation of trends and seasonal variations in surface urban heat islands

    Science.gov (United States)

    Quan, Jinling; Zhan, Wenfeng; Chen, Yunhao; Wang, Mengjie; Wang, Jinfei

    2016-03-01

    Previous time series methods have difficulties in simultaneous characterization of seasonal, gradual, and abrupt changes of remotely sensed land surface temperature (LST). This study proposed a model to decompose LST time series into trend, seasonal, and noise components. The trend component indicates long-term climate change and land development and is described as a piecewise linear function with iterative breakpoint detection. The seasonal component illustrates annual insolation variations and is modeled as a sinusoidal function on the detrended data. This model is able to separate the seasonal variation in LST from the long-term (including gradual and abrupt) change. Model application to nighttime Moderate Resolution Imaging Spectroradiometer (MODIS)/LST time series during 2000-2012 over Beijing yielded an overall root-mean-square error of 1.62 K between the combination of the decomposed trend and seasonal components and the actual MODIS/LSTs. LST decreased (~ -0.086 K/yr, p sixth ring roads. The decreasing trend was stronger over croplands than over urban lands (p < 0.05), resulting in an increasing trend in surface urban heat island intensity (SUHII, 0.022 ± 0.006 K/yr). This was mainly attributed to the trends in urban-rural differences in rainfall and albedo. The SUHII demonstrated a concave seasonal variation primarily due to the seasonal variations of urban-rural differences in temperature cooling rate (related to canyon structure, vegetation, and soil moisture) and surface heat dissipation (affected by humidity and wind).

  19. Urban Surface Temperature Time Series Estimation at the Local Scale by Spatial-Spectral Unmixing of Satellite Observations

    Directory of Open Access Journals (Sweden)

    Zina Mitraka

    2015-04-01

    Full Text Available The study of urban climate requires frequent and accurate monitoring of land surface temperature (LST, at the local scale. Since currently, no space-borne sensor provides frequent thermal infrared imagery at high spatial resolution, the scientific community has focused on synergistic methods for retrieving LST that can be suitable for urban studies. Synergistic methods that combine the spatial structure of visible and near-infrared observations with the more frequent, but low-resolution surface temperature patterns derived by thermal infrared imagery provide excellent means for obtaining frequent LST estimates at the local scale in cities. In this study, a new approach based on spatial-spectral unmixing techniques was developed for improving the spatial resolution of thermal infrared observations and the subsequent LST estimation. The method was applied to an urban area in Crete, Greece, for the time period of one year. The results were evaluated against independent high-resolution LST datasets and found to be very promising, with RMSE less than 2 K in all cases. The developed approach has therefore a high potential to be operationally used in the near future, exploiting the Copernicus Sentinel (2 and 3 observations, to provide high spatio-temporal resolution LST estimates in cities.

  20. French Frigate Shoals, NWHI, 2005 Sea Surface Temperature and Meteorological Enhanced (Iridium) Mooring - CRED CREWS Near Real Time and Historical Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site - French Frigate Shoals, NWHI (23.85678, -166.27183 ) ARGOS ID 261-003 Time series data from this mooring provide high resolution sea surface temperature, and...

  1. Time series analysis of data for sea surface temperature and upwelling components from the southwest coast of Portugal

    Science.gov (United States)

    Goela, Priscila Costa; Cordeiro, Clara; Danchenko, Sergei; Icely, John; Cristina, Sónia; Newton, Alice

    2016-11-01

    This study relates sea surface temperature (SST) to the upwelling conditions off the southwest coast of Portugal using statistical analyses of publically available data. Optimum Interpolation (OI) of daily SST data were extracted from the United States (US) National Oceanic and Atmospheric Administration (NOAA) and data for wind speed and direction were from the US National Climatic Data Center. Time series were extracted at a daily frequency for a time horizon of 26 years. Upwelling indices were estimated using westerly (Qx) and southerly (Qy) Ekman transport components. In the first part of the study, time series were inspected for trend and seasonality over the whole period. The seasonally adjusted time series revealed an increasing slope for SST (0.15 °C per decade) and decreasing slopes for Qx (- 84.01 m3 s- 1 km- 1 per decade) and Qy (- 25.20 m3 s- 1 km- 1 per decade), over the time horizon. Structural breaks analysis applied to the time series showed that a statistically significant incremental increase in SST was more pronounced during the last decade. Cross-correlation between upwelling indices and SST revealed a time delay of 5 and 2 days between Qx and SST, and between Qy and SST, respectively. A spectral analysis combined with the previous analysis enabled the identification of four oceanographic seasons. Those seasons were later recognised over a restricted time period of 4 years, between 2008 and 2012, when there was an extensive sampling programme for the validation of ocean colour remote sensing imagery. The seasons were defined as: summer, with intense and regular events of upwelling; autumn, indicating relaxation of upwelling conditions; and spring and winter, showing high interannual variability in terms of number and intensity of upwelling events.

  2. An Examination of the Hadley Sea-Surface Temperature Time Series for the Nino 3.4 Region

    Science.gov (United States)

    Wilson, Robert M.

    2010-01-01

    The Hadley sea-surface temperature (HadSST) dataset is investigated for the interval 1871-2008. The purpose of this investigation is to determine the degree of success in identifying and characterizing El Nino (EN) southern (ENSO) extreme events, both EN and La Nina (LN) events. Comparisons are made against both the Southern Oscillation Index for the same time interval and with published values of the Oceanic Nino Index for the interval since 1950. Some 60 ENSO extreme events are identified in the HadSST dataset, consisting of 33 EN and 27 LN events. Also, preferential associations are found to exist between the duration of ENSO extreme events and their maximum anomalous excursion temperatures and between the recurrence rate for an EN event and the duration of the last known EN event. Because the present ongoing EN is a strong event, it should persist 11 months or longer, inferring that the next EN event should not be expected until June 2012 or later. Furthermore, the decadal sum of EN-related months is found to have increased somewhat steadily since the decade of 1920-1929, suggesting that the present decade (2010-2019) possibly will see about 3-4 EN events, totaling about 37 +/- 3 EN-related months (i.e., months that meet the definition for the occurrence of an EN event).

  3. A Quasi-Global Approach to Improve Day-Time Satellite Surface Soil Moisture Anomalies through the Land Surface Temperature Input

    Directory of Open Access Journals (Sweden)

    Robert M. Parinussa

    2016-10-01

    Full Text Available Passive microwave observations from various spaceborne sensors have been linked to the soil moisture of the Earth’s surface layer. A new generation of passive microwave sensors are dedicated to retrieving this variable and make observations in the single theoretically optimal L-band frequency (1–2 GHz. Previous generations of passive microwave sensors made observations in a range of higher frequencies, allowing for simultaneous estimation of additional variables required for solving the radiative transfer equation. One of these additional variables is land surface temperature, which plays a unique role in the radiative transfer equation and has an influence on the final quality of retrieved soil moisture anomalies. This study presents an optimization procedure for soil moisture retrievals through a quasi-global precipitation-based verification technique, the so-called Rvalue metric. Various land surface temperature scenarios were evaluated in which biases were added to an existing linear regression, specifically focusing on improving the skills to capture the temporal variability of soil moisture. We focus on the relative quality of the day-time (01:30 pm observations from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E, as these are theoretically most challenging due to the thermal equilibrium theory, and existing studies indicate that larger improvements are possible for these observations compared to their night-time (01:30 am equivalent. Soil moisture data used in this study were retrieved through the Land Parameter Retrieval Model (LPRM, and in line with theory, both satellite paths show a unique and distinct degradation as a function of vegetation density. Both the ascending (01:30 pm and descending (01:30 am paths of the publicly available and widely used AMSR-E LPRM soil moisture products were used for benchmarking purposes. Several scenarios were employed in which the land surface temperature input for

  4. GODAE, SFCOBS - Surface Temperature Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GODAE, SFCOBS - Surface Temperature Observations: Ship, fixed/drifting buoy, and CMAN in-situ surface temperature. Global Telecommunication System (GTS) Data. The...

  5. The surface temperature of Europa

    CERN Document Server

    Ashkenazy, Yosef

    2016-01-01

    Previous estimates of the surface temperature of Jupiter's moon, Europa, neglected the effect of the eccentricity of Jupiter's orbit around the Sun, the effect of the eclipse of Europa (i.e., the relative time that Europa is within the shadow of Jupiter), and the effect of Europa's internal heating. Here we estimate the surface temperature of Europa, when Europa's obliquity, eclipse and internal heating, as well as the eccentricity of Jupiter, are all taken into account. For a typical internal heating rate of 0.05 W/m$^2$ (corresponding to an ice thickness of about 10 kms), the equator, pole, and global mean surface temperatures are 101.7 K, 45.26 K, and 94.75 K, respectively. We found that the temperature at the high latitudes is significantly affected by the internal heating. We also studied the effect of the internal heating on the mean thickness of Europa's icy shell and conclude that the polar region temperature can be used to constrain the internal heating and the depth of the ice. Our approach and form...

  6. Constructing new satellite-only time series of global mean, sea surface temperature data for climate from ATSR data

    Science.gov (United States)

    Veal, Karen; Remedios, John; Ghent, Darren

    2013-04-01

    The Along Track Scanning Radiometers (ATSRs) have provided a near-continuous record of sea surface temperature (SST) data for climate from the launch of ATSR-1 in 1991 to the loss of the Advanced ATSR (AATSR) in April 2012. The intention was always to provide an SST record, independent of in situ data, to corroborate and improve climate data records in recent times. We show that the ATSR record provides a very suitable data set with which to study the recent climate record, particularly during the ATSR-2 and AATSR periods (1995 to 2012) in three major respects. First, ATSR climate time series achieve anomaly accuracies of better than 0.05 K (and high stability). Second, the overlap between instruments allows for excellent determination and removal of biases; between ATSR-2 and AATSR, these are less than 0.05 K for the highest accuracy SST data. Finally, uncertainties on global monthly mean data are less than 0.02 K and hence comparable to those achieved by in situ analyses such as HadSST3. A particular hallmark of the ATSR instruments was their exceptional design for accuracy incorporating high accuracy radiometric calibration, dual-view of the Earth's surface and the use of three thermal emission channels; additional channels are included for cloud clearing in this context. The use of dual-view and multiple thermnal wavelengths allows a number of combinations for retrievals of SST, the most accurate being the dual-view, three-channel retrieval (D3) at nighttime. This restriction is due to the use of the 3.7 micron channel which is sensitive to solar radiation during the day. Extensive work has resulted in a major advances recently resulting in both an operational V2.0 SST product and a further improved ATSR Re-analysis for Climate (ARC) product, a particular feature of the latter being the development of a depth SST product in addition to the skin SST directly determined from satellite data. We will discuss the characteristics of these data sets in terms of

  7. Inferring near surface soil temperature time series from different land uses to quantify the variation of heat fluxes into a shallow aquifer in Austria

    Science.gov (United States)

    Kupfersberger, Hans; Rock, Gerhard; Draxler, Johannes C.

    2017-09-01

    Different land uses exert a strong spatially distributed and temporal varying signal of heat fluxes from the surface in or out of the ground. In this paper we show an approach to quantify the heat fluxes into a groundwater body differentiating between near surface soil temperatures under grass, forest, asphalt, agriculture and surface water bodies and heat fluxes from subsurface structures like heated basements or sewage pipes. Based on observed time series of near surface soil temperatures we establish individual parameters (e.g. shift, moving average) of a simple empirical function that relates air temperature to soil temperature. This procedure is useful since air temperature time series are readily available and the complex energy flux processes at the soil atmosphere interface do not need to be described in detail. To quantify the heat flux from heated subsurface structures that have lesser depths to the groundwater table the 1D heat conduction module SoilTemp is developed. Based on soil temperature time series observed at different depths in a research lysimeter heat conduction and heat storage capacity values are calibrated disregarding their dependence on the water content. With SoilTemp the strong interaction between time series of groundwater temperature and groundwater level, near surface soil temperatures and the basement temperatures in heated buildings could be evaluated showing the dynamic nature of thermal gradients. The heat fluxes from urban areas are calculated considering the land use patterns within a spatial unit by mixing the heat fluxes from basements with those under grass and asphalt. The heat fluxes from sewage pipes and of sewage leakage are shown to be negligible for evaluated pipe diameters and sewage discharges. The developed methodology will allow to parameterize the upper boundary of heat transport models and to differentiate between the heat fluxes from different surface usages and their dynamics into the subsurface.

  8. GISS Surface Temperature Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The GISTEMP dataset is a global 2x2 gridded temperature anomaly dataset. Temperature data is updated around the middle of every month using current data files from...

  9. Real-Time Thermographic-Phosphor-Based Temperature Measurements of Thermal Barrier Coating Surfaces Subjected to a High-Velocity Combustor Burner Environment

    Science.gov (United States)

    Eldridge, Jeffrey I.; Jenkins, Thomas P.; Allison, Stephen W.; Cruzen, Scott; Condevaux, J. J.; Senk, J. R.; Paul, A. D.

    2011-01-01

    Surface temperature measurements were conducted on metallic specimens coated with an yttria-stabilized zirconia (YSZ) thermal barrier coating (TBC) with a YAG:Dy phosphor layer that were subjected to an aggressive high-velocity combustor burner environment. Luminescence-based surface temperature measurements of the same TBC system have previously been demonstrated for specimens subjected to static furnace or laser heating. Surface temperatures were determined from the decay time of the luminescence signal of the YAG:Dy phosphor layer that was excited by a pulsed laser source. However, the furnace and laser heating provides a much more benign environment than that which exists in a turbine engine, where there are additional challenges of a highly radiant background and high velocity gases. As the next step in validating the suitability of luminescence-based temperature measurements for turbine engine environments, new testing was performed where heating was provided by a high-velocity combustor burner rig at Williams International. Real-time surface temperature measurements during burner rig heating were obtained from the decay of the luminescence from the YAG:Dy surface layer. The robustness of several temperature probe designs in the sonic velocity, high radiance flame environment was evaluated. In addition, analysis was performed to show whether the luminescence decay could be satisfactorily extracted from the high radiance background.

  10. A simple model for the short-time evolution of near-surface current and temperature profiles

    CERN Document Server

    Jenkins, A D; Jenkins, Alastair D.; Ward, Brian

    2005-01-01

    A simple analytical/numerical model has been developed for computing the evolution, over periods of up to a few hours, of the current and temperature profile in the upper layer of the ocean. The model is based upon conservation laws for heat and momentum, and employs an eddy diffusion parameterisation which is dependent on both the wind speed and the wind stress applied at the sea surface. Other parameters such as the bulk-skin surface temperature difference and CO$_2$ flux are determined by application of the Molecular Oceanic Boundary Layer Model (MOBLAM) of Schluessel and Soloviev. A similar model, for the current profile only, predicts a temporary increase in wave breaking intensity and decrease in wave height under conditions where the wind speed increases suddenly, such as, for example, during gusts and squalls. The model results are compared with measurements from the lagrangian Skin Depth Experimental Profiler (SkinDeEP) surface profiling instrument made during the 1999 MOCE-5 field experiment in the ...

  11. Temperature dependence of surface nanobubbles

    NARCIS (Netherlands)

    Berkelaar, R.P.; Seddon, James Richard Thorley; Zandvliet, Henricus J.W.; Lohse, Detlef

    2012-01-01

    The temperature dependence of nanobubbles was investigated experimentally using atomic force microscopy. By scanning the same area of the surface at temperatures from 51 °C to 25 °C it was possible to track geometrical changes of individual nanobubbles as the temperature was decreased.

  12. Surface properties of nitrided layer on AISI 316L austenitic stainless steel produced by high temperature plasma nitriding in short time

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yang, E-mail: metalytu@163.com [Department of Materials Science and Engineering, Yantai University, Qingquan Road 32, Yantai 264005 (China); Wang, Zhuo [Department of Materials Science and Engineering, Yantai University, Qingquan Road 32, Yantai 264005 (China); Wang, Liang [Department of Materials Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026 (China)

    2014-04-01

    Graphical abstract: - Highlights: • The 8 μm nitrided layer was produced on the surface of AISI 316L stainless steel by plasma nitrided at high temperatures (540 °C) within 1 h. • The nitrided layer consisted of nitrogen expanded austenite and possibly a small amount of free-CrN and iron nitrides. • It could critically reduce processing time compared with low temperature nitriding. • High temperature plasma nitriding could improve pitting corrosion resistance of the substrate in 3.5% NaCl solution. - Abstract: It has generally been believed that the formation of the S phase or expanded austenite γ{sub N} with enough thickness depends on the temperature (lower than 480 °C) and duration of the process. In this work, we attempt to produce nitrogen expanded austenite layer at high temperature in short time. Nitriding of AISI 316L austenitic stainless steel was carried out at high temperatures (>520 °C) for times ranging from 5 to 120 min. The microstructures, chemical composition, the thickness and the morphology of the nitrided layer, as well as its surface hardness, were investigated using X-ray diffraction, X-ray photoelectron spectroscopy, optical microscopy, scanning electron microscopy, and microhardness tester. The corrosion properties of the untreated and nitrided samples were evaluated using anodic polarization tests in 3.5% NaCl solution. The results confirmed that nitrided layer was shown to consist of γ{sub N} and a small amount of free-CrN and iron nitrides. High temperature plasma nitriding not only increased the surface hardness but also improved the corrosion resistance of the austenitic stainless steel, and it can critically reduce processing time compared with low temperature nitriding.

  13. Reply to comment on "A simple model for the short-time evolution of near-surface current and temperature profiles"

    CERN Document Server

    Jenkins, A D; Jenkins, Alastair D.; Ward, Brian

    2005-01-01

    This is our response to a comment by Walter Eifler on our paper `A simple model for the short-time evolution of near-surface current and temperature profiles' (arXiv:physics/0503186, accepted for publication in Deep-Sea Research II). Although Eifler raises genuine issues regarding our model's validity and applicability, we are nevertheless of the opinion that it is of value for the short-term evolution of the upper-ocean profiles of current and temperature. The fact that the effective eddy viscosity tends to infinity for infinite time under a steady wind stress may not be surprising. It can be interpreted as a vertical shift of the eddy viscosity profile and an increase in the size of the dominant turbulent eddies under the assumed conditions of small stratification and infinite water depth.

  14. Using Coarse Resolution Land Surface Temperature Time Series Data for Vegetation Analysis in the Taiga Tundra Transition Zone. a Case Study for Yamal, Krasnoyarsk Kray and Yakutia

    Science.gov (United States)

    Urban, M.; Schmullius, C. C.; Hese, S.; Herold, M.

    2011-12-01

    Predictions from Global Climate Models have shown increasing trends of global temperature for the 21th century. Since the arctic regions are highly vulnerable to global climate changes, rising temperatures will lead to an intensification of vegetation activity which benefits the extension of the boreal forest into tundra areas. Especially the recruitment of trees into the northern regions, which were controlled by summer temperature and the length of the growing season, is of high importance for the Global Climate System. The tree line movement will lead to a positive feedback in climate conditions since dark forest areas will reduce the albedo which leads to higher warming rates. A multi scale concept for the monitoring of the arctic tree line and changes in vegetation structure in the taiga tundra transition zone of Siberia using Earth Observation data and products on coarse, medium and high spatial resolution is presented. On coarse scale, global land surface temperature data from TERRA, AQUA, ERS and ENVISAT as well as land cover, biomass and phenological information will be integrated to analyze the vegetation composition within the taiga tundra transition zone. On medium spatial resolution, optical and SAR remote sensing data with a pixel size of approx. 30 m will be used to analyze the vegetation structure at the tree line. On very high spatial scale recent Rapideye and Corona imagery from the 1960s will be used to identify vegetation changes and the movement of trees within this 40-50 year time period. As this is a multi-scale approach, the findings on all spatial scales can be connected to each other to verify the results. The first results at coarse scale level have shown the relation between the mean summer temperature and the location of the arctic tree line, which was extracted from the Circumpolar Arctic Vegetation Map (CAVM) by Walker et al. (2005). The assumption is that trees have their optimal growing conditions at a mean summer temperature of 10

  15. The Pacific sea surface temperature

    Energy Technology Data Exchange (ETDEWEB)

    Douglass, David H., E-mail: douglass@pas.rochester.edu [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States)

    2011-12-05

    The Pacific sea surface temperature data contains two components: N{sub L}, a signal that exhibits the familiar El Niño/La Niña phenomenon and N{sub H}, a signal of one-year period. Analysis reveals: (1) The existence of an annual solar forcing F{sub S}; (2) N{sub H} is phase locked directly to F{sub S} while N{sub L} is frequently phase locked to the 2nd or 3rd subharmonic of F{sub S}. At least ten distinct subharmonic time segments of N{sub L} since 1870 are found. The beginning or end dates of these segments have a near one-to-one correspondence with the abrupt climate changes previously reported. Limited predictability is possible. -- Highlights: ► El Niño/La Niña consists of 2 components phase-locked to annual solar cycle. ► The first component N{sub L} is the familiar El Niño/La Niña effect. ► The second N{sub H} component has a period of 1 cycle/year. ► N{sub L} can be phase-locked to 2nd or 3rd subharmonic of annual cycle. ► Ends of phase-locked segments correspond to abrupt previously reported climate changes.

  16. Daily scale winter-time sea surface temperature variability and the Iberian Poleward Current in the southern Bay of Biscay from 1981 to 2010

    Directory of Open Access Journals (Sweden)

    G. Esnaola

    2012-12-01

    Full Text Available The combination of remotely sensed gappy sea surface temperature (SST images with the missing data filling Data Interpolating EOFs (DINEOF technique followed by a Principal Component Analysis of the reconstructed data, has been used to identify the time evolution and the daily scale variability of the winter-time surface signal of the Iberian Poleward Current (IPC during the 1981–2010 period. An exhaustive comparison with the existing bibliography, and the vertical temperature and salinity profiles related to its extremes over the Bay of Biscay area, show that the obtained time series accurately reflect the variability of the IPC. A physical mechanism involving both atmospheric and oceanic variables is proposed in relation to the variability of the IPC. It jointly takes into account several mechanisms that have separately been related to the variability of the IPC, i.e. the south-westerly winds, the Joint Effect of Baroclinicity And Relief (JEBAR effect, the topographic β effect and a weakened North Atlantic Gyre. This mechanism emerges from an atmospheric 500 hPa circulation anomaly that has not a simple relationship with any of the most common North Atlantic teleconnection patterns. It then generates mutually coherent SST and sea level anomaly patterns in the North Atlantic area due to the action of anomalous wind-stress and heat-fluxes, and locally, it also generates the conditions for the mentioned mechanisms in the Bay of Biscay area.

  17. Application of Response Surface Methodology to Study the Combined Effect of Temperature, Time and pH on Antioxidant Activity of Cherry (Prunus avium Honey

    Directory of Open Access Journals (Sweden)

    Nayik Gulzar Ahmad

    2016-12-01

    Full Text Available Response surface methodology (RSM was employed to analyze the effect of independent variables viz. temperature, time and pH on antioxidant properties of cherry honey. Seventeen runs including five replicates were used to study the combined effect of temperature (60–80°C, time (10–15 min and pH (3 to 6 on the antioxidant properties [radical scavenging activity (DPPH-RSA, total phenolic content (TPC and total flavonoid content (TFC] of cherry honey. Statistical analysis revealed that process variables significantly affected all the responses. All the three parameters viz. DPPH-RSA, TPC and TFC increased with increase in time and temperature. The antioxidant properties of cherry honey were significantly decreased with increase in pH from 3 to 6. The thermal treatment of honey at 80°C was found to be more effective than at 70 and 60°C. The results demonstrated that antioxidant activity significantly increased with formation of browning pigments.

  18. The Teleconnection of the Tropical Atlantic to Indo-Pacific Sea Surface Temperatures on Inter-Annual to Centennial Time Scales: A Review of Recent Findings

    Directory of Open Access Journals (Sweden)

    Fred Kucharski

    2016-02-01

    Full Text Available In this paper, the teleconnections from the tropical Atlantic to the Indo-Pacific region from inter-annual to centennial time scales will be reviewed. Identified teleconnections and hypotheses on mechanisms at work are reviewed and further explored in a century-long pacemaker coupled ocean-atmosphere simulation ensemble. There is a substantial impact of the tropical Atlantic on the Pacific region at inter-annual time scales. An Atlantic Niño (Niña event leads to rising (sinking motion in the Atlantic region, which is compensated by sinking (rising motion in the central-western Pacific. The sinking (rising motion in the central-western Pacific induces easterly (westerly surface wind anomalies just to the west, which alter the thermocline. These perturbations propagate eastward as upwelling (downwelling Kelvin-waves, where they increase the probability for a La Niña (El Niño event. Moreover, tropical North Atlantic sea surface temperature anomalies are also able to lead La Niña/El Niño development. At multidecadal time scales, a positive (negative Atlantic Multidecadal Oscillation leads to a cooling (warming of the eastern Pacific and a warming (cooling of the western Pacific and Indian Ocean regions. The physical mechanism for this impact is similar to that at inter-annual time scales. At centennial time scales, the Atlantic warming induces a substantial reduction of the eastern Pacific warming even under CO2 increase and to a strong subsurface cooling.

  19. Trend patterns in global sea surface temperature

    DEFF Research Database (Denmark)

    Barbosa, S.M.; Andersen, Ole Baltazar

    2009-01-01

    Isolating long-term trend in sea surface temperature (SST) from El Nino southern oscillation (ENSO) variability is fundamental for climate studies. In the present study, trend-empirical orthogonal function (EOF) analysis, a robust space-time method for extracting trend patterns, is applied...

  20. Real-time measurement system for tracking birefringence, weight, thickness, and surface temperature during drying of solution cast coatings and films

    Science.gov (United States)

    Unsal, E.; Drum, J.; Yucel, O.; Nugay, I. I.; Yalcin, B.; Cakmak, M.

    2012-02-01

    This paper describes the design and performance of a new instrument to track temporal changes in physical parameters during the drying behavior of solutions, as well as curing of monomers. This real-time instrument follows in-plane and out-of-plane birefringence, weight, thickness, and surface temperature during the course of solidification of coatings and films through solvent evaporation and thermal or photocuring in a controlled atmosphere. It is specifically designed to simulate behavior of polymer solutions inside an industrial size, continuous roll-to-roll solution casting line and other coating operations where resins are subjected to ultraviolet (UV) curing from monomer precursors. Controlled processing parameters include air speed, temperature, initial cast thickness, and solute concentration, while measured parameters are thickness, weight, film temperature, in-plane and out-of-plane birefringence. In this paper, we illustrate the utility of this instrument with solution cast and dried poly (amide-imide)/DMAc (Dimethylacetamide) solution, water based black paint, and organo-modified clay/NMP (N-Methylpyrrolidone) solution. In addition, the physical changes that take place during UV photo polymerization of a monomer are tracked. This instrument is designed to be generic and it can be used for tracking any drying/swelling/solidification systems including paper, foodstuffs such as; grains, milk as well as pharmaceutical thin paste and slurries.

  1. Sea surface temperature as a tracer to estimate cross-shelf turbulent diffusivity and flushing time in the Great Barrier Reef lagoon

    Science.gov (United States)

    Mao, Yadan; Ridd, Peter V.

    2015-06-01

    Accurate parameterization of spatially variable diffusivity in complex shelf regions such as the Great Barrier Reef (GBR) lagoon is an unresolved issue for hydrodynamic models. This leads to large uncertainties to the flushing time derived from them and to the evaluation of ecosystem resilience to terrestrially derived pollution. In fact, numerical hydrodynamic models and analytical cross-shore diffusion models have predicted very different flushing times for the GBR lagoon. Nevertheless, scarcity of in situ measurements used previously in the latter method prevents derivation of detailed diffusivity profiles. Here detailed cross-shore profiles of diffusivity were calculated explicitly in a closed form for the first time from the steady state transects of sea surface temperature for different sections of the GBR lagoon. We find that diffusivity remains relatively constant within the inner lagoon (reef-devoid regions, but increases dramatically where the reef matrixes start and fluctuates with reef size and density. The cross-shelf profile of steady state salinity calculated using the derived diffusivity values agrees well with field measurements. The calculated diffusivity values are also consistent with values derived from satellite-tracked drifters. Flushing time by offshore diffusion is of the order of 1 month, suggesting the important role of turbulent diffusion in flushing the lagoon, especially in reef-distributed regions. The results imply that previous very large residence times predicted by numerical hydrodynamic models may result from underestimation of diffusivity. Our findings can guide parameterization of diffusivity in hydrodynamic modeling.

  2. Analysis of Satellite sea surface temperature time series in the Brazil-Malvinas Current confluence region: Dominance of the annual and semiannual periods

    Science.gov (United States)

    Provost, Christine; Garcia, Omar; GarçOn, VéRonique

    1992-11-01

    We study the dominant periodic variations of sea surface temperature (SST) in the Brazil-Malvinas Confluence region from a satellite-derived data set compiled by Olson et al. (1988). This data set is composed of 202 sea surface temperature images with a 4 × 4 km resolution and extends over 3 years (from July 1984 to July 1987). Each image is a 5-day composite. The dominant signal, as already observed by Podesta et al. (1991), has a 1-year period. We first fit a single-frequency sinusoidal model of the annual cycle in order to estimate mean temperature, amplitude, and phase at 159 points uniformly distributed over the region. The residuals are generally small (less than 2°C). The largest departures from this cycle are located either in the Brazil-Malvinas frontal region or in the southeastern part of the region. Other periods in SST variations are identified by means of periodograms of the 159 residual time series in which the annual cycle has been substracted. The periodograms show that a semiannual frequency signal is present at almost every location. The ratio of the semiannual amplitude to the annual amplitude increases southward from 0% at 30°S to reach up to 45% at 50°S. In the south the semiannual signal creates an asymmetry, and the resulting (total) annual cycle has a cold period (winter) longer than the warm one (summer). In the frontal region the annual and semiannual signals have an important interannual variation. This semiannual frequency is associated with the semiannual wave present in the atmospheric forcing of the southern hemisphere. Differential heating over the mid-latitude oceans and the high-latitude ice-covered Antarctic Continent has been suggested as the cause of this semiannual wave (Van Loon, 1967).

  3. Extended Reconstructed Sea Surface Temperature (ERSST)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature analysis derived from the International Comprehensive...

  4. NOAA Global Surface Temperature (NOAAGlobalTemp)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Global Surface Temperature Dataset (NOAAGlobalTemp) is a merged land–ocean surface temperature analysis (formerly known as MLOST) (link is external). It is...

  5. Geomagnetic effects on the average surface temperature

    Science.gov (United States)

    Ballatore, P.

    Several results have previously shown as the solar activity can be related to the cloudiness and the surface solar radiation intensity (Svensmark and Friis-Christensen, J. Atmos. Sol. Terr. Phys., 59, 1225, 1997; Veretenenkoand Pudovkin, J. Atmos. Sol. Terr. Phys., 61, 521, 1999). Here, the possible relationships between the averaged surface temperature and the solar wind parameters or geomagnetic activity indices are investigated. The temperature data used are the monthly SST maps (generated at RAL and available from the related ESRIN/ESA database) that represent the averaged surface temperature with a spatial resolution of 0.5°x0.5° and cover the entire globe. The interplanetary data and the geomagnetic data are from the USA National Space Science Data Center. The time interval considered is 1995-2000. Specifically, possible associations and/or correlations of the average temperature with the interplanetary magnetic field Bz component and with the Kp index are considered and differentiated taking into account separate geographic and geomagnetic planetary regions.

  6. Surface temperature measurements of diamond

    CSIR Research Space (South Africa)

    Masina, BN

    2006-07-01

    Full Text Available ) and the waist position (z0) 3. TEMPERATURE MEASUREMENTS There are many methods to measure the temperature of a body. Here we used a thermocou- ple and a pyrometer, while future plans involve emission spectroscopy. A thermocouple is a temperature... sensor that consists of two wires con- nected together made from different metals, which produces an electrical voltage that is dependant on tem- perature. A Newport electronic thermocou- ple was used to meas- ured temperature. It can measure...

  7. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

  8. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment concentrati

  9. Technique for the estimation of surface temperatures from embedded temperature sensing for rapid, high energy surface deposition.

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, Tyson R.; Schunk, Peter Randall; Roberts, Scott Alan

    2014-07-01

    Temperature histories on the surface of a body that has been subjected to a rapid, highenergy surface deposition process can be di cult to determine, especially if it is impossible to directly observe the surface or attach a temperature sensor to it. In this report, we explore two methods for estimating the temperature history of the surface through the use of a sensor embedded within the body very near to the surface. First, the maximum sensor temperature is directly correlated with the peak surface temperature. However, it is observed that the sensor data is both delayed in time and greatly attenuated in magnitude, making this approach unfeasible. Secondly, we propose an algorithm that involves tting the solution to a one-dimensional instantaneous energy solution problem to both the sensor data and to the results of a one-dimensional CVFEM code. This algorithm is shown to be able to estimate the surface temperature 20 C.

  10. Role of surface temperature in fluorocarbon plasma-surface interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Caleb T.; Overzet, Lawrence J.; Goeckner, Matthew J. [Department of Electrical Engineering, University of Texas at Dallas, PO Box 830688, Richardson, TX 75083 (United States)

    2012-07-15

    This article examines plasma-surface reaction channels and the effect of surface temperature on the magnitude of those channels. Neutral species CF{sub 4}, C{sub 2}F{sub 6}, and C{sub 3}F{sub 8} are produced on surfaces. The magnitude of the production channel increases with surface temperature for all species, but favors higher mass species as the temperature is elevated. Additionally, the production rate of CF{sub 2} increases by a factor of 5 as the surface temperature is raised from 25 Degree-Sign C to 200 Degree-Sign C. Fluorine density, on the other hand, does not change as a function of either surface temperature or position outside of the plasma glow. This indicates that fluorine addition in the gas-phase is not a dominant reaction. Heating reactors can result in higher densities of depositing radical species, resulting in increased deposition rates on cooled substrates. Finally, the sticking probability of the depositing free radical species does not change as a function of surface temperature. Instead, the surface temperature acts together with an etchant species (possibly fluorine) to elevate desorption rates on that surface at temperatures lower than those required for unassisted thermal desorption.

  11. The surface temperature of free evaporating drops

    Science.gov (United States)

    Borodulin, V. Y.; Letushko, V. N.; Nizovtsev, M. I.; Sterlyagov, A. N.

    2016-10-01

    Complex experimental and theoretical investigation of heat and mass transfer processes was performed at evaporation of free liquid drops. For theoretical calculation the emission-diffusion model was proposed. This allowed taking into account the characteristics of evaporation of small droplets, for which heat and mass transfer processes are not described in the conventional diffusion model. The calculation results of evaporation of droplets of different sizes were compared using two models: the conventional diffusion and emission-diffusion models. To verify the proposed physical model, the evaporation of droplets suspended on a polypropylene fiber was experimentally investigated. The form of droplets in the evaporation process was determined using microphotographing. The temperature was measured on the surfaces of evaporating drops using infrared thermography. The experimental results have showed good agreement with the numerical data for the time of evaporation and the temperature of evaporating drops.

  12. Infrared surface temperature measurements for long pulse operation, and real time feedback control in Tore-Supra, an actively cooled Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Guilhem, D.; Adjeroud, B.; Balorin, C.; Buravand, Y.; Bertrand, B.; Bondil, J.L.; Desgranges, C.; Gauthier, E.; Lipa, M.; Messina, P.; Missirlian, M.; Mitteau, R.; Moulin, D.; Pocheau, C.; Portafaix, C.; Reichle, R.; Roche, H.; Saille, A.; Vallet, S

    2004-07-01

    Tore-Supra has a steady-state magnetic field using super-conducting magnets and water-cooled plasma facing components for high performances long pulse plasma discharges. When not actively cooled, plasma-facing components can only accumulate a limited amount of energy since the temperature increase continuously (T proportional to {radical}(t)) during the discharge until radiation cooling is equal to the incoming heat flux (T > 1800 K). Such an environment is found in most today Tokamaks. In the present paper we report the recent results of Tore-Supra, especially the design of the new generation of infrared endoscopes to measure the surface temperature of the plasma facing components. The Tore-Supra infrared thermography system is composed of 7 infrared endoscopes, this system is described in details in the paper, the new JET infrared thermography system is presented and some insights of the ITER set of visible/infrared endoscope is given. (authors)

  13. Gravity increased by lunar surface temperature

    Science.gov (United States)

    Keene, James

    2013-04-01

    Quantitatively large effects of lunar surface temperature on apparent gravitational force measured by lunar laser ranging (LLR) and lunar perigee may challenge widely accepted theories of gravity. LLR data grouped by days from full moon shows the moon is about 5 percent closer to earth at full moon compared to 8 days before or after full moon. In a second, related result, moon perigees were least distant in days closer to full moon. Moon phase was used as proxy independent variable for lunar surface temperature. The results support the prediction by binary mechanics that gravitational force increases with object surface temperature.

  14. COBE-SST2 Sea Surface Temperature and Ice

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A new sea surface temperature (SST) analysis on a centennial time scale is presented. The dataset starts in 1850 with monthly 1x1 means and is periodically updated....

  15. Low Temperature Surface Carburization of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Sunniva R; Heuer, Arthur H; Sikka, Vinod K

    2007-12-07

    Thermodynamic modeling to explain the high degree of carbon solubility possible in austenitic grades under the LTCSS process and experimental validation of model results • Corrosion testing to determine the corrosion resistance improvement possible from the LTCSS process • Erosion testing to determine the erosion resistance improvement possible from the LTCSS process • Wear testing to quantify the wear resistance improvement possible from the LTCSS process • Fatigue testing for quantifying the extent of improvement from the LTCSS process • Component treating and testing under simulated and in-line commercial operations XRD verified expanded austenite lattice, with no evidence of carbide precipitation. Carbon concentration profiles via Auger and electron dispersion spectroscopy (EDS) showed carbon levels in excess of 12 at. % in treated, type 316 SS. Scanning electron microscopy (SEM) of pulled-to-failure treated tensile specimens showed slip bands and no de-cohesion of the treated layer, verifying that the layer remains ductile. Compressive stresses in excess of 2 GPa (300 ksi) have been calculated at the surface of the case. Phase diagram (CALPHAD) (ThermoCalc) and Wagner dilute solution thermodynamic models were developed that calculate the solubility of carbon in austenite as a function of alloying content for the process time and temperature. Several commercial alloys have been modeled, and the model has been used to design experimental alloys with enhanced affinity for carbon solubility at treatment temperatures. Four experimental alloys were melted, rolled, and manufactured into test specimens, and the LTCSS treatment indicated successfully enhanced results and validated the predictions based on thermodynamic modeling. Electrochemical polarization curves show a 600 to 800 mV increase in pitting potential in treated (900-1000 mV) versus non-treated (200-300 mV) type 316 in chloride solutions. Treated 316L showed crevice-corrosion behavior similar to that of Ti-6

  16. Sea Surface Temperature Average_SST_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea surface temperature collected via satellite imagery from http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.html and averaged for each region using ArcGIS...

  17. OW NOAA GOES Sea-Surface Temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface temperature measurements collected by means of the Geostationary Orbiting Environmental Satellite. The data is...

  18. evaluation of land surface temperature parameterization ...

    African Journals Online (AJOL)

    user

    1 DEPARTMENT OF PHYSICS, ADEYEMI COLLEGE OF EDUCATION, ONDO, ... Surface temperature (Ts) is vital to the study of land-atmosphere interactions and climate variabilities. .... value = 0.167 m3m-3), and very low for dry days (mean.

  19. Monthly Near-Surface Air Temperature Averages

    Data.gov (United States)

    National Aeronautics and Space Administration — Global surface temperatures in 2010 tied 2005 as the warmest on record. The International Satellite Cloud Climatology Project (ISCCP) was established in 1982 as part...

  20. Sea Surface Temperature (14 KM North America)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Product shows local sea surface temperatures (degrees C). It is a composite gridded-image derived from 8-km resolution SST Observations. It is generated every 48...

  1. Analysed foundation sea surface temperature, global

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The through-cloud capabilities of microwave radiometers provide a valuable picture of global sea surface temperature (SST). To utilize this, scientists at Remote...

  2. Coastal sea-surface temperature anomalies during the 2014-2016 northeast Pacific marine heat wave: regional variability, timing, and relation to wind stress anomalies

    Science.gov (United States)

    Gentemann, C. L.; Fewings, M. R.; Garcia-Reyes, M.

    2016-12-01

    In 2014-2016, sea-surface temperatures (SSTs) in the region along the Washington, Oregon, and California coasts were significantly warmer than usual, with a maximum SST anomaly of 6.2°C measured near Santa Barbara. This marine heat wave was associated with major ecosystem disturbances, including a toxic algae bloom of Pseudo-nitzschia that had massive economic and ecological impacts. Here, we use satellite and blended reanalysis products to report the magnitude, extent, duration, and evolution of SST, wind stress, and wind stress curl anomalies along the west coast of the continental United States during 2014-2016. Using high-resolution wind stress instead of the Bakun upwelling index shows clear differences in upwelling phenology in 2015.

  3. Urban aerosol effects on surface insolation and surface temperature

    Science.gov (United States)

    Jin, M.; Burian, S. J.; Remer, L. A.; Shepherd, M. J.

    2007-12-01

    Urban aerosol particulates may play a fundamental role in urban microclimates and city-generated mesoscale circulations via its effects on energy balance of the surface. Key questions that need to be addressed include: (1) How do these particles affect the amount of solar energy reaching the surface and resulting surface temperature? (2) Is the effect the same in all cities? and (3) How does it vary from city to city? Using NASA AERONET in-situ observations, a radiative transfer model, and a regional climate mode (MM5), we assess aerosol effects on surface insolation and surf ace temperature for dense urban-polluted regions. Two big cities, one in a developing country (Beijing, P.R. China) and another in developed country (New York City, USA), are selected for inter-comparison. The study reveals that aerosol effects on surface temperature depends largely on aerosols' optical and chemical properties as well as atmosphere and land surface conditions, such as humidity and land cover. Therefore, the actual magnitudes of aerosol effects differ from city to city. Aerosol measurements from AERONET show both average and extreme cases for aerosol impacts on surface insolation. In general, aerosols reduce surface insolation by 30Wm-2. Nevertheless, in extreme cases, such reduction can exceed 100 Wm-2. Consequently, this reduces surface skin temperature 2-10C in an urban environment.

  4. Modeling of global surface air temperature

    Science.gov (United States)

    Gusakova, M. A.; Karlin, L. N.

    2012-04-01

    A model to assess a number of factors, such as total solar irradiance, albedo, greenhouse gases and water vapor, affecting climate change has been developed on the basis of Earth's radiation balance principle. To develop the model solar energy transformation in the atmosphere was investigated. It's a common knowledge, that part of the incoming radiation is reflected into space from the atmosphere, land and water surfaces, and another part is absorbed by the Earth's surface. Some part of outdoing terrestrial radiation is retained in the atmosphere by greenhouse gases (carbon dioxide, methane, nitrous oxide) and water vapor. Making use of the regression analysis a correlation between concentration of greenhouse gases, water vapor and global surface air temperature was obtained which, it is turn, made it possible to develop the proposed model. The model showed that even smallest fluctuations of total solar irradiance intensify both positive and negative feedback which give rise to considerable changes in global surface air temperature. The model was used both to reconstruct the global surface air temperature for the 1981-2005 period and to predict global surface air temperature until 2030. The reconstructions of global surface air temperature for 1981-2005 showed the models validity. The model makes it possible to assess contribution of the factors listed above in climate change.

  5. Sea surface temperature and ocean colour (MODIS/AQUA) space and time variability in Indonesian Sea coral reef systems from 2002 to 2011

    Science.gov (United States)

    Polónia, A. R.; Figueiredo, M.; Cleary, D. F. R.; de Voogd, N. J.; Martins, A.

    2011-11-01

    Presently, there are already Indonesian coral reefs experiencing massive destruction caused by anthropogenic localscale sources (sedimentation, eutrophication) and/or natural climatic global-scale sources (temperature) which can inflict acute and/or chronic impacts on these ecosystems. This study was carried out with the aim of identifying possible sources of impact in coral reef systems associated with two of the most populated Indonesian cities (Makassar and Jakarta). MODIS/AQUA satellite-derived Ocean Colour (Chl a in mg m-3) and Sea Surface Temperature (SST in °C) data were used for the 2002-2011 period. These were related with large-scale atmospheric climatic indices, namely the Southern Oscillation Index (SOI), the Dipole Mode Index (DMI), and the North Atlantic Oscillation Index (NAOI). Beyond the expected influence of the El Niño Index over the Indonesian region, we present first evidence of the significant influence of the NAOI in Indonesian ecosystems. The results show strong seasonal correlation between the NAOI and two key parameters for the coral reef health: chlorophyll a (at Jakarta) and SST (at Makassar). During the dry season, and especially over the Spermonde coral reef system, a seasonal SST uptrend was observed culminating in the first bleaching event registered in this area during the hottest year (2010) since 2002.

  6. Middle Pliocene sea surface temperature variability

    Science.gov (United States)

    Dowsett, H.J.; Chandler, M.A.; Cronin, T. M.; Dwyer, G.S.

    2005-01-01

    Estimates of sea surface temperature (SST) based upon foraminifer, diatom, and ostracod assemblages from ocean cores reveal a warm phase of the Pliocene between about 3.3 and 3.0 Ma. Pollen records and plant megafossils, although not as well dated, show evidence for a warmer climate at about the same time. Increased greenhouse forcing and altered ocean heat transport are the leading candidates for the underlying cause of Pliocene global warmth. Despite being a period of global warmth, this interval encompasses considerable variability. Two new SST reconstructions are presented that are designed to provide a climatological error bar for warm peak phases of the Pliocene and to document the spatial distribution and magnitude of SST variability within the mid-Pliocene warm period. These data suggest long-term stability of low-latitude SST and document greater variability in regions of maximum warming. Copyright 2005 by the American Geophysical Union.

  7. Determination of temperature of moving surface by sensitivity analysis

    CERN Document Server

    Farhanieh, B

    2002-01-01

    In this paper sensitivity analysis in inverse problem solutions is employed to estimate the temperature of a moving surface. Moving finite element method is used for spatial discretization. Time derivatives are approximated using Crank-Nicklson method. The accuracy of the solution is assessed by simulation method. The convergence domain is investigated for the determination of the temperature of a solid fuel.

  8. International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 2 Monthly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

  9. International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 2 Daily

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

  10. International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 3 Monthly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Land Surface Temperature Databank contains monthly timescale mean, maximum, and minimum temperature for approximately 40,000 stations globally. It was...

  11. International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 1 Daily

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

  12. International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 1 Monthly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

  13. North American regional climate reconstruction from ground surface temperature histories

    Science.gov (United States)

    Jaume-Santero, Fernando; Pickler, Carolyne; Beltrami, Hugo; Mareschal, Jean-Claude

    2016-12-01

    Within the framework of the PAGES NAm2k project, 510 North American borehole temperature-depth profiles were analyzed to infer recent climate changes. To facilitate comparisons and to study the same time period, the profiles were truncated at 300 m. Ground surface temperature histories for the last 500 years were obtained for a model describing temperature changes at the surface for several climate-differentiated regions in North America. The evaluation of the model is done by inversion of temperature perturbations using singular value decomposition and its solutions are assessed using a Monte Carlo approach. The results within 95 % confidence interval suggest a warming between 1.0 and 2.5 K during the last two centuries. A regional analysis, composed of mean temperature changes over the last 500 years and geographical maps of ground surface temperatures, show that all regions experienced warming, but this warming is not spatially uniform and is more marked in northern regions.

  14. Turbulent Flow past High Temperature Surfaces

    Science.gov (United States)

    Mehmedagic, Igbal; Thangam, Siva; Carlucci, Pasquale; Buckley, Liam; Carlucci, Donald

    2014-11-01

    Flow over high-temperature surfaces subject to wall heating is analyzed with applications to projectile design. In this study, computations are performed using an anisotropic Reynolds-stress model to study flow past surfaces that are subject to radiative flux. The model utilizes a phenomenological treatment of the energy spectrum and diffusivities of momentum and heat to include the effects of wall heat transfer and radiative exchange. The radiative transport is modeled using Eddington approximation including the weighted effect of nongrayness of the fluid. The time-averaged equations of motion and energy are solved using the modeled form of transport equations for the turbulence kinetic energy and the scalar form of turbulence dissipation with an efficient finite-volume algorithm. The model is applied for available test cases to validate its predictive capabilities for capturing the effects of wall heat transfer. Computational results are compared with experimental data available in the literature. Applications involving the design of projectiles are summarized. Funded in part by U.S. Army, ARDEC.

  15. Calibration of surface temperature on rocky exoplanets

    Science.gov (United States)

    Kashyap Jagadeesh, Madhu

    2016-07-01

    Study of exoplanets and the search for life elsewhere has been a very fascinating area in recent years. Presently, lots of efforts have been channelled in this direction in the form of space exploration and the ultimate search for the habitable planet. One of the parametric methods to analyse the data available from the missions such as Kepler, CoRoT, etc, is the Earth Similarity Index (ESI), defined as a number between zero (no similarity) and one (identical to Earth), introduced to assess the Earth likeness of exoplanets. A multi-parameter ESI scale depends on the radius, density, escape velocity and surface temperature of exoplanets. Our objective is to establish how exactly the individual parameters, entering the interior ESI and surface ESI, are contributing to the global ESI, using the graphical analysis. Presently, the surface temperature estimates are following a correction factor of 30 K, based on the Earth's green-house effect. The main objective of this work in calculations of the global ESI using the HabCat data is to introduce a new method to better estimate the surface temperature of exoplanets, from theoretical formula with fixed albedo factor and emissivity (Earth values). From the graphical analysis of the known data for the Solar System objects, we established the calibration relation between surface and equilibrium temperatures for the Solar System objects. Using extrapolation we found that the power function is the closest description of the trend to attain surface temperature. From this we conclude that the correction term becomes very effective way to calculate the accurate value of the surface temperature, for further analysis with our graphical methodology.

  16. Integrative inversion of land surface component temperature

    Institute of Scientific and Technical Information of China (English)

    FAN Wenjie; XU Xiru

    2005-01-01

    In this paper, the row winter wheat was selected as the example to study the component temperature inversion method of land surface target in detail. The result showed that the structural pattern of row crop can affect the inversion precision of component temperature evidently. Choosing appropriate structural pattern of row crop can improve the inversion precision significantly. The iterative method combining inverse matrix was a stable method that was fit for inversing component temperature of land surface target. The result of simulation and field experiment showed that the integrative method could remarkably improve the inversion accuracy of the lighted soil surface temperature and the top layer canopy temperature, and enhance inversion stability of components temperature. Just two parameters were sufficient for accurate atmospheric correction of multi-angle and multi-spectral thermal infrared data: atmospheric transmittance and the atmospheric upwelling radiance. If the atmospheric parameters and component temperature can be inversed synchronously, the really and truly accurate atmospheric correction can be achieved. The validation using ATSRII data showed that the method was useful.

  17. Remotely sensed soil temperatures beneath snow-free skin-surface using thermal observations from tandem polar-orbiting satellites: An analytical three-time-scale model

    DEFF Research Database (Denmark)

    Zhan, Wenfeng; Zhou, Ji; Ju, Weimin

    2014-01-01

    ), which represents the instantaneous temperature; and the weather-change temperature cycle (WTC), which is divided into two parts to represent both the daily-averaged (WTCavg) and the instantaneous temperature (WTCinst). The DTC and WTCinst were further parameterized into four undetermined variables...

  18. Low Temperature Surface Carburization of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Sunniva R; Heuer, Arthur H; Sikka, Vinod K

    2007-12-07

    Thermodynamic modeling to explain the high degree of carbon solubility possible in austenitic grades under the LTCSS process and experimental validation of model results • Corrosion testing to determine the corrosion resistance improvement possible from the LTCSS process • Erosion testing to determine the erosion resistance improvement possible from the LTCSS process • Wear testing to quantify the wear resistance improvement possible from the LTCSS process • Fatigue testing for quantifying the extent of improvement from the LTCSS process • Component treating and testing under simulated and in-line commercial operations XRD verified expanded austenite lattice, with no evidence of carbide precipitation. Carbon concentration profiles via Auger and electron dispersion spectroscopy (EDS) showed carbon levels in excess of 12 at. % in treated, type 316 SS. Scanning electron microscopy (SEM) of pulled-to-failure treated tensile specimens showed slip bands and no de-cohesion of the treated layer, verifying that the layer remains ductile. Compressive stresses in excess of 2 GPa (300 ksi) have been calculated at the surface of the case. Phase diagram (CALPHAD) (ThermoCalc) and Wagner dilute solution thermodynamic models were developed that calculate the solubility of carbon in austenite as a function of alloying content for the process time and temperature. Several commercial alloys have been modeled, and the model has been used to design experimental alloys with enhanced affinity for carbon solubility at treatment temperatures. Four experimental alloys were melted, rolled, and manufactured into test specimens, and the LTCSS treatment indicated successfully enhanced results and validated the predictions based on thermodynamic modeling. Electrochemical polarization curves show a 600 to 800 mV increase in pitting potential in treated (900-1000 mV) versus non-treated (200-300 mV) type 316 in chloride solutions. Treated 316L showed crevice-corrosion behavior similar to that of Ti-6

  19. Temperature limit values for gripping cold surfaces

    NARCIS (Netherlands)

    Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.

    2002-01-01

    Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four

  20. Temperature limit values for gripping cold surfaces

    NARCIS (Netherlands)

    Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.

    2002-01-01

    Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four hund

  1. Surface temperature excess in heterogeneous catalysis

    NARCIS (Netherlands)

    Zhu, L.

    2005-01-01

    In this dissertation we study the surface temperature excess in heterogeneous catalysis. For heterogeneous reactions, such as gas-solid catalytic reactions, the reactions take place at the interfaces between the two phases: the gas and the solid catalyst. Large amount of reaction heats are released

  2. Surface temperature excess in heterogeneous catalysis

    NARCIS (Netherlands)

    Zhu, L.

    2005-01-01

    In this dissertation we study the surface temperature excess in heterogeneous catalysis. For heterogeneous reactions, such as gas-solid catalytic reactions, the reactions take place at the interfaces between the two phases: the gas and the solid catalyst. Large amount of reaction heats are released

  3. Managing Perishables with Time and temperature History

    NARCIS (Netherlands)

    Ketzenberg, M.; Bloemhof, J.M.; Gaukler, G.

    2015-01-01

    We address the use and value of time and temperature information to manage perishables in the contextof a retailer that sells a random lifetime product subject to stochastic demand and lost sales. The product’s lifetime is largely determined by the temperature history and the flow time through the s

  4. Managing Perishables with Time and temperature History

    NARCIS (Netherlands)

    Ketzenberg, M.; Bloemhof, J.M.; Gaukler, G.

    2015-01-01

    We address the use and value of time and temperature information to manage perishables in the contextof a retailer that sells a random lifetime product subject to stochastic demand and lost sales. The product’s lifetime is largely determined by the temperature history and the flow time through the

  5. Managing Perishables with Time and temperature History

    NARCIS (Netherlands)

    Ketzenberg, M.; Bloemhof, J.M.; Gaukler, G.

    2015-01-01

    We address the use and value of time and temperature information to manage perishables in the contextof a retailer that sells a random lifetime product subject to stochastic demand and lost sales. The product’s lifetime is largely determined by the temperature history and the flow time through the s

  6. DISAGGREGATION OF GOES LAND SURFACE TEMPERATURES USING SURFACE EMISSIVITY

    Science.gov (United States)

    Accurate temporal and spatial estimation of land surface temperatures (LST) is important for modeling the hydrological cycle at field to global scales because LSTs can improve estimates of soil moisture and evapotranspiration. Using remote sensing satellites, accurate LSTs could be routine, but unfo...

  7. Surface defects and temperature on atomic friction

    Energy Technology Data Exchange (ETDEWEB)

    Fajardo, O Y; Mazo, J J, E-mail: yovany@unizar.es [Departamento de Fisica de la Materia Condensada and Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, 50009 Zaragoza (Spain)

    2011-09-07

    We present a theoretical study of the effect of surface defects on atomic friction in the stick-slip dynamical regime of a minimalistic model. We focus on how the presence of defects and temperature change the average properties of the system. We have identified two main mechanisms which modify the mean friction force of the system when defects are considered. As expected, defects change the potential profile locally and thus affect the friction force. But the presence of defects also changes the probability distribution function of the tip slip length and thus the mean friction force. We corroborated both effects for different values of temperature, external load, dragging velocity and damping. We also show a comparison of the effects of surface defects and surface disorder on the dynamics of the system. (paper)

  8. Surface temperature distribution in broiler houses

    Directory of Open Access Journals (Sweden)

    MS Baracho

    2011-09-01

    Full Text Available In the Brazilian meat production scenario broiler production is the most dynamic segment. Despite of the knowledge generated in the poultry production chain, there are still important gaps on Brazilian rearing conditions as housing is different from other countries. This research study aimed at analyzing the variation in bird skin surface as function of heat distribution inside broiler houses. A broiler house was virtually divided into nine sectors and measurements were made during the first four weeks of the grow-out in a commercial broiler farm in the region of Rio Claro, São Paulo, Brazil. Rearing ambient temperature and relative humidity, as well as light intensity and air velocity, were recorded in the geometric center of each virtual sector to evaluate the homogeneity of these parameters. Broiler surface temperatures were recorded using infrared thermography. Differences both in surface temperature (Ts and dry bulb temperature (DBT were significant (p<0.05 as a function of week of rearing. Ts was different between the first and fourth weeks (p<0.05 in both flocks. Results showed important variations in rearing environment parameters (temperature and relative humidity and in skin surface temperature as a function of week and house sector. Air velocity data were outside the limits in the first and third weeks in several sectors. Average light intensity values presented low variation relative to week and house sector. The obtained values were outside the recommended ranges, indicating that broilers suffered thermal distress. This study points out the need to record rearing environment data in order to provide better environmental control during broiler grow-out.

  9. High temperature photoelectron emission and surface photovoltage in semiconducting diamond

    Science.gov (United States)

    Williams, G. T.; Cooil, S. P.; Roberts, O. R.; Evans, S.; Langstaff, D. P.; Evans, D. A.

    2014-08-01

    A non-equilibrium photovoltage is generated in semiconducting diamond at above-ambient temperatures during x-ray and UV illumination that is sensitive to surface conductivity. The H-termination of a moderately doped p-type diamond (111) surface sustains a surface photovoltage up to 700 K, while the clean (2 × 1) reconstructed surface is not as severely affected. The flat-band C 1s binding energy is determined from 300 K measurement to be 283.87 eV. The true value for the H-terminated surface, determined from high temperature measurement, is (285.2 ± 0.1) eV, corresponding to a valence band maximum lying 1.6 eV below the Fermi level. This is similar to that of the reconstructed (2 × 1) surface, although this surface shows a wider spread of binding energy between 285.2 and 285.4 eV. Photovoltage quantification and correction are enabled by real-time photoelectron spectroscopy applied during annealing cycles between 300 K and 1200 K. A model is presented that accounts for the measured surface photovoltage in terms of a temperature-dependent resistance. A large, high-temperature photovoltage that is sensitive to surface conductivity and photon flux suggests a new way to use moderately B-doped diamond in voltage-based sensing devices.

  10. Assessment of surface temperatures of buffalo bulls (Bubalus bubalis) raised under tropical conditions using infrared thermography

    National Research Council Canada - National Science Library

    Barros, D.V; Silva, L.K.X; Kahwage, P.R; Lourenço Júnior, J.B; Sousa, J.S; Silva, A.G.M; Franco, I.M; Martorano, L.G; Garcia, A.R

    2016-01-01

    This paper aimed to evaluate the surface temperatures of buffalo bulls using infrared thermography, considering four distinct anatomical parts over time, and to correlate surface temperatures and thermal comfort indexes...

  11. SURFACE TEMPERATURES ON TITAN DURING NORTHERN WINTER AND SPRING

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, D. E.; Cottini, V.; Nixon, C. A.; Achterberg, R. K.; Flasar, F. M.; Kunde, V. G.; Romani, P. N.; Samuelson, R. E. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mamoutkine, A. [ADNET Systems, Inc., Bethesda, MD 20817 (United States); Gorius, N. J. P. [The Catholic University of America, Washington, DC 20064 (United States); Coustenis, A. [Laboratoire d’Etudes Spatiales et d’Instrumentation en Astrophysique (LESIA), Observatoire de Paris, CNRS, UPMC Univ. Paris 06, Univ. Paris-Diderot, 5, place Jules Janssen, F-92195 Meudon Cedex (France); Tokano, T., E-mail: donald.e.jennings@nasa.gov [Universität zu Köln, Albertus-Magnus-Platz, D-50923 Köln (Germany)

    2016-01-01

    Meridional brightness temperatures were measured on the surface of Titan during the 2004–2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two-year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 91.7 ± 0.3 to 89.7 ± 0.5 K while at the north pole the temperature increased by 1 K from 90.7 ± 0.5 to 91.5 ± 0.2 K. The latitude of maximum temperature moved from 19 S to 16 N, tracking the sub-solar latitude. As the latitude changed, the maximum temperature remained constant at 93.65 ± 0.15 K. In 2010 our temperatures repeated the north–south symmetry seen by Voyager one Titan year earlier in 1980. Early in the mission, temperatures at all latitudes had agreed with GCM predictions, but by 2014 temperatures in the north were lower than modeled by 1 K. The temperature rise in the north may be delayed by cooling of sea surfaces and moist ground brought on by seasonal methane precipitation and evaporation.

  12. The effect of MAO processing time on surface properties and low temperature infrared emissivity of ceramic coating on aluminium 6061 alloy

    Science.gov (United States)

    Al Bosta, Mohannad M. S.; Ma, Keng-Jeng; Chien, Hsi-Hsin

    2013-09-01

    MAO ceramic coatings were prepared on aluminium 6061 surfaces at different treating durations (10, 20, ... 60 min), using alkali silicate electrolyte and pulsed bipolar current mode. The surface microstructures and properties were studied using SEM, XRD, EDX and a surface roughness tester. Image-Pro Plus and MATCH! softwares were used to analyze SEM micrographs and XRD results, respectively. The infrared emissivities of the ceramic coatings were measured at the 70 °C using FTIR spectrometer. We found a linear correlation between the volcano-like area and the surface roughness. The compositions and phases were associated with the volcano-like population and area. The curve of IR spectral emissivity was influenced by surface roughness, γ-alumina, sillimanite and cristobalite phases. The emissivity was enhanced by the surface roughness in the ranges 4.0-9.6 μm and 10.5-14.8 μm. In the range 7.0-8.0 μm, α-alumina and sillimanite phases enhanced the emissivity, while the cristobalite has a negative impact to the emissivity. A negative contributions were found for α-alumina in the region 9.6-16.0 μm and for the surface thickness in the region 15.0-16.0 μm. Overall, the average of long wave infrared (LWIR) emissivity ranged from 87.05% to 91.65%.

  13. Investigating the effect of surface water - groundwater interactions on stream temperature using Distributed temperature sensing and instream temperature model

    DEFF Research Database (Denmark)

    Karthikeyan, Matheswaran; Blemmer, Morten; Mortensen, Julie Flor;

    2011-01-01

    Surface water–groundwater interactions at the stream interface influences, and at times controls the stream temperature, a critical water property driving biogeochemical processes. This study investigates the effects of these interactions on temperature of Stream Elverdamsåen in Denmark using...... the Distributed Temperature Sensing (DTS) system and instream temperature modelling. Locations of surface water–groundwater interactions were identified from the temperature data collected over a 2-km stream reach using a DTS system with 1-m spatial and 5-min temporal resolution. The stream under consideration...... exhibits three distinct thermal regimes within a 2 km reach length due to two major interactions. An energy balance model is used to simulate the instream temperature and to quantify the effect of these interactions on the stream temperature. This research demonstrates the effect of reach level small scale...

  14. Time-temperature superposition in viscous liquids

    DEFF Research Database (Denmark)

    Olsen, Niels Boye; Dyre, Jeppe; Christensen, Tage Emil

    2001-01-01

    with a reduced time definition based on a recently proposed expression for the relaxation time, where G [infinity] reflects the fictive temperature. All parameters entering the reduced time were determined from independent measurements of the frequency-dependent shear modulus of the equilibrium liquid....

  15. MODIS Surface Temperatures for Cryosphere Studies (Invited)

    Science.gov (United States)

    Hall, D. K.; Comiso, J. C.; DiGirolamo, N. E.; Shuman, C. A.; Riggs, G. A.

    2013-12-01

    We have used Moderate-resolution Imaging Spectroradiometer (MODIS) land-surface temperature (LST) and ice-surface temperature (IST) products for several applications in studies of the cryosphere. A climate-quality climate data record (CDR) of the IST of the Greenland ice sheet has been developed and was one of the data sources used to monitor the extreme melt event covering nearly the entire Greenland ice sheet on 11 - 12 July 2012. The IST CDR is available online for users to employ in models, and to study temperature distributions and melt trends on the ice sheet. We continue to assess accuracy of the IST product through comparative analysis with air temperature data from the NOAA Logan temperature sensor at Summit Station, Greenland. We find a small offset between the air temperature and the IST with the IST being slightly lower which is consistent with findings of other studies. The LST data product has been applied in studies of snow melt in regions where snow is a significant water resource. We have used LST data in seasonally snow-covered areas such as the Wind River Range, Wyoming, to monitor the relationship between LST and seasonal streamflow. A close association between a sudden and sustained increase in LST and complete snowmelt, and between melt-season maximum LST and maximum daily streamflow has been documented. Use of LST and MODIS snow-cover and products in hydrological models increases the accuracy of the modeled prediction of runoff. The IST and LST products have also been applied to study of sea ice, e.g. extent and concentration, and lake ice, such as determining ice-out dates, and these efforts will also be described.

  16. Investigation of surface properties of high temperature nitrided titanium alloys

    Directory of Open Access Journals (Sweden)

    E. Koyuncu

    2009-12-01

    Full Text Available Purpose: The purpose of paper is to investigate surface properties of high temperature nitrided titanium alloys.Design/methodology/approach: In this study, surface modification of Ti6Al4V titanium alloy was made at various temperatures by plasma nitriding process. Plasma nitriding treatment was performed in 80% N2-20% H2 gas mixture, for treatment times of 2-15 h at the temperatures of 700-1000°C. Surface properties of plasma nitrided Ti6Al4V alloy were examined by metallographic inspection, X-Ray diffraction and Vickers hardness.Findings: Two layers were determined by optic inspection on the samples that were called the compound and diffusion layers. Compound layer contain TiN and Ti2N nitrides, XRD results support in this formations. Maximum hardness was obtained at 10h treatment time and 1000°C treatment temperature. Micro hardness tests showed that hardness properties of the nitrided samples depend on treatment time and temperature.Practical implications: Titanium and its alloys have very attractive properties for many industries. But using of titanium and its alloys is of very low in mechanical engineering applications because of poor tribological properties.Originality/value: The nitriding of titanium alloy surfaces using plasma processes has already reached the industrial application stage in the biomedical field.

  17. The international surface temperature initiative's global land surface databank

    Science.gov (United States)

    Lawrimore, J. H.; Rennie, J.; Gambi de Almeida, W.; Christy, J.; Flannery, M.; Gleason, B.; Klein-Tank, A.; Mhanda, A.; Ishihara, K.; Lister, D.; Menne, M. J.; Razuvaev, V.; Renom, M.; Rusticucci, M.; Tandy, J.; Thorne, P. W.; Worley, S.

    2013-09-01

    The International Surface Temperature Initiative (ISTI) consists of an end-to-end process for land surface air temperature analyses. The foundation is the establishment of a global land surface Databank. This builds upon the groundbreaking efforts of scientists in the 1980s and 1990s. While using many of their principles, a primary aim is to improve aspects including data provenance, version control, openness and transparency, temporal and spatial coverage, and improved methods for merging disparate sources. The initial focus is on daily and monthly timescales. A Databank Working Group is focused on establishing Stage-0 (original observation forms) through Stage-3 data (merged dataset without quality control). More than 35 sources of data have already been added and efforts have now turned to development of the initial version of the merged dataset. Methods have been established for ensuring to the extent possible the provenance of all data from the point of observation through all intermediate steps to final archive and access. Databank submission procedures were designed to make the process of contributing data as easy as possible. All data are provided openly and without charge. We encourage the use of these data and feedback from interested users.

  18. Low temperature surface conductivity of hydrogenated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Sauerer, C.; Ertl, F.; Nebel, C.E.; Stutzmann, M. [Technische Univ. Muenchen, Garching (Germany). Walter-Schottky-Inst. fuer Physikalische Grundlagen der Halbleiterelektronik; Bergonzo, P. [LIST(CEA-Recherche Technology)/DIMIR/SIAR/Saclay, Gif-sur-Yvette (France); Williams, O.A.; Jackman, R.A. [University Coll., London (United Kingdom). Dept. of Electrical and Electronic Engineering

    2001-07-23

    Conductivity and Hall experiments are performed on hydrogenated poly-CVD, atomically flat homoepitaxially grown Ib and natural type IIa diamond layers in the regime 0.34 to 400 K. For all experiments hole transport is detected with sheet resistivities at room temperature in the range 10{sup 4} to 10{sup 5} {omega}/{radical}. We introduce a transport model where a disorder induced tail of localized states traps holes at very low temperatures (T < 70 K). The characteristic energy of the tail is in the range of 6 meV. Towards higher temperatures (T > 70 K) the hole density is approximately constant and the hole mobility {mu} is increasing two orders of magnitude. In the regime 70 K < T < 200 K, {mu} is exponentially activated with 22 meV, above it follows a {proportional_to}T{sup 3/2} law. The activation energy of the hole density at T < 70 K is governed by the energy gap between holes trapped in the tail and the mobility edge which they can propagate. In the temperature regime T < 25 K an increasing hole mobility is detected which is attributed to transport in delocalized states at the surface. (orig.)

  19. The Remote Sensing of Surface Radiative Temperature over Barbados.

    Science.gov (United States)

    remote sensing of surface radiative temperature over Barbados was undertaken using a PRT-5 attached to a light aircraft. Traverses across the centre of the island, over the rugged east coast area, and the urban area of Bridgetown were undertaken at different times of day and night in the last week of June and the first week of December, 1969. These traverses show that surface variations in long-wave radiation emission lie within plus or minus 5% of the observations over grass at a representative site. The quick response of the surface to sunset and sunrise was

  20. Time-temperature equivalence in Martensite tempering

    Energy Technology Data Exchange (ETDEWEB)

    Hackenberg, Robert E. [Los Alamos National Laboratory; Thomas, Grant A. [CSM; Speer, John G. [CSM; Matlock, David K. [CSM; Krauss, George [CSM

    2008-06-16

    The relationship between time and temperature is of great consequence in many materials-related processes including the tempering of martensite. In 1945, Hollomon and Jaffe quantified the 'degree of tempering' as a function of both tempering time, t, and tempering temperature, T, using the expression, T(log t + c). Here, c is thought to be a material constant and appears to decrease linearly with increasing carbon content. The Hollomon-Jaffe tempering parameter is frequently cited in the literature. This work reviews the original derivation of the tempering parameter concept, and presents the use of the characteristics diffusion distance as an alternative time-temperature relationship during martensite tempering. During the tempering of martensite, interstitial carbon atoms diffuse to form carbides. In addition, austenite decomposes, dislocations and grain boundaries rearrange, associated with iron self diffusion. Since these are all diffusional processes, it is reasonable to expect the degree of tempering to relate to the extent of diffusion.

  1. Investigations of Low Temperature Time Dependent Cracking

    Energy Technology Data Exchange (ETDEWEB)

    Van der Sluys, W A; Robitz, E S; Young, B A; Bloom, J

    2002-09-30

    The objective of this project was to investigate metallurgical and mechanical phenomena associated with time dependent cracking of cold bent carbon steel piping at temperatures between 327 C and 360 C. Boiler piping failures have demonstrated that understanding the fundamental metallurgical and mechanical parameters controlling these failures is insufficient to eliminate it from the field. The results of the project consisted of the development of a testing methodology to reproduce low temperature time dependent cracking in laboratory specimens. This methodology was used to evaluate the cracking resistance of candidate heats in order to identify the factors that enhance cracking sensitivity. The resultant data was integrated into current available life prediction tools.

  2. High-Temperature Surface-Acoustic-Wave Transducer

    Science.gov (United States)

    Zhao, Xiaoliang; Tittmann, Bernhard R.

    2010-01-01

    Aircraft-engine rotating equipment usually operates at high temperature and stress. Non-invasive inspection of microcracks in those components poses a challenge for the non-destructive evaluation community. A low-profile ultrasonic guided wave sensor can detect cracks in situ. The key feature of the sensor is that it should withstand high temperatures and excite strong surface wave energy to inspect surface/subsurface cracks. As far as the innovators know at the time of this reporting, there is no existing sensor that is mounted to the rotor disks for crack inspection; the most often used technology includes fluorescent penetrant inspection or eddy-current probes for disassembled part inspection. An efficient, high-temperature, low-profile surface acoustic wave transducer design has been identified and tested for nondestructive evaluation of structures or materials. The development is a Sol-Gel bismuth titanate-based surface-acoustic-wave (SAW) sensor that can generate efficient surface acoustic waves for crack inspection. The produced sensor is very thin (submillimeter), and can generate surface waves up to 540 C. Finite element analysis of the SAW transducer design was performed to predict the sensor behavior, and experimental studies confirmed the results. One major uniqueness of the Sol-Gel bismuth titanate SAW sensor is that it is easy to implement to structures of various shapes. With a spray coating process, the sensor can be applied to surfaces of large curvatures. Second, the sensor is very thin (as a coating) and has very minimal effect on airflow or rotating equipment imbalance. Third, it can withstand temperatures up to 530 C, which is very useful for engine applications where high temperature is an issue.

  3. Satellite Sensed Skin Sea Surface Temperature

    Science.gov (United States)

    Donlon, Craig

    1997-01-01

    Quantitative predictions of spatial and temporal changes the global climate rely heavily on the use of computer models. Unfortunately, such models cannot provide the basis for climate prediction because key physical processes are inadequately treated. Consequently, fine tuning procedures are often used to optimize the fit between model output and observational data and the validation of climate models using observations is essential if model based predictions of climate change are to be treated with any degree of confidence. Satellite Sea Surface Temperature (SST) observations provide high spatial and temporal resolution data which is extremely well suited to the initialization, definition of boundary conditions and, validation of climate models. In the case of coupled ocean-atmosphere models, the SST (or more correctly the 'Skin' SST (SSST)) is a fundamental diagnostic variable to consider in the validation process. Daily global SST maps derived from satellite sensors also provide adequate data for the detection of global patterns of change which, unlike any other SST data set, repeatedly extend into the southern hemisphere extra-tropical regions. Such data are essential to the success of the spatial 'fingerprint' technique, which seeks to establish a north-south asymmetry where warming is suppressed in the high latitude Southern Ocean. Some estimates suggest that there is a greater than 80% chance of directly detecting significant change (97.5 % confidence level) after 10-12 years of consistent global observations of mean sea surface temperature. However, these latter statements should be qualified with the assumption that a negligible drift in the observing system exists and that biases between individual instruments required to derive a long term data set are small. Given that current estimates for the magnitude of global warming of 0.015 K yr(sup -1) - 0.025 K yr(sup -1), satellite SST data sets need to be both accurate and stable if such a warming trend is to

  4. Extended Reconstructed Sea Surface Temperature (ERSST), Version 4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature analysis on a 2x2 degree grid derived from the...

  5. NOAA Global Surface Temperature Dataset, Version 4.0

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Global Surface Temperature Dataset (NOAAGlobalTemp) is derived from two independent analyses: the Extended Reconstructed Sea Surface Temperature (ERSST)...

  6. HTPro: Low-temperature Surface Hardening of Stainless Steel

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2013-01-01

    Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance.......Low-temperature surface hardening of stainless steel provides the required performance properties without affecting corrosion resistance....

  7. Merged Land and Ocean Surface Temperature, Version 3.5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The historical Merged Land-Ocean Surface Temperature Analysis (MLOST) is derived from two independent analyses, an Extended Reconstructed Sea Surface Temperature...

  8. Primary magmas and mantle temperatures through time

    Science.gov (United States)

    Ganne, Jérôme; Feng, Xiaojun

    2017-03-01

    Chemical composition of mafic magmas is a critical indicator of physicochemical conditions, such as pressure, temperature, and fluid availability, accompanying melt production in the mantle and its evolution in the continental or oceanic lithosphere. Recovering this information has fundamental implications in constraining the thermal state of the mantle and the physics of mantle convection throughout the Earth's history. Here a statistical approach is applied to a geochemical database of about 22,000 samples from the mafic magma record. Potential temperatures (Tps) of the mantle derived from this database, assuming melting by adiabatic decompression and a Ti-dependent (Fe2O3/TiO2 = 0.5) or constant redox condition (Fe2+/∑Fe = 0.9 or 0.8) in the magmatic source, are thought to be representative of different thermal "horizons" (or thermal heterogeneities) in the ambient mantle, ranging in depth from a shallow sublithospheric mantle (Tp minima) to a lower thermal boundary layer (Tp maxima). The difference of temperature (ΔTp) observed between Tp maxima and minima did not change significantly with time (˜170°C). Conversely, a progressive but limited cooling of ˜150°C is proposed since ˜2.5 Gyr for the Earth's ambient mantle, which falls in the lower limit proposed by Herzberg et al. [2010] (˜150-250°C hotter than today). Cooling of the ambient mantle after 2.5 Ga is preceded by a high-temperature plateau evolution and a transition from dominant plumes to a plate tectonics geodynamic regime, suggesting that subductions stabilized temperatures in the Archaean mantle that was in warming mode at that time.abstract type="synopsis">Plain Language SummaryThe Earth's upper mantle constitutes a major interface between inner and outer envelops of the planet. We explore at high resolution its thermal state evolution (potential temperature of the ambient mantle, Tp) in depth and time using a multi-dimensional database of mafic lavas chemistry (>22,000 samples formed in

  9. Impact of Atlantic sea surface temperatures on the warmest global surface air temperature of 1998

    Science.gov (United States)

    Lu, Riyu

    2005-03-01

    The year 1998 is the warmest year in the record of instrumental measurements. In this study, an atmospheric general circulation model is used to investigate the role of sea surface temperatures (SSTs) in this warmth, with a focus on the role of the Atlantic Ocean. The model forced with the observed global SSTs captures the main features of land surface air temperature anomalies in 1998. A sensitivity experiment shows that in comparison with the global SST anomalies, the Atlantic SST anomalies can explain 35% of the global mean surface air temperature (GMAT) anomaly, and 57% of the land surface air temperature anomaly in 1998. The mechanisms through which the Atlantic Ocean influences the GMAT are likely different from season to season. Possible detailed mechanisms involve the impact of SST anomalies on local convection in the tropical Atlantic region, the consequent excitation of a Rossby wave response that propagates into the North Atlantic and the Eurasian continent in winter and spring, and the consequent changes in tropical Walker circulation in summer and autumn that induce changes in convection over the tropical Pacific. This in turn affects climate in Asia and Australia. The important role of the Atlantic Ocean suggests that attention should be paid not only to the tropical Pacific Ocean, but also to the tropical Atlantic Ocean in understanding the GMAT variability and its predictability.

  10. The dependence of surface temperature on IGBTs load and ambient temperature

    Science.gov (United States)

    Alexander, Čaja; Marek, Patsch

    2015-05-01

    Currently, older power electronics and electrotechnics are improvement and at the same time developing new and more efficient devices. These devices produce in their activities a significant part of the heat which, if not effectively drained, causing damage to these elements. In this case, it is important to develop new and more efficient cooling system. The most widespread of modern methods of cooling is the cooling by heat pipe. This contribution is aimed at cooling the insulated-gate bipolar transistor (IGBT) elements by loop heat pipe (LHP). IGBTs are very prone to damage due to high temperatures, and therefore is the important that the surface temperature was below 100°C. It was therefore created a model that examined what impact of surface temperature on the IGBT element and heat removal at different load and constant ambient temperature.

  11. The dependence of surface temperature on IGBTs load and ambient temperature

    Directory of Open Access Journals (Sweden)

    Alexander Čaja

    2015-01-01

    Full Text Available Currently, older power electronics and electrotechnics are improvement and at the same time developing new and more efficient devices. These devices produce in their activities a significant part of the heat which, if not effectively drained, causing damage to these elements. In this case, it is important to develop new and more efficient cooling system. The most widespread of modern methods of cooling is the cooling by heat pipe. This contribution is aimed at cooling the insulated-gate bipolar transistor (IGBT elements by loop heat pipe (LHP. IGBTs are very prone to damage due to high temperatures, and therefore is the important that the surface temperature was below 100°C. It was therefore created a model that examined what impact of surface temperature on the IGBT element and heat removal at different load and constant ambient temperature.

  12. Use of satellite land surface temperatures in the EUSTACE global surface air temperature analysis

    Science.gov (United States)

    Ghent, D.; Good, E.; Rayner, N. A.

    2015-12-01

    EUSTACE (EU Surface Temperatures for All Corners of Earth) is a Horizon2020 project that will produce a spatially complete, near-surface air temperature (NSAT) analysis for the globe for every day since 1850. The analysis will be based on both satellite and in situ surface temperature observations over land, sea, ice and lakes, which will be combined using state-of-the-art statistical methods. The use of satellite data will enable the EUSTACE analysis to offer improved estimates of NSAT in regions that are poorly observed in situ, compared with existing in-situ based analyses. This presentation illustrates how satellite land surface temperature (LST) data - sourced from the European Space Agency (ESA) Data User Element (DUE) GlobTemperature project - will be used in EUSTACE. Satellite LSTs represent the temperature of the Earth's skin, which can differ from the corresponding NSAT by several degrees or more, particularly during the hottest part of the day. Therefore the first challenge is to develop an approach to estimate global NSAT from satellite observations. Two methods will be trialled in EUSTACE, both of which are summarised here: an established empirical regression-based approach for predicting NSAT from satellite data, and a new method whereby NSAT is calculated from LST and other parameters using a physics-based model. The second challenge is in estimating the uncertainties for the satellite NSAT estimates, which will determine how these data are used in the final blended satellite-in situ analysis. This is also important as a key component of EUSTACE is in delivering accurate uncertainty information to users. An overview of the methods to estimate the satellite NSATs is also included in this presentation.

  13. Piglets’ Surface Temperature Change at Different Weights at Birth

    Science.gov (United States)

    Caldara, Fabiana Ribeiro; dos Santos, Luan Sousa; Machado, Sivanilza Teixeira; Moi, Marta; de Alencar Nääs, Irenilza; Foppa, Luciana; Garcia, Rodrigo Garófallo; de Kássia Silva dos Santos, Rita

    2014-01-01

    The study was carried out in order to verify the effects of piglets’ weight at birth on their surface temperature change (ST) after birth, and its relationship with ingestion time of colostrum. Piglets from four different sows were weighed at birth and divided into a totally randomized design with three treatments according to birth weight (PBW): T1 - less than 1.00 kg, T2 - 1.00 to 1.39 kg, and T3 - higher than or equal to 1.40 kg. The time spent for the first colostrum ingestion was recorded (TFS). Images of piglets’ surface by thermal imaging camera were recorded at birth (STB) and 15, 30, 45, 60, and 120 min after birth. The air temperature and relative humidity were recorded every 30 min and the indexes of temperature and humidity (THI) were calculated. A ST drop after 15 min from birth was observed, increasing again after sixty minutes. Positive correlations were found between the PBW and the ST at 30 and 45 min after birth. The PBW was negatively correlated with the TFS. The THI showed high negative correlations (−0.824 and −0.815) with STB and after 15 min from birth. The piglet’s surface temperature at birth was positively correlated with temperature thereof to 15 min, influencing therefore the temperatures in the interval of 45 to 120 min. The birth weight contributes significantly to postnatal hypothermia and consequently to the time it takes for piglets ingest colostrum, requiring special attention to those of low birth weight. PMID:25049971

  14. Piglets' surface temperature change at different weights at birth.

    Science.gov (United States)

    Caldara, Fabiana Ribeiro; Dos Santos, Luan Sousa; Machado, Sivanilza Teixeira; Moi, Marta; de Alencar Nääs, Irenilza; Foppa, Luciana; Garcia, Rodrigo Garófallo; de Kássia Silva Dos Santos, Rita

    2014-03-01

    The study was carried out in order to verify the effects of piglets' weight at birth on their surface temperature change (ST) after birth, and its relationship with ingestion time of colostrum. Piglets from four different sows were weighed at birth and divided into a totally randomized design with three treatments according to birth weight (PBW): T1 - less than 1.00 kg, T2 - 1.00 to 1.39 kg, and T3 - higher than or equal to 1.40 kg. The time spent for the first colostrum ingestion was recorded (TFS). Images of piglets' surface by thermal imaging camera were recorded at birth (STB) and 15, 30, 45, 60, and 120 min after birth. The air temperature and relative humidity were recorded every 30 min and the indexes of temperature and humidity (THI) were calculated. A ST drop after 15 min from birth was observed, increasing again after sixty minutes. Positive correlations were found between the PBW and the ST at 30 and 45 min after birth. The PBW was negatively correlated with the TFS. The THI showed high negative correlations (-0.824 and -0.815) with STB and after 15 min from birth. The piglet's surface temperature at birth was positively correlated with temperature thereof to 15 min, influencing therefore the temperatures in the interval of 45 to 120 min. The birth weight contributes significantly to postnatal hypothermia and consequently to the time it takes for piglets ingest colostrum, requiring special attention to those of low birth weight.

  15. Piglets’ Surface Temperature Change at Different Weights at Birth

    Directory of Open Access Journals (Sweden)

    Fabiana Ribeiro Caldara

    2014-03-01

    Full Text Available The study was carried out in order to verify the effects of piglets’ weight at birth on their surface temperature change (ST after birth, and its relationship with ingestion time of colostrum. Piglets from four different sows were weighed at birth and divided into a totally randomized design with three treatments according to birth weight (PBW: T1 - less than 1.00 kg, T2 - 1.00 to 1.39 kg, and T3 - higher than or equal to 1.40 kg. The time spent for the first colostrum ingestion was recorded (TFS. Images of piglets’ surface by thermal imaging camera were recorded at birth (STB and 15, 30, 45, 60, and 120 min after birth. The air temperature and relative humidity were recorded every 30 min and the indexes of temperature and humidity (THI were calculated. A ST drop after 15 min from birth was observed, increasing again after sixty minutes. Positive correlations were found between the PBW and the ST at 30 and 45 min after birth. The PBW was negatively correlated with the TFS. The THI showed high negative correlations (−0.824 and −0.815 with STB and after 15 min from birth. The piglet’s surface temperature at birth was positively correlated with temperature thereof to 15 min, influencing therefore the temperatures in the interval of 45 to 120 min. The birth weight contributes significantly to postnatal hypothermia and consequently to the time it takes for piglets ingest colostrum, requiring special attention to those of low birth weight.

  16. A model of the tropical Pacific sea surface temperature climatology

    Science.gov (United States)

    Seager, Richard; Zebiak, Stephen E.; Cane, Mark A.

    1988-01-01

    A model for the climatological mean sea surface temperature (SST) of the tropical Pacific Ocean is developed. The upper ocean response is computed using a time dependent, linear, reduced gravity model, with the addition of a constant depth frictional surface layer. The full three-dimensional temperature equation and a surface heat flux parameterization that requires specification of only wind speed and total cloud cover are used to evaluate the SST. Specification of atmospheric parameters, such as air temperature and humidity, over which the ocean has direct influence, is avoided. The model simulates the major features of the observed tropical Pacific SST. The seasonal evolution of these features is generally captured by the model. Analysis of the results demonstrates the control the ocean has over the surface heat flux from ocean to atmosphere and the crucial role that dynamics play in determining the mean SST in the equatorial Pacific. The sensitivity of the model to perturbations in the surface heat flux, cloud cover specification, diffusivity, and mixed layer depth is discussed.

  17. Temperature dependence of exciton-surface plasmon polariton coupling in Ag, Au, and Al films on In{sub x}Ga{sub 1−x}N/GaN quantum wells studied with time-resolved cathodoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Estrin, Y.; Rich, D. H., E-mail: danrich@bgu.ac.il [Department of Physics and The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, P.O.B 653, Beer-Sheva 84105 (Israel); Keller, S.; DenBaars, S. P. [Electrical and Computer Engineering and Materials Departments, University of California, Santa Barbara, California 93111 (United States)

    2015-01-28

    The optical properties and coupling of excitons to surface plasmon polaritons (SPPs) in Ag, Au, and Al-coated In{sub x}Ga{sub 1−x}N/GaN multiple and single quantum wells (SQWs) were probed with time-resolved cathodoluminescence. Excitons were generated in the metal coated SQWs by injecting a pulsed high-energy electron beam through the thin metal films. The Purcell enhancement factor (F{sub p}) was obtained by direct measurement of changes in the temperature-dependent radiative lifetime caused by the SQW exciton-SPP coupling. Three chosen plasmonic metals of Al, Ag, and Au facilitate an interesting comparison of the exciton-SPP coupling for energy ranges in which the SP energy is greater than, approximately equal to, and less than the excitonic transition energy for the InGaN/GaN QW emitter. A modeling of the temperature dependence of the Purcell enhancement factor, F{sub p}, included the effects of ohmic losses of the metals and changes in the dielectric properties due to the temperature dependence of (i) the intraband behavior in the Drude model and (ii) the interband critical point transition energies which involve the d-bands of Au and Ag. We show that an inclusion of both intraband and interband effects is essential when calculating the ω vs k SPP dispersion relation, plasmon density of states (DOS), and the dependence of F{sub p} on frequency and temperature. Moreover, the “back bending” in the SPP dispersion relation when including ohmic losses can cause a finite DOS above ω{sub sp} and lead to a measurable F{sub p} in a limited energy range above ω{sub sp}, which can potentially be exploited in plasmonic devices utilizing Ag and Au.

  18. Statistics of particle time-temperature histories.

    Energy Technology Data Exchange (ETDEWEB)

    Hewson, John C.; Lignell, David O.; Sun, Guangyuan

    2014-10-01

    Particles in non - isothermal turbulent flow are subject to a stochastic environment tha t produces a distribution of particle time - temperature histories. This distribution is a function of the dispersion of the non - isothermal (continuous) gas phase and the distribution of particles relative to that gas phase. In this work we extend the one - dimensional turbulence (ODT) model to predict the joint dispersion of a dispersed particle phase and a continuous phase. The ODT model predicts the turbulent evolution of continuous scalar fields with a model for the cascade of fluctuations to smaller sc ales (the 'triplet map') at a rate that is a function of the fully resolved one - dimens ional velocity field . Stochastic triplet maps also drive Lagrangian particle dispersion with finite Stokes number s including inertial and eddy trajectory - crossing effect s included. Two distinct approaches to this coupling between triplet maps and particle dispersion are developed and implemented along with a hybrid approach. An 'instantaneous' particle displacement model matches the tracer particle limit and provide s an accurate description of particle dispersion. A 'continuous' particle displacement m odel translates triplet maps into a continuous velocity field to which particles respond. Particles can alter the turbulence, and modifications to the stochastic rate expr ession are developed for two - way coupling between particles and the continuous phase. Each aspect of model development is evaluated in canonical flows (homogeneous turbulence, free - shear flows and wall - bounded flows) for which quality measurements are ava ilable. ODT simulations of non - isothermal flows provide statistics for particle heating. These simulations show the significance of accurately predicting the joint statistics of particle and fluid dispersion . Inhomogeneous turbulence coupled with the in fluence of the mean flow fields on particles of varying properties

  19. Monitoring temperature and pressure over surfaces using sensitive paints

    Science.gov (United States)

    Guerrero-Viramontes, J. Ascención; Moreno Hernández, David; Mendoza Santoyo, Fernando; Morán Loza, José Miguel; García Arreola, Alicia

    2007-03-01

    Two techniques for monitoring temperature and pressure variations over surfaces using sensitive paints are presented. The analysis is done by the acquisition of a set of images of the surface under analysis. The surface is painted by a paint called Pressure Sensitive Paint (PSP) for pressure measurements and Temperature Sensitive Paints (TSP) for temperature measurements. These kinds of paints are deposited over the surface under analysis. The recent experimental advances in calibration process are presented in this paper.

  20. Low temperature rate coefficients of the H + CH{sup +} → C{sup +} + H{sub 2} reaction: New potential energy surface and time-independent quantum scattering

    Energy Technology Data Exchange (ETDEWEB)

    Werfelli, Ghofran [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence Cedex (France); Faculté des Sciences de Tunis, Université de Tunis El-Manar, Laboratoire de Physique de la Matière Condensée, 2092 Tunis (Tunisia); Halvick, Philippe; Stoecklin, Thierry [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence Cedex (France); Honvault, Pascal [Université de Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, CNRS UMR 6303, 21078 Dijon Cedex (France); Université de Franche-Comté, UFR ST, 25030 Besançon Cedex (France); Kerkeni, Boutheïna [Faculté des Sciences de Tunis, Université de Tunis El-Manar, Laboratoire de Physique de la Matière Condensée, 2092 Tunis (Tunisia); Institut Supérieur des Arts Multimédia de la Manouba, Université de la Manouba, 2010 la Manouba (Tunisia)

    2015-09-21

    The observed abundances of the methylidyne cation, CH{sup +}, in diffuse molecular clouds can be two orders of magnitude higher than the prediction of the standard gas-phase models which, in turn, predict rather well the abundances of neutral CH. It is therefore necessary to investigate all the possible formation and destruction processes of CH{sup +} in the interstellar medium with the most abundant species H, H{sub 2}, and e{sup −}. In this work, we address the destruction process of CH{sup +} by hydrogen abstraction. We report a new calculation of the low temperature rate coefficients for the abstraction reaction, using accurate time-independent quantum scattering and a new high-level ab initio global potential energy surface including a realistic model of the long-range interaction between the reactants H and CH{sup +}. The calculated thermal rate coefficient is in good agreement with the experimental data in the range 50 K–800 K. However, at lower temperatures, the experimental rate coefficient takes exceedingly small values which are not reproduced by the calculated rate coefficient. Instead, the latter rate coefficient is close to the one given by the Langevin capture model, as expected for a reaction involving an ion and a neutral species. Several recent theoretical works have reported a seemingly good agreement with the experiment below 50 K, but an analysis of these works show that they are based on potential energy surfaces with incorrect long-range behavior. The experimental results were explained by a loss of reactivity of the lowest rotational states of the reactant; however, the quantum scattering calculations show the opposite, namely, a reactivity enhancement with rotational excitation.

  1. Dynamic behavior of a vibrated droplet on a low-temperature micropillared surface

    Science.gov (United States)

    Tan, Chen-chuan; Jia, Zhi-hai; Yang, Hui-nan; Zhang, Zhi-tao

    2017-02-01

    The dynamic behavior of a vibrated droplet on a micropillared hydrophobic surface under low temperature was investigated in this paper. It was observed that solidified time of droplets on the micropillared surface were much larger than on the smooth surface due to the existence of wetting transition at low temperature, without vibration. The solidified time of droplets was longer while vibration was exerted on the surfaces, even though the wetting transition time of droplets at low temperature was shorter than at room temperature. It was found that resonance frequency of droplet increased as surface tension increased due to low temperature. Moreover, when a droplet was in its resonance frequency, the wetting area between the droplet and the micropillared surface increased obviously and its solidified time decreased substantially, and it led to the decline of anti-icing performance. This work is helpful to design a more efficient anti-icing device.

  2. Change point detection of the Persian Gulf sea surface temperature

    Science.gov (United States)

    Shirvani, A.

    2017-01-01

    In this study, the Student's t parametric and Mann-Whitney nonparametric change point models (CPMs) were applied to detect change point in the annual Persian Gulf sea surface temperature anomalies (PGSSTA) time series for the period 1951-2013. The PGSSTA time series, which were serially correlated, were transformed to produce an uncorrelated pre-whitened time series. The pre-whitened PGSSTA time series were utilized as the input file of change point models. Both the applied parametric and nonparametric CPMs estimated the change point in the PGSSTA in 1992. The PGSSTA follow the normal distribution up to 1992 and thereafter, but with a different mean value after year 1992. The estimated slope of linear trend in PGSSTA time series for the period 1951-1992 was negative; however, that was positive after the detected change point. Unlike the PGSSTA, the applied CPMs suggested no change point in the Niño3.4SSTA time series.

  3. Surface layer temperature inversion in the Bay of Bengal

    Science.gov (United States)

    Thadathil, Pankajakshan; Gopalakrishna, V. V.; Muraleedharan, P. M.; Reddy, G. V.; Araligidad, Nilesh; Shenoy, Shrikant

    2002-10-01

    Surface layer temperature inversion occurring in the Bay of Bengal has been addressed. Hydrographic data archived in the Indian Oceanographic Data Center are used to understand various aspects of the temperature inversion of surface layer in the Bay of Bengal, such as occurrence time, characteristics, stability, inter-annual variability and generating mechanisms. Spatially organized temperature inversion occurs in the coastal waters of the western and northeastern Bay during winter (November-February). Although the inversion in the northeastern Bay is sustained until February (with remnants seen even in March), in the western Bay it becomes less organized in January and almost disappears by February. Inversion is confined to the fresh water induced seasonal halocline of the surface layer. Inversions of large temperature difference (of the order of 1.6-2.4°C) and thin layer thickness (10-20 m) are located adjacent to major fresh water inputs from the Ganges, Brahmaputra, Irrawaddy, Krishna and Godavari rivers. The inversion is stable with a mean stability of 3600×10 -8 m -1. Inter-annual variability of the inversion is significantly high and it is caused by the inter-annual variability of fresh water flux and surface cooling in the northern Bay. Fresh water flux leads the occurrence process in association with surface heat flux and advection. The leading role of fresh water flux is understood from the observation that the two occurrence regions of inversion (the western and northeastern Bay) have proximity to the two low salinity (with values about 28-29‰) zones. In the western Bay, the East India Coastal Current brings less saline and cold water from the head of the Bay to the south-west Bay, where it advects over warm, saline water, promoting temperature inversion in this region in association with the surface heat loss. For inversion occurring in the northeastern Bay (where the surface water gains heat from atmosphere), surface advection of the less saline

  4. Estimating Temperature Fields from MODIS Land Surface Temperature and Air Temperature Observations in a Sub-Arctic Alpine Environment

    Directory of Open Access Journals (Sweden)

    Scott N. Williamson

    2014-01-01

    Full Text Available Spatially continuous satellite infrared temperature measurements are essential for understanding the consequences and drivers of change, at local and regional scales, especially in northern and alpine environments dominated by a complex cryosphere where in situ observations are scarce. We describe two methods for producing daily temperature fields using MODIS “clear-sky” day-time Land Surface Temperatures (LST. The Interpolated Curve Mean Daily Surface Temperature (ICM method, interpolates single daytime Terra LST values to daily means using the coincident diurnal air temperature curves. The second method calculates daily mean LST from daily maximum and minimum LST (MMM values from MODIS Aqua and Terra. These ICM and MMM models were compared to daily mean air temperatures recorded between April and October at seven locations in southwest Yukon, Canada, covering characteristic alpine land cover types (tundra, barren, glacier at elevations between 1,408 m and 2,319 m. Both methods for producing mean daily surface temperatures have advantages and disadvantages. ICM signals are strongly correlated with air temperature (R2 = 0.72 to 0.86, but have relatively large variability (RMSE = 4.09 to 4.90 K, while MMM values had a stronger correlation to air temperature (R2 = 0.90 and smaller variability (RMSE = 2.67 K. Finally, when comparing 8-day LST averages, aggregated from the MMM method, to air temperature, we found a high correlation (R2 = 0.84 with less variability (RMSE = 1.54 K. Where the trend was less steep and the y-intercept increased by 1.6 °C compared to the daily correlations. This effect is likely a consequence of LST temperature averages being differentially affected by cloud cover over warm and cold surfaces. We conclude that satellite infrared skin temperature (e.g., MODIS LST, which is often aggregated into multi-day composites to mitigate data reductions caused by cloud cover, changes in its relationship to air temperature

  5. Estimation of sea surface temperature (SST) using marine seismic data

    Digital Repository Service at National Institute of Oceanography (India)

    Sinha, S.K.; Dewangan, P.; Sain, K.

    .g. Wu et al. [1999]). However, due to the skin effect, sea surface temperatures as measured by satellites can be very different from temperatures a few centimeters below the sea surface (i.e. in-situ temperatures) [Emery et al., 1994]. Therefore...

  6. Noncontact Monitoring of Surface Temperature Distribution by Laser Ultrasound Scanning

    Science.gov (United States)

    Yamada, Hiroyuki; Kosugi, Akira; Ihara, Ikuo

    2011-07-01

    A laser ultrasound scanning method for measuring a surface temperature distribution of a heated material is presented. An experiment using an aluminum plate heated up to 120 °C is carried out to verify the feasibility of the proposed method. A series of one-dimensional surface acoustic wave (SAW) measurements within an area of a square on the aluminum surface are performed by scanning a pulsed laser for generating SAW using a galvanometer system, where the SAWs are detected at a fixed location on the surface. An inverse analysis is then applied to SAW data to determine the surface temperature distribution in a certain direction. The two-dimensional distribution of the surface temperature in the square is constructed by combining the one-dimensional surface temperature distributions obtained within the square. The surface temperature distributions obtained by the proposed method almost agrees with those obtained using an infrared radiation camera.

  7. Global Surface Temperature Response Explained by Multibox Energy Balance Models

    Science.gov (United States)

    Fredriksen, H. B.; Rypdal, M.

    2016-12-01

    We formulate a multibox energy balance model, from which global temperature evolution can be described by convolving a linear response function and a forcing record. We estimate parameters in the response function from instrumental data and historic forcing, such that our model can produce a response to both deterministic forcing and stochastic weather forcing consistent with observations. Furthermore, if we make separate boxes for upper ocean layer and atmosphere over land, we can also make separate response functions for global land and sea surface temperature. By describing internal variability as a linear response to white noise, we demonstrate that the power-law form of the observed temperature spectra can be described by linear dynamics, contrary to a common belief that these power-law spectra must arise from nonlinear processes. In our multibox model, the power-law form can arise due to the multiple response times. While one of our main points is that the climate system responds over a wide range of time scales, we cannot find one set of time scales that can be preferred compared to other choices. Hence we think the temperature response can best be characterized as something that is scale-free, but still possible to approximate by a set of well separated time scales.

  8. 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.

  9. A New Estimate of the Earth's Land Surface Temperature History

    Science.gov (United States)

    Muller, R. A.; Curry, J. A.; Groom, D.; Jacobsen, B.; Perlmutter, S.; Rohde, R. A.; Rosenfeld, A.; Wickham, C.; Wurtele, J.

    2011-12-01

    The Berkeley Earth Surface Temperature team has re-evaluated the world's atmospheric land surface temperature record using a linear least-squares method that allow the use of all the digitized records back to 1800, including short records that had been excluded by prior groups. We use the Kriging method to estimate an optimal weighting of stations to give a world average based on uniform weighting of the land surface. We have assembled a record of the available data by merging 1.6 billion temperature reports from 16 pre-existing data archives; this data base will be made available for public use. The former Global Historic Climatology Network (GHCN) monthly data base shows a sudden drop in the number of stations reporting monthly records from 1980 to the present; we avoid this drop by calculating monthly averages from the daily records. By using all the data, we reduce the effects of potential data selection bias. We make an independent estimate of the urban heat island effect by calculating the world land temperature trends based on stations chosen to be far from urban sites. We calculate the effect of poor station quality, as documented in the US by the team led by Anthony Watts by estimating the temperature trends based solely on the stations ranked good (1,2 or 1,2,3 in the NOAA ranking scheme). We avoid issues of homogenization bias by using raw data; at times when the records are discontinuous (e.g. due to station moves) we break the record into smaller segments and analyze those, rather than attempt to correct the discontinuity. We estimate the uncertainties in the final results using the jackknife procedure developed by J. Tukey. We calculate spatial uncertainties by measuring the effects of geographical exclusion on recent data that have good world coverage. The results we obtain are compared to those published by the groups at NOAA, NASA-GISS, and Hadley-CRU in the UK.

  10. Temperature dependent droplet impact dynamics on flat and textured surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Azar Alizadeh; Vaibhav Bahadur; Sheng Zhong; Wen Shang; Ri Li; James Ruud; Masako Yamada; Liehi Ge; Ali Dhinojwala; Manohar S Sohal (047160)

    2012-03-01

    Droplet impact dynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling and heat transfer. We study impact dynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Droplet retraction shows very strong temperature dependence especially for hydrophilic surfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures can explain the decreased retraction. The present findings serve to guide further studies of dynamic fluid-structure interaction at various temperatures.

  11. A Method to Determine the Mean Temperature at the Planet Surface

    Institute of Scientific and Technical Information of China (English)

    GAOChong-Yi

    2003-01-01

    The escape time of a given species of partlcles in the planetary atmosphere is related to atmospheric temperature. The mean temperature at the planet surface may be inferred from the escape of a given kind of particles in the planetary atmosphere. For example, CH4 escaping from the Pluto atmosphere results in the variation of its partial pressure and escape time, then the mean temperature at the Pluto surface, 42.2 K, is got on the barns of it.

  12. 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

  13. Estimation of Surface Heat Flux and Surface Temperature during Inverse Heat Conduction under Varying Spray Parameters and Sample Initial Temperature

    Directory of Open Access Journals (Sweden)

    Muhammad Aamir

    2014-01-01

    Full Text Available An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck’s sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa.

  14. Estimation of surface heat flux and surface temperature during inverse heat conduction under varying spray parameters and sample initial temperature.

    Science.gov (United States)

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong; Zubair, Muhammad

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m(2) was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa.

  15. Predicting monsoon rainfall and pressure indices from sea surface temperature

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.

    The relationship between the sea surface temperature (SST) in the Indian Ocean and monsoon rainfall has been examined by using 21 years data set (1967-87) of MOHSST.6 (Met. Office Historical Sea Surface Temperature data set, obtained from U.K. Met...

  16. Metal surface temperature induced by moving laser beams

    NARCIS (Netherlands)

    Römer, G.R.B.E.; Meijer, J.

    1995-01-01

    Whenever a metal is irradiated with a laser beam, electromagnetic energy is transformed into heat in a thin surface layer. The maximum surface temperature is the most important quantity which determines the processing result. Expressions for this maximum temperature are provided by the literature fo

  17. Recent trends in sea surface temperature off Mexico

    NARCIS (Netherlands)

    Lluch-Cota, S.E.; Tripp-Valdéz, M.; Lluch-Cota, D.B.; Lluch-Belda, D.; Verbesselt, J.; Herrera-Cervantes, H.; Bautista-Romero, J.

    2013-01-01

    Changes in global mean sea surface temperature may have potential negative implications for natural and socioeconomic systems; however, measurements to predict trends in different regions have been limited and sometimes contradictory. In this study, an assessment of sea surface temperature change si

  18. Recent trends in sea surface temperature off Mexico

    NARCIS (Netherlands)

    Lluch-Cota, S.E.; Tripp-Valdéz, M.; Lluch-Cota, D.B.; Lluch-Belda, D.; Verbesselt, J.; Herrera-Cervantes, H.; Bautista-Romero, J.

    2013-01-01

    Changes in global mean sea surface temperature may have potential negative implications for natural and socioeconomic systems; however, measurements to predict trends in different regions have been limited and sometimes contradictory. In this study, an assessment of sea surface temperature change

  19. Reintroducing radiometric surface temperature into the Penman-Monteith formulation

    DEFF Research Database (Denmark)

    Mallick, Kaniska; Bøgh, Eva; Trebs, Ivonne;

    2015-01-01

    Here we demonstrate a novel method to physically integrate radiometric surface temperature (TR) into the Penman-Monteith (PM) formulation for estimating the terrestrial sensible and latent heat fluxes (H and λE) in the framework of a modified Surface Temperature Initiated Closure (STIC). It combi...

  20. Interferometric measurements of sea surface temperature and emissivity

    Science.gov (United States)

    Fiedler, Lars; Bakan, Stephan

    1997-09-01

    A new multispectral method to derive sea surface emissivity and temperature by using interferometer measurements of the near surface upwelling radiation in the infrared window region is presented. As reflected sky radiation adds substantial spectral variability to the otherwise spectrally smooth surface radiation, an appropriate estimate of surface emissivity allows the measured upwelling radiation to be corrected for the reflected sky component. The remaining radiation, together with the estimated surface emissivity, yields an estimate of the sea surface temperature. Measurements from an ocean pier in the Baltic Sea in October 1995 indicate an accuracy of about 0.1 K for the sea surface temperature thus derived. A strong sea surface skin effect of about 0.6 K is found in that particular case.

  1. Age-surface temperature estimation model: When will oil palm plantation reach the same surface temperature as natural forest?

    Science.gov (United States)

    Rushayati, S. B.; Hermawan, R.; Meilani, R.

    2017-01-01

    Oil palm plantation has often been accused as the cause of global warming. However, along with its growth, it would be able to decrease surface temperature. The question is ‘when will the plantation be able to reach the same surface temperature as natural forest’. This research aimed to estimate the age of oil palm plantation that create similar surface temperature to those in natural forest (land cover before the opening and planting of oil palm). The method used in this research was spatial analysis of land cover and surface temperature distribution. Based on the spatial analysis of surface temperature, five points was randomly taken from each planting age (age 1 15 years). Linear regression was then employed in the analysis. The linear regression formula between surface temperature and age of oil palm plantation was Y = 26.002 – 0.1237X. Surface temperature will decrease as much as 0.1237 ° C with one year age growth oil palm. Surface temperature that was similar to the initial temperature, when the land cover was natural forest (23.04 °C), was estimated to occur when the oil palm plantation reach the age 24 year.

  2. Decadal trends in Red Sea maximum surface temperature

    KAUST Repository

    Chaidez, Veronica

    2017-08-09

    Ocean warming is a major consequence of climate change, with the surface of the ocean having warmed by 0.11 °C decade-1 over the last 50 years and is estimated to continue to warm by an additional 0.6 - 2.0 °C before the end of the century1. However, there is considerable variability in the rates experienced by different ocean regions, so understanding regional trends is important to inform on possible stresses for marine organisms, particularly in warm seas where organisms may be already operating in the high end of their thermal tolerance. Although the Red Sea is one of the warmest ecosystems on earth, its historical warming trends and thermal evolution remain largely understudied. We characterized the Red Sea\\'s thermal regimes at the basin scale, with a focus on the spatial distribution and changes over time of sea surface temperature maxima, using remotely sensed sea surface temperature data from 1982 - 2015. The overall rate of warming for the Red Sea is 0.17 ± 0.07 °C decade-1, while the northern Red Sea is warming between 0.40 and 0.45 °C decade-1, all exceeding the global rate. Our findings show that the Red Sea is fast warming, which may in the future challenge its organisms and communities.

  3. Statistics of particle time-temperature histories :

    Energy Technology Data Exchange (ETDEWEB)

    Hewson, John C.; Gin, Craig; Lignell, David O.; Sun, Guangyuan

    2013-10-01

    Progress toward predictions of the statistics of particle time-temperature histories is presented. These predictions are to be made using Lagrangian particle models within the one-dimensional turbulence (ODT) model. In the present reporting period we have further characterized the performance, behavior and capabilities of the particle dispersion models that were added to the ODT model in the first period. We have also extended the capabilities in two manners. First we provide alternate implementations of the particle transport process within ODT; within this context the original implementation is referred to as the type-I and the new implementations are referred to as the type-C and type-IC interactions. Second we have developed and implemented models for two-way coupling between the particle and fluid phase. This allows us to predict the reduced rate of turbulent mixing associated with particle dissipation of energy and similar phenomena. Work in characterizing these capabilities has taken place in homogeneous decaying turbulence, in free shear layers, in jets and in channel flow with walls, and selected results are presented.

  4. Climate change impact of livestock CH4 emission in India: Global temperature change potential (GTP) and surface temperature response.

    Science.gov (United States)

    Kumari, Shilpi; Hiloidhari, Moonmoon; Kumari, Nisha; Naik, S N; Dahiya, R P

    2017-09-12

    Two climate metrics, Global surface Temperature Change Potential (GTP) and the Absolute GTP (AGTP) are used for studying the global surface temperature impact of CH4 emission from livestock in India. The impact on global surface temperature is estimated for 20 and 100 year time frames due to CH4 emission. The results show that the CH4 emission from livestock, worked out to 15.3 Tg in 2012. In terms of climate metrics GTP of livestock-related CH4 emission in India in 2012 were 1030 Tg CO2e (GTP20) and 62 Tg CO2e (GTP100) at the 20 and 100 year time horizon, respectively. The study also illustrates that livestock-related CH4 emissions in India can cause a surface temperature increase of up to 0.7mK and 0.036mK over the 20 and 100 year time periods, respectively. The surface temperature response to a year of Indian livestock emission peaks at 0.9mK in the year 2021 (9 years after the time of emission). The AGTP gives important information in terms of temperature change due to annual CH4 emissions, which is useful when comparing policies that address multiple gases. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Temperature Calculation in Respect of Basic Elements of Power Oil Transformer on the Basis of Its Tank Surface Temperature Analysis

    Directory of Open Access Journals (Sweden)

    D. Zalizny

    2012-01-01

    Full Text Available The paper proposes a real-time calculation algorithm of oil, winding and magnetic core temperature of power transformer on the basis of measured values of tank surface temperature and air temperature without measuring current. The algorithm is based on the calculation of the equivalent load factor of the transformer. Imitation simulation has confirmed efficiency of the algorithm. After tests on functioning transformers the algorithm can be used in thermal protection devices and diagnostic devices for power oil transformers.

  6. Spatial patterns in timing of the diurnal temperature cycle

    Directory of Open Access Journals (Sweden)

    T. R. H. Holmes

    2013-05-01

    Full Text Available This paper investigates the structural difference in timing of the diurnal temperature cycle (DTC over land resulting from choice of measuring device or model framework. It is shown that the timing can be reliably estimated from temporally sparse observations acquired from a constellation of low Earth orbiting satellites given record lengths of at least three months. Based on a year of data, the spatial patterns of mean DTC timing are compared between Ka-band temperature estimates, geostationary thermal infrared (TIR temperature estimates and numerical weather prediction model output from the Global Modeling and Assimilation Office (GMAO. It is found that the spatial patterns can be explained by vegetation effects, sensing depth differences and more speculatively the orientation of orographic relief features. In absolute terms, the GMAO model puts the peak of the DTC on average at 12:50 local solar time, 23 min before TIR with a peak temperature at 13:13. Since TIR is the shallowest observation of the land surface, this small difference represents a structural error that possibly affects the models ability to assimilate observations that are closely tied to the DTC. For non-desert areas, the Ka-band observations have only a small delay of about 15 min with the TIR observations which is in agreement with their respective theoretical sensing depth. The results of this comparison provide insights into the structural differences between temperature measurements and models, and can be used as a first step to account for these differences in a coherent way.

  7. Evaluation of MODIS Land Surface Temperature with In Situ Snow Surface Temperature from CREST-SAFE

    Science.gov (United States)

    Perez Diaz, C. L.; Lakhankar, T.; Romanov, P.; Munoz, J.; Khanbilvardi, R.; Yu, Y.

    2016-12-01

    This paper presents the procedure and results of a temperature-based validation approach for the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) product provided by the National Aeronautics and Space Administration (NASA) Terra and Aqua Earth Observing System satellites using in situ LST observations recorded at the Cooperative Remote Sensing Science and Technology Center - Snow Analysis and Field Experiment (CREST-SAFE) during the years of 2013 (January-April) and 2014 (February-April). A total of 314 day and night clear-sky thermal images, acquired by the Terra and Aqua satellites, were processed and compared to ground-truth data from CREST-SAFE with a frequency of one measurement every 3 min. Additionally, this investigation incorporated supplementary analyses using meteorological CREST-SAFE in situ variables (i.e. wind speed, cloud cover, incoming solar radiation) to study their effects on in situ snow surface temperature (T-skin) and T-air. Furthermore, a single pixel (1km2) and several spatially averaged pixels were used for satellite LST validation by increasing the MODIS window size to 5x5, 9x9, and 25x25 windows for comparison. Several trends in the MODIS LST data were observed, including the underestimation of daytime values and nighttime values. Results indicate that, although all the data sets (Terra and Aqua, diurnal and nocturnal) showed high correlation with ground measurements, day values yielded slightly higher accuracy ( 1°C), both suggesting that MODIS LST retrievals are reliable for similar land cover classes and atmospheric conditions. Results from the CREST-SAFE in situ variables' analyses indicate that T-air is commonly higher than T-skin, and that a lack of cloud cover results in: lower T-skin and higher T-air minus T-skin difference (T-diff). Additionally, the study revealed that T-diff is inversely proportional to cloud cover, wind speed, and incoming solar radiation. Increasing the MODIS window size

  8. Estimation of minimum surface temperature at stage ll (Short Communication

    Directory of Open Access Journals (Sweden)

    A. P. Dimri

    2001-04-01

    Full Text Available Forecasting minimum surface temperature at a station, Stage II, located in mountainous region requires information on the meteorological fields. An attempt has been made to develop a statistical model for forecasting minimum temperature at ground level using previous years' data. Surface data were collected at StageII (longitude 73 oB, latitude 34 oN, and altitude 2650 m. Atmospheric variables are influenced by complex orography and surface features to a great extent. In the present study, statistical relationship between atmosphere parameters and minimum temperature at the site has been established. Multivariate linear regression analysis has been used to establish the relationship to predict the minimum surface temperature for the following day. A comparison between the observed and the calculated forecast minimum temperature has been made. Most of the cases are well predicted (multiple correlation coefficient of 0.94.

  9. Organic Materials for Time-Temperature Integrator Devices.

    Science.gov (United States)

    Cavallini, Massimiliano; Melucci, Manuela

    2015-08-12

    Time-temperature integrators (TTIs) are devices capable of recording the thermal history of a system. They have an enormous impact in the food and pharmaceutical industries. TTIs exploit several irreversible thermally activated transitions such as recrystallization, dewetting, smoothening, chemical decomposition, and polymorphic transitions, usually considered drawbacks for many technological applications. The aim of this article is to sensitize research groups working in organic synthesis and surface science toward TTI devices, enlarging the prospects of many new materials. We reviewed the principal applications highlighting the need and criticisms of TTIs, which offer a new opportunity for the development of many materials.

  10. In situ monitoring of internal surface temperature of the historic building envelope

    Science.gov (United States)

    Labovská, Veronika; Katunský, Dušan

    2016-06-01

    Historical building envelope is characterized by a large accumulation that impact is mainly by changing the inner surface temperature over time. The minimum value of the inner surface temperature is set Code requirements. In the case of thermal technology assessment of building envelope contemplates a steady state external temperature and internal environment, thereby neglecting the heat accumulation capacity of building envelopes. Monitoring surface temperature in real terms in situ shows the real behavior of the building envelope close to reality. The recorded data can be used to create a numerical model for the simulation.

  11. Detecting climate rationality and homogeneities of sea surface temperature data in Longkou marine station using surface air temperature

    Science.gov (United States)

    Li, Yan; Li, Huan; Wang, Qingyuan; Wang, Guosong; Fan, Wenjing

    2017-08-01

    This study presents a systematic evaluation of the climate rationality and homogeneity of monthly sea surface temperature (SST) in Longkou marine station from 1960 to 2011. The reference series are developed using adjacent surface air temperature (SAT) on a monthly timescale. The results suggest SAT as a viable option for use in evaluating climate rationality and homogeneity in the SST data on the coastal China Seas. According to the large-scale atmospheric circulation patterns and SAT of the adjacent meteorological stations, we confirm that there is no climate shift in 1972/1973 and then the climate shift in 1972/1973 is corrected. Besides, the SST time series has serious problems of inhomogeneity. Three documented break points have been checked using penalized maximum T (PMT) test and metadata. The changes in observation instruments and observation system are the main causes of the break points. For the monthly SST time series, the negative adjustments may be greatly due to the SST decreasing after automation. It is found that the increasing trend of annual mean SST after adjustment is higher than before, about 0.24 °C/10 yr.

  12. Investigat ing the effect of surface water – groundwater interactions on stream temperature using D istributed Temperature Sensing and instream temperature model

    DEFF Research Database (Denmark)

    Matheswaran, K.; Blemmer, M.; Mortensen, J.

    2011-01-01

    Surface water–groundwater interactions at the stream interface influences, and at times controls the stream temperature, a critical water property driving biogeochemical processes. This study investigates the effects of these interactions on temperature of Stream Elverdamsåen in Denmark using the...

  13. Investigat ing the effect of surface water – groundwater interactions on stream temperature using D istributed Temperature Sensing and instream temperature model

    DEFF Research Database (Denmark)

    Matheswaran, K.; Blemmer, M.; Mortensen, J.;

    2011-01-01

    Surface water–groundwater interactions at the stream interface influences, and at times controls the stream temperature, a critical water property driving biogeochemical processes. This study investigates the effects of these interactions on temperature of Stream Elverdamsåen in Denmark using the...

  14. Climate Prediction Center (CPC) Global Temperature Time Series

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The global temperature time series provides time series charts using station based observations of daily temperature. These charts provide information about the...

  15. Ground-based measurement of surface temperature and thermal emissivity

    Science.gov (United States)

    Owe, M.; Van De Griend, A. A.

    1994-01-01

    Motorized cable systems for transporting infrared thermometers have been used successfully during several international field campaigns. Systems may be configured with as many as four thermal sensors up to 9 m above the surface, and traverse a 30 m transect. Ground and canopy temperatures are important for solving the surface energy balance. The spatial variability of surface temperature is often great, so that averaged point measurements result in highly inaccurate areal estimates. The cable systems are ideal for quantifying both temporal and spatial variabilities. Thermal emissivity is also necessary for deriving the absolute physical temperature, and measurements may be made with a portable measuring box.

  16. Spatial patterns in timing of the diurnal temperature cycle

    Directory of Open Access Journals (Sweden)

    T. R. H. Holmes

    2013-10-01

    Full Text Available This paper investigates the structural difference in timing of the diurnal temperature cycle (DTC over land resulting from choice of measuring device or model framework. It is shown that the timing can be reliably estimated from temporally sparse observations acquired from a constellation of low Earth-orbiting satellites given record lengths of at least three months. Based on a year of data, the spatial patterns of mean DTC timing are compared between temperature estimates from microwave Ka-band, geostationary thermal infrared (TIR, and numerical weather prediction model output from the Global Modeling and Assimilation Office (GMAO. It is found that the spatial patterns can be explained by vegetation effects, sensing depth differences and more speculatively the orientation of orographic relief features. In absolute terms, the GMAO model puts the peak of the DTC on average at 12:50 local solar time, 23 min before TIR with a peak temperature at 13:13 (both averaged over Africa and Europe. Since TIR is the shallowest observation of the land surface, this small difference represents a structural error that possibly affects the model's ability to assimilate observations that are closely tied to the DTC. The equivalent average timing for Ka-band is 13:44, which is influenced by the effect of increased sensing depth in desert areas. For non-desert areas, the Ka-band observations lag the TIR observations by only 15 min, which is in agreement with their respective theoretical sensing depth. The results of this comparison provide insights into the structural differences between temperature measurements and models, and can be used as a first step to account for these differences in a coherent way.

  17. Effect of milling temperatures on surface area, surface energy and cohesion of pharmaceutical powders.

    Science.gov (United States)

    Shah, Umang V; Wang, Zihua; Olusanmi, Dolapo; Narang, Ajit S; Hussain, Munir A; Tobyn, Michael J; Heng, Jerry Y Y

    2015-11-10

    Particle bulk and surface properties are influenced by the powder processing routes. This study demonstrates the effect of milling temperatures on the particle surface properties, particularly surface energy and surface area, and ultimately on powder cohesion. An active pharmaceutical ingredient (API) of industrial relevance (brivanib alaninate, BA) was used to demonstrate the effect of two different, but most commonly used milling temperatures (cryogenic vs. ambient). The surface energy of powders milled at both cryogenic and room temperatures increased with increasing milling cycles. The increase in surface energy could be related to the generation of surface amorphous regions. Cohesion for both cryogenic and room temperature milled powders was measured and found to increase with increasing milling cycles. For cryogenic milling, BA had a surface area ∼ 5× higher than the one obtained at room temperature. This was due to the brittle nature of this compound at cryogenic temperature. By decoupling average contributions of surface area and surface energy on cohesion by salinization post-milling, the average contribution of surface energy on cohesion for powders milled at room temperature was 83% and 55% at cryogenic temperature.

  18. A protocol for validating Land Surface Temperature from Sentinel-3

    Science.gov (United States)

    Ghent, D.

    2015-12-01

    One of the main objectives of the Sentinel-3 mission is to measure sea- and land-surface temperature with high-end accuracy and reliability in support of environmental and climate monitoring in an operational context. Calibration and validation are thus key criteria for operationalization within the framework of the Sentinel-3 Mission Performance Centre (S3MPC).Land surface temperature (LST) has a long heritage of satellite observations which have facilitated our understanding of land surface and climate change processes, such as desertification, urbanization, deforestation and land/atmosphere coupling. These observations have been acquired from a variety of satellite instruments on platforms in both low-earth orbit and in geostationary orbit. Retrieval accuracy can be a challenge though; surface emissivities can be highly variable owing to the heterogeneity of the land, and atmospheric effects caused by the presence of aerosols and by water vapour absorption can give a bias to the underlying LST. As such, a rigorous validation is critical in order to assess the quality of the data and the associated uncertainties. The Sentinel-3 Cal-Val Plan for evaluating the level-2 SL_2_LST product builds on an established validation protocol for satellite-based LST. This set of guidelines provides a standardized framework for structuring LST validation activities, and is rapidly gaining international recognition. The protocol introduces a four-pronged approach which can be summarised thus: i) in situ validation where ground-based observations are available; ii) radiance-based validation over sites that are homogeneous in emissivity; iii) intercomparison with retrievals from other satellite sensors; iv) time-series analysis to identify artefacts on an interannual time-scale. This multi-dimensional approach is a necessary requirement for assessing the performance of the LST algorithm for SLSTR which is designed around biome-based coefficients, thus emphasizing the importance of

  19. TEMPERATURE CONTROL CIRCUIT FOR SURFACE ACOUSTIC WAVE (SAW RESONATORS

    Directory of Open Access Journals (Sweden)

    Zainab Mohamad Ashari

    2011-10-01

    Full Text Available Surface Acoustic Wave (SAW resonators are key components in oscillators, frequency synthesizers and transceivers. One of the drawbacks of SAW resonators are that its piezoelectric substrates are highly sensitive to ambient temperature resulting in performance degradation. This work propose a simple circuit design which stabalizes the temperature of the SAW resonator, making it independet of temperature change. This circuit is based on the oven control method which elevates the temperature of the resonator to a high temperature, making it tolerant to minor changes in ambient temperature.This circuit consist of a temperature sensor, heaters and a comparator which turn the heater on or off depending on the ambient temperature. Several SAW resonator were tested using this circuit. Experimental results indicate the temperature coefficient of frequency (TCF decreases from maximum of 130.44/°C to a minimum of -1.11/°C. 

  20. Relaxation time estimation in surface NMR

    Science.gov (United States)

    Grunewald, Elliot D.; Walsh, David O.

    2017-03-21

    NMR relaxation time estimation methods and corresponding apparatus generate two or more alternating current transmit pulses with arbitrary amplitudes, time delays, and relative phases; apply a surface NMR acquisition scheme in which initial preparatory pulses, the properties of which may be fixed across a set of multiple acquisition sequence, are transmitted at the start of each acquisition sequence and are followed by one or more depth sensitive pulses, the pulse moments of which are varied across the set of multiple acquisition sequences; and apply processing techniques in which recorded NMR response data are used to estimate NMR properties and the relaxation times T.sub.1 and T.sub.2* as a function of position as well as one-dimensional and two-dimension distributions of T.sub.1 versus T.sub.2* as a function of subsurface position.

  1. Relaxation time estimation in surface NMR

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, Elliot D.; Walsh, David O.

    2017-03-21

    NMR relaxation time estimation methods and corresponding apparatus generate two or more alternating current transmit pulses with arbitrary amplitudes, time delays, and relative phases; apply a surface NMR acquisition scheme in which initial preparatory pulses, the properties of which may be fixed across a set of multiple acquisition sequence, are transmitted at the start of each acquisition sequence and are followed by one or more depth sensitive pulses, the pulse moments of which are varied across the set of multiple acquisition sequences; and apply processing techniques in which recorded NMR response data are used to estimate NMR properties and the relaxation times T.sub.1 and T.sub.2* as a function of position as well as one-dimensional and two-dimension distributions of T.sub.1 versus T.sub.2* as a function of subsurface position.

  2. Mapping the body surface temperature of cattle by infrared thermography.

    Science.gov (United States)

    Salles, Marcia Saladini Vieira; da Silva, Suelen Corrêa; Salles, Fernando André; Roma, Luiz Carlos; El Faro, Lenira; Bustos Mac Lean, Priscilla Ayleen; Lins de Oliveira, Celso Eduardo; Martello, Luciane Silva

    2016-12-01

    Infrared thermography (IRT) is an alternative non-invasive method that has been studied as a tool for identifying many physiological and pathological processes related to changes in body temperature. The objective of the present study was to evaluate the body surface temperature of Jersey dairy cattle in a thermoneutral environment in order to contribute to the determination of a body surface temperature pattern for animals of this breed in a situation of thermal comfort. Twenty-four Jersey heifers were used over a period of 35 days at APTA Brazil. Measurements were performed on all animals, starting with the physiological parameters. Body surface temperature was measured by IRT collecting images in different body regions: left and right eye area, right and left eye, caudal left foreleg, cranial left foreleg, right and left flank, and forehead. High correlations were observed between temperature and humidity index (THI) and right flank, left flank and forehead temperatures (0.85, 0.81, and 0.81, respectively). The IRT variables that exhibited the five highest correlation coefficients in principal component 1 were, in decreasing order: forehead (0.90), right flank (0.87), left flank (0.84), marker 1 caudal left foreleg (0.83), marker 2 caudal left foreleg (0.74). The THI showed a high correlation coefficient (0.88) and moderate to low correlations were observed for the physiological variables rectal temperature (0.43), and respiratory frequency (0.42). The thermal profile obtained indicates a surface temperature pattern for each region studied in a situation of thermal comfort and may contribute to studies investigating body surface temperature. Among the body regions studied, IRT forehead temperature showed the highest association with rectal temperature, and forehead and right and left flank temperatures are strongly associated with THI and may be adopted in future studies on thermoregulation and body heat production.

  3. eMODIS Global Land Surface Temperature Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The EROS Moderate Resolution Imaging Spectroradiometer (eMODIS) Aqua Land Surface Temperature (LST) product is similar to the Land Processes Distributed Active...

  4. 2002 Average Monthly Sea Surface Temperature for California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA/ NASA AVHRR Oceans Pathfinder sea surface temperature data are derived from the 5-channel Advanced Very High Resolution Radiometers (AVHRR) on board the...

  5. 2003 Average Monthly Sea Surface Temperature for California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA/ NASA AVHRR Oceans Pathfinder sea surface temperature data are derived from the 5-channel Advanced Very High Resolution Radiometers (AVHRR) on board the...

  6. Sea surface temperature anomalies in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    . Further analysis has shown that the sea surface anomalies are well correlated to the anomalies of air temperature and latent heat flux values; whereas they are least correlated to the anomalies of wind stress and net radiation values, except over...

  7. An Estimation of Land Surface Temperatures from Landsat ETM+ ...

    African Journals Online (AJOL)

    Dr-Adeline

    2 National Authority for Remote Sensing and Space Sciences, Cairo, Egypt. 3University of ... Keywords: Urban growth, urban heat Island, land surface temperatures, satellite remote sensing .... observed target includes green vegetation or not.

  8. Global 1-km Sea Surface Temperature (G1SST)

    Data.gov (United States)

    National Aeronautics and Space Administration — JPL OurOcean Portal: A daily, global Sea Surface Temperature (SST) data set is produced at 1-km (also known as ultra-high resolution) by the JPL ROMS (Regional Ocean...

  9. Surface layer temperature inversion in the Arabian Sea during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Ghosh, A.K.

    Surface layer temperature inversion in the south eastern Arabian Sea, during winter has been studied using Bathythermograph data collected from 1132 stations. It is found that the inversion in this area is a stable seasonal feature...

  10. Seasonal Sea Surface Temperature Averages, 1985-2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of four images showing seasonal sea surface temperature (SST) averages for the entire earth. Data for the years 1985-2001 are averaged to...

  11. 1996 Average Monthly Sea Surface Temperature for California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA/ NASA AVHRR Oceans Pathfinder sea surface temperature data are derived from the 5-channel Advanced Very High Resolution Radiometers (AVHRR) on board the...

  12. 2000 Average Monthly Sea Surface Temperature for California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA/ NASA AVHRR Oceans Pathfinder sea surface temperature data are derived from the 5-channel Advanced Very High Resolution Radiometers (AVHRR) on board the...

  13. OW NOAA Pathfinder/GAC Sea-Surface Temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface temperature measurements collected by means of the Advanced Very High Resolution Radiometer - Global Area Coverage...

  14. OW NOAA AVHRR-GAC Sea-Surface Temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface temperature measurements collected by means of the Advanced Very High Resolution Radiometer - Global Area Coverage...

  15. NOAA High-Resolution Sea Surface Temperature (SST) Analysis Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archive covers two high resolution sea surface temperature (SST) analysis products developed using an optimum interpolation (OI) technique. The analyses have a...

  16. Tropical sea surface temperatures and the earth's orbital eccentricity cycles

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.; Fernandes, A.A.; Mohan, R.

    The tropical oceanic warm pools are climatologically important regions because their sea surface temperatures (SSTs) are positively related to atmospheric greenhouse effect and the cumulonimbus-cirrus cloud anvil. Such a warm pool is also present...

  17. Extreme temperatures in summer time. Health implications

    Directory of Open Access Journals (Sweden)

    Julio Díaz Jiménez

    2005-12-01

    Full Text Available The increment that has been detected in summer temperatures in the last years joined to the trends expected to climate for the next century provide an increase in frequency and intensity of the extreme climate events, basically in heat waves. The undoubted relationship between temperature and mortality makes necessary a quantifying in order to characterize the expected effects of temperature over mortality particularly in heat waves.This study show a state-of-the-art review this problem, with a special emphasis in the heat wave that Europe suffered in summer of 2003 and how the heat waves has been characterized until now. Lastly, which are the characteristics that should have the preventive measures designed to minimized the effects of heat waves over population ́s health.

  18. Temperature Distribution Measurement of The Wing Surface under Icing Conditions

    Science.gov (United States)

    Isokawa, Hiroshi; Miyazaki, Takeshi; Kimura, Shigeo; Sakaue, Hirotaka; Morita, Katsuaki; Japan Aerospace Exploration Agency Collaboration; Univ of Notre Dame Collaboration; Kanagawa Institute of Technology Collaboration; Univ of Electro-(UEC) Team, Comm

    2016-11-01

    De- or anti-icing system of an aircraft is necessary for a safe flight operation. Icing is a phenomenon which is caused by a collision of supercooled water frozen to an object. For the in-flight icing, it may cause a change in the wing cross section that causes stall, and in the worst case, the aircraft would fall. Therefore it is important to know the surface temperature of the wing for de- or anti-icing system. In aerospace field, temperature-sensitive paint (TSP) has been widely used for obtaining the surface temperature distribution on a testing article. The luminescent image from the TSP can be related to the temperature distribution. (TSP measurement system) In icing wind tunnel, we measured the surface temperature distribution of the wing model using the TSP measurement system. The effect of icing conditions on the TSP measurement system is discussed.

  19. Levitation of Liquid Microdroplets Above A Solid Surface Subcooled to the Leidenfrost Temperature

    Directory of Open Access Journals (Sweden)

    Kirichenko D. P.

    2016-01-01

    Full Text Available Evaporation of liquid microdroplets that fall on a solid surface with the temperature of below the Leidenfrost temperature is studied. It has been found out that sufficiently small liquid droplets of about 10 microns can suspend at some distance from the surface (levitate and do not reach the surface; at that, the rate of droplet evaporation is reduced by an order as compared to microdroplets, which touch the surface. It is determined that in contrast to microdroplets, which touch the surface, the specific evaporation rate of levitating droplets is constant in time.

  20. Validation of AIRS V6 Surface Temperature over Greenland with GCN and NOAA Stations

    Science.gov (United States)

    Lee, Jae N.; Hearty, Thomas; Cullather, Richard; Nowicki, Sophie; Susskind, Joel

    2016-01-01

    This work compares the temporal and spatial characteristics of the AIRSAMSU (Atmospheric Infrared Sounder Advanced Microwave Sounding Unit A) Version 6 and MODIS (Moderate resolution Imaging Spectroradiometer) Collection 5 derived surface temperatures over Greenland. To estimate uncertainties in space-based surface temperature measurements, we re-projected the MODIS Ice Surface Temperature (IST) to 0.5 by 0.5 degree spatial resolution. We also re-gridded AIRS Skin Temperature (Ts) into the same grid but classified with different cloud conditions and surface types. These co-located data sets make intercomparison between the two instruments relatively straightforward. Using this approach, the spatial comparison between the monthly mean AIRS Ts and MODIS IST is in good agreement with RMS 2K for May 2012. This approach also allows the detection of any long-term calibration drift and the careful examination of calibration consistency in the MODIS and AIRS temperature data record. The temporal correlations between temperature data are also compared with those from in-situ measurements from GC-Net (GCN) and NOAA stations. The coherent time series of surface temperature evident in the correlation between AIRS Ts and GCN temperatures suggest that at monthly time scales both observations capture the same climate signal over Greenland. It is also suggested that AIRS surface air temperature (Ta) can be used to estimate the boundary layer inversion.

  1. Temperature Compensation of Surface Acoustic Waves on Berlinite

    Science.gov (United States)

    Searle, David Michael Marshall

    The surface acoustic wave properties of Berlinite (a-AlPO4) have been investigated theoretically and experimentally, for a variety of crystallographic orientations, to evaluate its possible use as a substrate material for temperature compensated surface acoustic wave devices. A computer program has been developed to calculate the surface wave properties of a material from its elastic, piezoelectric, dielectric and lattice constants and their temperature derivatives. The program calculates the temperature coefficient of delay, the velocity of the surface wave, the direction of power flow and a measure of the electro-mechanical coupling. These calculations have been performed for a large number of orientations using a modified form of the data given by Chang and Barsch for Berlinite and predict several new temperature compensated directions. Experimental measurements have been made of the frequency-temperature response of a surface acoustic wave oscillator on an 80° X axis boule cut which show it to be temperature compensated in qualitative agreement with the theoretical predictions. This orientation shows a cubic frequency-temperature dependence instead of the expected parabolic response. Measurements of the electro-mechanical coupling coefficient k gave a value lower than predicted. Similar measurements on a Y cut plate gave a value which is approximately twice that of ST cut quartz, but again lower than predicted. The surface wave velocity on both these cuts was measured to be slightly higher than predicted by the computer program. Experimental measurements of the lattice parameters a and c are also presented for a range of temperatures from 25°C to just above the alpha-beta transition at 584°C. These results are compared with the values obtained by Chang and Barsch. The results of this work indicate that Berlinite should become a useful substrate material for the construction of temperature compensated surface acoustic wave devices.

  2. Temperature dependence of surface enhanced Raman scattering on C70

    Institute of Scientific and Technical Information of China (English)

    GAO Ying; Zhang Zhenlong; DU Yinxiao; DONG Hua; MO Yujun

    2005-01-01

    The temperature dependence of surface enhanced Raman scattering of the C70 molecule is reported.The Raman scattering of C70 molecules adsorbed on the surface of a silver mirror was measured at different temperatures. The experimental results indicate that the relative intensities of the Raman features vary with the temperature of the sample. When the temperature decreases from room temperature to 0℃, the relative intensities of certain Raman bands decrease abruptly. If we take the strongest band 1565cm-1 as a standard value 100, the greatest decrease approaches to 43%. However, with the further decrease in the temperature these relative intensities increase and resume the value at room temperature. And such a temperature dependence is reversible. Our results show that the adsorption state of the C70 molecules on the silver surface around 0℃changes greatly with the temperature, resulting in a decrease in relative intensities for some main Raman features of C70molecule. When the temperature is lower than 0℃, the adsorption state changes continually and more slowly. Synchronously, eight new Raman featu res, which have not ever been reported in literature, are observed in our experiment and this enriches the basic information of the vibrational modes for C70 molecule.

  3. Sea Surface Temperature from EUMETSAT Including Sentinel-3 SLSTR

    Science.gov (United States)

    O'Carroll, Anne; Bonekamp, Hans; Montagner, Francois; Santacesaria, Vincenzo; Tomazic, Igor

    2015-12-01

    The paper gives an overview of sea surface temperature (SST) activities at EUMETSAT including information on SST planned from the Sea and Land Surface Temperature Radiometer (SLSTR). Operational oceanography activities within the Marine Applications group at EUMETSAT continue with a focus on SST, sea surface winds, sea-ice products, radiative fluxes, significant wave height and sea surface topography. These are achieved through the mandatory, optional and third-party programmes, and for some products with the EUMETSAT Ocean and Sea-Ice Satellite Application Facility (OSI SAF). Progress towards products from sea-ice surface temperature, ocean colour products, turbidity and aerosol optical depth over water continue. Information on oceanography products from EUMETSAT can be found through the product navigator (http://navigator.eumetsat.int). EUMETSAT have been collaborating with ESA for a number of years on the development of SST for SLSTR.

  4. A model of the ground surface temperature for micrometeorological analysis

    Science.gov (United States)

    Leaf, Julian S.; Erell, Evyatar

    2017-07-01

    Micrometeorological models at various scales require ground surface temperature, which may not always be measured in sufficient spatial or temporal detail. There is thus a need for a model that can calculate the surface temperature using only widely available weather data, thermal properties of the ground, and surface properties. The vegetated/permeable surface energy balance (VP-SEB) model introduced here requires no a priori knowledge of soil temperature or moisture at any depth. It combines a two-layer characterization of the soil column following the heat conservation law with a sinusoidal function to estimate deep soil temperature, and a simplified procedure for calculating moisture content. A physically based solution is used for each of the energy balance components allowing VP-SEB to be highly portable. VP-SEB was tested using field data measuring bare loess desert soil in dry weather and following rain events. Modeled hourly surface temperature correlated well with the measured data (r 2 = 0.95 for a whole year), with a root-mean-square error of 2.77 K. The model was used to generate input for a pedestrian thermal comfort study using the Index of Thermal Stress (ITS). The simulation shows that the thermal stress on a pedestrian standing in the sun on a fully paved surface, which may be over 500 W on a warm summer day, may be as much as 100 W lower on a grass surface exposed to the same meteorological conditions.

  5. A new interpolation method for Antarctic surface temperature

    Institute of Scientific and Technical Information of China (English)

    Yetang Wang; Shugui Hou

    2009-01-01

    We propose a new methodology for the spatial interpolation of annual mean temperature into a regular grid with a geographic resolution of 0.01° for Antarctica by applying a recent compilation of the Antarctic temperature data.A multiple linear regression model of the dependence of temperature on some geographic parameters (i.e.,latitude,longitude,and elevation) is proposed empirically,and the kriging method is used to determine the spatial distribution of regional and local deviations from the temperature calculated from the multiple linear regression model.The modeled value and residual grids are combined to derive a high-resolution map of surface air temperature.The performance of our new methodology is superior to a variety of benchmark methods (e.g.,inverse distance weighting,kriging,and spline methods) via cross-validation techniques.Our simulation resembles well with those distinct spatial features of surface temperature,such as the decrease in annual mean surface temperature with increasing latitude and the distance away from the coast line;and it also reveals the complex topographic effects on the spatial distribution of surface temperature.

  6. Analysis of Anomaly in Land Surface Temperature Using MODIS Products

    Science.gov (United States)

    Yorozu, K.; Kodama, T.; Kim, S.; Tachikawa, Y.; Shiiba, M.

    2011-12-01

    Atmosphere-land surface interaction plays a dominant role on the hydrologic cycle. Atmospheric phenomena cause variation of land surface state and land surface state can affect on atmosphereic conditions. Widely-known article related in atmospheric-land interaction was published by Koster et al. in 2004. The context of this article is that seasonal anomaly in soil moisture or soil surface temperature can affect summer precipitation generation and other atmospheric processes especially in middle North America, Sahel and south Asia. From not only above example but other previous research works, it is assumed that anomaly of surface state has a key factor. To investigate atmospheric-land surface interaction, it is necessary to analyze anomaly field in land surface state. In this study, soil surface temperature should be focused because it can be globally and continuously observed by satellite launched sensor. To land surface temperature product, MOD11C1 and MYD11C1 products which are kinds of MODIS products are applied. Both of them have 0.05 degree spatial resolution and daily temporal resolution. The difference of them is launched satellite, MOD11C1 is Terra and MYD11C1 is Aqua. MOD11C1 covers the latter of 2000 to present and MYD11C1 covers the early 2002 to present. There are unrealistic values on provided products even if daily product was already calibrated or corrected. For pre-analyzing, daily data is aggregated into 8-days data to remove irregular values for stable analysis. It was found that there are spatial and temporal distribution of 10-years average and standard deviation for each 8-days term. In order to point out extreme anomaly in land surface temperature, standard score for each 8-days term is applied. From the analysis of standard score, it is found there are large anomaly in land surface temperature around north China plain in early April 2005 and around Bangladesh in early May 2009.

  7. Radar Backscatter Across the Gulf Stream Sea Surface Temperature Front

    Science.gov (United States)

    Nghiem, S. V.; Li, F. K.; Walsh, E. J.; Lou, S. H.

    1998-01-01

    Ocean backscatter signatures were measured by the Jet Propulsion Laboratory airborne NUSCAT K(sub u)-band scatterometer across the Gulf Stream sea surface temperature front. The measurements were made during the Surface Wave Dynamics Experiment (SWADE) off the coast of Virginia and Maryland in the winter of 1991.

  8. estimation of land surface temperature of kaduna metropolis, nigeria

    African Journals Online (AJOL)

    Zaharaddeen et. al

    Understanding the spatial variation of Land Surface Temperature. (LST), will be ... positive correlation between mean of surface emissivity with date and ... deviation of 1.92 of LST and coefficient determinant R2 (0.46) show a ... (LST), as the prime and basic physical parameter of the earth's ..... thorough review of the paper.

  9. An Open and Transparent Databank of Global Land Surface Temperature

    Science.gov (United States)

    Rennie, J.; Thorne, P.; Lawrimore, J. H.; Gleason, B.; Menne, M. J.; Williams, C.

    2013-12-01

    The International Surface Temperature Initiative (ISTI) consists of an effort to create an end-to-end process for land surface air temperature analyses. The foundation of this process is the establishment of a global land surface databank. The databank builds upon the groundbreaking efforts of scientists who led efforts to construct global land surface datasets in the 1980's and 1990's. A primary aim of the databank is to improve aspects including data provenance, version control, temporal and spatial coverage, and improved methods for bringing dozens of source data together into an integrated dataset. The databank consists of multiple stages, with each successive stage providing a higher level of processing, quality and integration. Currently more than 50 sources of data have been added to the databank. An automated algorithm has been developed that merges these sources into one complete dataset by removing duplicate station records, identifying two or more station records that can be merged into a single record, and incorporating new and unique stations. The program runs iteratively through all the sources which are ordered based upon criteria established by the ISTI. The highest preferred source, known as the target, runs through all the candidate sources, calculating station comparisons that are acceptable for merging. The process is probabilistic in approach, and the final fate of a candidate station is based upon metadata matching and data equivalence criteria. If there is not enough information, the station is withheld for further investigation. The algorithm has been validated using a pseudo-source of stations with a known time of observation bias, and correct matches have been made nearly 95% of the time. The final product, endorsed and recommended by ISTI, contains over 30,000 stations, however slight changes in the algorithm can perturb results. Subjective decisions, such as the ordering of the sources, or changing metadata and data matching thresholds

  10. ESTIMATION OF PV MODULE SURFACE TEMPERATURE USING ARTIFICIAL NEURAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Can Coskun

    2016-12-01

    Full Text Available This study aimed to use the artificial neural network (ANN method to estimate the surface temperature of a photovoltaic (PV panel. Using the experimentally obtained PV data, the accuracy of the ANN model was evaluated. To train the artificial neural network (ANN, outer temperature solar radiation and wind speed values were inputs and surface temperature was an output. The ANN was used to estimate PV panel surface temperature. Using the Levenberg-Marquardt (LM algorithm the feed forward artificial neural network was trained. Two back propagation type ANN algorithms were used and their performance was compared with the estimate from the LM algorithm. To train the artificial neural network, experimental data were used for two thirds with the remaining third used for testing. Additionally scaled conjugate gradient (SCG back propagation and resilient back propagation (RB type ANN algorithms were used for comparison with the LM algorithm. The performances of these three types of artificial neural network were compared and mean error rates of between 0.005962 and 0.012177% were obtained. The best estimate was produced by the LM algorithm. Estimation of PV surface temperature with artificial neural networks provides better results than conventional correlation methods. This study showed that artificial neural networks may be effectively used to estimate PV surface temperature.

  11. Effect of fast mold surface temperature evolution on iPP part morphology gradients

    Energy Technology Data Exchange (ETDEWEB)

    Liparoti, Sara [Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (Italy); Sorrentino, Andrea [Institute for Polymers, Composites and Biomaterials (IPCB), National Research Council (CNR), P. Enrico Fermi 1, 80055 Portici (Italy); Guzman, Gustavo; Cakmak, Mukerrem; Titomanlio, Giuseppe, E-mail: gtitomanlio@unisa.it [Department of Polymer Engineering, The University of Akron, Akron, OH 44325 (United States)

    2016-03-09

    The control of mold surface temperature is an important factor that affects the sample surface morphology as well as the structural gradients (orientation crystal size, and type) as well as cooling stresses. The frozen layer thickness formed during the filling stage also has a very significant effect on the flow resistance and thus on the resulting pressure drop and flow length in thin wall parts. The possibility to have a hot mold during filling and a quick cooling soon afterward is a significant process enhancement particularly for specialized applications such as micro injection molding and for the reproduction of micro structured surfaces. Up to now, several methods (electromagnetic, infrared, hot vapor fleshing etc,) were tried to achieve fast temperature evolution of the mold. Unfortunately, all these methods require a complex balance between thermal and mechanical problems, equipment cost, energy consumption, safety, molding cycle time and part quality achievable. In this work, a thin electrical resistance was designed and used to generate a fast and confined temperature variation on mold surface (by joule effect). Since the whole temperature evolution can take place in a few seconds, one can couple the advantages of a high surface temperature during filling with the advantages of a low mold temperature, fast cooling and low heating dissipation. Some experiments were performed with a commercial iPP resin. The effects of the surface temperature and of the heating time (under constant electric power) on surface finishing and on the final morphology (thickness and structure of the different layers) are explored and discussed.

  12. Estimation of Land Surface Temperature under Cloudy Skies Using Combined Diurnal Solar Radiation and Surface Temperature Evolution

    Directory of Open Access Journals (Sweden)

    Xiaoyu Zhang

    2015-01-01

    Full Text Available Land surface temperature (LST is a key parameter in the interaction of the land-atmosphere system. However, clouds affect the retrieval of LST data from thermal-infrared remote sensing data. Thus, it is important to determine a method for estimating LSTs at times when the sky is overcast. Based on a one-dimensional heat transfer equation and on the evolution of daily temperatures and net shortwave solar radiation (NSSR, a new method for estimating LSTs under cloudy skies (Tcloud from diurnal NSSR and surface temperatures is proposed. Validation is performed against in situ measurements that were obtained at the ChangWu ecosystem experimental station in China. The results show that the root-mean-square error (RMSE between the actual and estimated LSTs is as large as 1.23 K for cloudy data. A sensitivity analysis to the errors in the estimated LST under clear skies (Tclear and in the estimated NSSR reveals that the RMSE of the obtained Tcloud is less than 1.5 K after adding a 0.5 K bias to the actual Tclear and 10 percent NSSR errors to the actual NSSR. Tcloud is estimated by the proposed method using Tclear and NSSR products of MSG-SEVIRI for southern Europe. The results indicate that the new algorithm is practical for retrieving the LST under cloudy sky conditions, although some uncertainty exists. Notably, the approach can only be used during the daytime due to the assumption of the variation in LST caused by variations in insolation. Further, if there are less than six Tclear observations on any given day, the method cannot be used.

  13. Surface Integrity and Structural Stability of Broached Inconel 718 at High Temperatures

    Science.gov (United States)

    Chen, Z.; Peng, R. Lin; Moverare, J.; Avdovic, P.; Zhou, J. M.; Johansson, S.

    2016-07-01

    The current study focused on the surface integrity issues associated with broaching of Inconel 718 and the structural stability of the broached specimen at high temperatures, mainly involving the microstructural changes and residual stress relaxation. The broaching operation was performed using similar cutting conditions as that used in turbo machinery industries for machining fir-tree root fixings on turbine disks. Thermal exposure was conducted at 723 K, 823 K, and 923 K (450 °C, 550 °C, and 650 °C) for 30, 300, and 3000 hours, respectively. Surface cavities and debris dragging, sub-surface cracks, high intensity of plastic deformation, as well as the generation of tensile residual stresses were identified to be the main issues in surface integrity for the broached Inconel 718. When a subsequent heating was applied, surface recrystallization and α-Cr precipitation occurred beneath the broached surface depending on the applied temperature and exposure time. The plastic deformation induced by the broaching is responsible for these microstructural changes. The surface tension was completely relaxed in a short time at the temperature where surface recrystallization occurred. The tensile layer on the sub-surface, however, exhibited a much higher resistance to the stress relief annealing. Oxidation is inevitable at high temperatures. The study found that the surface recrystallization could promote the local Cr diffusion on the broached surface.

  14. Mathematical model of the metal mould surface temperature optimization

    Energy Technology Data Exchange (ETDEWEB)

    Mlynek, Jaroslav, E-mail: jaroslav.mlynek@tul.cz; Knobloch, Roman, E-mail: roman.knobloch@tul.cz [Department of Mathematics, FP Technical University of Liberec, Studentska 2, 461 17 Liberec, The Czech Republic (Czech Republic); Srb, Radek, E-mail: radek.srb@tul.cz [Institute of Mechatronics and Computer Engineering Technical University of Liberec, Studentska 2, 461 17 Liberec, The Czech Republic (Czech Republic)

    2015-11-30

    The article is focused on the problem of generating a uniform temperature field on the inner surface of shell metal moulds. Such moulds are used e.g. in the automotive industry for artificial leather production. To produce artificial leather with uniform surface structure and colour shade the temperature on the inner surface of the mould has to be as homogeneous as possible. The heating of the mould is realized by infrared heaters located above the outer mould surface. The conceived mathematical model allows us to optimize the locations of infrared heaters over the mould, so that approximately uniform heat radiation intensity is generated. A version of differential evolution algorithm programmed in Matlab development environment was created by the authors for the optimization process. For temperate calculations software system ANSYS was used. A practical example of optimization of heaters locations and calculation of the temperature of the mould is included at the end of the article.

  15. Analysis of Temperature Maps of Selected Dawn Data Over the Surface of Vesta

    Science.gov (United States)

    Tosi, F.; Capria, M. T.; DeSanctis, M. C.; Palomba, E.; Grassi, D.; Capaccioni, F.; Ammannito, E.; Combe, J.-Ph.; Sunshine, J. M.; McCord, T. B.; Li, Y.-Y.; Titus, T. N.; Russell, C. T.; Raymond, C. A.; Mittlefehldt, D. W.; Toplis, M. J.; Forni, O.; Sykes, M. V.

    2012-01-01

    The thermal behavior of areas of unusual albedo at the surface of Vesta can be related to physical properties that may provide some information about the origin of those materials. Dawn s Visible and Infrared Mapping Spectrometer (VIR) [1] hyperspectral cubes can be used to retrieve surface temperatures. Due to instrumental constraints, high accuracy is obtained only if temperatures are greater than 180 K. Bright and dark surface materials on Vesta are currently investigated by the Dawn team [e.g., 2 and 3 respectively]. Here we present temperature maps of several local-scale features that were observed by Dawn under different illumination conditions and different local solar times.

  16. Influence of Annealing Temperature on CZTS Thin Film Surface Properties

    Science.gov (United States)

    Feng, Wenmei; Han, Junfeng; Ge, Jun; Peng, Xianglin; Liu, Yunong; Jian, Yu; Yuan, Lin; Xiong, Xiaolu; Cha, Limei; Liao, Cheng

    2017-01-01

    In this work, copper zinc tin sulfide (CZTS) films were deposited by direct current sputtering and the samples were annealed in different oven-set temperatures and atmosphere (Ar and H2S). The surface evolution was investigated carefully by using scanning electron microscopy (SEM), Raman spectroscopy and x-ray photoelectron spectroscopy. The surface of the as-sputtered precursor contained little Cu and large amounts of Zn and Sn. The metallic precursor was continuous and compact without pinholes or cracks. With the increase of the temperature from room temperature to 250°C, Cu atoms diffused to the film surface to form Cu1- x S and covered other compounds. Some small platelets were smaller than 500 nm spreading randomly in the holes of the film surfaces. When the temperature reached 350°C, Zn and Sn atoms began to diffuse to the surface and react with S or Cu1- x S. At 400°C, SEM showed the melting of large particles and small particles with a size from 100 nm to 200 nm in the background of the film surface. Excess Zn segregated towards the surface regions and formed ZnS phase on the surface. In addition, the signal of sodium in the CZTS surface was observed above 400°C. At 600°C, a large amount of regular structures with clear edges and corners were observed in the film surface in SEM images. A clear recrystallized process on the surface was assumed from those observations.

  17. Climate Change Signal Analysis for Northeast Asian Surface Temperature

    Institute of Scientific and Technical Information of China (English)

    Jeong-Hyeong LEE; Byungsoo KIM; Keon-Tae SOHN; Won-Tae KOWN; Seung-Ki MIN

    2005-01-01

    Climate change detection, attribution, and prediction were studied for the surface temperature in the Northeast Asian region using NCEP/NCAR reanalysis data and three coupled-model simulations from ECHAM4/OPYC3, HadCM3, and CCCma GCMs (Canadian Centre for Climate Modeling and Analysis general circulation model). The Bayesian fingerprint approach was used to perform the detection and attribution test for the anthropogenic climate change signal associated with changes in anthropogenic carbon dioxide (CO2) and sulfate aerosol (SO42-) concentrations for the Northeast Asian temperature. It was shown that there was a weak anthropogenic climate change signal in the Northeast Asian temperature change. The relative contribution of CO2 and SOl- effects to total temperature change in Northeast Asia was quantified from ECHAM4/OPYC3 and CCCma GCM simulations using analysis of variance. For the observed temperature change for the period of 1959-1998, the CO2 effect contributed 10%-21% of the total variance and the direct cooling effect of SO42- played a less important role (0% 7%) than the CO2effect. The prediction of surface temperature change was estimated from the second CO2+SO24- scenario run of ECHAM4/OPYC3 which has the least error in the simulation of the present-day temperature field near the Korean Peninsula. The result shows that the area-mean surface temperature near the Korean Peninsula will increase by about 1.1° by the 2040s relative to the 1990s.

  18. SISTEM PENGENDALIAN TEMPERATUR PADA DINDING BIOREAKTOR ANAEROB SECARA REAL TIME

    OpenAIRE

    Ika Nurina Rachmawati; Rony Dwi Noriyati; Totok Soehartanto

    2013-01-01

    Temperatur merupakan salah satu faktor yang mempengaruhi proses anaerob pada bioreaktor. Dimana pertumbuhan mikroorganisme dipengaruhi oleh perubahan suhu. Maka dari itu akan dilakukan pengendalian temperatur secara real-time pada dinding tabung bioreaktor anaerob. Pengendalian temperatur berguna untuk menjaga suhu permukaan bioreaktor saat terjadi perubahan cuaca dari luar. Sebab jika temperatur dinding dijaga pada suhu 35 0C maka temperatur dalam tabung bioreaktor akan berada pada range ope...

  19. A comparison of Argo nominal surface and near-surface temperature for validation of AMSR-E SST

    Science.gov (United States)

    Liu, Zenghong; Chen, Xingrong; Sun, Chaohui; Wu, Xiaofen; Lu, Shaolei

    2017-05-01

    Satellite SST (sea surface temperature) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is compared with in situ temperature observations from Argo profiling floats over the global oceans to evaluate the advantages of Argo NST (near-surface temperature: water temperature less than 1 m from the surface). By comparing Argo nominal surface temperature ( 5 m) with its NST, a diurnal cycle caused by daytime warming and nighttime cooling was found, along with a maximum warming of 0.08±0.36°C during 14:00-15:00 local time. Further comparisons between Argo 5-m temperature/Argo NST and AMSR-E SST retrievals related to wind speed, columnar water vapor, and columnar cloud water indicate warming biases at low wind speed (28 mm during daytime. The warming tendency is more remarkable for AMSR-E SST/Argo 5-m temperature compared with AMSR-E SST/Argo NST, owing to the effect of diurnal warming. This effect of diurnal warming events should be excluded before validation for microwave SST retrievals. Both AMSR-E nighttime SST/Argo 5-m temperature and nighttime SST/Argo NST show generally good agreement, independent of wind speed and columnar water vapor. From our analysis, Argo NST data demonstrated their advantages for validation of satellite-retrieved SST.

  20. The influence of topographic structures on night-time surface temperatures: Evaluation of a satellite thermal image of the upper Rhine plain and the surrounding highlands. [Germany and Switzerland

    Science.gov (United States)

    Gossmann, H. (Principal Investigator)

    1980-01-01

    The author has identified the following significant results. Satellite data supplied the same information as aerial IR registrations with corresponding averaging for all studies requiring a survey of the thermal pattern within an area measuring 10 km x 10 km ore more, provided that sufficiently precise control points could be established for the purpose of geometric rectification in the surroundings of the area observed. Satellite thermal data are more comprehensive than aircraft data for studies on a regional, rather than a local scale, since airborne images often obscure the basic correlation in thermal patterns because of a variety of irrelevant topographical detail. The satellite data demonstrate the dependence of surface temperature on relief more clearly than comparable airborne imagery.

  1. Comparison of MODIS Land Surface Temperature and Air Temperature over the Continental USA Meteorological Stations

    Science.gov (United States)

    Zhang, Ping; Bounoua, Lahouari; Imhoff, Marc L.; Wolfe, Robert E.; Thome, Kurtis

    2014-01-01

    The National Land Cover Database (NLCD) Impervious Surface Area (ISA) and MODIS Land Surface Temperature (LST) are used in a spatial analysis to assess the surface-temperature-based urban heat island's (UHIS) signature on LST amplitude over the continental USA and to make comparisons to local air temperatures. Air-temperature-based UHIs (UHIA), calculated using the Global Historical Climatology Network (GHCN) daily air temperatures, are compared with UHIS for urban areas in different biomes during different seasons. NLCD ISA is used to define urban and rural temperatures and to stratify the sampling for LST and air temperatures. We find that the MODIS LST agrees well with observed air temperature during the nighttime, but tends to overestimate it during the daytime, especially during summer and in nonforested areas. The minimum air temperature analyses show that UHIs in forests have an average UHIA of 1 C during the summer. The UHIS, calculated from nighttime LST, has similar magnitude of 1-2 C. By contrast, the LSTs show a midday summer UHIS of 3-4 C for cities in forests, whereas the average summer UHIA calculated from maximum air temperature is close to 0 C. In addition, the LSTs and air temperatures difference between 2006 and 2011 are in agreement, albeit with different magnitude.

  2. Observational evidence of temperature trends at two levels in the surface layer

    Directory of Open Access Journals (Sweden)

    X. Lin

    2015-09-01

    Full Text Available Long-term surface air temperatures at 1.5 m screen level over land are used in calculating a global average surface temperature trend. This global trend is used by the IPCC and others to monitor, assess, and describe global warming or warming hiatus. Current knowledge of near-surface temperature trends with respect to height, however, is limited and inadequately understood because surface temperature observations at different heights in the surface layer in the world are rare especially from a high-quality and long-term climate monitoring network. Here we use high-quality two-height Oklahoma Mesonet observations, synchronized in time, fixed in height, and situated in relatively flat terrain, to assess temperature trends and differentiating temperature trends with respect to heights (i.e., near-surface lapse rate trend over the period 1997 to 2013. We show that the near-surface lapse rate has significantly decreased with a trend of −0.18 ± 0.03 °C (10 m−1 decade−1 indicating that the 9 m height temperatures increased faster than temperatures at the 1.5 m screen level and conditions at the 1.5 m height cooled faster than at the 9 m height. However, neither of the two individual height temperature trends by themselves were statistically significant. The magnitude of lapse rate trend is greatest under lighter winds at night. Nighttime lapse rate trends were significantly more negative than daytime lapse rate trends and the average lapse rate trend was three times more negative under calm conditions than under windy conditions. Our results provide the first observational evidence of near-surface temperature changes with respect to height that could enhance the assessment of climate model predictions.

  3. Evaporation of liquid microdroplets levitated above a solid surface heated below the saturation temperature

    Science.gov (United States)

    Kirichenko, D. P.; Zaitsev, D. V.; Kabov, O. A.

    2016-10-01

    This paper presents a study of the interaction of liquid microdroplets falling on a solid surface whose temperature is varied from 75 °C to 155 °C. It has been shown for the first time that droplet levitation above a solid surface is possible at a temperature below the saturation temperature. It has been found that for levitated droplets, the specific evaporation rate is constant in time, but for sessile droplets, it increases sharply. The evaporation rate for sessile droplet was found an order of magnitude higher than that for levitated droplets.

  4. Fiber-Optic Surface Temperature Sensor Based on Modal Interference

    Directory of Open Access Journals (Sweden)

    Frédéric Musin

    2016-07-01

    Full Text Available Spatially-integrated surface temperature sensing is highly useful when it comes to controlling processes, detecting hazardous conditions or monitoring the health and safety of equipment and people. Fiber-optic sensing based on modal interference has shown great sensitivity to temperature variation, by means of cost-effective image-processing of few-mode interference patterns. New developments in the field of sensor configuration, as described in this paper, include an innovative cooling and heating phase discrimination functionality and more precise measurements, based entirely on the image processing of interference patterns. The proposed technique was applied to the measurement of the integrated surface temperature of a hollow cylinder and compared with a conventional measurement system, consisting of an infrared camera and precision temperature probe. As a result, the optical technique is in line with the reference system. Compared with conventional surface temperature probes, the optical technique has the following advantages: low heat capacity temperature measurement errors, easier spatial deployment, and replacement of multiple angle infrared camera shooting and the continuous monitoring of surfaces that are not visually accessible.

  5. Assessment of broiler surface temperature variation when exposed to different air temperatures

    Directory of Open Access Journals (Sweden)

    GR Nascimento

    2011-12-01

    Full Text Available This study was conducted to determine the effect of the air temperature variation on the mean surface temperature (MST of 7- to 35-day-old broiler chickens using infrared thermometry to estimate MST, and to study surface temperature variation of the wings, head, legs, back and comb as affected by air temperature and broiler age. One hundred Cobb® broilers were used in the experiment. Starting on day 7, 10 birds were weekly selected at random, housed in an environmental chamber and reared under three distinct temperatures (18, 25 and 32 ºC to record their thermal profile using an infrared thermal camera. The recorded images were processed to estimate MST by selecting the whole area of the bird within the picture and comparing it with the values obtained using selected equations in literature, and to record the surface temperatures of the body parts. The MST estimated by infrared images were not statistically different (p > 0.05 from the values obtained by the equations. MST values significantly increased (p < 0.05 when the air temperature increased, but were not affected by bird age. However, age influenced the difference between MST and air temperature, which was highest on day 14. The technique of infrared thermal image analysis was useful to estimate the mean surface temperature of broiler chickens.

  6. Effects of drying temperature and surface characteristics of vegetable on the survival of salmonella.

    Science.gov (United States)

    Hawaree, N; Chiewchan, N; Devahastin, S

    2009-01-01

    The heat resistance of Salmonella Anatum inoculated on the surface of a model vegetable as affected by hot-air drying temperature (50 to 70 degrees C) and surface characteristics was determined in this study. Cabbage was selected as a model vegetable to demonstrate the effect of topographical feature of vegetable surface on the Salmonella attachment ability. An image analysis technique was developed to monitor the change of cabbage surface during drying and the specific surface characteristics were described in terms of the roughness factor (R). It was found that the water activity of the vegetable decreased while R-value increased with longer drying time and higher drying temperature. However, the changes of both parameters during drying did not show a significant effect on the susceptibility of Salmonella attached on the cabbage surface. Drying temperature was found to be a major factor influencing the heat resistance of Salmonella during drying.

  7. Uncertainties and shortcomings of ground surface temperature histories derived from inversion of temperature logs

    OpenAIRE

    Hartmann, Andreas; Rath, Volker

    2008-01-01

    Analysing borehole temperature data in terms of ground surface history can add useful information to reconstructions of past climates. Therefore, a rigorous assessment of uncertainties and error sources is a necessary prerequisite for the meaningful interpretation of such ground surface temperature histories. This study analyses the most prominent sources of uncertainty. The diffusive nature of the process makes the inversion relatively robust against incomplete knowledge of the thermal diffu...

  8. Comparison of Satellite-Derived Land Surface Temperature and Air Temperature from Meteorological Stations on the Pan-Arctic Scale

    Directory of Open Access Journals (Sweden)

    Christiane Schmullius

    2013-05-01

    Full Text Available Satellite-based temperature measurements are an important indicator for global climate change studies over large areas. Records from Moderate Resolution Imaging Spectroradiometer (MODIS, Advanced Very High Resolution Radiometer (AVHRR and (Advanced Along Track Scanning Radiometer ((AATSR are providing long-term time series information. Assessing the quality of remote sensing-based temperature measurements provides feedback to the climate modeling community and other users by identifying agreements and discrepancies when compared to temperature records from meteorological stations. This paper presents a comparison of state-of-the-art remote sensing-based land surface temperature data with air temperature measurements from meteorological stations on a pan-arctic scale (north of 60° latitude. Within this study, we compared land surface temperature products from (AATSR, MODIS and AVHRR with an in situ air temperature (Tair database provided by the National Climate Data Center (NCDC. Despite analyzing the whole acquisition time period of each land surface temperature product, we focused on the inter-annual variability comparing land surface temperature (LST and air temperature for the overlapping time period of the remote sensing data (2000–2005. In addition, land cover information was included in the evaluation approach by using GLC2000. MODIS has been identified as having the highest agreement in comparison to air temperature records. The time series of (AATSR is highly variable, whereas inconsistencies in land surface temperature data from AVHRR have been found.

  9. Flat meridional temperature gradient in the early Eocene in the subsurface rather than surface ocean

    Science.gov (United States)

    Ho, Sze Ling; Laepple, Thomas

    2016-08-01

    The early Eocene (49-55 million years ago) is a time interval characterized by elevated surface temperatures and atmospheric CO2 (refs ,), and a flatter-than-present latitudinal surface temperature gradient. The multi-proxy-derived flat temperature gradient has been a challenge to reproduce in model simulations, especially the subtropical warmth at the high-latitude surface oceans, inferred from the archaeal lipid-based palaeothermometry, . Here we revisit the interpretation by analysing a global collection of multi-proxy temperature estimates from sediment cores spanning millennia to millions of years. Comparing the variability between proxy types, we demonstrate that the present interpretation overestimates the magnitude of past climate changes on all timescales. We attribute this to an inappropriate calibration, which reflects subsurface ocean but is calibrated to the sea surface, where the latitudinal temperature gradient is steeper. Recalibrating the proxy to the temperatures of subsurface ocean, where the signal is probably formed, yields colder -temperatures and latitudinal gradient consistent with standard climate model simulations of the Eocene climate, invalidating the apparent, extremely warm polar sea surface temperatures. We conclude that there is a need to reinterpret -inferred marine temperature records in the literature, especially for reconstructions of past warm climates that rely heavily on this proxy as reflecting subsurface ocean.

  10. Real-time optoacoustic monitoring of temperature in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Larina, Irina V [Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX 77555-0456 (United States); Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-0456 (United States); Larin, Kirill V [Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX 77555-0456 (United States); Esenaliev, Rinat O [Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX 77555-0456 (United States); Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-0456 (United States); Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555-0456 (United States)

    2005-08-07

    To improve the safety and efficacy of thermal therapy, it is necessary to map tissue temperature in real time with submillimetre spatial resolution. Accurate temperature maps may provide the necessary control of the boundaries of the heated regions and minimize thermal damage to surrounding normal tissues. Current imaging modalities fail to monitor tissue temperature in real time with high resolution and accuracy. We investigated a non-invasive optoacoustic method for accurate, real-time monitoring of tissue temperature during thermotherapy. In this study, we induced temperature gradients in tissue and tissue-like samples and monitored the temperature distribution using the optoacoustic technique. The fundamental harmonic of a Q-switched Nd : YAG laser ({lambda} = 1064 nm) was used for optoacoustic wave generation and probing of tissue temperature. The tissue temperature was also monitored with a multi-sensor temperature probe inserted in the samples. Good agreement between optoacoustically measured and actual tissue temperatures was obtained. The accuracy of temperature monitoring was better than 1{sup 0}C, while the spatial resolution was about 1 mm. These data suggest that the optoacoustic technique has the potential to be used for non-invasive, real-time temperature monitoring during thermotherapy.

  11. Surface Intermediates on Metal Electrodes at High Temperature

    DEFF Research Database (Denmark)

    Zachau-Christiansen, Birgit; Jacobsen, Torben; Bay, Lasse

    1997-01-01

    The mechanisms widely suggested for the O2-reduc-tion or H2-oxidation SOFC reactions involve inter-mediate O/H species adsorbed on the electrode surface. The presence of these intermediates is investigated by linear sweep voltammetry. In airat moderate temperatures (500øC) Pt in contact with YSZ ...... is covered with adsorbed oxygen which vanishes at high temperature (1000øC). On Ni (YSZ) a specific layer of NiO is observed abovethe equilibrium potential while no surface species can identified at SOFC anode conditions....

  12. Determination of sea surface temperatures from microwave and IR data

    Science.gov (United States)

    Rangaswamy, S.; Grover, J.

    1982-01-01

    Microwave measurements from the Nimbus 7 SMMR were used to derive the atmospheric precipitable water, which was then used to obtain the atmospheric correction for use with AVHRR thermal IR measurements to obtain sea surface temperature (SST). The resulting SST's were compared with the NOAA operational sea surface temperature measurements, and the two sets of measurements were found to be in reasonable agreement. The average residuals between the two sets of measurements was 0.15 K with the NOAA operational SST's being slightly greater.

  13. Surface intermediates on metal electrodes at high temperatures

    DEFF Research Database (Denmark)

    Zachau-Christiansen, Birgit; Jacobsen, Torben; Bay, Lasse;

    1998-01-01

    in contact with YSZ is covered with adsorbed oxygen which vanishes at high temperature (1000 degrees C). On Ni (YSZ) a specific layer of NiO is observed above the equilibrium potential while no surface species involving hydrogen can be identified at SOFC anode conditions. (C) 1998 Published by Elsevier......The mechanisms widely conceived for the O(2)-reduction or H(2)-oxidation reactions in SOFC's involve intermediate O/H species adsorbed on the electrode surface. The presence of these intermediates is investigated by linear sweep voltammetry. In air at moderate temperatures (500 degrees C) Pt...

  14. Surface air temperature variability in global climate models

    CERN Document Server

    Davy, Richard

    2012-01-01

    New results from the Coupled Model Inter-comparison Project phase 5 (CMIP5) and multiple global reanalysis datasets are used to investigate the relationship between the mean and standard deviation in the surface air temperature. A combination of a land-sea mask and orographic filter were used to investigate the geographic region with the strongest correlation and in all cases this was found to be for low-lying over-land locations. This result is consistent with the expectation that differences in the effective heat capacity of the atmosphere are an important factor in determining the surface air temperature response to forcing.

  15. Finite element simulation for mechanical response of surface mounted solder joints under different temperature cycling

    Institute of Scientific and Technical Information of China (English)

    马鑫; 钱乙余

    2001-01-01

    Nonlinear finite element simulation for mechanical response of surface mounted solder joint under different temperature cycling was carried out. Seven sets of parameters were used in order to evaluate the influence of temperature cycling profile parameters. The results show that temperature cycling history has significant effect on the stress response of the solder joint. Based on the concept of relative damage stress proposed by the authors, it is found that enough high temperature holding time is necessary for designing the temperature cycling profile in accelerated thermal fatigue test.

  16. Computer Modeling of Planetary Surface Temperatures in Introductory Astronomy Courses

    Science.gov (United States)

    Barker, Timothy; Goodman, J.

    2013-01-01

    Barker, T., and Goodman, J. C., Wheaton College, Norton, MA Computer modeling is an essential part of astronomical research, and so it is important that students be exposed to its powers and limitations in the first (and, perhaps, only) astronomy course they take in college. Building on the ideas of Walter Robinson (“Modeling Dynamic Systems,” Springer, 2002) we have found that STELLA software (ISEE Systems) allows introductory astronomy students to do sophisticated modeling by the end of two classes of instruction, with no previous experience in computer programming or calculus. STELLA’s graphical interface allows students to visualize systems in terms of “flows” in and out of “stocks,” avoiding the need to invoke differential equations. Linking flows and stocks allows feedback systems to be constructed. Students begin by building an easily understood system: a leaky bucket. This is a simple negative feedback system in which the volume in the bucket (a “stock”) depends on a fixed inflow rate and an outflow that increases in proportion to the volume in the bucket. Students explore how changing inflow rate and feedback parameters affect the steady-state volume and equilibration time of the system. This model is completed within a 50-minute class meeting. In the next class, students are given an analogous but more sophisticated problem: modeling a planetary surface temperature (“stock”) that depends on the “flow” of energy from the Sun, the planetary albedo, the outgoing flow of infrared radiation from the planet’s surface, and the infrared return from the atmosphere. Students then compare their STELLA model equilibrium temperatures to observed planetary temperatures, which agree with model ones for worlds without atmospheres, but give underestimates for planets with atmospheres, thus introducing students to the concept of greenhouse warming. We find that if we give the students part of this model at the start of a 50-minute class they are

  17. Investigation of transient temperature's influence on damage of high-speed sliding electrical contact rail surface

    Science.gov (United States)

    Zhang, Yuyan; Sun, Shasha; Guo, Quanli; Yang, Degong; Sun, Dongtao

    2016-11-01

    In the high speed sliding electrical contact with large current, the temperature of contact area rises quickly under the coupling action of the friction heating, the Joule heating and electric arc heating. The rising temperature seriously affects the conductivity of the components and the yield strength of materials, as well affects the contact state and lead to damage, so as to shorten the service life of the contact elements. Therefore, there is vital significance to measure the temperature accurately and investigate the temperature effect on damage of rail surface. Aiming at the problem of components damage in high speed sliding electrical contact, the transient heat effect on the contact surface was explored and its influence and regularity on the sliding components damage was obtained. A kind of real-time temperature measurement method on rail surface of high speed sliding electrical contact is proposed. Under the condition of 2.5 kA current load, based on the principle of infrared radiation non-contact temperature sensor was used to measure the rail temperature. The dynamic distribution of temperature field was obtained through the simulation analysis, further, the connection between temperature changes and the rail surface damage morphology, the damage volume was analyzed and established. Finally, the method to reduce rail damage and improve the life of components by changing the temperature field was discussed.

  18. Observing the Agulhas Current with sea surface temperature and altimetry data: challenges and perspectives

    CSIR Research Space (South Africa)

    Krug, Marjolaine, J

    2014-06-01

    Full Text Available -Red Sea Surface Temperature datasets still suffer from inadequate cloud masking algorithms, particularly in regions of strong temperature gradient. Despite both Sea Surface Height and Sea Surface Temperature observations being severely compromised...

  19. The Land Surface Temperature Impact to Land Cover Types

    Science.gov (United States)

    Ibrahim, I.; Abu Samah, A.; Fauzi, R.; Noor, N. M.

    2016-06-01

    Land cover type is an important signature that is usually used to understand the interaction between the ground surfaces with the local temperature. Various land cover types such as high density built up areas, vegetation, bare land and water bodies are areas where heat signature are measured using remote sensing image. The aim of this study is to analyse the impact of land surface temperature on land cover types. The objectives are 1) to analyse the mean temperature for each land cover types and 2) to analyse the relationship of temperature variation within land cover types: built up area, green area, forest, water bodies and bare land. The method used in this research was supervised classification for land cover map and mono window algorithm for land surface temperature (LST) extraction. The statistical analysis of post hoc Tukey test was used on an image captured on five available images. A pixel-based change detection was applied to the temperature and land cover images. The result of post hoc Tukey test for the images showed that these land cover types: built up-green, built up-forest, built up-water bodies have caused significant difference in the temperature variation. However, built up-bare land did not show significant impact at p<0.05. These findings show that green areas appears to have a lower temperature difference, which is between 2° to 3° Celsius compared to urban areas. The findings also show that the average temperature and the built up percentage has a moderate correlation with R2 = 0.53. The environmental implications of these interactions can provide some insights for future land use planning in the region.

  20. Daytime sensible heat flux estimation over heterogeneous surfaces using multitemporal land-surface temperature observations

    Science.gov (United States)

    Castellví, F.; Cammalleri, C.; Ciraolo, G.; Maltese, A.; Rossi, F.

    2016-05-01

    Equations based on surface renewal (SR) analysis to estimate the sensible heat flux (H) require as input the mean ramp amplitude and period observed in the ramp-like pattern of the air temperature measured at high frequency. A SR-based method to estimate sensible heat flux (HSR-LST) requiring only low-frequency measurements of the air temperature, horizontal mean wind speed, and land-surface temperature as input was derived and tested under unstable conditions over a heterogeneous canopy (olive grove). HSR-LST assumes that the mean ramp amplitude can be inferred from the difference between land-surface temperature and mean air temperature through a linear relationship and that the ramp frequency is related to a wind shear scale characteristic of the canopy flow. The land-surface temperature was retrieved by integrating in situ sensing measures of thermal infrared energy emitted by the surface. The performance of HSR-LST was analyzed against flux tower measurements collected at two heights (close to and well above the canopy top). Crucial parameters involved in HSR-LST, which define the above mentioned linear relationship, were explained using the canopy height and the land surface temperature observed at sunrise and sunset. Although the olive grove can behave as either an isothermal or anisothermal surface, HSR-LST performed close to H measured using the eddy covariance and the Bowen ratio energy balance methods. Root mean square differences between HSR-LST and measured H were of about 55 W m-2. Thus, by using multitemporal thermal acquisitions, HSR-LST appears to bypass inconsistency between land surface temperature and the mean aerodynamic temperature. The one-source bulk transfer formulation for estimating H performed reliable after calibration against the eddy covariance method. After calibration, the latter performed similar to the proposed SR-LST method.

  1. New indexing and surface temperature analysis of exoplanets

    CERN Document Server

    Kashyap, J M; Safonova, M

    2016-01-01

    Study of exoplanets is the holy grail of present research in planetary sciences and astrobiology. Analysis of huge planetary data from space missions such as CoRoT and Kepler is directed ultimately at finding a planet similar to Earth\\-the Earth's twin, and answering the question of potential exo-habitability. The Earth Similarity Index (ESI) is a first step in this quest, ranging from 1 (Earth) to 0 (totally dissimilar to Earth). It was defined for the four physical parameters of a planet: radius, density, escape velocity and surface temperature. The ESI is further sub-divided into interior ESI (geometrical mean of radius and density) and surface ESI (geometrical mean of escape velocity and surface temperature). The challenge here is to determine which exoplanet parameter(s) is important in finding this similarity; how exactly the individual parameters entering the interior ESI and surface ESI are contributing to the global ESI. Since the surface temperature entering surface ESI is a non-observable quantity,...

  2. Influence of Sensor Ingestion Timing on Consistency of Temperature Measures

    Science.gov (United States)

    2009-01-01

    Copyright @ 200 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.9 Influence of Sensor Ingestion ... Ingestion Timing on Consistency of Temperature Measures. Med. Sci. Sports Exerc., Vol. 41, No. 3, pp. 597–602, 2009. Purpose: The validity and the...reliability of using intestinal temperature (Tint) via ingestible temperature sensors (ITS) to measure core body temperature have been demonstrated. However

  3. INVESTIGATION OF SURFACE TEMPERATURE IN HIGH-EFFICIENCY DEEP GRINDING

    Institute of Scientific and Technical Information of China (English)

    Zhao Henghua; Cai Guangqi; Jin Tan

    2005-01-01

    A new thermal model with triangular heat flux distribution is given in high-efficiency deep grinding. The mathematical expressions are driven to calculate the surface temperature. The transient behavior of the maximum temperature on contact area is investigated in different grinding conditions with a J-type thermocouple. The maximum contact temperatures measured in different conditions are found to be between 1 000 ℃ and 1 500 ℃ in burn-out conditions. The experiment results show good agreement with the new thermal model.

  4. Analysis of the sensible heat flux from the exterior surface of buildings using time sequential thermography

    Science.gov (United States)

    Hoyano, Akira; Asano, Kohichi; Kanamaru, Takehisa

    In this study, the distribution of surface temperature on the surface of two buildings having different characteristics was measured using a thermal infrared camera. Measurements were made in the summer, the period in Japan during which heat flux from buildings is of major interest, and again in the winter for comparison purposes. The heat characteristics of each building were obtained throughout the day by time-sequential thermography (TST), and the surface temperature of each physical element was classified according to temperature, shape, material and position. When the temperature of a surface could not be determined by an infrared camera mounted on the top of a building or a pole, temperature measurements were made using a hand-held IR camera. In addition, the sensible heat flux from each surface was calculated using TST and the surface area of each element as calculated from blueprints of the buildings.

  5. On-Line Life Monitoring Technique for Tube Bundles of Boiler High-Temperature Heating Surface

    Institute of Scientific and Technical Information of China (English)

    Yang Dong; Wang Zhongyuan

    2005-01-01

    High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and economic operation of boiler. An on-line life monitoring model of high-temperature heating surface was set up according to the well-known L-M formula of the creep damages. The tube wall metal temperature and working stress was measured by on-line monitoring, and with this model, the real-time calculation of the life expenditure of the heating surface tube bundles were realized. Based on the technique the on-line life monitoring and management system of high-temperature heating surface was developed for a 300 MW utility boiler. An effective device was thus suggested for the implementation of the safe operation and the condition-based maintenance of utility boilers.

  6. SISTEM PENGENDALIAN TEMPERATUR PADA DINDING BIOREAKTOR ANAEROB SECARA REAL TIME

    Directory of Open Access Journals (Sweden)

    Ika Nurina Rachmawati

    2013-03-01

    Full Text Available Temperatur merupakan salah satu faktor yang mempengaruhi proses anaerob pada bioreaktor. Dimana pertumbuhan mikroorganisme dipengaruhi oleh perubahan suhu. Maka dari itu akan dilakukan pengendalian temperatur secara real-time pada dinding tabung bioreaktor anaerob. Pengendalian temperatur berguna untuk menjaga suhu permukaan bioreaktor saat terjadi perubahan cuaca dari luar. Sebab jika temperatur dinding dijaga pada suhu 35 0C maka temperatur dalam tabung bioreaktor akan berada pada range operasionalnya. Sistem pengendalian temperatur pada dinding bioreaktor berupa elemen pemanas atau heater yang diletakkan pada dinding bioreaktor. Pengukuran temperatur dilakukan pada 3 posisi yaitu temperatur luar, temperature dinding dan temperatur dalam tabung bioreaktor. Pengujian sistem pengendalian dilakukan dengan memberi gangguan pada dinding bioreaktor berupa aliran air dingin pada dinding bioreaktor ketika kondisi telah stabil dengan mengamati pHnya. Pemberian gangguan dilakukan selama beberapa saat hingga terjadi penurunan temperatur di dalam tabung bioreaktor. Dengan turunnya temperatur maka kontroler akan bekerja untuk mencapai temperatur yang diinginkan sesuai dengan setpoint yang diberikan. Hasil pengujian menunjukkan bahwa sistem pengendalian temperatur berhasil menjaga suhu dinding bioreaktor anaerob pada suhu 35 0C dari temperatur 25 0C dalam waktu 1900 detik.

  7. The effects of artificial surface temperature on mechanical properties and player kinematics during landing and acceleration

    Institute of Scientific and Technical Information of China (English)

    Laura Charalambous a; Wolfgang Potthast c; Gareth Irwin b

    2016-01-01

    Background: Artificial turf is considered a feasible global alternative to natural turf by many sports governing bodies. Consequently, its ability to provide a safe and consistent playing surface regardless of climate becomes essential. The aims of this study were to determine the effects of artificial surface temperature on:(1) mechanical properties of the turf and (2) the kinematics of a turf-sport related movement. Methods: Two identical artificial turf pitches were tested:one with a cold surface temperature (1.8°C–2.4°C) and one with a warm surface temperature (14.5°C–15.2°C). Mechanical testing was performed to measure the surface properties. Four amateur soccer players performed a hurdle jump to sprint acceleration movement, with data (contact time, step length and hip, knee and ankle kinematics) collected using CODASport (200 Hz). Results: The temperature difference had a significant influence on the mechanical properties of the artificial turf, including force absorption, energy restitution, rotational resistance, and the height where the head injury criterion was met. Both step length (p=0.008) and contact time (p=0.002) of the initial step after the landing were significantly longer on the warm surface. In addition, significant range of motion and joint angular velocity differences were found. Conclusion: These findings highlight different demands placed on players due to the surface temperature and suggest a need for coaches, practitioners, and sports governing bodies to be aware of these differences.

  8. A comparison of all-weather land surface temperature products

    Science.gov (United States)

    Martins, Joao; Trigo, Isabel F.; Ghilain, Nicolas; Goettche, Frank-M.; Ermida, Sofia; Olesen, Folke-S.; Gellens-Meulenberghs, Françoise; Arboleda, Alirio

    2017-04-01

    The Satellite Application Facility on Land Surface Analysis (LSA-SAF, http://landsaf.ipma.pt) has been providing land surface temperature (LST) estimates using SEVIRI/MSG on an operational basis since 2006. The LSA-SAF service has since been extended to provide a wide range of satellite-based quantities over land surfaces, such as emissivity, albedo, radiative fluxes, vegetation state, evapotranspiration, and fire-related variables. Being based on infra-red measurements, the SEVIRI/MSG LST product is limited to clear-sky pixels only. Several all-weather LST products have been proposed by the scientific community either based on microwave observations or using Soil-Vegetation-Atmosphere Transfer models to fill the gaps caused by clouds. The goal of this work is to provide a nearly gap-free operational all-weather LST product and compare these approaches. In order to estimate evapotranspiration and turbulent energy fluxes, the LSA-SAF solves the surface energy budget for each SEVIRI pixel, taking into account the physical and physiological processes occurring in vegetation canopies. This task is accomplished with an adapted SVAT model, which adopts some formulations and parameters of the Tiled ECMWF Scheme for Surface Exchanges over Land (TESSEL) model operated at the European Center for Medium-range Weather Forecasts (ECMWF), and using: 1) radiative inputs also derived by LSA-SAF, which includes surface albedo, down-welling fluxes and fire radiative power; 2) a land-surface characterization obtained by combining the ECOCLIMAP database with both LSA-SAF vegetation products and the H(ydrology)-SAF snow mask; 3) meteorological fields from ECMWF forecasts interpolated to SEVIRI pixels, and 4) soil moisture derived by the H-SAF and LST from LSA-SAF. A byproduct of the SVAT model is surface skin temperature, which is needed to close the surface energy balance. The model skin temperature corresponds to the radiative temperature of the interface between soil and atmosphere

  9. The Sensitivity of African Easterly Waves to Eastern Tropical Atlantic Sea-Surface Temperatures

    Science.gov (United States)

    Druyan, Leonard M.; Fulakeza, Matthew

    2011-01-01

    The results of two regional atmospheric model simulations are compared to assess the influence of the eastern tropical Atlantic sea-surface temperature maximum on local precipitation, transient easterly waves and the West African summer monsoon. Both model simulations were initialized with reanalysis 2 data (US National Center for Environmental Prediction and Department of Energy) on 15 May 2006 and extended through 6 October 2006, forced by synchronous reanalysis 2 lateral boundary conditions introduced four times daily. One simulation uses 2006 reanalysis 2 sea-surface temperatures, also updated four times daily, while the second simulation considers ocean forcing absent the sea-surface temperature maximum, achieved here by subtracting 3 K at every ocean grid point between 0 and 15 N during the entire simulation. The simulation with 2006 sea-surface temperature forcing produces a realistic distribution of June-September mean precipitation and realistic westward propagating swaths of maximum rainfall, based on validation against Tropical Rainfall Measuring Mission (TRMM) estimates. The simulation without the sea-surface temperature maximum produces only 57% of the control June-September total precipitation over the eastern tropical Atlantic and about 83% of the Sahel precipitation. The simulation with warmer ocean temperatures generates generally stronger circulation, which in turn enhances precipitation by increasing moisture convergence. Some local precipitation enhancement is also attributed to lower vertical thermal stability above the warm water. The study shows that the eastern tropical Atlantic sea-surface temperature maximum enhances the strength of transient easterly waves and broadens the spatial extent of associated precipitation. However, large-scale circulation and its interaction with the African continent, and not sea-surface temperatures, control the timing and trajectories of the waves.

  10. Enzyme surface rigidity tunes the temperature dependence of catalytic rates.

    Science.gov (United States)

    Isaksen, Geir Villy; Åqvist, Johan; Brandsdal, Bjørn Olav

    2016-07-12

    The structural origin of enzyme adaptation to low temperature, allowing efficient catalysis of chemical reactions even near the freezing point of water, remains a fundamental puzzle in biocatalysis. A remarkable universal fingerprint shared by all cold-active enzymes is a reduction of the activation enthalpy accompanied by a more negative entropy, which alleviates the exponential decrease in chemical reaction rates caused by lowering of the temperature. Herein, we explore the role of protein surface mobility in determining this enthalpy-entropy balance. The effects of modifying surface rigidity in cold- and warm-active trypsins are demonstrated here by calculation of high-precision Arrhenius plots and thermodynamic activation parameters for the peptide hydrolysis reaction, using extensive computer simulations. The protein surface flexibility is systematically varied by applying positional restraints, causing the remarkable effect of turning the cold-active trypsin into a variant with mesophilic characteristics without changing the amino acid sequence. Furthermore, we show that just restraining a key surface loop causes the same effect as a point mutation in that loop between the cold- and warm-active trypsin. Importantly, changes in the activation enthalpy-entropy balance of up to 10 kcal/mol are almost perfectly balanced at room temperature, whereas they yield significantly higher rates at low temperatures for the cold-adapted enzyme.

  11. Temperature limit values for touching cold surfaces with the fingertip

    NARCIS (Netherlands)

    Geng, Q.; Holme, I.; Hartog, E.A. den; Havenith, G.; Jay, O.; Malchaires, J.; Piette, A.; Rintama, H.; Rissanen, S.

    2006-01-01

    Objectives: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold

  12. Temperature limit values for touching cold surfaces with the fingertip

    NARCIS (Netherlands)

    Geng, Q.; Holme, I.; Hartog, E.A. den; Havenith, G.; Jay, O.; Malchaires, J.; Piette, A.; Rintama, H.; Rissanen, S.

    2006-01-01

    Objectives: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfa

  13. Climate Prediction Center (CPC) Global Land Surface Air Temperature Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A station observation-based global land monthly mean surface air temperature dataset at 0.5 x 0.5 latitude-longitude resolution for the period from 1948 to the...

  14. Quantifying and specifying the solar influence on terrestrial surface temperature

    NARCIS (Netherlands)

    de Jager, C.; Duhau, S.; van Geel, B.

    2010-01-01

    This investigation is a follow-up of a paper in which we showed that both major magnetic components of the solar dynamo, viz. the toroidal and the poloidal ones, are correlated with average terrestrial surface temperatures. Here, we quantify, improve and specify that result and search for their caus

  15. A physically based model of global freshwater surface temperature

    NARCIS (Netherlands)

    Beek, van L.P.H.; Eikelboom, T.; Vliet, van M.T.H.; Bierkens, M.F.P.

    2012-01-01

    Temperature determines a range of physical properties of water and exerts a strong control on surface water biogeochemistry. Thus, in freshwater ecosystems the thermal regime directly affects the geographical distribution of aquatic species through their growth and metabolism and indirectly through

  16. Climate Prediction Center (CPC) Global Land Surface Air Temperature Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A station observation-based global land monthly mean surface air temperature dataset at 0.5 0.5 latitude-longitude resolution for the period from 1948 to the present...

  17. Processes of India's offshore summer intraseasonal sea surface temperature variability

    Digital Repository Service at National Institute of Oceanography (India)

    Kurian, N.; Lengaigne, M.; Gopalakrishna, V.V.; Vialard, J.; Pous, S.; Peter, A-C.; Durand; Naik, Shweta

    ., vol.63; 2013; 329-346 Processes of India’s offshore summer intraseasonal sea surface temperature variability K. Nisha1, M. Lengaigne1,2, V.V. Gopalakrishna,1 J. Vialard2, S. Pous2, A.-C. Peter2, F. Durand3, S.Naik1 1. NIO, CSIR, Goa, India 2...

  18. A physically based model of global freshwater surface temperature

    NARCIS (Netherlands)

    Beek, van L.P.H.; Eikelboom, T.; Vliet, van M.T.H.; Bierkens, M.F.P.

    2012-01-01

    Temperature determines a range of physical properties of water and exerts a strong control on surface water biogeochemistry. Thus, in freshwater ecosystems the thermal regime directly affects the geographical distribution of aquatic species through their growth and metabolism and indirectly through

  19. Surface temperature maps for II Peg during 1999-2002

    CERN Document Server

    Lindborg, M; Tuominen, I; Hackman, T; Ilyin, I; Piskunov, N

    2009-01-01

    The active RS CVn star II Peg has been spectroscopically monitored for almost 18 years with the SOFIN spectrograph at NOT, La Palma, Spain. In this paper we present five new surface temperature maps of the object for the years 1999 (two maps), 2001 (one map) and 2002 (two maps).

  20. A Microring Temperature Sensor Based on the Surface Plasmon Wave

    Directory of Open Access Journals (Sweden)

    Wenchao Li

    2015-01-01

    Full Text Available A structure of microring sensor suitable for temperature measurement based on the surface plasmon wave is put forward in this paper. The sensor uses surface plasmon multilayer waveguiding structure in the vertical direction and U-shaped microring structure in the horizontal direction and utilizes SOI as the thermal material. The transfer function derivation of the structure of surface plasmon microring sensor is according to the transfer matrix method. While the change of refractive index of Si is caused by the change of ambient temperature, the effective refractive index of the multilayer waveguiding structure is changed, resulting in the drifting of the sensor output spectrum. This paper focuses on the transmission characteristics of multilayer waveguide structure and the impact on the output spectrum caused by refractive index changes in temperature parts. According to the calculation and simulation, the transmission performance of the structure is stable and the sensitivity is good. The resonance wavelength shift can reach 0.007 μm when the temperature is increased by 100 k and FSR can reach about 60 nm. This structure achieves a high sensitivity in the temperature sense taking into account a wide range of filter frequency selections, providing a theoretical basis for the preparation of microoptics.

  1. A review of progress towards understanding the transient global mean surface temperature response to radiative perturbation

    Science.gov (United States)

    Yoshimori, Masakazu; Watanabe, Masahiro; Shiogama, Hideo; Oka, Akira; Abe-Ouchi, Ayako; Ohgaito, Rumi; Kamae, Youichi

    2016-12-01

    The correct understanding of the transient response to external radiative perturbation is important for the interpretation of observed climate change, the prediction of near-future climate change, and committed warming under climate stabilization scenarios, as well as the estimation of equilibrium climate sensitivity based on observation data. It has been known for some time that the radiative damping rate per unit of global mean surface temperature increase varies with time, and this inconstancy affects the transient response. Knowledge of the equilibrium response alone is insufficient, but understanding the transient response of the global mean surface temperature has made rapid progress. The recent progress accompanies the relatively new concept of the efficacies of ocean heat uptake and forcing. The ocean heat uptake efficacy associates the temperature response induced by ocean heat uptake with equilibrium temperature response, and the efficacy of forcing compares the temperature response caused by non-CO2 forcing with that by CO2 forcing.

  2. Modeling the surface temperature of Earth-like planets

    CERN Document Server

    Vladilo, G; Murante, G; Filippi, L; Provenzale, A

    2015-01-01

    We introduce a novel Earth-like planet surface temperature model (ESTM) for habitability studies based on the spatial-temporal distribution of planetary surface temperatures. The ESTM adopts a surface Energy Balance Model complemented by: radiative-convective atmospheric column calculations, a set of physically-based parameterizations of meridional transport, and descriptions of surface and cloud properties more refined than in standard EBMs. The parameterization is valid for rotating terrestrial planets with shallow atmospheres and moderate values of axis obliquity (epsilon >= 45^o). Comparison with a 3D model of atmospheric dynamics from the literature shows that the equator-to-pole temperature differences predicted by the two models agree within ~5K when the rotation rate, insolation, surface pressure and planet radius are varied in the intervals 0.5 <= Omega/Omega_o <= 2, 0.75 <= S/S_o <= 1.25, 0.3 <= p/(1 bar) <= 10, and 0.5 <= R/R_o <= 2, respectively. The ESTM has an extremely l...

  3. Modeling Apple Surface Temperature Dynamics Based on Weather Data

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-10-01

    Full Text Available The exposure of fruit surfaces to direct sunlight during the summer months can result in sunburn damage. Losses due to sunburn damage are a major economic problem when marketing fresh apples. The objective of this study was to develop and validate a model for simulating fruit surface temperature (FST dynamics based on energy balance and measured weather data. A series of weather data (air temperature, humidity, solar radiation, and wind speed was recorded for seven hours between 11:00–18:00 for two months at fifteen minute intervals. To validate the model, the FSTs of “Fuji” apples were monitored using an infrared camera in a natural orchard environment. The FST dynamics were measured using a series of thermal images. For the apples that were completely exposed to the sun, the RMSE of the model for estimating FST was less than 2.0 °C. A sensitivity analysis of the emissivity of the apple surface and the conductance of the fruit surface to water vapour showed that accurate estimations of the apple surface emissivity were important for the model. The validation results showed that the model was capable of accurately describing the thermal performances of apples under different solar radiation intensities. Thus, this model could be used to more accurately estimate the FST relative to estimates that only consider the air temperature. In addition, this model provides useful information for sunburn protection management.

  4. Temperature maps measurements on 3D surfaces with infrared thermography

    Energy Technology Data Exchange (ETDEWEB)

    Cardone, Gennaro; Ianiro, Andrea [University of Naples Federico II, Department of Aerospace Engineering (DIAS), Naples (Italy); Ioio, Gennaro dello [University of Cambridge, BP Institute for Multiphase Flow, Cambridge, England (United Kingdom); Passaro, Andrea [Alta SpA, Ospedaletto, PI (Italy)

    2012-02-15

    The use of the infrared camera as a temperature transducer in wind tunnel applications is convenient and widespread. Nevertheless, the infrared data are available in the form of 2D images while the observed surfaces are often not planar and the reconstruction of temperature maps over them is a critical task. In this work, after recalling the principles of IR thermography, a methodology to rebuild temperature maps on the surfaces of 3D object is proposed. In particular, an optical calibration is applied to the IR camera by means of a novel target plate with control points. The proposed procedure takes also into account the directional emissivity by estimating the viewing angle. All the needed steps are described and analyzed. The advantages given by the proposed method are shown with an experiment in a hypersonic wind tunnel. (orig.)

  5. A Surface Temperature Initiated Closure (STIC) for surface energy balance fluxes

    DEFF Research Database (Denmark)

    Mallick, Kaniska; Jarvis, Andrew J.; Boegh, Eva;

    2014-01-01

    of four state equations. Taking advantage of the psychrometric relationship between temperature and vapor pressure, the present method also estimates the near surface moisture availability (M) from TS, air temperature (TA) and relative humidity (RH), thereby being capable of decomposing λ...

  6. Ocean Surface Current Vectors from MODIS Terra/Aqua Sea Surface Temperature Image Pairs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Satellites that record imagery of the same sea surface area, at times separated by a few hours, can be used to estimate ocean surface velocity fields based on the...

  7. Quality control methods for KOOS operational sea surface temperature products

    Institute of Scientific and Technical Information of China (English)

    YANG Chansu; KIM Sunhwa

    2016-01-01

    Sea surface temperature SST obtained from the initial version of the Korea Operational Oceanographic System (KOOS) SST satellite have low accuracy during summer and daytime. This is attributed to the diurnal warming effect. Error estimation of SST data must be carried out to use the real-time forecasting numerical model of the KOOS. This study suggests two quality control methods for the KOOS SST system. To minimize the diurnal warming effect, SSTs of areas where wind speed is higher than 5 m/s were used. Depending on the wind threshold value, KOOS SST data for August 2014 were reduced by 0.15°C. Errors in SST data are considered to be a combination of random, sampling, and bias errors. To estimate bias error, the standard deviation of bias between KOOS SSTs and climatology SSTs were used. KOOS SST data yielded an analysis error standard deviation value similar to OSTIA and NOAA NCDC (OISST) data. The KOOS SST shows lower random and sampling errors with increasing number of observations using six satellite datasets. In further studies, the proposed quality control methods for the KOOS SST system will be applied through more long-term case studies and comparisons with other SST systems.

  8. Bias correction methods for decadal sea-surface temperature forecasts

    Directory of Open Access Journals (Sweden)

    Balachandrudu Narapusetty

    2014-04-01

    Full Text Available Two traditional bias correction techniques: (1 systematic mean correction (SMC and (2 systematic least-squares correction (SLC are extended and applied on sea-surface temperature (SST decadal forecasts in the North Pacific produced by Climate Forecast System version 2 (CFSv2 to reduce large systematic biases. The bias-corrected forecast anomalies exhibit reduced root-mean-square errors and also significantly improve the anomaly correlations with observations. The spatial pattern of the SST anomalies associated with the Pacific area average (PAA index (spatial average of SST anomalies over 20°–60°N and 120°E–100°W is improved after employing the bias correction methods, particularly SMC. Reliability diagrams show that the bias-corrected forecasts better reproduce the cold and warm events well beyond the 5-yr lead-times over the 10 forecasted years. The comparison between both correction methods indicates that: (1 prediction skill of SST anomalies associated with the PAA index is improved by SMC with respect to SLC and (2 SMC-derived forecasts have a slightly higher reliability than those corrected by SLC.

  9. Designing high-temperature steels via surface science and thermodynamics

    Science.gov (United States)

    Gross, Cameron T.; Jiang, Zilin; Mathai, Allan; Chung, Yip-Wah

    2016-06-01

    Electricity in many countries such as the US and China is produced by burning fossil fuels in steam-turbine-driven power plants. The efficiency of these power plants can be improved by increasing the operating temperature of the steam generator. In this work, we adopted a combined surface science and computational thermodynamics approach to the design of high-temperature, corrosion-resistant steels for this application. The result is a low-carbon ferritic steel with nanosized transition metal monocarbide precipitates that are thermally stable, as verified by atom probe tomography. High-temperature Vickers hardness measurements demonstrated that these steels maintain their strength for extended periods at 700 °C. We hypothesize that the improved strength of these steels is derived from the semi-coherent interfaces of these thermally stable, nanosized precipitates exerting drag forces on impinging dislocations, thus maintaining strength at elevated temperatures.

  10. New Measurements from Old Boreholes: A Look at Interaction Between Surface Air Temperature and Ground Surface Temperature

    Science.gov (United States)

    Heinle, S. M.; Gosnold, W. D.

    2007-12-01

    We recently logged new field measurements of several boreholes throughout the Midwest, including North Dakota, South Dakota, and Nebraska. We then compared these new measurements against measurements previously obtained. Our comparisons included inverse modeling of past and recent measurements as well as climate modeling based on past surface air temperatures obtained from the weather stations. The data show a good correlation between climate warming in the last century and ground surface warming. Of particular importance is that cooling of air temperatures beginning in the mid 1990s reflects in the ground surface temperatures. The boreholes included in the study consist of three boreholes located in north central North Dakota, including two deeper than 200 meters. Two boreholes in the southwestern part of South Dakota, and two from southeastern South Dakota, all approximately 180 meters deep. Also included, were two boreholes (135 meters and over 200 meters deep) located in southwestern Nebraska, and two boreholes in the panhandle of Nebraska, each over 100 meters deep. We obtained historical surface air temperature from climate stations located near the boreholes, both from the United States Historical Climatology Network and from the Western Regional Climate Center.

  11. Reconstructing Variations of Global Sea-Surface Temperature during the Last Interglaciation

    Science.gov (United States)

    Hoffman, J. S.; Clark, P. U.; He, F.; Parnell, A. C.

    2015-12-01

    The last interglaciation (LIG; ~130-116 ka) was the most recent period in Earth history with higher-than-present global sea level (≥6 m) under similar-to-preindustrial concentrations of atmospheric CO2, suggesting additional feedbacks related to albedo, insolation, and ocean circulation in generating the apparent climatic differences between the LIG and present Holocene. However, our understanding of how much warmer the LIG sea surface was relative to the present interglaciation remains uncertain, with current estimates suggesting from 0°C to 2°C warmer than late-20thcentury average global temperatures. Moreover, the timing, spatial expression, and amplitude of regional and global sea surface temperature variability related to other climate forcing during the LIG are poorly constrained, largely due to uncertainties in age control and proxy temperature reconstructions. An accurate characterization of global and regional temperature change during the LIG can serve as a benchmark for paleoclimate modeling intercomparison projects and help improve understanding of sea-level sensitivity to temperature change. We will present a global compilation (~100 published records) of sea surface temperature (SST) and other climate reconstructions spanning the LIG. Using a Monte Carlo-enabled cross-correlation maximization algorithm to climatostratigraphically align proxy records and then account for both the resulting chronologic and proxy calibration uncertainties with Bayesian statistical inference, our results quantify the spatial timing, amplitude, and uncertainty in estimates of global and regional sea surface temperature change during the LIG and its relation to potential forcings.

  12. Surface emissivity and temperature retrieval for a hyperspectral sensor

    Energy Technology Data Exchange (ETDEWEB)

    Borel, C.C.

    1998-12-01

    With the growing use of hyper-spectral imagers, e.g., AVIRIS in the visible and short-wave infrared there is hope of using such instruments in the mid-wave and thermal IR (TIR) some day. The author believes that this will enable him to get around using the present temperature-emissivity separation algorithms using methods which take advantage of the many channels available in hyper-spectral imagers. A simple fact used in coming up with a novel algorithm is that a typical surface emissivity spectrum are rather smooth compared to spectral features introduced by the atmosphere. Thus, a iterative solution technique can be devised which retrieves emissivity spectra based on spectral smoothness. To make the emissivities realistic, atmospheric parameters are varied using approximations, look-up tables derived from a radiative transfer code and spectral libraries. One such iterative algorithm solves the radiative transfer equation for the radiance at the sensor for the unknown emissivity and uses the blackbody temperature computed in an atmospheric window to get a guess for the unknown surface temperature. By varying the surface temperature over a small range a series of emissivity spectra are calculated. The one with the smoothest characteristic is chosen. The algorithm was tested on synthetic data using MODTRAN and the Salisbury emissivity database.

  13. Sea-surface temperature and salinity mapping from remote microwave radiometric measurements of brightness temperature

    Science.gov (United States)

    Hans-Juergen, C. B.; Kendall, B. M.; Fedors, J. C.

    1977-01-01

    A technique to measure remotely sea surface temperature and salinity was demonstrated with a dual frequency microwave radiometer system. Accuracies in temperature of 1 C and in salinity of part thousand for salinity greater than 5 parts per thousand were attained after correcting for the influence of extraterrestrial background radiation, atmospheric radiation and attenuation, sea-surface roughness, and antenna beamwidth. The radiometers, operating at 1.43 and 2.65 GHz, comprise a third-generation system using null balancing and feedback noise injection. Flight measurements from an aircraft at an altitude of 1.4 km over the lower Chesapeake Bay and coastal areas of the Atlantic Ocean resulted in contour maps of sea-surface temperature and salinity with a spatial resolution of 0.5 km.

  14. Prediction of Monthly Mean Surface Air Temperature in a Region of China

    Institute of Scientific and Technical Information of China (English)

    Jeong-Hyeong LEE; Keon-Tae SOHN

    2007-01-01

    In conventional time series analysis, a process is often modeled as three additive components: linear trend, seasonal effect, and random noise. In this paper, we perform an analysis of surface air temperature in a region of China using a decomposition method in time series analysis. Applications to the National Centers for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) Collaborative Reanalysis data in this region of China are discussed. The main finding was that the surface air temperature trend estimated for January 1948 to February 2006 was not statistically significant at 0.5904℃ (100 yr)-1.Forecasting aspects are also considered.

  15. Ultraviolet surface plasmon-mediated low temperature hydrazine decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Siying; Sheldon, Matthew T.; Atwater, Harry A. [Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States); Liu, Wei-Guang; Jaramillo-Botero, Andres; Goddard, William Andrew [Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-01-12

    Conventional methods require elevated temperatures in order to dissociate high-energy nitrogen bonds in precursor molecules such as ammonia or hydrazine used for nitride film growth. We report enhanced photodissociation of surface-absorbed hydrazine (N{sub 2}H{sub 4}) molecules at low temperature by using ultraviolet surface plasmons to concentrate the exciting radiation. Plasmonic nanostructured aluminum substrates were designed to provide resonant near field concentration at λ = 248 nm (5 eV), corresponding to the maximum optical cross section for hydrogen abstraction from N{sub 2}H{sub 4}. We employed nanoimprint lithography to fabricate 1 mm × 1 mm arrays of the resonant plasmonic structures, and ultraviolet reflectance spectroscopy confirmed resonant extinction at 248 nm. Hydrazine was cryogenically adsorbed to the plasmonic substrate in a low-pressure ambient, and 5 eV surface plasmons were resonantly excited using a pulsed KrF laser. Mass spectrometry was used to characterize the photodissociation products and indicated a 6.2× overall enhancement in photodissociation yield for hydrazine adsorbed on plasmonic substrates compared with control substrates. The ultraviolet surface plasmon enhanced photodissociation demonstrated here may provide a valuable method to generate reactive precursors for deposition of nitride thin film materials at low temperatures.

  16. Reconstruction of MODIS daily land surface temperature under clouds

    Science.gov (United States)

    Sun, L.; Gao, F.; Chen, Z.; Song, L.; Xie, D.

    2015-12-01

    Land surface temperature (LST), generally defined as the skin temperature of the Earth's surface, controls the process of evapotranspiration, surface energy balance, soil moisture change and climate change. Moderate Resolution Imaging Spectrometer (MODIS) is equipped with 1km resolution thermal sensor andcapable of observing the earth surface at least once per day.Thermal infrared bands cannot penetrate cloud, which means we cannot get consistency drought monitoring condition at one area. However, the cloudy-sky conditions represent more than half of the actual day-to-day weather around the global. In this study, we developed an LST filled model based on the assumption that under good weather condition, LST difference between two nearby pixels are similar among the closest 8 days. We used all the valid pixels covered by a 9*9 window to reconstruct the gap LST. Each valid pixel is assigned a weight which is determined by the spatial distance and the spectral similarity. This model is applied in the Middle-East of China including Gansu, Ningxia, Shaanxi province. The terrain is complicated in this area including plain and hill. The MODIS daily LST product (MOD11A3) from 2000 to 2004 is tested. Almost all the gap pixels are filled, and the terrain information is reconstructed well and smoothly. We masked two areas in order to validate the model, one located in the plain, another located in the hill. The correlation coefficient is greater than 0.8, even up to 0.92 in a few days. We also used ground measured day maximum and mean surface temperature to valid our model. Although both the temporal and spatial scale are different between ground measured temperature and MODIS LST, they agreed well in all the stations. This LST filled model is operational because it only needs LST and reflectance, and does not need other auxiliary information such as climate factors. We will apply this model to more regions in the future.

  17. Dynamic time warping for temperature compensation in structural health monitoring

    Science.gov (United States)

    Douglass, Alexander; Harley, Joel B.

    2017-02-01

    Guided wave structural health monitoring uses ultrasonic waves to identify changes in structures. To identify these changes, most guided wave methods require a pristine baseline measurement with which other measurements are compared. Damage signatures arise when there is a deviation between the baseline and the recorded measurement. However, temperature significantly complicates this analysis by creating misalignment between the baseline and measurements. This leads to false alarms of damage and significantly reduces the reliability of these systems. Several methods have been created to account for these temperature perturbations. Yet, most of these compensation methods fail in harsh, highly variable temperature conditions or require a prohibitive amount of prior data. In this paper, we use an algorithm known as dynamic time warping to compensate for temperature in these harsh conditions. We demonstrate that dynamic time warping is able to account for temperature variations whereas the more traditional baseline signal stretch method is unable to resolve damage under high temperature fluctuations.

  18. Temperature Distribution and Heat Saturating Time of Regenerative Heat Transfer

    Institute of Scientific and Technical Information of China (English)

    Li JIA; Ying MAO; Lixin YANG

    2006-01-01

    In this paper, heat transfer of the ceramic honeycomb regenerator was numerically simulated based on the computational fluid dynamics numerical analysis software CFX5. The longitudinal temperature distribution of regenerator and gas were obtained. The variation of temperature with time was discussed. In addition, the effects of some parameters such as switching time, gas temperature at the inlet of regenerator, height of regenerator and specific heat of the regenerative materials on heat saturating time were discussed. It provided primarily theoretic basis for further study of regenerative heat transfer mechanism.

  19. Spatial-temporal analysis of building surface temperatures in Hung Hom

    Science.gov (United States)

    Zeng, Ying; Shen, Yueqian

    2015-12-01

    This thesis presents a study on spatial-temporal analysis of building surface temperatures in Hung Hom. Observations were collected from Aug 2013 to Oct 2013 at a 30-min interval, using iButton sensors (N=20) covering twelve locations in Hung Hom. And thermal images were captured in PolyU from 05 Aug 2013 to 06 Aug 2013. A linear regression model of iButton and thermal records is established to calibrate temperature data. A 3D modeling system is developed based on Visual Studio 2010 development platform, using ArcEngine10.0 component, Microsoft Access 2010 database and C# programming language. The system realizes processing data, spatial analysis, compound query and 3D face temperature rendering and so on. After statistical analyses, building face azimuths are found to have a statistically significant relationship with sun azimuths at peak time. And seasonal building temperature changing also corresponds to the sun angle and sun azimuth variations. Building materials are found to have a significant effect on building surface temperatures. Buildings with lower albedo materials tend to have higher temperatures and larger thermal conductivity material have significant diurnal variations. For the geographical locations, the peripheral faces of campus have higher temperatures than the inner faces during day time and buildings located at the southeast are cooler than the western. Furthermore, human activity is found to have a strong relationship with building surface temperatures through weekday and weekend comparison.

  20. Near–surface air temperature and snow skin temperature comparison from CREST-SAFE station data with MODIS land surface temperature data

    Directory of Open Access Journals (Sweden)

    C. L. Pérez Díaz

    2015-08-01

    Full Text Available Land Surface Temperature (LST is a key variable (commonly studied to understand the hydrological cycle that helps drive the energy balance and water exchange between the Earth's surface and its atmosphere. One observable constituent of much importance in the land surface water balance model is snow. Snow cover plays a critical role in the regional to global scale hydrological cycle because rain-on-snow with warm air temperatures accelerates rapid snow-melt, which is responsible for the majority of the spring floods. Accurate information on near-surface air temperature (T-air and snow skin temperature (T-skin helps us comprehend the energy and water balances in the Earth's hydrological cycle. T-skin is critical in estimating latent and sensible heat fluxes over snow covered areas because incoming and outgoing radiation fluxes from the snow mass and the air temperature above make it different from the average snowpack temperature. This study investigates the correlation between MODerate resolution Imaging Spectroradiometer (MODIS LST data and observed T-air and T-skin data from NOAA-CREST-Snow Analysis and Field Experiment (CREST-SAFE for the winters of 2013 and 2014. LST satellite validation is imperative because high-latitude regions are significantly affected by climate warming and there is a need to aid existing meteorological station networks with the spatially continuous measurements provided by satellites. Results indicate that near-surface air temperature correlates better than snow skin temperature with MODIS LST data. Additional findings show that there is a negative trend demonstrating that the air minus snow skin temperature difference is inversely proportional to cloud cover. To a lesser extent, it will be examined whether the surface properties at the site are representative for the LST properties within the instrument field of view.

  1. Near-surface air temperature and snow skin temperature comparison from CREST-SAFE station data with MODIS land surface temperature data

    Science.gov (United States)

    Pérez Díaz, C. L.; Lakhankar, T.; Romanov, P.; Muñoz, J.; Khanbilvardi, R.; Yu, Y.

    2015-08-01

    Land Surface Temperature (LST) is a key variable (commonly studied to understand the hydrological cycle) that helps drive the energy balance and water exchange between the Earth's surface and its atmosphere. One observable constituent of much importance in the land surface water balance model is snow. Snow cover plays a critical role in the regional to global scale hydrological cycle because rain-on-snow with warm air temperatures accelerates rapid snow-melt, which is responsible for the majority of the spring floods. Accurate information on near-surface air temperature (T-air) and snow skin temperature (T-skin) helps us comprehend the energy and water balances in the Earth's hydrological cycle. T-skin is critical in estimating latent and sensible heat fluxes over snow covered areas because incoming and outgoing radiation fluxes from the snow mass and the air temperature above make it different from the average snowpack temperature. This study investigates the correlation between MODerate resolution Imaging Spectroradiometer (MODIS) LST data and observed T-air and T-skin data from NOAA-CREST-Snow Analysis and Field Experiment (CREST-SAFE) for the winters of 2013 and 2014. LST satellite validation is imperative because high-latitude regions are significantly affected by climate warming and there is a need to aid existing meteorological station networks with the spatially continuous measurements provided by satellites. Results indicate that near-surface air temperature correlates better than snow skin temperature with MODIS LST data. Additional findings show that there is a negative trend demonstrating that the air minus snow skin temperature difference is inversely proportional to cloud cover. To a lesser extent, it will be examined whether the surface properties at the site are representative for the LST properties within the instrument field of view.

  2. Approximating snow surface temperature from standard temperature and humidity data: new possibilities for snow model and remote sensing validation (Invited)

    Science.gov (United States)

    Raleigh, M. S.; Landry, C.; Hayashi, M.; Quinton, W. L.; Lundquist, J. D.

    2013-12-01

    The snow surface skin temperature (Ts) is important in the snowmelt energy balance, land-atmosphere interactions, weak layer formation (avalanche risk), and winter recreation, but is rarely measured at observational networks. Reliable Ts datasets are needed to validate remote sensing and distributed modeling, in order to represent land-atmosphere feedbacks. Previous research demonstrated that the dew point temperature (Td) close to the snow surface approximates Ts well because air is saturated immediately above snow. However, standard height (2 to 4 m) measurements of the saturation temperatures, Td and wet-bulb temperature (Tw), are much more readily available than measurements of Ts or near-surface Td. There is limited understanding of how these standard height variables approximate Ts, and how the approximations vary with climate, seasonality, time of day, and atmospheric conditions (stability and radiation). We used sub-daily measurements from seven sites in varying snow climates and environments to test Ts approximations with standard height temperature and moisture. Td produced the lowest bias (-2.2 °C to +2.6 °C) and root mean squared error (RMSE) when approximating mean daily Ts, but tended to underestimate daily extremes in Ts. For comparison, air temperature (Ta) was biased +3.2 °C to +6.8 °C. Ts biases increased with increasing frequency in nighttime stability and daytime clear sky conditions. We illustrate that mean daily Td can be used to detect systematic input data bias in physically-based snowmelt modeling, a useful tool when validating spatially distributed snow models in data sparse regions. Thus, improved understanding of Td variations can advance understanding of Ts in space and time, providing a simple yet robust measure of surface feedback to the atmospheric energy budget.

  3. Effect of temperature-dependent surface heat transfer coefficient on the maximum surface stress in ceramics during quenching

    Science.gov (United States)

    Shao, Y. F.; Song, F.; Jiang, C. P.; Xu, X. H.; Wei, J. C.; Zhou, Z. L.

    2016-02-01

    We study the difference in the maximum stress on a cylinder surface σmax using the measured surface heat transfer coefficient hm instead of its average value ha during quenching. In the quenching temperatures of 200, 300, 400, 500, 600 and 800°C, the maximum surface stress σmmax calculated by hm is always smaller than σamax calculated by ha, except in the case of 800°C; while the time to reach σmax calculated by hm (fmmax) is always earlier than that by ha (famax). It is inconsistent with the traditional view that σmax increases with increasing Biot number and the time to reach σmax decreases with increasing Biot number. Other temperature-dependent properties also have a small effect on the trend of their mutual ratios with quenching temperatures. Such a difference between the two maximum surface stresses is caused by the dramatic variation of hm with temperature, which needs to be considered in engineering analysis.

  4. Temperature-dependent photoluminescence of surface-engineered silicon nanocrystals

    Science.gov (United States)

    Mitra, Somak; Švrček, Vladimir; Macias-Montero, Manual; Velusamy, Tamilselvan; Mariotti, Davide

    2016-01-01

    In this work we report on temperature-dependent photoluminescence measurements (15–300 K), which have allowed probing radiative transitions and understanding of the appearance of various transitions. We further demonstrate that transitions associated with oxide in SiNCs show characteristic vibronic peaks that vary with surface characteristics. In particular we study differences and similarities between silicon nanocrystals (SiNCs) derived from porous silicon and SiNCs that were surface-treated using a radio-frequency (RF) microplasma system. PMID:27296771

  5. Biological control of surface temperature in the Arabian Sea

    Science.gov (United States)

    Sathyendranath, Shubha; Gouveia, Albert D.; Shetye, Satish R.; Ravindran, P.; Platt, Trevor

    1991-01-01

    In the Arabian Sea, the southwest monsoon promotes seasonal upwelling of deep water, which supplies nutrients to the surface layer and leads to a marked increase in phytoplankton growth. Remotely sensed data on ocean color are used here to show that the resulting distribution of phytoplankton exerts a controlling influence on the seasonal evolution of sea surface temperature. This results in a corresponding modification of ocean-atmosphere heat exchange on regional and seasonal scales. It is shown that this biological mechanism may provide an important regulating influence on ocean-atmosphere interactions.

  6. Calibration plan for the sea and land surface temperature radiometer

    Science.gov (United States)

    Smith, David L.; Nightingale, Tim J.; Mortimer, Hugh; Middleton, Kevin; Edeson, Ruben; Cox, Caroline V.; Mutlow, Chris T.; Maddison, Brian J.

    2013-10-01

    The Sea and Land Surface Temperature Radiometer (SLSTR) to be flown on ESA's Sentinel-3 mission is a multichannel scanning radiometer that will continue the 21-year datasets of the Along Track Scanning Radiometer (ATSR) series. As its name implies, measurements from SLSTR will be used to retrieve global sea surface temperatures to an uncertainty of SLSTR instrument, infrared calibration sources and alignment equipment. The calibration rig has been commissioned and results of these tests will be presented. Finally the authors will present the planning for the on-orbit monitoring and calibration activities to ensure that calibration is maintained. These activities include vicarious calibration techniques that have been developed through previous missions, and the deployment of ship-borne radiometers.

  7. Reconnoitering the effect of shallow groundwater on land surface temperature and surface energy balance using MODIS and SEBS

    Directory of Open Access Journals (Sweden)

    F. Alkhaier

    2012-07-01

    Full Text Available The possibility of observing shallow groundwater depth and areal extent using satellite measurements can support groundwater models and vast irrigation systems management. Moreover, these measurements can help to include the effect of shallow groundwater on surface energy balance within land surface models and climate studies, which broadens the methods that yield more reliable and informative results. To examine the capacity of MODIS in detecting the effect of shallow groundwater on land surface temperature and the surface energy balance in an area within Al-Balikh River basin in northern Syria, we studied the interrelationship between in-situ measured water table depths and land surface temperatures measured by MODIS. We, also, used the Surface Energy Balance System (SEBS to calculate surface energy fluxes, evaporative fraction and daily evaporation, and inspected their relationships with water table depths. We found out that the daytime temperature increased while the nighttime temperature decreased when the depth of the water table increased. And, when the water table depth increased, net radiation, latent and ground heat fluxes, evaporative fraction and daily evaporation decreased, while sensible heat flux increased. This concords with the findings of a companion paper (Alkhaier et al., 2012. The observed clear relationships were the result of meeting both conditions that were concluded in the companion paper, i.e. high potential evaporation and big contrast in day-night temperature. Moreover, the prevailing conditions in this study area helped SEBS to yield accurate estimates. Under bare soil conditions and under the prevailing weather conditions, we conclude that MODIS is suitable for detecting the effect of shallow groundwater because it has proper imaging times and adequate sensor accuracy; nevertheless, its coarse spatial resolution is disadvantageous.

  8. Effect of temperature on aging and time-temperature superposition in nonergodic laponite suspensions

    Science.gov (United States)

    Awasthi, Varun; Joshi, Yogesh M.

    We have studied the effect of temperature on aging dynamics of laponite suspensions by carrying out the rheological oscillatory and creep experiments. We observed that at higher temperatures the mechanism responsible for aging became faster thereby shifting the evolution of elastic modulus to lower ages. Significantly, in the creep experiments, all the aging time and the temperature dependent strain data superposed to form a master curve. Possibility of such superposition suggests that the rheological behavior depends on the temperature and the aging time only through the relaxation processes and both the variables do not affect the distribution but only the average value of relaxation times. In addition, this procedure allows us to predict long time rheological behavior by carrying out short time tests at high temperatures and small ages.

  9. Long-range cross-correlation between urban impervious surfaces and land surface temperatures

    Institute of Scientific and Technical Information of China (English)

    Qin NIE; Jianhua XU; Wang MAN

    2016-01-01

    The thermal effect of urban impervious surfaces (UIS) is a complex problem.It is thus necessary to study the relationship between UIS and land surface temperatures (LST) using complexity science theory and methods.This paper investigates the long-range cross-correlation between UIS and LST with detrended cross-correlation analysis and multifractal detrended cross-correlation analysis,utilizing data from downtown Shanghai,China.UIS estimates were obtained from linear spectral mixture analysis,and LST was retrieved through application of the mono-window algorithm,using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus data for 1997-2010.These results highlight a positive long-range cross-correlation between UIS and LST across People's Square in Shanghai.LST has a long memory for a certain spatial range of UIS values,such that a large increment in UIS is likely to be followed by a large increment in LST.While the multifractal long-range cross-correlation between UIS and LST was observed over a longer time period in the W-E direction (2002-2010) than in the N-S (2007-2010),these observed correlations show a weakening during the study period as urbanization increased.

  10. Long-range cross-correlation between urban impervious surfaces and land surface temperatures

    Science.gov (United States)

    Nie, Qin; Xu, Jianhua; Man, Wang

    2016-03-01

    The thermal effect of urban impervious surfaces (UIS) is a complex problem. It is thus necessary to study the relationship between UIS and land surface temperatures (LST) using complexity science theory and methods. This paper investigates the long-range cross-correlation between UIS and LST with detrended cross-correlation analysis and multifractal detrended cross-correlation analysis, utilizing data from downtown Shanghai, China. UIS estimates were obtained from linear spectral mixture analysis, and LST was retrieved through application of the mono-window algorithm, using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus data for 1997-2010. These results highlight a positive long-range cross-correlation between UIS and LST across People's Square in Shanghai. LST has a long memory for a certain spatial range of UIS values, such that a large increment in UIS is likely to be followed by a large increment in LST. While the multifractal long-range cross-correlation between UIS and LST was observed over a longer time period in the W-E direction (2002-2010) than in the N-S (2007-2010), these observed correlations show a weakening during the study period as urbanization increased.

  11. Empirical analysis of the solar contribution to global mean air surface temperature change

    CERN Document Server

    Scafetta, Nicola

    2009-01-01

    The solar contribution to global mean air surface temperature change is analyzed by using an empirical bi-scale climate model characterized by both fast and slow characteristic time responses to solar forcing: $\\tau_1 =0.4 \\pm 0.1$ yr, and $\\tau_2= 8 \\pm 2$ yr or $\\tau_2=12 \\pm 3$ yr. Since 1980 the solar contribution to climate change is uncertain because of the severe uncertainty of the total solar irradiance satellite composites. The sun may have caused from a slight cooling, if PMOD TSI composite is used, to a significant warming (up to 65% of the total observed warming) if ACRIM, or other TSI composites are used. The model is calibrated only on the empirical 11-year solar cycle signature on the instrumental global surface temperature since 1980. The model reconstructs the major temperature patterns covering 400 years of solar induced temperature changes, as shown in recent paleoclimate global temperature records.

  12. A surface acoustic wave ICP sensor with good temperature stability.

    Science.gov (United States)

    Zhang, Bing; Hu, Hong; Ye, Aipeng; Zhang, Peng

    2017-07-20

    Intracranial pressure (ICP) monitoring is very important for assessing and monitoring hydrocephalus, head trauma and hypertension patients, which could lead to elevated ICP or even devastating neurological damage. The mortality rate due to these diseases could be reduced through ICP monitoring, because precautions can be taken against the brain damage. This paper presents a surface acoustic wave (SAW) pressure sensor to realize ICP monitoring, which is capable of wireless and passive transmission with antenna attached. In order to improve the temperature stability of the sensor, two methods were adopted. First, the ST cut quartz was chosen as the sensor substrate due to its good temperature stability. Then, a differential temperature compensation method was proposed to reduce the effects of temperature. Two resonators were designed based on coupling of mode (COM) theory and the prototype was fabricated and verified using a system established for testing pressure and temperature. The experiment result shows that the sensor has a linearity of 2.63% and hysteresis of 1.77%. The temperature stability of the sensor has been greatly improved by using the differential compensation method, which validates the effectiveness of the proposed method.

  13. Temperature and curing time affect composite sorption and solubility

    Directory of Open Access Journals (Sweden)

    Fabrício Luscino Alves de Castro

    2013-04-01

    Full Text Available Objective: This study evaluated the effect of temperature and curing time on composite sorption and solubility. Material and Methods: Seventy five specimens (8×2 mm were prepared using a commercial composite resin (ICE, SDI. Three temperatures (10°C, 25°C and 60°C and five curing times (5 s, 10 s, 20 s, 40 s and 60 s were evaluated. The specimens were weighed on an analytical balance three times: A: before storage (M1; B: 7 days after storage (M2; C: 7 days after storage plus 1 day of drying (M3. The storage solution consisted of 75% alcohol/25% water. Sorption and solubility were calculated using these three weights and specimen dimensions. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U Tests (α=5%. Results: The results showed that time, temperature and their interaction influenced the sorption and solubility of the composite (p0.05. The 60°C composite temperature led to lower values of sorption for all curing times when compared with the 10°C temperature (p0.05. Solubility was similar at 40 s and 60 s for all temperatures (p>0.05, but was higher at 10°C than at 60°C for all curing times (p0.05. Conclusions: In conclusion, higher temperatures or longer curing times led to lower sorption and solubility values for the composite tested; however, this trend was only significant in specific combinations of temperature and curing times.

  14. Effect of floor surface temperature on blood flow and skin temperature in the foot.

    Science.gov (United States)

    Song, G-S

    2008-12-01

    A total of 16 healthy college students participated as subjects to elucidate the hypothesis that blood flow and skin temperature in foot are affected by the floor surface temperature. The floor surface temperature was controlled by varying the temperature of water (tw) flowing underneath the floor, and it ranged from tw 15 to 40 degrees C at 5 degrees C intervals. The blood flow rate was measured in the dorsal right toe, and skin temperatures were measured for 60 min at 8 points: the neck, right scapular, left hand, right shin, left bottom of the toe, right instep, left finger, and rectum. The blood flow rate in the foot tissue was increased until the foot skin temperature warmed up to 34 degrees C (P = 0.000). The final skin temperatures on the bottom of the toe were 19.4 +/- 2.44 degrees C for tw 15 degrees C, 22.4 +/- 2.45 degrees C for tw 20 degrees C, 24.8 +/- 2.80 degrees C for tw 25 degrees C, 27.7 +/- 2.13 degrees C for tw 30 degrees C, 30.6 +/- 2.06 degrees C for tw 35 degrees C, 33.2 +/- 1.45 degrees C for tw 40 degrees C, 34.2 +/- 1.55 degrees C for tw 45 degrees C, and 35.2 +/- 1.65 degrees C for tw 50 degrees C. Considering blood flow and comfort, the partial floor heating system is suggested and the recommended floor surface temperature range is 27-33 degrees C. A warm floor surface can serve to satisfy occupants when the ambient temperature maintained at 20 degrees C which represents an energy conscious temperature. A warm floor can induce high blood perfusion in the feet and consequently improve an occupant's health by treating many vascular-related disorders. Even in a well-insulated residential building, a partially heated floor system could prevent overheating while providing surface warmth.

  15. Actual evaporation estimation from infrared measurement of soil surface temperature

    Directory of Open Access Journals (Sweden)

    Davide Pognant

    2013-09-01

    Full Text Available Within the hydrological cycle, actual evaporation represents the second most important process in terms of volumes of water transported, second only to the precipitation phenomena. Several methods for the estimation of the Ea were proposed by researchers in scientific literature, but the estimation of the Ea from potential evapotranspiration often requires the knowledge of hard-to-find parameters (e.g.: vegetation morphology, vegetation cover, interception of rainfall by the canopy, evaporation from the canopy surface and uptake of water by plant roots and many existing database are characterized by missing or incomplete information that leads to a rough estimation of the actual evaporation amount. Starting from the above considerations, the aim of this study is to develop and validate a method for the estimation of the Ea based on two steps: i the potential evaporation estimation by using the meteorological data (i.e. Penman-Monteith; ii application of a correction factor based on the infrared soil surface temperature measurements. The dataset used in this study were collected during two measurement campaigns conducted both in a plain testing site (Grugliasco, Italy, and in a mountain South-East facing slope (Cogne, Italy. During those periods, hourly measurement of air temperature, wind speed, infrared surface temperature, soil heat flux, and soil water content were collected. Results from the dataset collected in the two testing sites show a good agreement between the proposed method and reference methods used for the Ea estimation.

  16. Land surface temperature shaped by urban fractions in megacity region

    Science.gov (United States)

    Zhang, Xiaoxuan; Hu, Yonghong; Jia, Gensuo; Hou, Meiting; Fan, Yanguo; Sun, Zhongchang; Zhu, Yuxiang

    2017-02-01

    Large areas of cropland and natural vegetation have been replaced by impervious surfaces during the recent rapid urbanization in China, which has resulted in intensified urban heat island effects and modified local or regional warming trends. However, it is unclear how urban expansion contributes to local temperature change. In this study, we investigated the relationship between land surface temperature (LST) change and the increase of urban land signals. The megacity of Tianjin was chosen for the case study because it is representative of the urbanization process in northern China. A combined analysis of LST and urban land information was conducted based on an urban-rural transect derived from Landsat 8 Thermal Infrared Sensor (TIRS), Terra Moderate Resolution Imaging Spectrometer (MODIS), and QuickBird images. The results indicated that the density of urban land signals has intensified within a 1-km2 grid in the urban center with an impervious land fraction >60 %. However, the construction on urban land is quite different with low-/mid-rise buildings outnumbering high-rise buildings in the urban-rural transect. Based on a statistical moving window analysis, positive correlation ( R 2 > 0.9) is found between LST and urban land signals. Surface temperature change (ΔLST) increases by 0.062 °C, which was probably caused by the 1 % increase of urbanized land (ΔIF) in this case region.

  17. High temperature surface degradation of III-V nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Vartuli, C.B.; Pearton, S.J.; Abernathy, C.R.; MacKenzie, J.D.; Lambers, E.S. [Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering; Zolper, J.C. [Sandia National Labs., Albuquerque, NM (United States)

    1996-05-01

    The surface stoichiometry, surface morphology and electrical conductivity of AlN, GaN, InN, InGaN and InAlN was examined at rapid thermal annealing temperatures up to 1,150 C. The sheet resistance of the AlN dropped steadily with annealing, but the surface showed signs of roughening only above 1,000 C. Auger Electronic Spectroscopy (AES) analysis showed little change in the surface stoichiometry even at 1,150 C. GaN root mean square (RMS) surface roughness showed an overall improvement with annealing, but the surface became pitted at 1,000 C, at which point the sheet resistance also dropped by several orders of magnitude, and AES confirmed a loss of N from the surface. The InN surface had roughened considerably even at 650 C, and scanning electron microscopy (SEM) showed significant degradation. In contrast to the binary nitrides the sheet resistance of InAlN was found to increase by {approximately} 10{sup 2} from the as grown value after annealing at 800 C and then remain constant up to 1,000 C, while that of InGaN increased rapidly above 700 C. The RMS roughness increased above 800 C and 700 C respectively for InAlN and InGaN samples. In droplets began to form on the surface at 900 C for InAlN and at 800 C for InGaN, and then evaporate at 1,000 C leaving pits. AES analysis showed a decrease in the N concentration in the top 500 {angstrom} of the sample for annealing {ge} 800 C in both materials.

  18. Real time ray tracing of skeletal implicit surfaces

    DEFF Research Database (Denmark)

    Rouiller, Olivier; Bærentzen, Jakob Andreas

    Modeling and rendering in real time is usually done via rasterization of polygonal meshes. We present a method to model with skeletal implicit surfaces and an algorithm to ray trace these surfaces in real time in the GPU. Our skeletal representation of the surfaces allows to create smooth models...

  19. Surface Tensions and Their Variations with Temperature and Impurities

    Science.gov (United States)

    Hardy, S. C.; Fine, J.

    1985-01-01

    The surface tensions in this work were determined using the sessile drop technique. This method is based on a comparison of the profile of a liquid drop with the profile calculated by solving the Young-Laplace equation. The comparison can be made in several ways; the traditional Bashforth-Adams procedure was used in conjunction with recently calculated drop shape tables which virtually eliminate interpolation errors. Although previous study has found little difference in measurements with pure and oxygen doped silicon, there is other evidence suggesting that oxygen in dilute concentrations severely depresses the surface tension of silicon. The surface tension of liquid silicon in purified argon atmospheres was measured. A temperature coefficient near -0.28 mJ/square meters K was found. The experiments show a high sensitivity of the surface tension to what is believed are low concentrations of oxygen. Thus one cannot rule out some effect of low levels of oxygen in the results. However, the highest surface tension values obtained in conditions which minimized the residual oxygen pressure are in good agreement with a previous measurement in pure hydrogen. Therefore, depression of the surface tension by oxygen is insignificant in these measurements.

  20. A model for quantification of temperature profiles via germination times

    DEFF Research Database (Denmark)

    Pipper, Christian Bressen; Adolf, Verena Isabelle; Jacobsen, Sven-Erik

    2013-01-01

    Current methodology to quantify temperature characteristics in germination of seeds is predominantly based on analysis of the time to reach a given germination fraction, that is, the quantiles in the distribution of the germination time of a seed. In practice interpolation between observed...... time and a specific type of accelerated failure time models is provided. As a consequence the observed number of germinated seeds at given monitoring times may be analysed directly by a grouped time-to-event model from which characteristics of the temperature profile may be identified and estimated...... germination fractions at given monitoring times is used to obtain the time to reach a given germination fraction. As a consequence the obtained value will be highly dependent on the actual monitoring scheme used in the experiment. In this paper a link between currently used quantile models for the germination...

  1. Temperature Effect and Correction Method of White Rabbit Timing Link

    CERN Document Server

    Li, Hongming; Pan, Weibin; Du, Qiang; Li, Jianmin

    2014-01-01

    To guarantee the angular resolution, the Large High Altitude Air Shower Observatory (LHAASO) requires a 500ps (rms) timing synchronization among the 6866 detect units for its KM2A sub-detector array. The White Rabbit technology is applied which combines sub-nanosecond precision timing transfer and gigabit Ethernet data transfer over the same fiber media. Deployed on a wild field at 4300m a.s.l. altitude, the WR network must maintain the precision over a wide temperature range. The temperature effect on a small WR link is measured, and contributions from different components like optical fiber, SFP module, fixed delay on PCB and ICs are separately studied and analyzed. An online real-time temperature correction method was applied based on the result which significantly reduce the synchronization variation from 300 ps to 50 ps in a temperature range of 50 degrees centigrade.

  2. Evaluation of near-surface temperature, humidity, and equivalent temperature from regional climate models applied in type II downscaling

    Science.gov (United States)

    Pryor, S. C.; Schoof, J. T.

    2016-04-01

    Atmosphere-surface interactions are important components of local and regional climates due to their key roles in dictating the surface energy balance and partitioning of energy transfer between sensible and latent heat. The degree to which regional climate models (RCMs) represent these processes with veracity is incompletely characterized, as is their ability to capture the drivers of, and magnitude of, equivalent temperature (Te). This leads to uncertainty in the simulation of near-surface temperature and humidity regimes and the extreme heat events of relevance to human health, in both the contemporary and possible future climate states. Reanalysis-nested RCM simulations are evaluated to determine the degree to which they represent the probability distributions of temperature (T), dew point temperature (Td), specific humidity (q) and Te over the central U.S., the conditional probabilities of Td|T, and the coupling of T, q, and Te to soil moisture and meridional moisture advection within the boundary layer (adv(Te)). Output from all RCMs exhibits discrepancies relative to observationally derived time series of near-surface T, q, Td, and Te, and use of a single layer for soil moisture by one of the RCMs does not appear to substantially degrade the simulations of near-surface T and q relative to RCMs that employ a four-layer soil model. Output from MM5I exhibits highest fidelity for the majority of skill metrics applied herein, and importantly most realistically simulates both the coupling of T and Td, and the expected relationships of boundary layer adv(Te) and soil moisture with near-surface T and q.

  3. Surface temperature of the equatorial Pacific Ocean and the Indian rainfall

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinathan, C.K.

    The time variation of the monthly mean surface temperature of the equatorial Pacific Ocean during 1982-1987 has been studied in relation to summer monsoon rainfall over India The ENSO events of 1982 and 1987 were related to a significant reduction...

  4. Sea surface temperature variability at the Scripps Institution of Oceanography Pier

    DEFF Research Database (Denmark)

    Checkley, David M.; Lindegren, Martin

    2014-01-01

    Sea surface temperature (SST) has been measured from near the end of the SIO pier daily since 1916. It is one of the world’s longest instrumental time series of SST. It is widely used in studies of climate and marine ecosystems and in fisheries management. We hypothesized that a discontinuity exi...

  5. A real time method for surface cleanliness measurement

    OpenAIRE

    Bilmes, Gabriel Mario; Orzi, Daniel Jesús Omar; Martínez , Oscar E.; Lencina, Alberto

    2005-01-01

    The measurement of surface cleanliness is a signifi cant problem in many industrial and technological processes. Existing methods are based on laboratory procedures, that are not performed in real time, can not be automated, and usually are restricted to a small portion of the sample. In this study we describe a new method for real time measurement of the amount of surface dirt or contamination deposited on a surface. It relies on the ablation of the surface dirt film by means of a ...

  6. Temperature dependence of fluctuation time scales in spin glasses

    DEFF Research Database (Denmark)

    Kenning, Gregory G.; Bowen, J.; Sibani, Paolo;

    2010-01-01

    Using a series of fast cooling protocols we have probed aging effects in the spin glass state as a function of temperature. Analyzing the logarithmic decay found at very long time scales within a simple phenomenological barrier model, leads to the extraction of the fluctuation time scale of the s...

  7. Chemical relaxation times in a hadron gas at finite temperature

    CERN Document Server

    Goity, J L

    1993-01-01

    The relaxation times of particle numbers in hot hadronic matter with vanishing baryon number are estimated using the ideal gas approximation and taking into account resonance decays and annihilation processes as the only sources of particle number fluctuations. Near the QCD critical temperature the longest relaxation times turn out to be of the order of 10 fm and grow roughly exponentially to become of the order of $10^{3}$ fm at temperatures around 100 MeV. As a consequence of such long relaxation times, a clear departure from chemical equilibrium must be observed in the momentum distribution of secondary particles produced in high energy nuclear collisions.

  8. Seasonally and diurnally different response of surface air temperature to historical urbanization in Sapporo, North Japan

    Science.gov (United States)

    Sato, T.; Sugimoto, S.; Sasaki, T.

    2014-12-01

    Anthropogenic landscape changes have dramatically altered near surface climate in many regions of the world. In particular, regional/local-scale land use change is attributed to the long-term change in observed surface air temperature through changes in surface radiation budget and energy partitioning. This study analyses the response of surface air temperature characteristics to the historical urbanization in Sapporo, a snowy city in North Japan. Around Sapporo, natural forest has been cleared and replaced with urban since the late 19th century. Annual mean temperature in Sapporo has increased dramatically, whose rate being approximately twice of that in the station without urbanization. The rate of temperature increase shows asymmetric feature among seasons and dependent on time of the day; a prominent warming in winter daily minimum temperature and no significant trend in summer daily maximum temperature. In order to clarify the seasonal and diurnal dependence of the response to land use change, two 27-year simulations were conducted using WRF-ARW model nudged to reanalysis data during 19872/1983 winter to 2008/2009 winter; a control run uses past land cover and a sensitivity run uses present land cover. The numerical experiments successfully replicate the observed influence of urbanization with higher temperature change in winter nights and smaller temperature change in summer days. An analysis on surface energy balance indicates the changes in Bowen ratio is a primal cause of increasing sensible heat in both summer and winter. However, atmospheric response to the elevated sensible heat flux is very different depending on boundary layer structure between winter and summer or between night and day. This mechanism could clearly explain the asymmetric temperature trend observed worldwide, especially in cold regions where nocturnal inversion develops.

  9. Time-resolved, local temperature measurements during pulsed laser heating

    Energy Technology Data Exchange (ETDEWEB)

    Kappes, Ralf S; Li Chen; Butt, Hans-Juergen; Gutmann, Jochen S, E-mail: kappes@mpip-mainz.mpg.d [Max Planck Institute for Polymer Research, D-55128 Mainz (Germany)

    2010-08-15

    To analyse processes during laser heating, one needs to be able to measure temperatures of about 1000 K within one microsecond and with micrometre resolution. To achieve this accuracy, we set up a high-performance optical detection system with a microsecond gated camera in combination with selected interference filters to detect the thermal emission spectrum in the visible range. By fitting the emission spectrum to Planck's law, we are able to collect an area temperature profile for time intervals as short as one microsecond. Thus we can show that a polymer film, which is doped with an organic dye for energy conversion, can reach temperatures of at least 900 K, which is high above its 'normal' decomposition temperature. It is, furthermore, possible to relate the temperature to the effect of the laser beam on the polymer film.

  10. Multiaxial Temperature- and Time-Dependent Failure Model

    Science.gov (United States)

    Richardson, David; McLennan, Michael; Anderson, Gregory; Macon, David; Batista-Rodriquez, Alicia

    2003-01-01

    A temperature- and time-dependent mathematical model predicts the conditions for failure of a material subjected to multiaxial stress. The model was initially applied to a filled epoxy below its glass-transition temperature, and is expected to be applicable to other materials, at least below their glass-transition temperatures. The model is justified simply by the fact that it closely approximates the experimentally observed failure behavior of this material: The multiaxiality of the model has been confirmed (see figure) and the model has been shown to be applicable at temperatures from -20 to 115 F (-29 to 46 C) and to predict tensile failures of constant-load and constant-load-rate specimens with failure times ranging from minutes to months..

  11. Global Changes in the Sea Ice Cover and Associated Surface Temperature Changes

    Science.gov (United States)

    Comiso, Josefino C.

    2016-06-01

    The trends in the sea ice cover in the two hemispheres have been observed to be asymmetric with the rate of change in the Arctic being negative at -3.8 % per decade while that of the Antarctic is positive at 1.7 % per decade. These observations are confirmed in this study through analyses of a more robust data set that has been enhanced for better consistency and updated for improved statistics. With reports of anthropogenic global warming such phenomenon appears physically counter intuitive but trend studies of surface temperature over the same time period show the occurrence of a similar asymmetry. Satellite surface temperature data show that while global warming is strong and dominant in the Arctic, it is relatively minor in the Antarctic with the trends in sea ice covered areas and surrounding ice free regions observed to be even negative. A strong correlation of ice extent with surface temperature is observed, especially during the growth season, and the observed trends in the sea ice cover are coherent with the trends in surface temperature. The trend of global averages of the ice cover is negative but modest and is consistent and compatible with the positive but modest trend in global surface temperature. A continuation of the trend would mean the disappearance of summer ice by the end of the century but modelling projections indicate that the summer ice could be salvaged if anthropogenic greenhouse gases in the atmosphere are kept constant at the current level.

  12. Changes in Skin Surface Temperature during Muscular Endurance indicated Strain – An Explorative Study

    Directory of Open Access Journals (Sweden)

    Michael Fröhlich

    2014-07-01

    Full Text Available Introduction: Non-contact thermography enables the diagnosis of the distribution of skin surface temperature during athletic movement. Resistance exercise results in stress of required musculature, which is supposed to be measurable thermographically in terms of skin surface temperature change. Objective: This study aims to evaluate the application of thermography to analyze changes in skin temperature, representing specific muscle groups, during and after resistance exercise. Method: Thirteen male participants (age: 27.1 ± 4.9 years, height: 181.5 ± 5.7 cm, mass: 74.8 ± 7.4 kg completed the study. On 5 separate visits to the laboratory, participants performed one of 5 resistance exercise to target specific muscles (M. pectoralis major, M. rectus abdominis, M. trapezius, M. erector spinae, M. quadriceps femoris. The exercise protocol consisted of 3 sets of 20 repetitions, with 1 minute rest between exercise sets. The average skin surface temperature above the muscle groups used was thermographically determined using standard methods at 7 time points; pre-exercise, immediately following each exercise set, and post exercise (2, 3, and 6 minutes after the finale exercise set. The measurement areas were standardized using anatomic reference points. Results: From an inferential statistical point of view, no significant change in the average temperature caused by the applied resistance training was found for the individual muscle groups over time at the individual measurement times (all P>0.08. However, thermography showed a characteristic chronological temperature curve for the five body areas between measurement times, as well as a distinctive spatial temperature distribution over the measurement areas. Discussion: Based on the thermographic image data and the characteristic temperature curve, it is possible to identify the primarily used functional musculature after device-controlled resistance training. Therefore, thermography seems to be

  13. Corrected Hawking Temperature in Snyder's Quantized Space-time

    Science.gov (United States)

    Ma, Meng-Sen; Liu, Fang; Zhao, Ren

    2015-06-01

    In the quantized space-time of Snyder, generalized uncertainty relation and commutativity are both included. In this paper we analyze the possible form for the corrected Hawking temperature and derive it from the both effects. It is shown that the corrected Hawking temperature has a form similar to the one of noncommutative geometry inspired Schwarzschild black hole, however with an requirement for the noncommutative parameter 𝜃 and the minimal length a.

  14. Time- and temperature-dependent failures of a bonded joint

    Science.gov (United States)

    Sihn, Sangwook

    This dissertation summarizes my study of time- and temperature-dependent behavior of a tubular lap bonded joint to provide a design methodology for windmill blade structures. The bonded joint is between a cast-iron rod and a GFRP composite pipe. The adhesive material is an epoxy containing chopped glass fibers. We proposed a new fabrication method to make concentric and void-less specimens of the tubular joint with a thick adhesive bondline to stimulate the root bond of a blade. The thick bondline facilitates the joint assembly of actual blades. For a better understanding of the behavior of the bonded joint, we studied viscoelastic behavior of the adhesive materials by measuring creep compliance at several temperatures during loading period. We observed that the creep compliance depends highly on the period of loading and the temperature. We applied time-temperature equivalence to the creep compliance of the adhesive material to obtain time-temperature shift factors. We also performed constant-rate of monotonically increased uniaxial tensile tests to measure static strength of the tubular lap joint at several temperatures and different strain-rates. We observed two failure modes from load-deflection curves and failed specimens. One is the brittle mode, which was caused by weakness of the interfacial strength occurring at low temperature and short period of loading. The other is the ductile mode, which was caused by weakness of the adhesive material at high temperature and long period of loading. Transition from the brittle to the ductile mode appeared as the temperature or the loading period increased. We also performed tests under uniaxial tensile-tensile cyclic loadings to measure fatigue strength of the bonded joint at several temperatures, frequencies and stress ratios. The fatigue data are analyzed statistically by applying the residual strength degradation model to calculate statistical distribution of the fatigue life. Combining the time-temperature

  15. Anomalous phonon behavior: blueshift of the surface boson peak in silica glass with increasing temperature.

    Science.gov (United States)

    Steurer, W; Apfolter, A; Koch, M; Ernst, W E; Søndergård, E; Manson, J R; Holst, B

    2008-04-04

    We present helium atom scattering measurements of the boson peak at the surface of vitreous silica between 127.0 and 368.5 K. The most probable energy shows a strong temperature dependence and increases linearly with temperature in the measured range. The observed blueshift of the surface boson peak (shift rate 0.008+/-0.002 meV/K) is a factor of 4 to 10 times stronger than shift rates measured in the bulk by inelastic neutron and Raman scattering. We suggest that the anomalous shift direction of the boson peak to higher energies with increasing temperature has the same origin as the unusual temperature dependence of the bulk modulus of silica glass.

  16. "Simultaneous measurement of flame impingement and piston surface temperatures in an optically accessible spark ignition engine"

    Science.gov (United States)

    Ding, Carl-Philipp; Honza, Rene; Böhm, Benjamin; Dreizler, Andreas

    2017-04-01

    This paper shows the results of spatially resolved temperature measurements of the piston surface of an optically accessible direct injection spark ignition engine during flame impingement. High-speed thermographic phosphor thermometry (TPT), using Gd3Ga5O12:Cr,Ce, and planar laser-induced fluorescence of the hydroxyl radical (OH-PLIF) were used to investigate the temperature increase and the time and position of flame impingement at the piston surface. Measurements were conducted at two operating cases and showed heating rates of up to 16,000 K/s. The OH-PLIF measurements were used to localize flame impingement and calculate conditioned statistics of the temperature profiles. The TPT coating was characterized and its influence on the temperature measurements evaluated.

  17. Temperature-mediated transition from Dyakonov-Tamm surface waves to surface-plasmon-polariton waves

    Science.gov (United States)

    Chiadini, Francesco; Fiumara, Vincenzo; Mackay, Tom G.; Scaglione, Antonio; Lakhtakia, Akhlesh

    2017-08-01

    The effect of changing the temperature on the propagation of electromagnetic surface waves (ESWs), guided by the planar interface of a homogeneous isotropic temperature-sensitive material (namely, InSb) and a temperature-insensitive structurally chiral material (SCM) was numerically investigated in the terahertz frequency regime. As the temperature rises, InSb transforms from a dissipative dielectric material to a dissipative plasmonic material. Correspondingly, the ESWs transmute from Dyakonov-Tamm surface waves into surface-plasmon-polariton waves. The effects of the temperature change are clearly observed in the phase speeds, propagation distances, angular existence domains, multiplicity, and spatial profiles of energy flow of the ESWs. Remarkably large propagation distances can be achieved; in such instances the energy of an ESW is confined almost entirely within the SCM. For certain propagation directions, simultaneous excitation of two ESWs with (i) the same phase speeds but different propagation distances or (ii) the same propagation distances but different phase speeds are also indicated by our results.

  18. Gaia FGK Benchmark Stars: Effective temperatures and surface gravities

    CERN Document Server

    Heiter, U; Gustafsson, B; Korn, A J; Soubiran, C; Thévenin, F

    2015-01-01

    Large Galactic stellar surveys and new generations of stellar atmosphere models and spectral line formation computations need to be subjected to careful calibration and validation and to benchmark tests. We focus on cool stars and aim at establishing a sample of 34 Gaia FGK Benchmark Stars with a range of different metallicities. The goal was to determine the effective temperature and the surface gravity independently from spectroscopy and atmospheric models as far as possible. Fundamental determinations of Teff and logg were obtained in a systematic way from a compilation of angular diameter measurements and bolometric fluxes, and from a homogeneous mass determination based on stellar evolution models. The derived parameters were compared to recent spectroscopic and photometric determinations and to gravity estimates based on seismic data. Most of the adopted diameter measurements have formal uncertainties around 1%, which translate into uncertainties in effective temperature of 0.5%. The measurements of bol...

  19. Geostatistical Solutions for Downscaling Remotely Sensed Land Surface Temperature

    Science.gov (United States)

    Wang, Q.; Rodriguez-Galiano, V.; Atkinson, P. M.

    2017-09-01

    Remotely sensed land surface temperature (LST) downscaling is an important issue in remote sensing. Geostatistical methods have shown their applicability in downscaling multi/hyperspectral images. In this paper, four geostatistical solutions, including regression kriging (RK), downscaling cokriging (DSCK), kriging with external drift (KED) and area-to-point regression kriging (ATPRK), are applied for downscaling remotely sensed LST. Their differences are analyzed theoretically and the performances are compared experimentally using a Landsat 7 ETM+ dataset. They are also compared to the classical TsHARP method.

  20. UAS Observations of Polynya Wave Height and Surface Temperature During the September 2012 Terra Nova Bay, Antarctica Field Campaign

    Science.gov (United States)

    Bradley, A. C.; Palo, S. E.; Knuth, S. L.; Cassano, J. J.

    2013-12-01

    A 2012 campaign flew Aerosonde unmanned aerial systems (UASs) over the Terra Nova Bay polynya in Antarctica to study air-sea fluxes in this environment. Sea ice forms over the open water of the polynya and is pushed out from the coast by strong offshore winds, resulting in significant heat and moisture flux out of the area. The Aerosonde UAS payloads contained a number of instruments, including the Everest IR surface temperature sensor and the CULPIS LIDAR profilometer system, for the purpose of measuring these fluxes. Wave heights were extracted from the CULPIS data and compared to wind speed measurements collected onboard the Aerosonde and to wind speed measurements from AWS stations upwind. Wave height showed minimal correlation to the co-located UAS wind speed measurements, but high geographic predictability. High moisture flux out of polynyas often results in cloud formation, limiting the utility of satellite-based IR measurement of surface temperatures and ice extent. This study compares sea surface temperature measurements from the Everest instrument to the MODIS sea ice surface temperature data product. Surface temperature measurements from the Everest system show high agreement with concurrent MODIS data over a variety of ice surface conditions. The sample time of the UAV instrument relative to the time of the MODIS data provides an estimate of the time rate of change of the surface temperatures of different ice surface types (thin ice, thick ice, open water), which is related to air temperature.

  1. The sign of temperature inhomogeneities deduced from time-distance helioseismology

    CERN Document Server

    Brüggen, M

    2000-01-01

    Inhomogeneities in wave propagation conditions near and below the solar surface have been detected by means of time-distance helioseismology. Here we calculate the effect of temperature inhomogeneities on the travel times of sound waves. A temperature increase, e.g. in active regions, not only increases the sound speed but also lengthens the path along which the wave travels because the expansion of the heated layers shifts the upper turning of the waves upward. Using a ray tracing approximation we find that in many cases the net effect of a temperature enhancement is an {\\it increase} of the travel times. We argue that the reduced travel times that are observed are caused by a combination of magnetic fields in the active region and {\\it reduced} subsurface temperatures. Such a reduction may be related to the increased radiative energy loss from small magnetic flux tubes.

  2. Electron density and electron temperature measurements in nanosecond pulse discharges over liquid water surface

    Science.gov (United States)

    Simeni Simeni, M.; Roettgen, A.; Petrishchev, V.; Frederickson, K.; Adamovich, I. V.

    2016-12-01

    Time-resolved electron density, electron temperature, and gas temperature in nanosecond pulse discharges in helium and O2-He mixtures near liquid water surface are measured using Thomson/pure rotational Raman scattering, in two different geometries, (a) ‘diffuse filament’ discharge between a spherical high-voltage electrode and a grounded pin electrode placed in a reservoir filled with distilled water, with the tip exposed, and (b) dielectric barrier discharge between the high-voltage electrode and the liquid water surface. A diffuse plasma filament generated between the electrodes in helium during the primary discharge pulse exhibits noticeable constriction during the secondary discharge pulse several hundred ns later. Adding oxygen to the mixture reduces the plasma filament diameter and enhances constriction during the secondary pulse. In the dielectric barrier discharge, diffuse volumetric plasma occupies nearly the entire space between the high voltage electrode and the liquid surface, and extends radially along the surface. In the filament discharge in helium, adding water to the container results in considerable reduction of plasma lifetime compared to the discharge in dry helium, by about an order of magnitude, indicating rapid electron recombination with water cluster ions. Peak electron density during the pulse is also reduced, by about a factor of two, likely due to dissociative attachment to water vapor during the discharge pulse. These trends become more pronounced as oxygen is added to the mixture, which increases net rate of dissociative attachment. Gas temperature during the primary discharge pulse remains near room temperature, after which it increases up to T ~ 500 K over 5 µs and decays back to near room temperature before the next discharge pulse several tens of ms later. As expected, electron density and electron temperature in diffuse DBD plasmas are considerably lower compared to peak values in the filament discharge. Use of Thomson

  3. Real-time temperature field measurement based on acoustic tomography

    Science.gov (United States)

    Bao, Yong; Jia, Jiabin; Polydorides, Nick

    2017-07-01

    Acoustic tomography can be used to measure the temperature field from the time-of-flight (TOF). In order to capture real-time temperature field changes and accurately yield quantitative temperature images, two improvements to the conventional acoustic tomography system are studied: simultaneous acoustic transmission and TOF collection along multiple ray paths, and an offline iteration reconstruction algorithm. During system operation, all the acoustic transceivers send modulated and filtered wideband Kasami sequences simultaneously to facilitate fast and accurate TOF measurements using cross-correlation detection. For image reconstruction, the iteration process is separated and executed offline beforehand to shorten computation time for online temperature field reconstruction. The feasibility and effectiveness of the developed methods are validated in the simulation study. The simulation results demonstrate that the proposed method can reduce the processing time per frame from 160 ms to 20 ms, while the reconstruction error remains less than 5%. Hence, the proposed method has great potential in the measurement of rapid temperature change with good temporal and spatial resolution.

  4. Effect of surface nanostructure on temperature programmed reaction spectroscopy

    Science.gov (United States)

    Rieger, Michael; Rogal, Jutta; Reuter, Karsten

    2008-03-01

    Using the catalytic CO oxidation at RuO2(110) as a showcase, we employ first-principles kinetic Monte Carlo simulations to illustrate the intricate effects on temperature programmed reaction (TPR) spectroscopy data brought about by the mere correlations between the locations of the active sites at a nanostructured surface. Even in the absence of lateral interactions, this nanostructure alone can cause inhomogeneities that cannot be grasped by prevalent mean-field data analysis procedures, which thus lead to wrong conclusions on the reactivity of the different surface species. The RuO2(110) surface studied here exhibits only two prominent active sites, arranged in simple alternating rows. Yet, the mere neglection of this still quite trivial nanostructure leads mean-field TPR data analysis [1] to extract kinetic parameters that are in error by several orders of magnitude and that do not even reflect the relative reactivity of the different surface species correctly [2].[1] S. Wendt, M. Knapp, and H. Over, JACS 126, 1537 (2004).[2] M. Rieger, J. Rogal, and K. Reuter, Phys. Rev. Lett (in press).

  5. Surface Morphology Dependent Copper Sulphide Ammonia Gas Sensor Working at Room Temperature: Effect of SHI Irradiation

    Directory of Open Access Journals (Sweden)

    Ramphal Sharma

    2009-02-01

    Full Text Available We report the synthesis of copper sulphide (CuS nano-pillars on copper sulphide thin film surface by using swift heavy ion (SHI irradiation. Thin films of CuS are irradiated with 100 MeV gold ions at fluence varying from 1011 to 5 ´ 1012 ions/cm2. These nanostructures grown on the surface of copper sulphide has been used for the detection of ammonia gas at room temperature. The time dependent surface conductance measurements show the utility of copper sulphide for the detection of ammonia. It is observed that the response of the material is highly influenced by the irradiation fluence.

  6. Surface Morphology Dependent Copper Sulphide Ammonia Gas Sensor Working at Room Temperature: Effect of SHI Irradiation

    OpenAIRE

    Ramphal Sharma; Sagade, Abhay A.; J. C. Vyas; P. K. Nema; Anil Ghule; Sung-Hwan Han

    2009-01-01

    We report the synthesis of copper sulphide (CuS) nano-pillars on copper sulphide thin film surface by using swift heavy ion (SHI) irradiation. Thin films of CuS are irradiated with 100 MeV gold ions at fluence varying from 1011 to 5 ´ 1012 ions/cm2. These nanostructures grown on the surface of copper sulphide has been used for the detection of ammonia gas at room temperature. The time dependent surface conductance measurements show the utility of copper sulphide for the detection of ammonia. ...

  7. Detection and attribution of near surface temperature changes over homogenous temperature zones in India

    Science.gov (United States)

    Achutarao, K. M.; R, D.

    2015-12-01

    The IPCC Fifth Assessment Report concluded, "More than half of the observed increase in global mean surface temperature (GMST) from 1951 to 2010 is very likely due to the observed anthropogenic increase in greenhouse gas (GHG) concentrations." Detecting and attributing the changes over regional scales can provide more relevant information to policymakers at the national level but the low signal-to-noise ratios at smaller spatial scales make this a harder problem. In this study, we analyze changes in temperature (annual and seasonal means of mean, minimum, and maximum temperatures) over 7 homogeneous temperature zones of India from 1901 -2005 using models from the CMIP5 database and multiple observational datasets (CRU-3.22, and IITM). We perform Detection and Attribution (D&A) analysis using fingerprint methods by defining a signal that concisely express both spatial and temporal changes found in the model runs with the CMIP5 individual forcing runs; greenhouse (historicalGHG), natural (historicalNat), anthropogenic (historicalAnthro), and anthropogenic aerosols (historicalAA). We are able to detect changes in annual mean temperature over many of the homogenous temperature zones as well as seasonal means in some of the homogenous zones. We quantify the contributions resulting from individual forcings in these cases. Preliminary results indicate large contributions from anthropogenic, forcings with a negligible contribution from natural forcings.

  8. Cleaning of SiC surfaces by low temperature ECR microwave hydrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Huang Lingqin; Zhu Qiaozhi; Gao Mingchao [School of Electronic Science and Technology, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, 116024 (China); Qin Fuwen [State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), Dalian University of Technology, 116024 (China); Wang Dejun, E-mail: dwang121@dlut.edu.cn [School of Electronic Science and Technology, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, 116024 (China)

    2011-09-15

    N-type 4H-SiC (0 0 0 1) surfaces were cleaned by low temperature hydrogen plasma in electronic cyclotron resonance (ECR) microware plasma system. The effects of the hydrogen plasma treatment (HPT) on the structure, chemical and electronic properties of surfaces were characterized by in situ reflection high energy electron diffraction (RHEED) and X-ray photoelectron spectroscopy (XPS). The RHEED results indicate that the structures of the films are strongly dependent on the treatment temperature and time. Significant improvements in quality of 4H-SiC films can be obtained with the temperature ranging from 200 deg. C to 700 deg. C for an appropriate treatment period. The XPS results show that the surface oxygen is greatly reduced and the carbon contamination is completely removed from the 4H-SiC surfaces. The hydrogenated SiC surfaces exhibit an unprecedented stability against oxidation in the air. The surface Fermi level moves toward the conduction band in 4H-SiC after the treatment indicating an unpinning Fermi level with the density of surfaces states as low as 8.09 x 10{sup 10} cm{sup -2} eV{sup -1}.

  9. Simultaneous measurement of gas concentration and temperature by the ball surface acoustic wave sensor

    Science.gov (United States)

    Yamanaka, Kazushi; Akao, Shingo; Takeda, Nobuo; Tsuji, Toshihiro; Oizumi, Toru; Tsukahara, Yusuke

    2017-07-01

    We have developed a ball surface acoustic wave (SAW) trace moisture sensor with an amorphous silica sensitive film and realized wide-range measurement from 0.017 ppmv [a frost point (FP) of -99 °C] to 6.0 × 103 ppmv (0 °C FP). However, since the sensitivity of the sensor depends on the temperature, measurement results are disturbed when the temperature largely changes. To overcome this problem, we developed a method to simultaneously measure temperature and gas concentration using a ball SAW sensor. Temperature and concentration is derived by solving equations for the delay time change at two frequencies. When the temperature had a large jump, the delay time change was significantly disturbed, but the water concentration was almost correctly measured, by compensating the sensitivity change using measured temperature. The temperature measured by a ball SAW sensor will also be used to control the ball temperature. This method will make a ball SAW sensor reliable in environments of varying temperatures.

  10. Theoretical study of cathode surfaces and high-temperature superconductors

    Science.gov (United States)

    Mueller, Wolfgang

    1995-01-01

    Calculations are presented for the work functions of BaO on W, Os, Pt, and alloys of Re-W, Os-W, and Ir-W that are in excellent agreement with experiment. The observed emission enhancement for alloy relative to tungsten dispenser cathodes is attributed to properties of the substrate crystal structure and explained by the smaller depolarization of the surface dipole on hexagonal as compared to cubic substrates. For Ba and BaO on W(100), the geometry of the adsorbates has been determined by a comparison of inverse photoemission spectra with calculated densities of unoccupied states based on the fully relativistic embedded cluster approach. Results are also discussed for models of scandate cathodes and the electronic structure of oxygen on W(100) at room and elevated temperatures. A detailed comparison is made for the surface electronic structure of the high-temperature superconductor YBa2Cu3O7 as obtained with non-, quasi-, and fully relativistic cluster calculations.

  11. Afforestation in China cools local land surface temperature.

    Science.gov (United States)

    Peng, Shu-Shi; Piao, Shilong; Zeng, Zhenzhong; Ciais, Philippe; Zhou, Liming; Li, Laurent Z X; Myneni, Ranga B; Yin, Yi; Zeng, Hui

    2014-02-25

    China has the largest afforested area in the world (∼62 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjacent grasslands or croplands in China to understand how afforestation affects LST. Afforestation is found to decrease daytime LST by about 1.1 ± 0.5 °C (mean ± 1 SD) and to increase nighttime LST by about 0.2 ± 0.5 °C, on average. The observed daytime cooling is a result of increased evapotranspiration. The nighttime warming is found to increase with latitude and decrease with average rainfall. Afforestation in dry regions therefore leads to net warming, as daytime cooling is offset by nighttime warming. Thus, it is necessary to carefully consider where to plant trees to realize potential climatic benefits in future afforestation projects.

  12. A New Global Climatology of Annual Land Surface Temperature

    Directory of Open Access Journals (Sweden)

    Benjamin Bechtel

    2015-03-01

    Full Text Available Land surface temperature (LST is an important parameter in various fields including hydrology, climatology, and geophysics. Its derivation by thermal infrared remote sensing has long tradition but despite substantial progress there remain limited data availability and challenges like emissivity estimation, atmospheric correction, and cloud contamination. The annual temperature cycle (ATC is a promising approach to ease some of them. The basic idea to fit a model to the ATC and derive annual cycle parameters (ACP has been proposed before but so far not been tested on larger scale. In this study, a new global climatology of annual LST based on daily 1 km MODIS/Terra observations was processed and evaluated. The derived global parameters were robust and free of missing data due to clouds. They allow estimating LST patterns under largely cloud-free conditions at different scales for every day of year and further deliver a measure for its accuracy respectively variability. The parameters generally showed low redundancy and mostly reflected real surface conditions. Important influencing factors included climate, land cover, vegetation phenology, anthropogenic effects, and geology which enable numerous potential applications. The datasets will be available at the CliSAP Integrated Climate Data Center pending additional processing.

  13. MEaSUREs Land Surface Temperature from GOES Satellites

    Science.gov (United States)

    Pinker, Rachel T.; Chen, Wen; Ma, Yingtao; Islam, Tanvir; Borbas, Eva; Hain, Chris; Hulley, Glynn; Hook, Simon

    2017-04-01

    Information on Land Surface Temperature (LST) can be generated from observations made from satellites in low Earth orbit (LEO) such as MODIS and ASTER and by sensors in geostationary Earth orbit (GEO) such as GOES. Under a project titled: "A Unified and Coherent Land Surface Temperature and Emissivity Earth System Data Record for Earth Science" led by Jet Propulsion Laboratory, an effort is underway to develop long term consistent information from both such systems. In this presentation we will describe an effort to derive LST information from GOES satellites. Results will be presented from two approaches: 1) based on regression developed from a wide range of simulations using MODTRAN, SeeBor Version 5.0 global atmospheric profiles and the CAMEL (Combined ASTER and MODIS Emissivity for Land) product based on the standard University of Wisconsin 5 km emissivity values (UWIREMIS) and the ASTER Global Emissivity Database (GED) product; 2) RTTOV radiative transfer model driven with MERRA-2 reanalysis fields. We will present results of evaluation of these two methods against various products, such as MOD11, and ground observations for the five year period of (2004-2008).

  14. A Preliminary Study of Surface Temperature Cold Bias in COAMPS

    Energy Technology Data Exchange (ETDEWEB)

    Chin, H-N S; Leach, M J; Sugiyama, G A; Aluzzi, F J

    2001-04-27

    It is well recognized that the model predictability is more or less hampered by the imperfect representations of atmospheric state and model physics. Therefore, it is a common problem for any numerical models to exhibit some sorts of biases in the prediction. In this study, the emphasis is focused on the cold bias of surface temperature forecast in Naval Research Laboratory's three-dimensional mesoscale model, COAMPS (Coupled Ocean/Atmosphere Mesoscale Prediction System). Based on the comparison with the ground station data, there were two types of ground temperature cold biases identified in LLNL (Lawrence Livermore National Laboratory) operational forecasts of COAMPS over the California and Nevada regions during the 1999 winter and the 2000 spring. The first type of cold bias appears at high elevation regions covered by snow, and its magnitude can be as large as 30 F - 40 F lower than observed. The second type of cold bias mainly exists in the snow-free clear-sky regions, where the surface temperature is above the freezing point, and its magnitude can be up to 5 F - 10 F lower than observed. These cold biases can affect the low-level stratification, and even the diurnal variation of winds in the mountain regions, and therefore impact the atmospheric dispersion forecast. The main objective of this study is to explore the causes of such cold bias, and to further the improvement of the forecast performance in COAMPS. A series of experiments are performed to gauge the sensitivity of the model forecast due to the physics changes and large-scale data with various horizontal and vertical resolutions.

  15. Evolution of the Specific Surface Area of Snow in a High Temperature Gradient Metamorphism

    Science.gov (United States)

    Wang, X.; Baker, I.

    2014-12-01

    The structural evolution of low-density snow under a high temperature gradient over a short period usually takes place in the surface layers during diurnal recrystallization or on a clear, cold night. To relate snow microstructures with their thermal properties, we combined X-ray computed microtomography (micro-CT) observations with numerical simulations. Different types of snow were tested over a large range of TGs (100 K m-1- 500 K m-1). The Specific Surface Area (SSA) was used to characterize the temperature gradient metamorphism (TGM). The magnitude of the temperature gradient and the initial snow type both influence the evolution of SSA. The SSA evolution under TGM was dominated by grain growth and the formation of complex surfaces. Fresh snow experienced a logarithmic decrease of SSA with time, a feature been observed previously by others [Calonne et al., 2014; Schneebeli and Sokratov, 2004; Taillandier et al., 2007]. However, for initial rounded and connected snow structures, the SSA will increase during TGM. Understanding the SSA increase is important in order to predict the enhanced uptake of chemical species by snow or increase in snow albedo. Calonne, N., F. Flin, C. Geindreau, B. Lesaffre, and S. Rolland du Roscoat (2014), Study of a temperature gradient metamorphism of snow from 3-D images: time evolution of microstructures, physical properties and their associated anisotropy, The Cryosphere Discussions, 8, 1407-1451, doi:10.5194/tcd-8-1407-2014. Schneebeli, M., and S. A. Sokratov (2004), Tomography of temperature gradient metamorphism of snow and associated changes in heat conductivity, Hydrological Processes, 18(18), 3655-3665, doi:10.1002/hyp.5800. Taillandier, A. S., F. Domine, W. R. Simpson, M. Sturm, and T. A. Douglas (2007), Rate of decrease of the specific surface area of dry snow: Isothermal and temperature gradient conditions, Journal of Geophysical Research: Earth Surface (2003-2012), 112(F3), doi: 10.1029/2006JF000514.

  16. Reevaluation of mid-Pliocene North Atlantic sea surface temperatures

    Science.gov (United States)

    Robinson, Marci M.; Dowsett, Harry J.; Dwyer, Gary S.; Lawrence, Kira T.

    2008-01-01

    Multiproxy temperature estimation requires careful attention to biological, chemical, physical, temporal, and calibration differences of each proxy and paleothermometry method. We evaluated mid-Pliocene sea surface temperature (SST) estimates from multiple proxies at Deep Sea Drilling Project Holes 552A, 609B, 607, and 606, transecting the North Atlantic Drift. SST estimates derived from faunal assemblages, foraminifer Mg/Ca, and alkenone unsaturation indices showed strong agreement at Holes 552A, 607, and 606 once differences in calibration, depth, and seasonality were addressed. Abundant extinct species and/or an unrecognized productivity signal in the faunal assemblage at Hole 609B resulted in exaggerated faunal-based SST estimates but did not affect alkenone-derived or Mg/Ca–derived estimates. Multiproxy mid-Pliocene North Atlantic SST estimates corroborate previous studies documenting high-latitude mid-Pliocene warmth and refine previous faunal-based estimates affected by environmental factors other than temperature. Multiproxy investigations will aid SST estimation in high-latitude areas sensitive to climate change and currently underrepresented in SST reconstructions.

  17. Greenland ice sheet surface temperature, melt and mass loss: 2000-06

    Science.gov (United States)

    Hall, D.K.; Williams, R.S.; Luthcke, S.B.; DiGirolamo, N.E.

    2008-01-01

    A daily time series of 'clear-sky' surface temperature has been compiled of the Greenland ice sheet (GIS) using 1 km resolution moderate-resolution imaging spectroradiometer (MODIS) land-surface temperature (LST) maps from 2000 to 2006. We also used mass-concentration data from the Gravity Recovery and Climate Experiment (GRACE) to study mass change in relationship to surface melt from 2003 to 2006. The mean LST of the GIS increased during the study period by ???0.27??Ca-1. The increase was especially notable in the northern half of the ice sheet during the winter months. Melt-season length and timing were also studied in each of the six major drainage basins. Rapid (meltwater is flowing rapidly to the base of the ice sheet, causing acceleration of outlet glaciers, thus highlighting the metastability of parts of the GIS and the vulnerability of the ice sheet to air-temperature increases. If air temperatures continue to rise over Greenland, increased surface melt will play a large role in ice-sheet mass loss.

  18. Martian Surface Temperature and Spectral Response from the MSL REMS Ground Temperature Sensor

    Science.gov (United States)

    Martin-Torres, Javier; Martínez-Frías, Jesús; Zorzano, María-Paz; Serrano, María; Mendaza, Teresa; Hamilton, Vicky; Sebastián, Eduardo; Armiens, Carlos; Gómez-Elvira, Javier; REMS Team

    2013-04-01

    The Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory (MSL) offers the opportunity to explore the near surface atmospheric conditions and, in particular will shed new light into the heat budget of the Martian surface. This is important for studies of the atmospheric boundary layer (ABL), as the ground and air temperatures measured directly by REMS control the coupling of the atmosphere with the surface [Zurek et al., 1992]. This coupling is driven by solar insolation. The ABL plays an important role in the general circulation and the local atmospheric dynamics of Mars. One of the REMS sensors, the ground temperature sensor (GTS), provides the data needed to study the thermal inertia properties of the regolith and rocks beneath the MSL rover. The GTS includes thermopile detectors, with infrared bands of 8-14 µm and 16-20 µm [Gómez-Elvira et al., 2012]. These sensors are clustered in a single location on the MSL mast and the 8-14 µm thermopile sounds the surface temperature. The infrared radiation reaching the thermopile is proportional to the emissivity of the surface minerals across these thermal wavelengths. We have developed a radiative transfer retrieval method for the REMS GTS using a database of thermal infrared laboratory spectra of analogue minerals and their mixtures. [Martín Redondo et al. 2009, Martínez-Frías et al. 2012 - FRISER-IRMIX database]. This method will be used to assess the perfomance of the REMS GTS as well as determine, through the error analysis, the surface temperature and emissivity values where MSL is operating. Comparisons with orbiter data will be performed. References Gómez-Elvira et al. [2012], REMS: The Environmental Sensor Suite for the Mars Science Laboratory Rover, Space Science Reviews, Volume 170, Issue 1-4, pp. 583-640. Martín-Redondo et al. [2009] Journal of Environmental Monitoring 11:, pp. 1428-1432. Martínez-Frías et al. [2012] FRISER-IRMIX database http

  19. "Deflategate": Time, Temperature, and Moisture Effects on Football Pressure

    Science.gov (United States)

    Blumenthal, Jack; Beljak, Lauren; Macatangay, Dahlia-Marie; Helmuth-Malone, Lilly; McWilliams, Catharina; Raptis, Sofia

    2016-01-01

    In a recent paper in "The Physics Teacher (TPT)", DiLisi and Rarick used the National Football League "Deflategate" controversy to introduce to physics students the physics of a bouncing ball. In this paper, we measure and analyze the environmental effects of time, ambient temperature, and moisture on the internal pressure of…

  20. "Deflategate": Time, Temperature, and Moisture Effects on Football Pressure

    Science.gov (United States)

    Blumenthal, Jack; Beljak, Lauren; Macatangay, Dahlia-Marie; Helmuth-Malone, Lilly; McWilliams, Catharina; Raptis, Sofia

    2016-01-01

    In a recent paper in "The Physics Teacher (TPT)", DiLisi and Rarick used the National Football League "Deflategate" controversy to introduce to physics students the physics of a bouncing ball. In this paper, we measure and analyze the environmental effects of time, ambient temperature, and moisture on the internal pressure of…

  1. Time- and temperature-dependent failures of a bonded joint

    Energy Technology Data Exchange (ETDEWEB)

    Sihn, Sangwook; Miyano, Yasushi; Tsai, S.W. [Stanford Univ., Palo Alto, CA (United States)

    1997-07-01

    Time and temperature dependent properties of a tubular lap bonded joint are reported. The joint bonds a cast iron rod and a composite pipe together with an epoxy type of an adhesive material containing chopped glass fiber. A new fabrication method is proposed.

  2. Increasing Temperature, Not Mean Temperature, Is a Cue for Avian Timing of Reproduction

    NARCIS (Netherlands)

    Schaper, Sonja V.; Dawson, Alistair; Sharp, Peter J.; Gienapp, Phillip; Caro, Samuel P.; Visser, Marcel E.

    2012-01-01

    Timing of reproduction in temperate-zone birds is strongly correlated with spring temperature, with an earlier onset of breeding in warmer years. Females adjust their timing of egg laying between years to be synchronized with local food sources and thereby optimize reproductive output. However, clim

  3. 反射式高能电子衍射实时监控的分子束外延生长GaAs晶体衬底温度校准及表面相变的研究%Study on temperature calibration and surface phase transition of GaAs crystal substrate in MBE growth by RHEED real-time monitoring

    Institute of Scientific and Technical Information of China (English)

    周勋; 杨再荣; 罗子江; 贺业全; 何浩; 韦俊; 邓朝勇; 丁召

    2011-01-01

    以反射式高能电子衍射(RHEED)作为实时监测工具,根据GaAs(100)表面重构相与衬底温度、As4等效束流压强之间的关系,对分子束外延(MBE)系统中衬底测温系统进行了校准,这种方法也适用于其他的MBE系统.为生长高质量的外延薄膜材料、研究InGaAs表面粗糙化及相变等过程提供了实验依据.%Using RHEED as a real-time monitoring tool, the MBE temperature measurement system was calibrated according to the relationship between GaAs ( 100 ) surface reconstruction phase and the substrate temperature, As4 beam equivalent pressure of the substrate. This approach can also be applied to other MBE systems. It provides an experimental basis of the growth of high-quality epitaxial thin films for studying of the surface roughness of InGaAs, the phase transformation process and the surface morphology.

  4. Optimisation of sea surface current retrieval using a maximum cross correlation technique on modelled sea surface temperature

    Science.gov (United States)

    Heuzé, Céline; Eriksson, Leif; Carvajal, Gisela

    2017-04-01

    Using sea surface temperature from satellite images to retrieve sea surface currents is not a new idea, but so far its operational near-real time implementation has not been possible. Validation studies are too region-specific or uncertain, due to the errors induced by the images themselves. Moreover, the sensitivity of the most common retrieval method, the maximum cross correlation, to the three parameters that have to be set is unknown. Using model outputs instead of satellite images, biases induced by this method are assessed here, for four different seas of Western Europe, and the best of nine settings and eight temporal resolutions are determined. For all regions, tracking a small 5 km pattern from the first image over a large 30 km region around its original location on a second image, separated from the first image by 6 to 9 hours returned the most accurate results. Moreover, for all regions, the problem is not inaccurate results but missing results, where the velocity is too low to be picked by the retrieval. The results are consistent both with limitations caused by ocean surface current dynamics and with the available satellite technology, indicating that automated sea surface current retrieval from sea surface temperature images is feasible now, for search and rescue operations, pollution confinement or even for more energy efficient and comfortable ship navigation.

  5. Eddy-Induced Ekman Pumping from Sea-Surface Temperature and Surface Current Effects

    Science.gov (United States)

    Gaube, P.; Chelton, D. B.; O'Neill, L. W.

    2011-12-01

    Numerous past studies have discussed the biological importance of upwelling of nutrients into the interiors of nonlinear eddies. Such upwelling can occur during the transient stages of formation of cyclones from shoaling of the thermocline. In their mature stages, upwelling can occur from Ekman pumping driven by eddy-induced wind stress curl. Previous investigations of ocean-atmosphere interaction in regions of persistent sea-surface temperature (SST) frontal features have shown that the wind field is locally stronger over warm water and weaker over cold water. Spatial variability of the SST field thus results in a wind stress curl and an associated Ekman pumping in regions of crosswind temperature gradients. It can therefore be anticipated that any SST anomalies associated with eddies can generate Ekman pumping in the eddy interiors. Another mechanism for eddy-induced Ekman pumping is the curl of the stress on the sea surface that arises from the difference between the surface wind velocity and the surface ocean velocity. While SST-induced Ekman upwelling can occur over eddies of either polarity surface current effects on Ekman upwelling occur only over anticyclonic eddies The objective of this study is to determine the spatial structures and relative magnitudes of the two mechanisms for eddy-induced Ekman pumping within the interiors of mesoscale eddies. This is achieved by collocating satellite-based measurements of SST, surface winds and wind stress curl to the interiors of eddies identified and tracked with an automated procedure applied to the sea-surface height (SSH) fields in the Reference Series constructed by AVISO from the combined measurements by two simultaneously operating altimeters. It is shown that, on average, the wind stress curl from eddy-induced surface currents is largest at the eddy center, resulting in Ekman pumping velocities of order 10 cm day-1. While this surface current-induced Ekman pumping depends only weakly on the wind direction

  6. Towards a Combined Surface Temperature Dataset for the Arctic from the Along-Track Scanning Radiometers

    Science.gov (United States)

    Dodd, Emma; Veal, Karen; Corlett, Gary; Ghent, Darren; Remedios, John

    2017-04-01

    Surface Temperature (ST) changes in the Polar Regions are predicted to be more rapid than either global averages or responses in lower latitudes. Observations increasingly confirm these findings, their urgency, and their significance in the Arctic. It is, therefore, particularly important to monitor Arctic climate change. Satellites are particularly relevant to observations of Polar Regions as they are well-served by low-Earth orbiting satellites. Whilst clouds often cause problems for satellite observations of the surface, in situ observations of STs are much sparser. The ATSRs are accurate infra-red satellite radiometers, designed explicitly for climate standard observations and particularly suited to ST observations. ATSR radiance observations have been used to retrieve sea and land ST for a series of three instruments over a period greater than twenty years. This series has been extended with the launch of SLSTR on Sentinel 3, which has the same key design features. We have combined land, ocean and sea-ice ST retrievals from ATSR-2 and AATSR to produce a new ST dataset for the Arctic; the ATSR Arctic combined Surface Temperature (AAST) dataset. The method of cloud-clearing, use of auxiliary data for ice classification and the ST retrievals used for each surface-type will be described. We will establish the accuracy of sea-ice and land-ice retrievals with results from validation against in situ data and comparison with other datasets. Time series of ST anomalies for each surface type will be presented. The time series for open ocean in the Arctic Polar Region shows a significant warming trend during the AATSR mission. Time series for land, land-ice and sea-ice show high variability as expected but also interesting patterns. Overall, our purpose is to present the state-of-the-art for ATSR observations of surface temperature change in the Arctic and hence indicate the confidence we can have in temperature change across all three domains, and in combination.

  7. Time and Space Resolved Wall Temperature Measurements during Nucleate Boiling with Constant Heat Flux Boundary Conditions

    Science.gov (United States)

    Myers, Jerry G.; Hussey, Sam W.; Yee, Glenda F.; Yerramilli, Vamsee K.; Kim, Jungho

    2005-01-01

    The lack of temporally and spatially resolved measurements under nucleate bubbles has complicated efforts to fully explain pool-boiling phenomena. The objective of this current work is to acquire time and space resolved temperature distributions under nucleate bubbles on a constant heat flux surface. This was performed using a microheater array with 100 micron resolution that allowed effectively simultaneous measurements of surface temperature while supplying a constant dissipative heat flux. This data is then correlated with high speed (> 1000Hz) visual recordings of the bubble growth and departure from the heater surface acquired from below and from the side of the heater. The data indicate that a significant source of energy during bubble nucleation and initial growth is the superheated layer around the bubble. Bubble coalescence was not observed to decrease surface temperature as significantly as bubble departure from the surface. Since bubble departure is typically followed by a sharp increase in the heater surface temperature, it is surmised that the departing bubble effectively removes the superheated layer, allowing a high local heat transfer rate with the bulk fluid through transient conduction/micro-convection during rewetting.

  8. Measuring surface temperature of isolated neutron stars and related problems

    Science.gov (United States)

    Teter, Marcus Alton

    New and exciting results for measuring neutron star surface temperatures began with the successful launch of the Chandra X-ray observatory. Among these results are new detections of neutron star surface temperatures which have made it possible to seriously test neutron star thermal evolution theories. The important new temperature determination of the Vela pulsar (Pavlov, et al., 2001a) requires a non-standard cooling scenario to explain it. Apart from this result, we have measured PSR B1055-52's surface temperature in this thesis, determining that it can be explained by standard cooling with heating. Our spectral fit of the combined data from ROSAT and Chandra have shown that a three component model, two thermal blackbodies and an non-thermal power-law, is required to explain the data. Furthermore, our phase resolved spectroscopy has begun to shed light on the geometry of the hot spot on PSR B1055-52's surface as well as the structure of the magnetospheric radiation. Also, there is strong evidence for a thermal distribution over its surface. Most importantly, the fact that PSR B1055-52 does not have a hydrogen atmosphere has been firmly established. To reconcile these two key observations, on the Vela pulsar and PSR B1055-52, we tested neutron star cooling with neutrino processes including the Cooper pair neutrino emission process. Overall, it has been found that a phase change associated with pions being present in the cores of more massive neutron stars explains all current of the data. A transition from neutron matter to pion condensates in the central stellar core explains the difference between standard and non-standard cooling scenarios, because the superfluid suppression of pion cooling will reduce the emissivity of the pion direct URCA process substantially. A neutron star with a mass of [Special characters omitted.] with a medium stiffness equation of state and a T72 type neutron superfluid models the standard cooling case well. A neutron star of [Special

  9. The Relationship Between Surface Temperature Anomaly Time Series and those of OLR, Water Vapor, and Cloud Cover as Observed Using Nine Years of AIRS Version-5 Level-3 Products

    Science.gov (United States)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena

    2011-01-01

    Outline: (1) Comparison of AIRS and CERES anomaly time series of outgoing longwave radiation (OLR) and OLR(sub CLR), i.e. Clear Sky OLR (2) Explanation of recent decreases in global and tropical mean values of OLR (3) AIRS "Short-term" Longwave Cloud Radiative Feedback -- A new product

  10. GHRSST Level 4 ODYSSEA Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  11. Comparison of MTI and Ground Truth Sea Surface Temperatures at Nauru

    Energy Technology Data Exchange (ETDEWEB)

    Kurzeja, R.

    2002-09-05

    This report evaluates MTI-derived surface water temperature near the tropical Pacific island of Nauru. The MTI sea-surface temperatures were determined by the Los Alamos National Laboratory based on the robust retrieval.

  12. GHRSST Level 4 GAMSSA Global Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Australian Bureau...

  13. GHRSST Level 4 RAMSSA Australian Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Australian Bureau...

  14. GHRSST Level 4 EUR Mediterranean Sea Regional Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily by Ifremer/CERSAT (France) using optimal...

  15. GHRSST Level 4 ODYSSEA Global Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  16. GHRSST Level 4 ODYSSEA Eastern Central Pacific Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at Ifremer/CERSAT...

  17. GHRSST Level 4 G1SST Global Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the JPL OurOcean...

  18. GHRSST Level 4 DMI_OI Global Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis by the Danish...

  19. GHRSST Level 4 OSTIA Global Foundation Sea Surface Temperature Analysis (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the UK Met Office...

  20. GHRSST Level 4 MW_OI Global Foundation Sea Surface Temperature analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) global Level 4 sea surface temperature analysis produced daily on a 0.25 degree grid at Remote Sensing...

  1. GHRSST Level 4 MUR North America Regional Foundation Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced as a retrospective dataset at the JPL Physical...

  2. GHRSST Level 4 OSPO Global Nighttime Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Office of...

  3. GHRSST Level 4 OSPO Global Foundation Sea Surface Temperature Analysis (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Office of...

  4. GHRSST Level 4 AVHRR_AMSR_OI Global Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) global Level 4 sea surface temperature analysis produced daily on a 0.25 degree grid at the NOAA...

  5. GHRSST Level 4 K10_SST Global 1 meter Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the Naval...

  6. Rectal temperature-based death time estimation in infants.

    Science.gov (United States)

    Igari, Yui; Hosokai, Yoshiyuki; Funayama, Masato

    2016-03-01

    In determining the time of death in infants based on rectal temperature, the same methods used in adults are generally used. However, whether the methods for adults are suitable for infants is unclear. In this study, we examined the following 3 methods in 20 infant death cases: computer simulation of rectal temperature based on the infinite cylinder model (Ohno's method), computer-based double exponential approximation based on Marshall and Hoare's double exponential model with Henssge's parameter determination (Henssge's method), and computer-based collinear approximation based on extrapolation of the rectal temperature curve (collinear approximation). The interval between the last time the infant was seen alive and the time that he/she was found dead was defined as the death time interval and compared with the estimated time of death. In Ohno's method, 7 cases were within the death time interval, and the average deviation in the other 12 cases was approximately 80 min. The results of both Henssge's method and collinear approximation were apparently inferior to the results of Ohno's method. The corrective factor was set within the range of 0.7-1.3 in Henssge's method, and a modified program was newly developed to make it possible to change the corrective factors. Modification A, in which the upper limit of the corrective factor range was set as the maximum value in each body weight, produced the best results: 8 cases were within the death time interval, and the average deviation in the other 12 cases was approximately 80min. There was a possibility that the influence of thermal isolation on the actual infants was stronger than that previously shown by Henssge. We conclude that Ohno's method and Modification A are useful for death time estimation in infants. However, it is important to accept the estimated time of death with certain latitude considering other circumstances.

  7. Temperature versus time curves for manual and automated soldering processes

    Energy Technology Data Exchange (ETDEWEB)

    Trent, M.A.

    1978-08-01

    Temperature-versus-time curves were recorded for various electronic components during pre-tinning, hand soldering, and drag soldering operations to determine the temperature ranges encountered. The component types investigated included a wide range of electronic assemblies. The data collected has been arranged by process and will help engineers to: (1) predetermine the thermal profile to which various components are subjected during the soldering operation; (2) decide--on the basis of component heat sensitivity and the need for thermal relief--where hand soldering would be more feasible than drag soldering; and (3) determine the optimum drag solder control parameters.

  8. A real time method for surface cleanliness measurement

    OpenAIRE

    Bilmes, Gabriel Mario; Orzi, Daniel Jesús Omar; Martínez , Oscar E.; Lencina, Alberto

    2006-01-01

    The measurement of surface cleanliness is a signifi cant problem in many industrial and technological processes. Existing methods are based on laboratory procedures, that are not performed in real time, can not be automated, and usually are restricted to a small portion of the sample. In this study we describe a new method for real time measurement of the amount of surface dirt or contamination deposited on a surface. It relies on the ablation of the surface dirt film by means of a short l...

  9. Physical mechanism and numerical simulations of surface layer temperature inversion in tropical ocean

    Institute of Scientific and Technical Information of China (English)

    FAN Haimei; LI Bingrui; ZHANG Qinghua; LIU Zhiliang

    2005-01-01

    The one-dimensional Kraus-Tumer mixed layer model improved by Liu is developed to consider the effect of salinity and the equations of temperature and salinity under the mixed layer. On this basis, the processes of growth and death of surface layer temperature inversion is numerically simulated under different environmental parameters. At the same time, the physical mechanism is preliminarily discussed combining the observations at the station of TOGA-COARE 0°N, 156°E. The results indicate that temperature inversion sensitively depends on the mixed layer depth, sea surface wind speed and solar shortwave radiation, etc., and appropriately meteorological and hydrological conditions often lead to the similarly periodical occurrence of this inversion phenomenon.

  10. High-Temperature Alkali Vapor Cells with Anti-Relaxation Surface Coatings

    CERN Document Server

    Seltzer, S J

    2009-01-01

    Anti-relaxation surface coatings allow long spin relaxation times in alkali-metal cells without buffer gas, enabling free motion of the alkali atoms and giving larger signals due to narrower optical linewidths. Effective coatings were previously unavailable for operation at temperatures above 80 C. We demonstrate that octadecyltrichlorosilane (OTS) can allow potassium or rubidium atoms to experience hundreds of collisions with the cell surface before depolarizing, and that an OTS coating remains effective up to about 170 C for both potassium and rubidium. We consider the experimental concerns of operating without buffer gas at high vapor density, studying the stricter need for effective quenching of excited atoms and deriving the optical rotation signal shape for atoms with resolved hyperfine structure in the spin-temperature regime. As an example of a high-temperature application of anti-relaxation coated alkali vapor cells, we operate a spin-exchange relaxation-free (SERF) atomic magnetometer with sensitivi...

  11. Mechanics of submerged jet cavitating action: material properties, exposure time and temperature effects on erosion

    Energy Technology Data Exchange (ETDEWEB)

    Hutli, Ezddin A.F.; Nedeljkovic, Milos S. [University of Belgrade, Faculty of Mechanical Engineering, Belgrade (RS); Radovic, Nenad A. [University of Belgrade, Faculty of Technology and Metallurgy, Belgrade (RS)

    2008-05-15

    Experimental setup with a submerged cavitating jet has been used for the study of influences of material, exposure time and working fluid temperature on the erosion process. Each of the parameters has been varied separately, and the results of erosion are analyzed in detail. Additionally, comparison of experiments with nitrated and non-nitrated material has been made in order to study the enhancement (mostly reflected as the prolonged incubation time) of erosion resistance achieved by nitrating the specimen surface. (orig.)

  12. Impacts of wind farms on surface air temperatures

    Science.gov (United States)

    Baidya Roy, Somnath; Traiteur, Justin J.

    2010-01-01

    Utility-scale large wind farms are rapidly growing in size and numbers all over the world. Data from a meteorological field campaign show that such wind farms can significantly affect near-surface air temperatures. These effects result from enhanced vertical mixing due to turbulence generated by wind turbine rotors. The impacts of wind farms on local weather can be minimized by changing rotor design or by siting wind farms in regions with high natural turbulence. Using a 25-y-long climate dataset, we identified such regions in the world. Many of these regions, such as the Midwest and Great Plains in the United States, are also rich in wind resources, making them ideal candidates for low-impact wind farms. PMID:20921371

  13. Surface Transformations and Water Uptake on Liquid and Solid Butanol near the Melting Temperature

    CERN Document Server

    Papagiannakopoulos, Panos; Thomson, Erik S; Markovic, Nikola; Pettersson, Jan B C

    2013-01-01

    Water interactions with organic surfaces are of central importance in biological systems and many Earth system processes. Here we describe experimental studies of water collisions and uptake kinetics on liquid and solid butanol from 160 to 200 K. Hyperthermal D2O molecules (0.32 eV) undergo efficient trapping on both solid and liquid butanol, and only a minor fraction scatters inelastically after an 80% loss of kinetic energy to surface modes. Trapped molecules either desorb within a few ms, or are taken up by the butanol phase during longer times. The water uptake and surface residence time increase with temperature above 180 K indicating melting of the butanol surface 4.5 K below the bulk melting temperature. Water uptake changes gradually across the melting point and trapped molecules are rapidly lost by diffusion into the liquid above 190 K. This indicates that liquid butanol maintains a surface phase with limited water permeability up to 5.5 K above the melting point. These surface observations are indic...

  14. Investigation of Sea Surface Temperature (SST) anomalies over Cyprus area

    Science.gov (United States)

    Georgiou, Andreas; Akçit, Nuhcan

    2016-08-01

    The temperature of the sea surface has been identified as an important parameter of the natural environment, governing processes that occur in the upper ocean. This paper focuses on the analysis of the Sea Surface Temperature (SST) anomalies at the greater area of Cyprus. For that, SST data derived from MODerate-resolution Imaging Spectroradiometer (MODIS) instrument on board both Aqua and Terra sun synchronous satellites were used. A four year period was chosen as a first approach to address and describe this phenomenon. Geographical Information Systems (GIS) has been used as an integrated platform of analysis and presentation in addition of the support of MATLAB®. The methodology consists of five steps: (i) Collection of MODIS SST imagery, (ii) Development of the digital geo-database; (iii) Model and run the methodology in GIS as a script; (iv) Calculation of SST anomalies; and (v) Visualization of the results. The SST anomaly values have presented a symmetric distribution over the study area with an increase trend through the years of analysis. The calculated monthly and annual average SST anomalies (ASST) make more obvious this trend, with negative and positive SST changes to be distributed over the study area. In terms of seasons, the same increase trend presented during spring, summer, autumn and winter with 2013 to be the year with maximum ASST observed values. Innovative aspects comprise of straightforward integration and modeling of available tools, providing a versatile platform of analysis and semi-automation of the operation. In addition, the fine resolution maps that extracted from the analysis with a wide spatial coverage, allows the detail representation of SST and ASST respectively in the region.

  15. A study of the coupling relationship between concrete surface temperature and concrete surface emissivity in natural conditions.

    Science.gov (United States)

    Tang, Lin-Ling; Chen, Xiao-Ling; Wang, Jia-Ning; Zhao, Hong-Mei; Huang, Qi-Ting

    2014-07-01

    Land surface emissivity (LSE) has already been recognized as a crucial parameter for the determination of land surface temperature (LST). There is an ill-posed problem for the retrieval of LST and LSE. And laboratory-based emissivity is measured in natural constant conditions, which is limited in the application in thermal remote sensing. To solve the above problems, the coupling of LST and LSE is explored to eliminate temperature effects and improve the accuracy of LES. And then, the estimation accuracy of LST from passive remote sensing images will be improved. For different land surface materials, the coupling of land surface emissivity and land surface temperature is various. This paper focuses on studying concrete surface that is one of the typical man-made materials in urban. First the experiments of measuring concrete surface emissivity and concrete surface temperature in natural conditions are arranged reasonably and the suitable data are selected under ideal atmosphere conductions. Then to improve the determination accuracy of concrete surface emissivity, the algorithm worked on the computer of Fourier Transform Infrared Spectroradiometer (FTIR) has been improved by the most adapted temperature and emissivity separation algorithm. Finally the coupling of concrete surface temperature and concrete surface emissivity is analyzed and the coupling model of concrete surface temperature and concrete surface emissivity is established. The results show that there is a highest correlation coefficient between the second derivative of emissivity spectra and concrete surface temperature, and the correlation coefficient is -0.925 1. The best coupling model is the stepwise regression model, whose determination coefficient (R2) is 0.886. The determination coefficient (R2) is 0.905 and the root mean squares error (RMSE) is 0.292 1 in the validation of the model. The coupling model of concrete surface temperature and concrete surface emissivity under natural conditions

  16. Spatial and temporal modeling of wetland surface temperature using Landsat-8 imageries in Sulduz, Iran

    Directory of Open Access Journals (Sweden)

    Vahid Eisavi

    2016-01-01

    Full Text Available Wetland Surface Temperature (WST maps are an increasingly important parameter to understand the extensive range of existing processes in wetlands. The Wetlands placed in neighborhoods of agricultural and industrial lands are exposed to more chemical pollutants and pesticides that can lead to spatial and temporal variations of their surface temperature. Therefore, more studies are required for temperature modeling and the management and conservation of these variations in their ecosystem. Landsat 8 time series data of Sulduz region, Western Azerbaijan province, Iran were used in this study. The WST was derived using a mono-window algorithm after implementation of atmospheric correction. The NDVI (Normalized Differential Vegetation Index threshold method was also employed to determine the surface emissivity. Our findings show that the WST experienced extensive spatial and temporal variations. It reached its maximum value in June and also experienced the highest mean in the same month. In this research, August (2013.12.08 had a lowest spatial standard deviation regarding surface temperature and June (2013.06.28 had the highest one. Wetlands' watersides adjacent to industrial zones have a higher surface temperature than the middle lands of these places. The map obtained from the WST variance over time can be exploited to reveal thermal stable and unstable zones. The outcome demonstrates that land use, land cover effectively contribute to wetland ecosystem health. The results are useful in the water management, preventive efforts against drying of wetland and evapotranspiration modeling. The approach employed in this research indicates that remote sensing is a valuable, low-cost and stable tool for thermal monitoring of wetlands health.

  17. Effects of Temperature on Time Dependent Rheological Characteristics of Koumiss

    Directory of Open Access Journals (Sweden)

    Serdal Sabancı

    2016-04-01

    Full Text Available The rheological properties of koumiss were investigated at different temperatures (4, 10, and 20°C. Experimental shear stress–shear rate data were fitted to different rheological models. The consistency of koumiss was predicted by using the power-law model since it described the consistency of koumiss best with highest regression coefficient and lowest errors (root mean square error and chi-square. Koumiss exhibited shear thinning behavior (n<1. The flow activation energy for temperature dependency of consistency was 25.532 kJ/mol, and the frequency constant was 2.18×10-7Pa.sn. As the temperature increased the time dependent thixotropic characteristics of koumiss decreased.

  18. Assessment of surface temperatures of buffalo bulls (Bubalus bubalis raised under tropical conditions using infrared thermography

    Directory of Open Access Journals (Sweden)

    D.V. Barros

    2016-04-01

    Full Text Available This paper aimed to evaluate the surface temperatures of buffalo bulls using infrared thermography, considering four distinct anatomical parts over time, and to correlate surface temperatures and thermal comfort indexes. The humid tropical climate (Köppen's Afi was predominant in the research station where the experiment was performed and the trial lasted from April to August. Ten bulls (n=10 were evaluated every 25 days (morning: 6:00-9:00; afternoon: 12:00-15:00 and the parameters assessed were respiratory rate (RR, rectal temperature (RT, and the thermograms of surface temperature for orbital area (ORB, right flank (RF, left flank (LF and scrotum (SCR. Climatological data was continuously monitored and the Temperature and Humidity Index (THI and the Index of Comfort of Benezra (ICB were calculated. The average values of THI were ≥78, and significant differences between shifts were observed (P<0.05. The ICB ranged from 1.96 to 2.25 and significant differences were observed for shifts and throughout the months (P<0.05. The averages of surface temperatures were RT=38.2±0.5°C, ORB=36.1±0.8°C, LF=33.5±2.5°C, RF=35.4±1.7ºC and SCR=33.3±1.1°C, which exhibited significant differences for shifts and throughout the months (P<0.05. Positive correlations were obtained between THI and ORB (0.72, RF (0.77, LF (0.75 and SCR (0.41 (P<0.0001. The maximum temperature of ORB showed the highest correlation with RT (0.58, P<0.0001. Therefore, the surface temperatures are subject to climatic variations and increase throughout the day, due to the variation in thermal comfort indexes, and the maximum ORB temperature was the parameter most related to rectal temperature. Lastly, the results indicate that IRT may be a useful non-invasive and accurate tool to detect the variations in ORB, LF, RF and SCR temperature in buffalo bulls.

  19. Wettability and Contact Time on a Biomimetic Superhydrophobic Surface

    Directory of Open Access Journals (Sweden)

    Yunhong Liang

    2017-03-01

    Full Text Available Inspired by the array microstructure of natural superhydrophobic surfaces (lotus leaf and cicada wing, an array microstructure was successfully constructed by high speed wire electrical discharge machining (HS-WEDM on the surfaces of a 7075 aluminum alloy without any chemical treatment. The artificial surfaces had a high apparent contact angle of 153° ± 1° with a contact angle hysteresis less than 5° and showed a good superhydrophobic property. Wettability, contact time, and the corresponding superhydrophobic mechanism of artificial superhydrophobic surface were investigated. The results indicated that the micro-scale array microstructure was an important factor for the superhydrophobic surface, while different array microstructures exhibited different effects on the wettability and contact time of the artificial superhydrophobic surface. The length (L, interval (S, and height (H of the array microstructure are the main influential factors on the wettability and contact time. The order of importance of these factors is H > S > L for increasing the apparent contact angle and reducing the contact time. The method, using HS-WEDM to fabricate superhydrophobic surface, is simple, low-cost, and environmentally friendly and can easily control the wettability and contact time on the artificial surfaces by changing the array microstructure.

  20. Spectroscopic determination of optimal hydration time of zircon surface

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Garcia R, G. [Instituto Tecnologico de Toluca, Division de Estudios del Posgrado, Av. Tecnologico s/n, Ex-Rancho La Virgen, 52140 Metepec, Estado de Mexico (Mexico); Garcia G, N., E-mail: eduardo.ordonez@inin.gob.m [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Av. Colon y Av. Tollocan, 50180 Toluca, Estado de Mexico (Mexico)

    2010-07-01

    When a mineral surface is immersed in an aqueous solution, it develops and electric charge produced by the amphoteric dissociation of hydroxyl groups created by the hydration of the solid surface. This is one influential surface property. The complete hydration process takes a time which is specific for each mineral species. The knowledge of the aqueous solution contact time for complete surface hydration is mandatory for further surface phenomena studies. This study deals with the optimal hydration time of the raw zircon (ZrSiO{sub 4}) surface comparing the classical potentiometric titrations with a fluorescence spectroscopy technique. The latter is easy and rea liable as it demands only one sample batch to determine the optimal time to ensure a total hydration of the zircon surface. The analytical results of neutron activation analysis showed the presence of trace quantities of Dy{sup 3+}, Eu{sup 3+} and Er{sup 3} in the bulk of zircon. The Dy{sup 3+} is structured in the zircon crystalline lattice and undergoes the same chemical reactions as zircon. Furthermore, the Dy{sup 3+} has a good fluorescent response whose intensity is enhanced by hydration molecules. The results show that, according to the potentiometric analysis, the hydration process for each batch (at least 8 sample batches) takes around 2 h, while the spectrometric method indicates only 5 minutes from only one batch. Both methods showed that the zircon surface have a 16 h optimal hydration time. (Author)

  1. Ocular Surface Temperature in Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Andrea Sodi

    2014-01-01

    Full Text Available Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320. The ocular surface temperature (OST of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272. OST in AMD patients was significantly lower than in controls (P>0.05. Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD.

  2. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    Science.gov (United States)

    Mamede, Anne-Sophie; Nuns, Nicolas; Cristol, Anne-Lise; Cantrel, Laurent; Souvi, Sidi; Cristol, Sylvain; Paul, Jean-François

    2016-04-01

    In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8-12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe2O3 oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  3. Automatic control system of brain temperature by air-surface cooling for therapeutic hypothermia.

    Science.gov (United States)

    Utsuki, T

    2013-01-01

    An automatic control system of brain temperature by air-surface cooling was developed for therapeutic hypothermia, which is increasingly recommended for hypoxic-ischemic encephalopathy after cardiac arrest and neonatal asphyxia in several guidelines pertinent to resuscitation. Currently, water-surface cooling is the most widespread cooling method in therapeutic hypothermia. However, it requires large electric power for precise control and also needs water-cooling blankets which have potential for compression of patients by its own weight and for water leakage in ICU. Air-surface cooling does not have such problems and is more suitable for clinical use than water-surface cooling, because air has lower specific heat and density as well as the impossibility of the contamination in ICU by its leakage. In the present system, brain temperature of patients is automatically controlled by suitable adjustment of the temperature of the air blowing into the cooling blankets. This adjustment is carried out by the regulation of mixing cool and warm air using proportional control valves. The computer in the developed control apparatus suitably calculates the air temperature and rotation angle of the valves every sampling time on the basis of the optimal-adaptive control algorithm. Thus, the proposed system actualizes automatic control of brain temperature by the inputting only the clinically desired temperature of brain. The control performance of the suggested system was verified by the examination using the mannequin in substitution for an adult patient. In the result, the control error of the head temperature of the mannequin was 0.12 °C on average in spite of the lack of the production capacity of warm air after the re-warming period. Thus, this system serves as a model for the clinically applied system.

  4. Global Distribution and Variability of Surface Skin and Surface Air Temperatures as Depicted in the AIRS Version-6 Data Set

    Science.gov (United States)

    Susskind, Joel; Lee, Jae N.; Iredell, Lena

    2014-01-01

    In this presentation, we will briefly describe the significant improvements made in the AIRS Version-6 retrieval algorithm, especially as to how they affect retrieved surface skin and surface air temperatures. The global distribution of seasonal 1:30 AM and 1:30 PM local time 12 year climatologies of Ts,a will be presented for the first time. We will also present the spatial distribution of short term 12 year anomaly trends of Ts,a at 1:30 AM and 1:30 PM, as well as the spatial distribution of temporal correlations of Ts,a with the El Nino Index. It will be shown that there are significant differences between the behavior of 1:30 AM and 1:30 PM Ts,a anomalies in some arid land areas.

  5. Decadal modulation of global surface temperature by internal climate variability

    Science.gov (United States)

    Dai, Aiguo; Fyfe, John C.; Xie, Shang-Ping; Dai, Xingang

    2015-06-01

    Despite a steady increase in atmospheric greenhouse gases (GHGs), global-mean surface temperature (T) has shown no discernible warming since about 2000, in sharp contrast to model simulations, which on average project strong warming. The recent slowdown in observed surface warming has been attributed to decadal cooling in the tropical Pacific, intensifying trade winds, changes in El Niño activity, increasing volcanic activity and decreasing solar irradiance. Earlier periods of arrested warming have been observed but received much less attention than the recent period, and their causes are poorly understood. Here we analyse observed and model-simulated global T fields to quantify the contributions of internal climate variability (ICV) to decadal changes in global-mean T since 1920. We show that the Interdecadal Pacific Oscillation (IPO) has been associated with large T anomalies over both ocean and land. Combined with another leading mode of ICV, the IPO explains most of the difference between observed and model-simulated rates of decadal change in global-mean T since 1920, and particularly over the so-called `hiatus' period since about 2000. We conclude that ICV, mainly through the IPO, was largely responsible for the recent slowdown, as well as for earlier slowdowns and accelerations in global-mean T since 1920, with preferred spatial patterns different from those associated with GHG-induced warming or aerosol-induced cooling. Recent history suggests that the IPO could reverse course and lead to accelerated global warming in the coming decades.

  6. Air Temperature estimation from Land Surface temperature and solar Radiation parameters

    Science.gov (United States)

    Lazzarini, Michele; Eissa, Yehia; Marpu, Prashanth; Ghedira, Hosni

    2013-04-01

    Air Temperature (AirT) is a fundamental parameter in a wide range of applications such as climate change studies, weather forecast, energy balance modeling, efficiency of Photovoltaic (PV) solar cells, etc. Air temperature data are generally obtained through regular measurements from meteorological stations. The distribution of these stations is normally sparse, so the spatial pattern of this parameter cannot be accurately estimated by interpolation methods. This work investigated the relationship between Air Temperature measured at meteorological stations and spatially contiguous measurements derived from Remote Sensing techniques, such as Land Surface Temperature (LST) maps, emissivity maps and shortwave radiation maps with the aim of creating a continuous map of AirT. For LST and emissivity, MSG-SEVIRI LST product from Land Surface Analysis Satellite Applications Facility (LSA-SAF) has been used. For shortwave radiation maps, an Artificial Neural Networks ensemble model has been developed and previously tested to create continuous maps from Global Horizontal Irradiance (GHI) point measurements, utilizing six thermal channels of MSG-SEVIRI. The testing sites corresponded to three meteorological stations located in the United Arab Emirates (UAE), where in situ measurements of Air Temperature were available. From the starting parameters, energy fluxes and net radiation have been calculated, in order to have information on the incoming and outgoing long-wave radiation and the incoming short-wave radiation. The preliminary analysis (day and Night measurements, cloud free) showed a strong negative correlation (0.92) between Outgoing long-wave radiation - GHI and LST- AirT, with a RMSE of 1.84 K in the AirT estimation from the initial parameters. Regression coefficients have been determined and tested on all the ground stations. The analysis also demonstrated the predominant impact of the incoming short-wave radiation in the AirT hourly variation, while the incoming

  7. EUMETSAT and OSI-SAF Sea Surface Temperature: Recent results and future developments

    Science.gov (United States)

    O'Carroll, Anne; Le Borgne, Pierre

    2014-05-01

    The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) delivers operational weather and climate-related satellite data, images and products throughout all day and year. EUMETSAT also has commitments to operational oceanography and atmospheric composition monitoring. Activities over the next twenty years include the continuation of the Mandatory Programmes (MSG, EPS) and future (MTG, EPS-SG), which all include ocean observations of Sea Surface Temperature. The EUMETSAT Ocean and Sea-ice (OSI) Satellite Application Facility (SAF) is lead by Meteo-France with a consortium of institutes from EUMETSAT member states, and provides reliable and timely operational services related to meteorology, oceanography and the marine environment. The OSI-SAF delivers level-2 Sea Surface Temperature products in GHRSST format from a range of EUMETSAT data including Metop AVHRR, IASI; and SEVIRI. EUMETSAT is participating in Copernicus Sentinel-3 in partnership with ESA, where EUMETSAT will operate the satellite and will serve the marine user community. The operational Sea Surface Temperature product delivered by EUMETSAT for Sentinel-3 SLSTR will be in GHRSST L2P format. On-going work towards access to relevant data from third-parties with the preparation of agreements with ISRO, SOA and JAXA, will give EUMETSAT access to an enhanced ocean products catalogue. The presentation will give an overview of activities relating to Sea Surface Temperature at EUMETSAT and the OSI-SAF, and their support to GHRSST, focusing on recent results and future developments.

  8. Modeled Seasonal Variations of Firn Density Induced by Steady State Surface Air Temperature Cycle

    Science.gov (United States)

    Jun, Li; Zwally, H. Jay; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Seasonal variations of firn density in ice-sheet firn layers have been attributed to variations in deposition processes or other processes within the upper firn. A recent high-resolution (mm scale) density profile, measured along a 181 m core from Antarctica, showed small-scale density variations with a clear seasonal cycle that apparently was not-related to seasonal variations in deposition or known near-surface processes (Gerland and others 1999). A recent model of surface elevation changes (Zwally and Li, submitted) produced a seasonal variation in firn densification, and explained the seasonal surface elevation changes observed by satellite radar altimeters. In this study, we apply our 1-D time-dependent numerical model of firn densification that includes a temperature-dependent formulation of firn densification based on laboratory measurements of grain growth. The model is driven by a steady-state seasonal surface temperature and a constant accumulation rate appropriate for the measured Antarctic ice core. The modeled seasonal variations in firn density show that the layers of snow deposited during spring to mid-summer with the highest temperature history compress to the highest density, and the layers deposited during later summer to autumn with the lowest temperature history compress to the lowest density. The initial amplitude of the seasonal difference of about 0.13 reduces to about 0.09 in five years and asymptotically to 0.92 at depth, which is consistent with the core measurements.

  9. Temperature Mapping of Air Film-Cooled Thermal Barrier Coated Surfaces Using Phosphor Thermometry

    Science.gov (United States)

    Eldridge, Jeffrey I.

    2016-01-01

    While the effects of thermal barrier coating (TBC) thermal protection and air film cooling effectiveness for jet engine components are usually studied separately, their contributions to combined cooling effectiveness are interdependent and are not simply additive. Therefore, combined cooling effectiveness must be measured to achieve an optimum balance between TBC thermal protection and air film cooling. Phosphor thermometry offers several advantages for mapping temperatures of air film cooled surfaces. While infrared thermography has been typically applied to study air film cooling effectiveness, temperature accuracy depends on knowing surface emissivity (which may change) and correcting for effects of reflected radiation. Because decay time-based full-field phosphor thermometry is relatively immune to these effects, it can be applied advantageously to temperature mapping of air film-cooled TBC-coated surfaces. In this presentation, an overview will be given of efforts at NASA Glenn Research Center to perform temperature mapping of air film-cooled TBC-coated surfaces in a burner rig test environment. The effects of thermal background radiation and flame chemiluminescence on the measurements are investigated, and the strengths and limitations of this method for studying air film cooling effectiveness are discussed.

  10. 2D surface temperature measurement of plasma facing components with modulated active pyrometry.

    Science.gov (United States)

    Amiel, S; Loarer, T; Pocheau, C; Roche, H; Gauthier, E; Aumeunier, M-H; Le Niliot, C; Rigollet, F; Courtois, X; Jouve, M; Balorin, C; Moncada, V

    2014-10-01

    In nuclear fusion devices, such as Tore Supra, the plasma facing components (PFC) are in carbon. Such components are exposed to very high heat flux and the surface temperature measurement is mandatory for the safety of the device and also for efficient plasma scenario development. Besides this measurement is essential to evaluate these heat fluxes for a better knowledge of the physics of plasma-wall interaction, it is also required to monitor the fatigue of PFCs. Infrared system (IR) is used to manage to measure surface temperature in real time. For carbon PFCs, the emissivity is high and known (ɛ ∼ 0.8), therefore the contribution of the reflected flux from environment and collected by the IR cameras can be neglected. However, the future tokamaks such as WEST and ITER will be equipped with PFCs in metal (W and Be/W, respectively) with low and variable emissivities (ɛ ∼ 0.1-0.4). Consequently, the reflected flux will contribute significantly in the collected flux by IR camera. The modulated active pyrometry, using a bicolor camera, proposed in this paper allows a 2D surface temperature measurement independently of the reflected fluxes and the emissivity. Experimental results with Tungsten sample are reported and compared with simultaneous measurement performed with classical pyrometry (monochromatic and bichromatic) with and without reflective flux demonstrating the efficiency of this method for surface temperature measurement independently of the reflected flux and the emissivity.

  11. Inter-annual variability of sea surface temperature, wind speed and sea surface height anomaly over the tropical Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Pankajakshan, T.; Sathe, P.V.

    have made an attempt to study the annual and inter-annual variability of certain prominent processes occurring over the tropical Indian Ocean. The monthly mean values of Wind Speed (FSU), Sea Surface Temperature (REYNOLDS) and Sea Surface Height Anomaly...

  12. Spatially and temporally resolved measurements of the temperature inside droplets impinging on a hot solid surface

    Science.gov (United States)

    Chaze, William; Caballina, Ophélie; Castanet, Guillaume; Lemoine, Fabrice

    2017-08-01

    Heat transfers at the impact of a droplet on a hot solid surface are investigated experimentally. Millimeter-sized water droplets impinge a flat sapphire window heated at 600 °C. The time evolution of the droplet temperature is characterized using the two-color laser-induced fluorescence technique. For that, a Q-switched Nd:YAG laser is used for the excitation of the fluorescence to obtain instantaneous images of the droplet temperature. Water is seeded with two fluorescent dyes, one sensitive to temperature (fluorescein disodium) and the other not (sulforhodamine 640). Owing to a wavelength shift between the dyes' emissions, the fluorescence signal of the dyes can be detected separately by two cameras. The liquid temperature is determined with a good accuracy by doing the ratio of the images of the dyes' fluorescence. A critical feature of the method is that the image ratio is not disturbed by the deformation of the impacting droplet, which affects the signals of the dyes almost identically. Experiments are performed in the conditions of film boiling. A thin vapor film at the interface between the droplet and the solid surface prevents the deposition of liquid on the hot solid surface. Measurements highlight some differences in the rate of heat transfers and in the temperature distribution within the droplet between the bouncing and splashing regimes of impact.

  13. Impacts of urban and industrial development on Arctic land surface temperature in Lower Yenisei River Region.

    Science.gov (United States)

    Li, Z.; Shiklomanov, N. I.

    2015-12-01

    Urbanization and industrial development have significant impacts on arctic climate that in turn controls settlement patterns and socio-economic processes. In this study we have analyzed the anthropogenic influences on regional land surface temperature of Lower Yenisei River Region of the Russia Arctic. The study area covers two consecutive Landsat scenes and includes three major cities: Norilsk, Igarka and Dudingka. Norilsk industrial region is the largest producer of nickel and palladium in the world, and Igarka and Dudingka are important ports for shipping. We constructed a spatio-temporal interpolated temperature model by including 1km MODIS LST, field-measured climate, Modern Era Retrospective-analysis for Research and Applications (MERRA), DEM, Landsat NDVI and Landsat Land Cover. Those fore-mentioned spatial data have various resolution and coverage in both time and space. We analyzed their relationships and created a monthly spatio-temporal interpolated surface temperature model at 1km resolution from 1980 to 2010. The temperature model then was used to examine the characteristic seasonal LST signatures, related to several representative assemblages of Arctic urban and industrial infrastructure in order to quantify anthropogenic influence on regional surface temperature.

  14. Trends of surface humidity and temperature during 1951-2012 in Beijing, China

    Science.gov (United States)

    Chu, Q.; Xu, Z.; Peng, D.; Yang, X.; Yang, G.

    2015-05-01

    In this paper, two datasets, a long time series (1951-2012) of daily surface observations at one meteorological station and a shorter time series (1979-2012) of three-hourly data with 0.1°×0.1° spatial resolution were analysed by using non-parametric methods to identify annual and seasonal variations in surface humidity and temperature. The results reveal that: (1) saturation water vapour pressure increased exponentially with temperature. Actual daily values at Beijing Meteorological Station are very close to the theoretical values estimated by using the simplified Clausius-Clapeyron equation, but with seasonal variations. (2) For both long- and short-term data, clear increasing tendencies of annual saturation specific humidity and temperature are found. Decreasing and drying trends were detected for winter. (3) The annual relative humidity showed a decreasing trend except for some suburban areas, somehow related to the lower temperature and increased specific humidity in those areas. (4) Regional changes in topography and elevation likely influenced trends in surface humidity, while local land use showed little effect on it.

  15. Detecting and Adjusting Temporal Inhomogeneity in Chinese Mean Surface Air Temperature Data

    Institute of Scientific and Technical Information of China (English)

    LI Qingxiang(李庆祥); LIU Xiaoning(刘小宁); ZHANG Hongzheng(张洪政); Thomas C. PETERSON; David R. EASTERLING

    2004-01-01

    Adopting the Easterling-Peterson (EP) techniques and considering the reality of Chinese meteorological observations, this paper designed several tests and tested for inhomogeneities in all Chinese historical surface air temperature series from 1951 to 2001. The result shows that the time series have been widely impacted by inhomogeneities resulting from the relocation of stations and changes in local environment such as urbanization or some other factors. Among these factors, station relocations caused the largest magnitude of abrupt changes in the time series, and other factors also resulted in inhomogeneities to some extent. According to the amplitude of change of the difference series and the monthly distribution features of surface air temperatures, discontinuities identified by applying both the E-P technique and supported by China's station history records, or by comparison with other approaches, have been adjusted. Based on the above processing, the most significant temporal inhomogeneities were eliminated, and China's most homogeneous surface air temperature series has thus been created. Results show that the inhomogeneity testing captured well the most important change of the stations, and the adjusted dataset is more reliable than ever. This suggests that the adjusted temperature dataset has great value of decreasing the uncertaities in the study of observed climate change in China.

  16. Surface morphology and physicochemical properties of ordered mesoporous silica SBA-15 synthesized at low temperature

    Science.gov (United States)

    Koh, M. H.; Haji Azaman, S. A.; Hameed, B. H.; Din, A. T. Mohd

    2017-06-01

    The effects of process parameters on the surface morphology and physicochemical characteristics of ordered mesoporous silica SBA-15 synthesized at low temperature have been investigated in this study. SBA-15 particles were synthesized through sol-gel method using non-ionic surfactant Pluronic P123 and TEOS as a silica source with aqueous hydrochloric acid (HCl) as a catalyst under the following conditions: HCl concentration (1.0-2.5 M), ageing temperature (40-70ºC) and ageing time (12-48 hours). A series of physicochemical characterizations and material analyses were performed on SBA-15 particles including Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Transmission Electron Microscopy (TEM), BET surface area analysis, Fourier transform infrared (FTIR) analysis and X-ray Diffraction (XRD) analysis. From the experimental observation, the conditions of HCl concentration, ageing temperature and ageing time were able to influence the surface morphology of SBA-15 particles. The presence of the ordered structures in SBA-15 particles was observed through the formation of 1-D cylindrical channels and 2-D hexagonal pores, inspected by using TEM. The detected XRD peak at (100) reflection signified the presence of ordered meso structures within the SBA-15 particles. Therefore, synthesis of SBA-15 particles through sol-gel method at low temperature is feasible and more sustainable if compared to the energy intensive hydrothermal method.

  17. Rayleigh surface acoustic wave as an efficient heating system for biological reactions: investigation of microdroplet temperature uniformity.

    Science.gov (United States)

    Roux-Marchand, Thibaut; Beyssen, Denis; Sarry, Frederic; Elmazria, Omar

    2015-04-01

    When a microdroplet is put on the Rayleigh surface acoustic wave path, longitudinal waves are radiated into the liquid and induce several phenomena such as the wellknown surface acoustic wave streaming. At the same time, the temperature of the microdroplet increases as it has been shown. In this paper, we study the temperature uniformity of a microdroplet heated by Rayleigh surface acoustic wave for discrete microfluidic applications such as biological reactions. To precisely ascertain the temperature uniformity and not interfere with the biological reaction, we used an infrared camera. We then tested the temperature uniformity as a function of three parameters: the microdroplet volume, the Rayleigh surface acoustic wave frequency, and the continuous applied radio frequency power. Based on these results, we propose a new device structure to develop a future lab on a chip based on reaction temperatures.

  18. Analyses of Inhomogeneities in Radiosonde Temperature and Humidity Time Series.

    Science.gov (United States)

    Zhai, Panmao; Eskridge, Robert E.

    1996-04-01

    Twice daily radiosonde data from selected stations in the United States (period 1948 to 1990) and China (period 1958 to 1990) were sorted into time series. These stations have one sounding taken in darkness and the other in sunlight. The analysis shows that the 0000 and 1200 UTC time series are highly correlated. Therefore, the Easterling and Peterson technique was tested on the 0000 and 1200 time series to detect inhomogeneities and to estimate the size of the biases. Discontinuities were detected using the difference series created from the 0000 and 1200 UTC time series. To establish that the detected bias was significant, a t test was performed to confirm that the change occurs in the daytime series but not in the nighttime series.Both U.S. and Chinese radiosonde temperature and humidity data include inhomogeneities caused by changes in radiosonde sensors and observation times. The U.S. humidity data have inhomogeneities that were caused by instrument changes and the censoring of data. The practice of reporting relative humidity as 19% when it is lower than 20% or the temperature is below 40°C is called censoring. This combination of procedural and instrument changes makes the detection of biases and adjustment of the data very difficult. In the Chinese temperatures, them are inhomogeneities related to a change in the radiation correction procedure.Test results demonstrate that a modified Easterling and Peterson method is suitable for use in detecting and adjusting time series radiosonde data.Accurate stations histories are very desirable. Stations histories can confirm that detected inhomogeneities are related to instrument or procedural changes. Adjustments can then he made to the data with some confidence.

  19. NOAA Climate Data Record (CDR) of Sea Surface Temperature -WHOI, Version 1.0

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Ocean Surface Bundle (OSB) Climate Data Record (CDR) consist of three parts: sea surface temperature, near-surface atmospheric properties, and heat fluxes....

  20. Surface-Borne Time-of-Reception Measurements (STORM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Invocon proposes the Surface-borne Time-Of-Reception Measurements (STORM) system as a method to locate the position of lightning strikes on aerospace vehicles....

  1. Persistence and Time Trends in the Temperatures in Spain

    Directory of Open Access Journals (Sweden)

    Luis A. Gil-Alana

    2009-01-01

    Full Text Available This paper deals with the analysis of the temperatures in several locations in Spain during the last 50 years. We focus on the degree of persistence of the series, measured through a fractional differencing parameter. This is crucial to properly estimate the parameters of the time trend coefficients in order to determine the degree of warming in the area. The results indicate that all series are fractionally integrated with orders of integration ranging between 0 and 0.5. Moreover, the time trend coefficients are all positive though they are statistically insignificant, which is in contrast with the results based on nonfractional integration.

  2. Surface temperature evolution and the location of maximum and average surface temperature of a lithium-ion pouch cell under variable load profiles

    DEFF Research Database (Denmark)

    Goutam, Shovon; Timmermans, Jean-Marc; Omar, Noshin;

    2014-01-01

    , manganese and cobalt (NMC) based and the anode is graphite based. In order to measure the surface temperature, thermal infrared (IR) camera and contact thermocouples were used. A fairly uniform temperature distribution was observed over the cell surface in case of continuous charge and discharge up to 100A...

  3. Estimation of Surface Temperature and Heat Flux by Inverse Heat Transfer Methods Using Internal Temperatures Measured While Radiantly Heating a Carbon/Carbon Specimen up to 1920 F

    Science.gov (United States)

    Pizzo, Michelle; Daryabeigi, Kamran; Glass, David

    2015-01-01

    The ability to solve the heat conduction equation is needed when designing materials to be used on vehicles exposed to extremely high temperatures; e.g. vehicles used for atmospheric entry or hypersonic flight. When using test and flight data, computational methods such as finite difference schemes may be used to solve for both the direct heat conduction problem, i.e., solving between internal temperature measurements, and the inverse heat conduction problem, i.e., using the direct solution to march forward in space to the surface of the material to estimate both surface temperature and heat flux. The completed research first discusses the methods used in developing a computational code to solve both the direct and inverse heat transfer problems using one dimensional, centered, implicit finite volume schemes and one dimensional, centered, explicit space marching techniques. The developed code assumed the boundary conditions to be specified time varying temperatures and also considered temperature dependent thermal properties. The completed research then discusses the results of analyzing temperature data measured while radiantly heating a carbon/carbon specimen up to 1920 F. The temperature was measured using thermocouple (TC) plugs (small carbon/carbon material specimens) with four embedded TC plugs inserted into the larger carbon/carbon specimen. The purpose of analyzing the test data was to estimate the surface heat flux and temperature values from the internal temperature measurements using direct and inverse heat transfer methods, thus aiding in the thermal and structural design and analysis of high temperature vehicles.

  4. Time-evolving statistics of cavitation damage on metallic surfaces.

    Science.gov (United States)

    Diodati, P; Marchesoni, F

    2002-11-01

    The statistics of surface damage on polycrystalline aluminium plates caused by acoustic cavitation is studied experimentally as a function of time. Cavitation is shown to produce a uniform distribution of crater-like holes with different depth, area and eccentricity. Most notably, the size distribution of such craters evolves with time from a gamma function into a power law. By contrast, on the surface of a martensitic Cu-Ni-Al crystal cavitation damage generates ramified patterns, reminiscent of a fractal object.

  5. Streaming Surface Reconstruction from Real Time 3D Measurements

    OpenAIRE

    Bodenmüller, Tim

    2009-01-01

    In this thesis, a robust method for fast surface reconstruction from real time 3D point streams is presented. It is designed for the integration in a fast visual feedback system that supports a user while manually 3D scanning objects. The method iteratively generates a dense and homogeneous triangular mesh by inserting sample points from the real time data stream and refining the surface model locally. A spatial data structure ensures a fast access to growing point sets and continuously updat...

  6. Causes of twentieth-century temperature change near the Earth's surface

    Science.gov (United States)

    Tett, Simon F. B.; Stott, Peter A.; Allen, Myles R.; Ingram, William J.; Mitchell, John F. B.

    1999-06-01

    Observations of the Earth's near-surface temperature show a global-mean temperature increase of approximately 0.6K since 1900 (ref. 1), occurring from 1910 to 1940 and from 1970 to the present. The temperature change over the past 30-50 years is unlikely to be entirely due to internal climate variability and has been attributed to changes in the concentrations of greenhouse gases and sulphate aerosols due to human activity. Attribution of the warming early in the century has proved more elusive. Here we present a quantification of the possible contributions throughout the century from the four components most likely to be responsible for the large-scale temperature changes, of which two vary naturally (solar irradiance and stratospheric volcanic aerosols) and two have changed decisively due to anthropogenic influence (greenhouse gases and sulphate aerosols). The patterns of time/space changes in near-surface temperature due to the separate forcing components are simulated with a coupled atmosphere-ocean general circulation model, and a linear combination of these is fitted to observations. Thus our analysis is insensitive to errors in the simulated amplitude of these responses. We find that solar forcing may have contributed to the temperature changes early in the century, but anthropogenic causes combined with natural variability would also present a possible explanation. For the warming from 1946 to 1996 regardless of any possible amplification of solar or volcanic influence, we exclude purely natural forcing, and attribute it largely to the anthropogenic components.

  7. Coral reef bleaching and sea surface temperature anomalies: 1991-1996 global patterns

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J.; Hayes, R.L.; Strong, A.

    1997-12-31

    Global spatio-temporal patterns of mass coral reef bleaching during the first half of the 1990s continued to show the strong temperature correlations which first became established in the 1980s. Satellite sea surface temperature data and field observations were used to track thermal bleaching events in real time. Most bleaching events followed warm season sea surface temperature anomalies of around +1 degree celsius above historical means. Global bleaching patterns appear to have been strongly affected by worldwide cooling which followed eruption of Mount Pinatubo in June 1991. High water temperatures and mass coral reef bleaching took place in the Caribbean, Indian Ocean, and South Pacific in 1991, but there were few thermal anomalies or bleaching events in 1992 and 1993, years which were markedly cooler worldwide. Following the settling of Mount Pinatubo aerosols and resumption of global warming trends, extensive ocean thermal hot spots and bleaching events resumed in the South Pacific, South Atlantic, and Indian Oceans in 1994. Bleaching again took place in hot spots in the Indian Ocean and Caribbean in 1995, and in the South Atlantic, Caribbean, South Pacific, North Pacific, and Persian Gulf in 1996. Coral reefs worldwide are now very close to their upper temperature tolerance limits. This sensitivity, and the fact that the warmest ecosystems have no source of immigrant species pre-adapted to warmer conditions, may make coral reef ecosystems the first to be severely impacted if global temperatures and sea levels remain at current values or increase further.

  8. Surface mapping of field-induced piezoelectric strain at elevated temperature employing full-field interferometry.

    Science.gov (United States)

    Stevenson, Tim; Quast, Tatjana; Bartl, Guido; Schmitz-Kempen, Thorsten; Weaver, Paul M

    2015-01-01

    Piezoelectric actuators and sensors are widely used for flow control valves, including diesel injectors, ultrasound generation, optical positioning, printing, pumps, and locks. Degradation and failure of material and electrical properties at high temperature typically limits these applications to operating temperatures below 200°C, based on the ubiquitous Pb(Zr,Ti)O3 ceramic. There are, however, many applications in sectors such as automotive, aerospace, energy and process control, and oil and gas, where the ability to operate at higher temperatures would open up new markets for piezoelectric actuation. Presented here is a review of recent progress and initial results toward a European effort to develop measurement techniques to characterize high-temperature materials. Full-field, multi-wavelength absolute length interferometry has, for the first time, been used to map the electric-field-induced piezoelectric strain across the surface of a PZT ceramic. The recorded variation as a function of temperature has been evaluated against a newly developed commercial single-beam system. Conventional interferometry allows measurement of the converse piezoelectric effect with high precision and resolution, but is often limited to a single point, average measurement and to limited sample environments because of optical aberrations in varying atmospheres. Here, the full-field technique allows the entire surface to be analyzed for strain and, in a bespoke sample chamber, for elevated temperatures.

  9. An assessment of precipitation and surface air temperature over China by regional climate models

    Science.gov (United States)

    Wang, Xueyuan; Tang, Jianping; Niu, Xiaorui; Wang, Shuyu

    2016-12-01

    An analysis of a 20-year summer time simulation of present-day climate (1989-2008) over China using four regional climate models coupled with different land surface models is carried out. The climatic means, interannual variability, linear trends, and extremes are examined, with focus on precipitation and near surface air temperature. The models are able to reproduce the basic features of the observed summer mean precipitation and temperature over China and the regional detail due to topographic forcing. Overall, the model performance is better for temperature than that of precipitation. The models reasonably grasp the major anomalies and standard deviations over China and the five subregions studied. The models generally reproduce the spatial pattern of high interannual variability over wet regions, and low variability over the dry regions. The models also capture well the variable temperature gradient increase to the north by latitude. Both the observed and simulated linear trend of precipitation shows a drying tendency over the Yangtze River Basin and wetting over South China. The models capture well the relatively small temperature trends in large areas of China. The models reasonably simulate the characteristics of extreme precipitation indices of heavy rain days and heavy precipitation fraction. Most of the models also performed well in capturing both the sign and magnitude of the daily maximum and minimum temperatures over China.

  10. Light mediated emergence of surface patterns in azopolymers at low temperatures

    CERN Document Server

    Teboul, V; Tajalli, P; Ahmadi-Kandjani, S; Tajalli, H; Zielinska, S; Ortyl, E

    2015-01-01

    Polymer thin films doped with azobenzene molecules do have the ability to organize themselves in spontaneous surface relief gratings (SRG) under irradiation with a single polarized beam. To shed some light in this still unexplained phenomenon, we use a new method that permits us to access experimentally the very first steps of the pattern formation process. Decreasing the temperature, we slow down the formation and organization of patterns, due to the large increase of the viscosity and relaxation time of the azopolymer. As a result decreasing the temperature allows us to access and study much shorter time scales,in the physical mechanisms underlying the pattern formation, than previously reported. We find that the patterns organize themselves in sub-structures which size increase with the temperature, following the diffusion coefficient evolution of the material. That result suggests that the pattern formation and organization is mainly governed by diffusive processes, in agreement with some theories of the ...

  11. Shear failure characterization of time-temperature sensitive interfaces

    Science.gov (United States)

    Canestrari, Francesco; Ferrotti, Gilda; Graziani, Andrea

    2016-08-01

    Poor interlayer bonding can lead to early failures and thus to a reduction in service life of bituminous pavements. For this reason, it is important to identify the parameters influencing the interlayer shear failure and to characterize their effect by means of laboratory test. In particular, this study is focussed on the effects of test temperature and deformation rate on the interlayer shear strength (ISS) of double-layered asphalt concrete specimens. First, the ISS was measured at temperatures ranging from 0 °C to 30 °C and deformation rates ranging from 0.5 mm/min to 9 mm/min using the Ancona Shear Testing Research and Analysis (ASTRA) device. Then the experimental data were analyzed using a two-stage statistical modelling approach. In the first stage, the variation of ISS versus deformation rate, at each testing temperature, was modelled using both a power-law and a logarithmic function. In the investigated range of deformation rate, the models allowed to estimate the mean ISS with residual standard error varying from 0.062 MPa to 0.128 MPa. Moreover, the linear regression coefficients, which measure the influence of the deformation rate on ISS, changed with temperature. In the second stage, both temperature and deformation rate were used as joint predictors of ISS by using an approach based on the superposition of their effects. Results showed that the time-temperature superposition approach is applicable and a sigmoid-shaped master curve for ISS was obtained. The proposed approach was validated by using ISS measurements obtained on the same materials with different test devices.

  12. Using distributed temperature sensing to monitor field scale dynamics of ground surface temperature and related substrate heat flux

    NARCIS (Netherlands)

    Bense, V.F.; Read, T.; Verhoef, A.

    2016-01-01

    We present one of the first studies of the use of distributed temperature sensing (DTS) along fibre-optic cables to purposely monitor spatial and temporal variations in ground surface temperature (GST) and soil temperature, and provide an estimate of the heat flux at the base of the canopy layer

  13. The impact of built-up surfaces on land surface temperatures in Italian urban areas.

    Science.gov (United States)

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Orlandini, Simone; Raschi, Antonio; Maracchi, Giampiero; Munafò, Michele

    2016-05-01

    Urban areas are characterized by the very high degree of soil sealing and continuous built-up areas: Italy is one of the European countries with the highest artificial land cover rate, which causes a substantial spatial variation in the land surface temperature (LST), modifying the urban microclimate and contributing to the urban heat island effect. Nevertheless, quantitative data regarding the contribution of different densities of built-up surfaces in determining urban spatial LST changes is currently lacking in Italy. This study, which aimed to provide clear and quantitative city-specific information on annual and seasonal spatial LST modifications resulting from increased urban built-up coverage, was conducted generally throughout the whole year, and specifically in two different periods (cool/cold and warm/hot periods). Four cities (Milan, Rome, Bologna and Florence) were included in the study. The LST layer and the built-up-surface indicator were obtained via use of MODIS remote sensing data products (1km) and a very high-resolution map (5m) of built-up surfaces recently developed by the Italian National Institute for Environmental Protection and Research. The relationships between the dependent (mean daily, daytime and nighttime LST values) and independent (built-up surfaces) variables were investigated through linear regression analyses, and comprehensive built-up-surface-related LST maps were also developed. Statistically significant linear relationships (pcities studied, with a higher impact during the warm/hot period than in the cool/cold ones. Daytime and nighttime LST slope patterns depend on the city size and relative urban morphology. If implemented in the existing city plan, the urban maps of built-up-surface-related LST developed in this study might be able to support more sustainable urban land management practices by identifying the critical areas (Hot-Spots) that would benefit most from mitigation actions by local authorities, land-use decision

  14. High temperature garnet growth in New England: regional temperature-time trends revealed

    Science.gov (United States)

    Sullivan, N.; Ostwald, C.; Chu, X.; Baxter, E. F.; Ague, J. J.; Eckert, J. O.

    2013-12-01

    A series of localized ultrahigh-temperature (UHT)/high-temperature (HT) granulite facies regions have been identified within the regional amphibolite facies metamorphic zone of the Central Maine Terrane stretching from north-central New Hampshire, through central Massachusetts, and into northeastern Connecticut. Here, we aim to constrain the age and peak temperature of metamorphism at three localities within this region: Bristol, NH, Phillipston, MA and Willington, CT. Garnet-forming reactions are linked directly to peak metamorphic temperatures through thermodynamic modeling and/or Zr-in-rutile thermometry. Precise garnet geochronology allows us to identify the timing of these peak temperatures, as well as the duration of garnet growth. Geochronologic and thermodynamic work was done on 12 samples collected throughout a ~5 km2 metamorphic 'hotspot' previously identified in Bristol, NH (Chamberlain and Rumble, 1988; Journal of Petrology). The highest temperature assemblage within this hotspot is characterized by the presence of garnet + sillimanite + K-feldspar + cordierite and reached temperatures >820οC. The lowest temperature periphery of the hotspot is characterized by sillimanite + muscovite + K-feldspar + minor garnet and reached a maximum temperature of 650οC. Bulk garnet ages from samples within the hotspot range significantly from at least 400.0 × 2.5 Ma to 352.7 × 1.8 Ma with the youngest ages associated with the lower temperature samples. This collection of ages indicates a prolonged period (~50 Ma) of >650οC temperatures interspersed by period(s) of garnet growth. Zoned garnet geochronology will help reveal whether garnet growth and related heating was continuous or episodic. Further south, in Phillipston, MA, zoned garnet geochronology performed on a 2.5 cm diameter garnet porphyroblast indicates garnet growth spanning 389 - 363 Ma, reaching peak temperatures at the end of that time span of 920-940οC, followed by a younger event recorded in

  15. Spatial pattern of impervious surfaces and their impacts on land surface temperature in Beijing, China

    Institute of Scientific and Technical Information of China (English)

    XIAO Rong-bo; OUYANG Zhi-yun; ZHENG Hua; LI Wei-feng; SCHIENKE Erich W; WANG Xiao-ke

    2007-01-01

    Land surface temperature (LST), which is heavily influenced by urban surface structures, is a significant parameter in urban environmental analysis. This study examined the effect impervious surfaces (IS) spatial patterns have on LST in Beijing, China. A classification and regression tree model (CART) was adopted to estimate IS as a continuous variable using Landsat images from two seasons combined with QuickBird. LST was retrieved from the Landsat Thematic Mapper (TM) image to examine the relationships between IS and LST. The results revealed that CART was capable of consistently predicting LST with acceptable accuracy (correlation coefficient of 0.94 and the average error of 8.59%). Spatial patterns of IS exhibited changing gradients across the various urban-rural transects, with LST values showing a concentric shape that increased as you moved from the outskirts towards the downtown areas.Transect analysis also indicated that the changes in both IS and LST patterns were similar at various resolution levels, which suggests a distinct linear relationship between them. Results of correlation analysis further showed that IS tended to be positively correlated with LST, and that the correlation coefficients increased from 0.807 to 0.925 with increases in IS pixel size. The findings identified in this study provide a theoretical basis for improving urban planning efforts to lessen urban temperatures and thus dampen urban heat island effects.

  16. The EUSTACE project: delivering global, daily information on surface air temperature

    Science.gov (United States)

    Rayner, Nick

    2017-04-01

    Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, in the EUSTACE project (2015-June 2018, https://www.eustaceproject.eu) we are developing an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals is used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. As the data volumes involved are considerable, such work needs to include development of new "Big Data" analysis methods. We will present recent progress along this road in the EUSTACE project: 1. providing new, consistent, multi-component estimates of uncertainty in surface skin temperature retrievals from satellites; 2. identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; 3. estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; 4. using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras. Information will also be given on how interested users can become involved.

  17. The EUSTACE project: delivering global, daily information on surface air temperature

    Science.gov (United States)

    Morice, C. P.; Rayner, N. A.; Auchmann, R.; Bessembinder, J.; Bronnimann, S.; Brugnara, Y.; Conway, E. A.; Ghent, D.; Good, E.; Herring, K.; Kennedy, J.; Lindgren, F.; Madsen, K. S.; Merchant, C. J.; van der Schrier, G.; Stephens, A.; Tonboe, R. T.; Waterfall, A. M.; Mitchelson, J.; Woolway, I.

    2015-12-01

    Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, we must develop an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. These relationships can be derived either empirically or with the help of a physical model.Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals would be used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. As the data volumes involved are considerable, such work needs to include development of new "Big Data" analysis methods.We will present plans and progress along this road in the EUSTACE project (2015-June 2018), i.e.: • providing new, consistent, multi-component estimates of uncertainty in surface skin temperature retrievals from satellites; • identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; • estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; • using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras.Information will also be given on how interested users can become

  18. STAND FOR TEMPERATURE SURFACE EVALUATION OF FRAGMENTS OF NATURAL ENVIRONMENTS AND ITS IMITATORS

    Directory of Open Access Journals (Sweden)

    V. V. Lobunov

    2016-01-01

    Full Text Available Research in the field of development of natural environments imitators that used for thermal cloaking of military machinery always connected with high material costs due to big sizes of cloaking objects. In this way we decided to create laboratory stand and methodic for obtaining data about temperature surface of fragments of natural environments and its imitators affected by the electromagnetic radiation of the optical wavelength range. We proposed to use a thermal imaging camera instead of the traditionally used spectrophotometric equipment for obtaining spectral characteristics of the objects under study affected by the optical radiation. This method allows us to evaluate the surface temperature of the object at different angles of lighting and viewing. Obtained data allows us to estimate the degree to which the imitator corresponds to a natural environment by the temperature and it’s dynamic of change.The construction of the stand allows to select angles of source of radiation and thermal detector in range 25–75 degrees from normal to the surface of object under study. The source of radiation consists of halogen lamps of MR16 type. The number of selected lamps and its power were chosen taking into account of imitation of intensity of sun radiation.The thermal camera MobIR M4 was used as infrared detecting unit in the range of 8–12 μm. This device has a matrix with a resolution of 160 × 120 pixels and its optical field of view, both vertically and horizontally is 25 to 19 degrees. Special remotely controlled device was created to automate the process of obtaining thermal images. Proposed methodic of measuring surface temperature of objects under study consists in obtaining thermal images at equal time intervals, their analysis using special software and plotting graphs. Thus we can use the developed laboratory stand and the methodic not only for temperature surface evaluation of fragments of natural environments but for its imitators. 

  19. Surface borehole synthesis tension deformation fracture time-space rule

    Institute of Scientific and Technical Information of China (English)

    Liu Jianzhong; Sun Haitao; Hu Qianting

    2012-01-01

    In order to release the tension and shear effect of the superjacent rock strata movement during excavation in coal mine,protect the surface borehole case from fracturing fast and make a good use of the surface borehole during goaf methane drawing,a common synthesis tension deformation fracture model was set up based on the synthesis tension effect of the rock strata,and the deformation rule of the surface borehole case with time and space was researched.The results suggest that,to reduce the deformation the surface borehole should be built between the boundary of the stope and the knee of subsidence curve.At the same time,a 3DEC simulation model and an engineering example were carried out to examine the rules of theoretical model.The result suggests that the model and the rules accord to the test and have good building and protection engineering application values to the surface borehole.

  20. Ice surface temperatures: seasonal cycle and daily variability from in-situ and satellite observations

    Science.gov (United States)

    Madsen, Kristine S.; Dybkjær, Gorm; Høyer, Jacob L.; Nielsen-Englyst, Pia; Rasmussen, Till A. S.; Tonboe, Rasmus T.

    2016-04-01

    Surface temperature is an important parameter for understanding the climate system, including the Polar Regions. Yet, in-situ temperature measurements over ice- and snow covered regions are sparse and unevenly distributed, and atmospheric circulation models estimating surface temperature may have large biases. To change this picture, we will analyse the seasonal cycle and daily variability of in-situ and satellite observations, and give an example of how to utilize the data in a sea ice model. We have compiled a data set of in-situ surface and 2 m air temperature observations over land ice, snow, sea ice, and from the marginal ice zone. 2523 time series of varying length from 14 data providers, with a total of more than 13 million observations, have been quality controlled and gathered in a uniform format. An overview of this data set will be presented. In addition, IST satellite observations have been processed from the Metop/AVHRR sensor and a merged analysis product has been constructed based upon the Metop/AVHRR, IASI and Modis IST observations. The satellite and in-situ observations of IST are analysed in parallel, to characterize the IST variability on diurnal and seasonal scales and its spatial patterns. The in-situ data are used to estimate sampling effects within the satellite observations and the good coverage of the satellite observations are used to complete the geographical variability. As an example of the application of satellite IST data, results will be shown from a coupled HYCOM-CICE ocean and sea ice model run, where the IST products have been ingested. The impact of using IST in models will be assessed. This work is a part of the EUSTACE project under Horizon 2020, where the ice surface temperatures form an important piece of the puzzle of creating an observationally based record of surface temperatures for all corners of the Earth, and of the ESA GlobTemperature project which aims at applying surface temperatures in models in order to

  1. Long-term surface temperature modeling of Pluto

    Science.gov (United States)

    Earle, Alissa M.; Binzel, Richard P.; Young, Leslie A.; Stern, S. A.; Ennico, K.; Grundy, W.; Olkin, C. B.; Weaver, H. A.

    2017-05-01

    NASA's New Horizons' reconnaissance of the Pluto system has revealed at high resolution the striking albedo contrasts from polar to equatorial latitudes on Pluto, as well as the sharpness of boundaries for longitudinal variations. These contrasts suggest that Pluto must undergo dynamic evolution that drives the redistribution of volatiles. Using the New Horizons results as a template, we explore the surface temperature variations driven seasonally on Pluto considering multiple timescales. These timescales include the current orbit (248 years) as well as the timescales for obliquity precession (peak-to-peak amplitude of 23° over 3 million years) and regression of the orbital longitude of perihelion (3.7 million years). These orbital variations create epochs of ;Extreme Seasons; where one pole receives a short, relatively warm summer and long winter, while the other receives a much longer, but less intense summer and short winter. We use thermal modeling to build upon the long-term insolation history model described by Earle and Binzel (2015) and investigate how these seasons couple with Pluto's albedo contrasts to create temperature effects. From this study we find that a bright region at the equator, once established, can become a site for net deposition. We see the region informally known as Sputnik Planitia as an example of this, and find it will be able to perpetuate itself as an ;always available; cold trap, thus having the potential to survive on million year or substantially longer timescales. Meanwhile darker, low-albedo, regions near the equator will remain relative warm and generally not attract volatile deposition. We argue that the equatorial region is a ;preservation zone; for whatever albedo is seeded there. This offers insight as to why the equatorial band of Pluto displays the planet's greatest albedo contrasts.

  2. High-temperature vesuvianite: crystal chemistry and surface considerations

    Science.gov (United States)

    Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Laurora, Angela; Malferrari, Daniele; Nannarone, Stefano

    2011-06-01

    A multi-methodical approach has been applied for characterizing the bulk and surface crystal chemical features of a high-temperature vesuvianite crystal from skarns of Mount Somma-Vesuvius Volcano (Naples, Italy). Vesuvianite belongs to the space group P4/ nnc with unit cell parameters a = 15.633(1) Å, c = 11.834(1) Å and chemical formula (Ca18.858 Na0.028 Ba0.004 K0.006 Sr0.005 □0.098)19.000 (Al8.813 Ti0.037 Mg2.954 Mn0.008 Fe{0.114/2+} Fe{1.375/3+} Cr0.008 B0.202)13.511 Si18.000(O0.261 F0.940 OH7.799)9.000. Structure refinement, which converges at R = 0.0328, demonstrates a strong positional disorder down the fourfold axes, indicating that the Y1 site is split into two positions (Y1A and Y1B) alternatively occupied. However, because of X4 proximity to Y1B and Y1A, X4 cannot be occupied if Y1B or Y1A are. Overall Y1 occupancy (Y1A + Y1B) reaches approximately 0.5, as common in vesuvianite and occupancy of Y1B site is extremely limited. Moreover, T1 position, limitedly occupied, accommodates the excess of cations generally related to Y position. A small quantity (0.202 apfu) of boron is sited at the T2 site that, like T1, is poorly occupied. The determination of the amount of each element on the (100) vesuvianite surface, obtained through X-ray photoelectron spectroscopy high-resolution spectra in the region of the Si2p, Al2p, Mg1s, and Ca2p core levels, evidences that a greater amount of aluminum and a smaller amount of calcium characterize the surface with respect to the bulk. Although both of these features require further investigation, we may consider the Al increase can be related to preferential orientation of Al-rich sites on the (100) plane. Furthermore, the surface structure of vesuvianite suggests that Al, Ca, and Mg cations maintain coordination features at the surface similar to the bulk. Silica, however, while presenting fourfold coordination, shows also a [1]-fold small coordinated component at binding energy 99.85 eV, due to broken Si-O bonds at

  3. Temperature, plant species and residence time effects on nitrogen removal in model treatment wetlands.

    Science.gov (United States)

    Allen, C R; Stein, O R; Hook, P B; Burr, M D; Parker, A E; Hafla, E C

    2013-01-01

    Total nitrogen (TN) removal in treatment wetlands (TWs) is challenging due to nitrogen cycle complexity and the variation of influent nitrogen species. Plant species, season, temperature and hydraulic loading most likely influence root zone oxygenation and appurtenant nitrogen removal, especially for ammonium-rich wastewater. Nitrogen data were collected from two experiments utilizing batch-loaded (3-, 6-, 9- and 20-day residence times), sub-surface TWs monitored for at least one year during which temperature was varied between 4 and 24 °C. Synthetic wastewater containing 17 mg/l N as NH4 and 27 mg/l amino-N, 450 mg/l chemical oxygen demand (COD), and 13 mg/l SO4-S was applied to four replicates of Carex utriculata, Schoenoplectus acutus and Typha latifolia and unplanted controls. Plant presence and species had a greater effect on TN removal than temperature or residence time. Planted columns achieved approximately twice the nitrogen removal of unplanted controls (40-95% versus 20-50% removal) regardless of season and temperature. TWs planted with Carex outperformed both Typha and Schoenoplectus and demonstrated less temperature dependency. TN removal with Carex was excellent at all temperatures and residence times; Schoenoplectus and Typha TN removal improved at longer residence times. Reductions in TN were not accompanied by increases in NO3, which was consistently below 1 mg/l N.

  4. Time-like Willmore surfaces in Lorentzian 3-space

    Institute of Scientific and Technical Information of China (English)

    DENG; Yanjuan; WANG; Changping

    2006-01-01

    Let R13 be the Lorentzian 3-space with inner product (,). Let Q3 be the conformal compactification of R13, obtained by attaching a light-cone C∞ to R13 in infinity.Then Q3 has a standard conformal Lorentzian structure with the conformal transformation group O(3, 2)/{±1}. In this paper, we study local conformal invariants of time-like surfaces in Q3 and dual theorem for Willmore surfaces in Q3. Let M ( ) R13 be a time-like surface.Let n be the unit normal andHthe mean curvature of the surface M. For any p ∈ M we define S12(p) = {X ∈ R13 | (X - c(p),X - c(p)) = 1/H(p)2} with c(p) = p + 1/H(p)n(p) ∈ R13.Then S12(p) is a one-sheet-hyperboloid in R13, which has the same tangent plane and mean curvature as M at the point p. We show that the family {S12(p),p ∈ M} of hyperboloid in R13defines in general two different enveloping surfaces, one is M itself, another is denoted by (M) (may be degenerate), and called the associated surface of M. We show that (i) if (M) is a time-like Willmore surface in Q3 with non-degenerate associated surface (M), then (M) is also a time-like Willmore surface in Q3 satisfying (M)= M; (ii) if M is a single point, then M is conformally equivalent to a minimal surface in R13.

  5. Global trends in lake surface temperatures observed using multi-sensor thermal infrared imagery

    Science.gov (United States)

    Schneider, Philipp; Hook, Simon J.; Radocinski, Robert G.; Corlett, Gary K.; Hulley, Glynn C.; Schladow, S. Geoffrey; Steissberg, Todd E.

    2010-05-01

    Recent research has shown that the temperature of lakes and other inland water bodies does not only act as a good indicator of climate variability but under certain conditions can even increase more rapidly than the regional air temperature. Further investigation of this phenomenon in particular and of the interaction between lake temperature and climate variability in general requires extensive observations of lake temperature on a global scale. Current in situ records are limited in their spatial and/or temporal coverage and are thus insufficient for this task. However, a nearly 30-year archive of satellite-derived thermal infrared imagery from multiple sensors is available at this point and can be used to fill this data gap. We describe research on utilizing the existing archive of spaceborne thermal infrared imagery to generate multi-decadal time series of lake surface temperature for 170 of the largest lakes worldwide. The data used for this purpose includes imagery from the Advanced Very High Resolution Radiometers (AVHRR), the series of (Advanced) Along-Track Scanning Radiometers ((A)ATSR), and the Moderate Resolution Imaging Spectroradiometer (MODIS). Used in combination, these data sets offer a gapless time series of daily to near-daily thermal infrared retrievals from 1981 through present. In this contribution we demonstrate using comprehensive in situ data at Lake Tahoe, California/Nevada, that lake water surface temperature can be estimated using these sensors with an accuracy of up to 0.2 K. We further show that accurate continuous time series of water surface temperature can be derived from the data and that these time series can be used to detect significant trends in the temporal thermal behavior of lakes and other inland water bodies worldwide. Complementing our recent case study for lakes in California and Nevada for which a rapid increase in mean nighttime summertime lake surface temperatures of 0.11 K per year on average was found, we present

  6. Seasonal Spatial Patterns of Surface Water Temperature, Surface Heat Fluxes and Meteorological Forcing Over Lake Geneva

    Science.gov (United States)

    Irani Rahaghi, A.; Lemmin, U.; Bouffard, D.; Riffler, M.; Wunderle, S.; Barry, D. A.

    2015-12-01

    In many lakes, surface heat flux (SHF) is the most important component controlling the lake's energy content. Accurate methods for the determination of SHF are valuable for water management, and for use in hydrological and meteorological models. Large lakes, not surprisingly, are subject to spatially and temporally varying meteorological conditions, and hence SHF. Here, we report on an investigation for estimating the SHF of a large European lake, Lake Geneva. We evaluated several bulk formulas to estimate Lake Geneva's SHF based on different data sources. A total of 64 different surface heat flux models were realized using existing representations for different heat flux components. Data sources to run the models included meteorological data (from an operational numerical weather prediction model, COSMO-2) and lake surface water temperature (LSWT, from satellite imagery). Models were calibrated at two points in the lake for which regular depth profiles of temperature are available, and which enabled computation of the total heat content variation. The latter, computed for 03.2008-12.2012, was the metric used to rank the different models. The best calibrated model was then selected to calculate the spatial distribution of SHF. Analysis of the model results shows that evaporative and convective heat fluxes are the dominant terms controlling the spatial pattern of SHF. The former is significant in all seasons while the latter plays a role only in fall and winter. Meteorological observations illustrate that wind-sheltering, and to some extent relative humidity variability, are the main reasons for the observed large-scale spatial variability. In addition, both modeling and satellite observations indicate that, on average, the eastern part of the lake is warmer than the western part, with a greater temperature contrast in spring and summer than in fall and winter whereas the SHF spatial splitting is stronger in fall and winter. This is mainly due to negative heat flux

  7. Retrieving Clear-Sky Surface Skin Temperature for Numerical Weather Prediction Applications from Geostationary Satellite Data

    Directory of Open Access Journals (Sweden)

    Baojuan Shan

    2013-01-01

    Full Text Available Atmospheric models rely on high-accuracy, high-resolution initial radiometric and surface conditions for better short-term meteorological forecasts, as well as improved evaluation of global climate models. Remote sensing of the Earth’s energy budget, particularly with instruments flown on geostationary satellites, allows for near-real-time evaluation of cloud and surface radiation properties. The persistence and coverage of geostationary remote sensing instruments grant the frequent retrieval of near-instantaneous quasi-global skin temperature. Among other cloud and clear-sky retrieval parameters, NASA Langley provides a non-polar, high-resolution land and ocean skin temperature dataset for atmospheric modelers by applying an inverted correlated k-distribution method to clear-pixel values of top-of-atmosphere infrared temperature. The present paper shows that this method yields clear-sky skin temperature values that are, for the most part, within 2 K of measurements from ground-site instruments, like the Southern Great Plains Atmospheric Radiation Measurement (ARM Infrared Thermometer and the National Climatic Data Center Apogee Precision Infrared Thermocouple Sensor. The level of accuracy relative to the ARM site is comparable to that of the Moderate-resolution Imaging Spectroradiometer (MODIS with the benefit of an increased number of daily measurements without added bias or increased error. Additionally, matched comparisons of the high-resolution skin temperature product with MODIS land surface temperature reveal a level of accuracy well within 1 K for both day and night. This confidence will help in characterizing the diurnal and seasonal biases and root-mean-square differences between the retrievals and modeled values from the NASA Goddard Earth Observing System Version 5 (GEOS-5 in preparation for assimilation of the retrievals into GEOS-5. Modelers should find the immediate availability and broad coverage of these skin temperature

  8. The mechanism for the impact of sea surface temperature anomaly on the ridgeline surface of Western Pacific

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the atmospheric circulation data provided by ECMWF and the sea surface temperature data by NOAA, we studied the mechanism for the impact of sea surface temperature anomaly on the ridgeline surface of western Pacific using an improved high truncated spectral model. Our results show that the wave-wave interaction and the wave-mean flow interactions are weaker in the inner dynamic process of atmospheric circulation, when atmospheric circulation is forced by the sea surface temperature of El Ni-o pattern. With the external thermal forcing changed from winter to summer pattern, the range of ridgeline surface of western Pacific moving northward is smaller, which causes the ridgeline surface of western Pacific on south of normal. On the contrary, the wave-wave interaction and the wave-mean flow interaction are stronger, when atmospheric circulation is forced by the sea surface temperature of La Ni-a pattern. With the external thermal forcing turning from winter to summer pattern, the ridgeline surface of western Pacific shifts northward about 19 latitude degrees, which conduces the ridgeline surface of western Pacific on north of normal. After moving to certain latitude, the ridgeline surface of western Pacific oscillates with the most obvious 30-60 d period and the 4°-7° amplitude. It is one of the important reasons for the interannual variation of ridgeline surface of Western Pacific that the at- mospheric inner dynamical process forced out by different sea surface temperature anomaly pattern is different.

  9. Cross-satellite comparison of operational land surface temperature products derived from MODIS and ASTER data over bare soil surfaces

    Science.gov (United States)

    Duan, Si-Bo; Li, Zhao-Liang; Cheng, Jie; Leng, Pei

    2017-04-01

    The collection 6 (C6) MODIS land surface temperature (LST) product is publicly available for the user community. Compared to the collection 5 (C5) MODIS LST product, the C6 MODIS LST product has been refined over bare soil pixels. Assessing the accuracy of the C6 MODIS LST product will help to facilitate the use of the LST product in various applications. In this study, we present a cross-satellite comparison to evaluate the accuracy of the C6 MODIS LST product (MOD11_L2) over bare soil surfaces under various atmospheric and surface conditions using the ASTER LST product as a reference. For comparison, the C5 MODIS LST product was also used in the analysis. The absolute biases (0.2-1.5 K) of the differences between the C6 MODIS LST and ASTER LST over bare soil surfaces are approximately two times less than those (0.6-3.8 K) of the differences between the C5 MODIS LST and ASTER LST. Furthermore, the RMSEs (0.7-2.3 K) over bare soil surfaces for the C6 MODIS LST are significantly smaller than those (0.9-4.2 K) for the C5 MODIS LST. These results indicate that the accuracy of the C6 MODIS LST product is much better than that of the C5 MODIS LST product. We recommend that the user community employs the C6 MODIS LST product in their applications.

  10. Spatial and temporal patterns of land surface fluxes from remotely sensed surface temperatures within an uncertainty modelling framework

    Directory of Open Access Journals (Sweden)

    M. F. McCabe

    2005-01-01

    Full Text Available Characterising the development of evapotranspiration through time is a difficult task, particularly when utilising remote sensing data, because retrieved information is often spatially dense, but temporally sparse. Techniques to expand these essentially instantaneous measures are not only limited, they are restricted by the general paucity of information describing the spatial distribution and temporal evolution of evaporative patterns. In a novel approach, temporal changes in land surface temperatures, derived from NOAA-AVHRR imagery and a generalised split-window algorithm, are used as a calibration variable in a simple land surface scheme (TOPUP and combined within the Generalised Likelihood Uncertainty Estimation (GLUE methodology to provide estimates of areal evapotranspiration at the pixel scale. Such an approach offers an innovative means of transcending the patch or landscape scale of SVAT type models, to spatially distributed estimates of model output. The resulting spatial and temporal patterns of land surface fluxes and surface resistance are used to more fully understand the hydro-ecological trends observed across a study catchment in eastern Australia. The modelling approach is assessed by comparing predicted cumulative evapotranspiration values with surface fluxes determined from Bowen ratio systems and using auxiliary information such as in-situ soil moisture measurements and depth to groundwater to corroborate observed responses.

  11. Semidiscrete central difference method in time for determining surface temperatures

    Directory of Open Access Journals (Sweden)

    Zhi Qian

    2005-01-01

    the data. Eldén (1995 has used a difference method for solving this problem, but he did not obtain the convergence at x=0. In this paper, we gave a logarithmic stability of the approximation solution at x=0 under a stronger a priori assumption ‖u(0,t‖p≤E with p>1/2. A numerical example shows that the computational effect of this method is satisfactory.

  12. The impact of heterogeneous surface temperatures on the 2-m air temperature over the Arctic Ocean in spring

    Directory of Open Access Journals (Sweden)

    A. Tetzlaff

    2012-07-01

    Full Text Available The influence of spatial surface temperature changes over the Arctic Ocean on the 2-m air temperature variability is estimated using backward trajectories based on ERA-Interim and the JRA25 wind fields. They are initiated at Alert, Barrow and at the Tara drifting station. Three different methods are used. The first one compares mean ice surface temperatures along the trajectories to the observed 2-m air temperatures at the stations. The second one correlates the observed temperatures to air temperatures obtained using a simple Lagrangian box model which only includes the effect of sensible heat fluxes. For the third method, mean sensible heat fluxes from the model are correlated with the difference of the air temperatures at the model starting point and the observed temperatures at the stations. The calculations are based on MODIS ice surface temperatures and four different sets of ice concentration derived from SSM/I and AMSR-E data. Under nearly cloud free conditions, up to 90% of the 2-m air temperature variance can be explained for Alert, and 60% for Barrow using these methods. The differences are attributed to the different ice conditions, which are characterized by high ice concentration around Alert and lower ice concentration near Barrow. These results are robust for the different sets of reanalyses and ice concentration data. Near-surface winds of both reanalyses show a large inconsistency in the Central Arctic, which leads to a large difference in the correlations between modeled and observed 2-m air temperatures at Tara. Explained variances amount to 70% using JRA and only 45% using ERA. The results also suggest that near-surface temperatures at a given site are influenced by the variability of surface temperatures in a domain of about 150 to 350 km radius around the site.

  13. Surface-temperature trends and variability in the low-latitude North Atlantic since 1552

    KAUST Repository

    Saenger, Casey

    2009-06-21

    Sea surface temperature variability in the North Atlantic Ocean recorded since about 1850 has been ascribed to a natural multidecadal oscillation superimposed on a background warming trend1-6. It has been suggested that the multidecadal variability may be a persistent feature6-8, raising the possibility that the associated climate impacts may be predictable7,8. owever, our understanding of the multidecadal ocean variability before the instrumental record is based on interpretations of high-latitude terrestrial proxy records. Here we present an absolutely dated and annually resolved record of sea surface temperature from the Bahamas, based on a 440-year time series of coral growth rates. The reconstruction indicates that temperatures were as warm as today from about 1552 to 1570, then cooled by about 1° C from 1650 to 1730 before warming until the present. Our estimates of background variability suggest that much of the warming since 1900 was driven by anthropogenic forcing. Interdecadal variability with a period of 15-25 years is superimposed on most of the record, but multidecadal variability becomes significant only after 1730. We conclude that the multidecadal variability in sea surface temperatures in the low-latitude western Atlantic Ocean may not be persistent, potentially making accurate decadal climate forecasts more difficult to achieve. © 2009 Macmillan Publishers Limited. All rights reserved.

  14. Surface-temperature trends and variability in the low-latitude North Atlantic since 1552

    Science.gov (United States)

    Saenger, Casey; Cohen, Anne L.; Oppo, Delia W.; Halley, Robert B.; Carilli, Jessica E.

    2009-07-01

    Sea surface temperature variability in the North Atlantic Ocean recorded since about 1850 has been ascribed to a natural multidecadal oscillation superimposed on a background warming trend. It has been suggested that the multidecadal variability may be a persistent feature, raising the possibility that the associated climate impacts may be predictable. However, our understanding of the multidecadal ocean variability before the instrumental record is based on interpretations of high-latitude terrestrial proxy records. Here we present an absolutely dated and annually resolved record of sea surface temperature from the Bahamas, based on a 440-year time series of coral growth rates. The reconstruction indicates that temperatures were as warm as today from about 1552 to 1570, then cooled by about 1∘C from 1650 to 1730 before warming until the present. Our estimates of background variability suggest that much of the warming since 1900 was driven by anthropogenic forcing. Interdecadal variability with a period of 15-25years is superimposed on most of the record, but multidecadal variability becomes significant only after 1730. We conclude that the multidecadal variability in sea surface temperatures in the low-latitude western Atlantic Ocean may not be persistent, potentially making accurate decadal climate forecasts more difficult to achieve.

  15. Global surface temperature in relation to northeast monsoon rainfall over Tamil Nadu

    Indian Academy of Sciences (India)

    S Balachandran; R Asokan; S Sridharan

    2006-06-01

    The local and teleconnective association between Northeast Monsoon Rainfall (NEMR)over Tamil Nadu and global Surface Temperature Anomalies (STA)is examined using the monthly grid-ded STA data for the period 1901-2004.Various geographical regions which have significant tele-connective signals associated with NEMR are identi fied.During excess (deficient)NEMR years,it is observed that the meridional gradient in surface air temperature anomalies between Europe and north Africa,in the month of September is directed from the subtropics (higher latitudes)to higher latitudes (subtropics).It is also observed that North Atlantic Oscillation (NAO)during September in fluences the surface air temperature distribution over north Africa and Europe.Also,the NAO index in January shows significant inverse relationship with NEMR since recent times.The central and eastern equatorial Pacific oceanic regions have signi ficant and consistent positive correlation with NEMR while the western equatorial region has significant negative correlation with NEMR. A zonal temperature anomaly gradient index (ZTAGI)de fined between eastern equatorial Pacific and western equatorial Pacific shows stable significant inverse relationship with NEMR.

  16. Surface temperature measurements of a levitated water drop during laser irradiation

    Science.gov (United States)

    Brownell, Cody; Tracey, Timothy

    2016-11-01

    Simulation of high energy laser propagation and scattering in the maritime environment is problematic, due to the high liklihood of turbulence, fog, and rain or sea spray within the beam path. Laser interactions with large water drops (diameters of approximately 1-mm), such as those found in a light rain, have received relatively less attention. In this regime a high energy laser will rapidly heat and vaporize a water drop as it traverses the beam path, but the exact heating / vaporization rate, its dependence on impurities, and ancillary effects on the drop or surroundings are unclear. In this work we present surface temperature measurements of a water drop obtained using a FLIR IR camera. The drop is acoustically levitated, and subject to a continuous wave laser with a wavelength of 1070-nm and a mean irradiance of approximately 500 W/cm2. These measurements show that the steady-state surface temperature of the drop is well below the saturation temperature, yet based on the time history of the drop volume vaporization begins almost immediately upon laser strike. Inferences on the turbulence characteristics within the drop are also made from measurements of the fluctuations in the surface temperature. Supported by ONR, HEL-JTO, and USNA Trident Scholar Program.

  17. Definition of the linearity loss of the surface temperature in static tensile tests

    Directory of Open Access Journals (Sweden)

    A. Risitano

    2014-10-01

    Full Text Available Static tensile tests on material for mechanical constructions have pointed out the linearity loss of the surface temperature with the application of load. This phenomenon is due to the heat generation caused by the local microplasticizations which carry the material to deviate from its completely thermoelastic behavior,. The identification of the static load which determines the loss of linearity of the temperature under stress, becomes extremely important to define a first dynamic characterization of the material. The temperature variations that can be recorded during the static test are often very limited (a few tenths of degree for every 100 MPa in steels and they require the use of special sensors able to measure very low temperature variations. The experience acquired in such analysis highlighted that, dealing with highly accurate sensors or with particular materials, the identification of the first linearity loss (often by eye in the temperature curves, can be influenced by the sensibility of the investigator himself and can lead to incorrect estimates. The aim of this work is to validate the above mentioned observations on different steels, by applying the autocorrelation function to the data collected during the application of a static load. This, in order to make the results of the thermal analysis free from the sensitivity of the operator and to make the results as objective as possible, for defining the closest time of the linearity loss in the temperature-time function.

  18. Downscaling MODIS Land Surface Temperature for Urban Public Health Applications

    Science.gov (United States)

    Al-Hamdan, M. Z.; Crosson, W. L.; Estes, M. G., Jr.; Estes, S. M.; Quattrochi, D. A.; Johnson, D.

    2013-12-01

    This study is part of a project funded by the NASA Applied Sciences Public Health Program, which focuses on Earth science applications of remote sensing data for enhancing public health decision-making. Heat related death is currently the number one weather-related killer in the United States. Mortality from these events is expected to increase as a function of climate change. This activity sought to augment current Heat Watch/Warning Systems (HWWS) with NASA remotely sensed data, and models used in conjunction with socioeconomic and heat-related mortality data. The current HWWS do not take into account intra-urban spatial variations in risk assessment. The purpose of this effort is to evaluate a potential method to improve spatial delineation of risk from extreme heat events in urban environments by integrating sociodemographic risk factors with land surface temperature (LST) estimates derived from thermal remote sensing data. In order to further improve the assessment of intra-urban variations in risk from extreme heat, we developed and evaluated a number of spatial statistical techniques for downscaling the 1-km daily MODerate-resolution Imaging Spectroradiometer (MODIS) LST data to 60 m using Landsat-derived LST data, which have finer spatial but coarser temporal resolution than MODIS. We will present these techniques, which have been demonstrated and validated for Phoenix, AZ using data from the summers of 2000-2006.

  19. Spatial Statistical Estimation for Massive Sea Surface Temperature Data

    Science.gov (United States)

    Marchetti, Y.; Vazquez, J.; Nguyen, H.; Braverman, A. J.

    2015-12-01

    We combine several large remotely sensed sea surface temperature (SST) datasets to create a single high-resolution SST dataset that has no missing data and provides an uncertainty associated with each value. This high resolution dataset will optimize estimates of SST in critical parts of the world's oceans, such as coastal upwelling regions. We use Spatial Statistical Data Fusion (SSDF), a statistical methodology for predicting global spatial fields by exploiting spatial correlations in the data. The main advantages of SSDF over spatial smoothing methodologies include the provision of probabilistic uncertainties, the ability to incorporate multiple datasets with varying footprints, measurement errors and biases, and estimation at any desired resolution. In order to accommodate massive input and output datasets, we introduce two modifications of the existing SSDF algorithm. First, we compute statistical model parameters based on coarse resolution aggregated data. Second, we use an adaptive spatial grid that allows us to perform estimation in a specified region of interest, but incorporate spatial dependence between locations in that region and all locations globally. Finally, we demonstrate with a case study involving estimations on the full globe at coarse resolution grid (30 km) and a high resolution (1 km) inset for the Gulf Stream region.

  20. Downscaling MODIS Land Surface Temperature for Urban Public Health Applications

    Science.gov (United States)

    Al-Hamdan, Mohammad; Crosson, William; Estes, Maurice, Jr.; Estes, Sue; Quattrochi, Dale; Johnson, Daniel

    2013-01-01

    This study is part of a project funded by the NASA Applied Sciences Public Health Program, which focuses on Earth science applications of remote sensing data for enhancing public health decision-making. Heat related death is currently the number one weather-related killer in the United States. Mortality from these events is expected to increase as a function of climate change. This activity sought to augment current Heat Watch/Warning Systems (HWWS) with NASA remotely sensed data, and models used in conjunction with socioeconomic and heatrelated mortality data. The current HWWS do not take into account intra-urban spatial variation in risk assessment. The purpose of this effort is to evaluate a potential method to improve spatial delineation of risk from extreme heat events in urban environments by integrating sociodemographic risk factors with estimates of land surface temperature (LST) derived from thermal remote sensing data. In order to further improve the consideration of intra-urban variations in risk from extreme heat, we also developed and evaluated a number of spatial statistical techniques for downscaling the 1-km daily MODerate-resolution Imaging Spectroradiometer (MODIS) LST data to 60 m using Landsat-derived LST data, which have finer spatial but coarser temporal resolution than MODIS. In this paper, we will present these techniques, which have been demonstrated and validated for Phoenix, AZ using data from the summers of 2000-2006.

  1. Impact of sea surface temperature on satellite retrieval of sea surface salinity

    Science.gov (United States)

    Jin, Xuchen; Zhu, Qiankun; He, Xianqiang; Chen, Peng; Wang, Difeng; Hao, Zengzhou; Huang, Haiqing

    2016-10-01

    Currently, global sea surface salinity (SSS) can be retrieved by the satellite microwave radiometer onboard the satellite, such as the Soil Moisture and Ocean Salinity(SMOS) and the Aqurius. SMOS is an Earth Explorer Opportunity Mission from the European Space Agency(ESA). It was launched at a sun-synchronous orbit in 2009 and one of the payloads is called MIRAS(Microwave Imaging Radiometer using Aperture Synthesis), which is the first interferometric microwave radiometer designed for observing SSS at L-band(1.41 GHz).The foundation of the salinity retrieval by microwave radiometer is that the sea surface radiance at L-band has the most suitable sensitivity with the variation of the salinity. It is well known that the sensitivity of brightness temperatures(TB) to SSS depends on the sea surface temperature (SST), but the quantitative impact of the SST on the satellite retrieval of the SSS is still poorly known. In this study, we investigate the impact of the SST on the accuracy of salinity retrieval from the SMOS. First of all, The dielectric constant model proposed by Klein and Swift has been used to estimate the vertically and horizontally polarized brightness temperatures(TV and TH) of a smooth sea water surface at L-band and derive the derivatives of TV and TH as a function of SSS to show the relative sensitivity at 45° incident angle. Then, we use the GAM(generalized additive model) method to evaluate the association between the satellite-measured brightness temperature and in-situ SSS at different SST. Moreover, the satellite-derived SSS from the SMOS is validated using the ARGO data to assess the RMSE(root mean squared error). We compare the SMOS SSS and ARGO SSS over two regions of Pacific ocean far from land and ice under different SST. The RMSE of retrieved SSS at different SST have been estimated. Our results showed that SST is one of the most significant factors affecting the accuracy of SSS retrieval. The satellite-measured brightness temperature has a

  2. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Mamede, Anne-Sophie, E-mail: anne-sophie.mamede@ensc-lille.fr [University Lille, CNRS, ENSCL, Centrale Lille, University Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Nuns, Nicolas, E-mail: nicolas.nuns@univ-lille1.fr [University Lille, CNRS, ENSCL, Centrale Lille, University Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Cristol, Anne-Lise, E-mail: anne-lise.cristol@ec-lille.fr [University Lille, CNRS, Centrale Lille, Arts et Métiers Paris Tech, FRE 3723 – LML – Laboratoire de Mécanique de Lille, F-59000 Lille (France); Cantrel, Laurent, E-mail: laurent.cantrel@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, PSN-RES, Cadarache, Saint Paul lez Durance, 13115 (France); Laboratoire de Recherche Commun IRSN-CNRS-Lille 1: «Cinétique Chimique, Combustion, Réactivité» (C3R), Cadarache, Saint Paul lez Durance, 13115 (France); Souvi, Sidi, E-mail: sidi.souvi@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, PSN-RES, Cadarache, Saint Paul lez Durance, 13115 (France); Laboratoire de Recherche Commun IRSN-CNRS-Lille 1: «Cinétique Chimique, Combustion, Réactivité» (C3R), Cadarache, Saint Paul lez Durance, 13115 (France); and others

    2016-04-30

    Graphical abstract: - Highlights: • Mutitechnique characterisation of oxidised 304L. • Oxidation at high temperature under steam and air conditions of 304L stainless steel. • Chromium and manganese oxides formed in the outer layer. • Oxide profiles differ in air or steam atmosphere. - Abstract: In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8–12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe{sub 2}O{sub 3} oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  3. Low temperature diffusion of Li atoms into Si nanoparticles and surfaces

    Science.gov (United States)

    Nienhaus, Hermann; Karacuban, Hatice; Krix, David; Becker, Felix; Hagemann, Ulrich; Steeger, Doris; Bywalez, Robert; Schulz, Christof; Wiggers, Hartmut

    2013-07-01

    The diffusion of Li atoms deposited on hydrogen-passivated Si(001) surfaces, chemically oxidized Si(001) surfaces, Si nanoparticle films, and thick SiO2 layers is investigated with electron-beam induced Auger electron spectroscopy. The nanoparticles exhibit an average diameter of 24 nm. The Li metal film is evaporated at a sample temperature below 120 K. The reappearance of the Si substrate Auger signal as a function of time and temperature can be measured to study the Li diffusion into the bulk material. Values for the diffusion barrier of 0.5 eV for H:Si(001) and 0.3 eV for the ox-Si(001) and Si nanoparticle films are obtained. The diffusion of the Li atoms results in the disruption of the crystalline Si surfaces observed with atomic force microscopy. Contrasting to that, the Si nanoparticle films show less disruption by Li diffusion due to filling of the porous films detected with cross section electron microscopy. Silicon dioxide acts as a diffusion barrier for temperatures up to 300 K. However, the electron beam induces a reaction between Li and SiO2, leading to LiOx and elemental Si floating on the surface.

  4. Satellite observations of surface temperature during the March 2015 total solar eclipse.

    Science.gov (United States)

    Good, Elizabeth

    2016-09-28

    The behaviour of remotely sensed land surface temperatures (LSTs) from the spinning-enhanced visible and infrared imager (SEVIRI) during the total solar eclipse of 20 March 2015 is analysed over Europe. LST is found to drop by up to several degrees Celcius during the eclipse, with the minimum LST occurring just after the eclipse mid-point (median=+1.5 min). The drop in LST is typically larger than the drop in near-surface air temperatures reported elsewhere, and correlates with solar obscuration (r=-0.47; larger obscuration = larger LST drop), eclipse duration (r=-0.62; longer duration = larger LST drop) and time (r=+0.37; earlier eclipse = larger LST drop). Locally, the LST drop is also correlated with vegetation (up to r=+0.6), with smaller LST drops occurring over more vegetated surfaces. The LSTs at locations near the coast and at higher elevation are also less affected by the eclipse. This study covers the largest area and uses the most observations of eclipse-induced surface temperature drops to date, and is the first full characterization of satellite LST during an eclipse (known to the author). The methods described could be applied to Geostationary Operational Environmental Satellite (GOES) LST data over North America during the August 2017 total solar eclipse.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  5. Molecular Dynamics of Carbon Nanotubes Deposited on a Silicon Surface via Collision: Temperature Dependence

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Leton C.; Mian, Shabeer A.; Kim, Hyo Jeong; Saha, Joyanta K.; Matin, Mohammad A.; Jang, Joon Kyung [Pusan National University, Miryang (Korea, Republic of)

    2011-02-15

    We investigated how temperature influences the structural and energetic dynamics of carbon nanotubes (CNTs) undergoing a high-speed impact with a Si (110) surface. By performing molecular dynamics simulations in the temperature range of 100 - 300 K, we found that a low temperature CNT ends up with a higher vibrational energy after collision than a high temperature CNT. The vibrational temperature of CNT increases by increasing the surface temperature. Overall, the structural and energy relaxation of low temperature CNTs are faster than those of high temperature CNTs.

  6. Monitoring of temperature profiles and surface morphologies during laser sintering of alumina ceramics

    Directory of Open Access Journals (Sweden)

    Bin Qian

    2014-06-01

    Full Text Available Additive manufacturing of alumina by laser is a delicate process and small changes of processing parameters might cause less controlled and understood consequences. The real-time monitoring of temperature profiles, spectrum profiles and surface morphologies were evaluated in off-axial set-up for controlling the laser sintering of alumina ceramics. The real-time spectrometer and pyrometer were used for rapid monitoring of the thermal stability during the laser sintering process. An active illumination imaging system successfully recorded the high temperature melt pool and surrounding area simultaneously. The captured images also showed how the defects form and progress during the laser sintering process. All of these real-time monitoring methods have shown a great potential for on-line quality control during laser sintering of ceramics.

  7. Can Reconstructed Land Surface Temperature Data from Space Predict a West Nile Virus Outbreak?

    Science.gov (United States)

    Andreo, V.; Metz, M.; Neteler, M.; Rosà, R.; Marcantonio, M.; Billinis, C.; Rizzoli, A.; Papa, A.

    2017-07-01

    Temperature is one of the main drivers of ecological processes. The availability of temporally and spatially continuous temperature time series is crucial in different research and application fields, such as epidemiology and control of zoonotic diseases. In 2010, several West Nile virus (WNV) outbreaks in humans were observed in Europe, with the largest number of cases recorded in Greece. Human cases continued to occur for four more years. The occurrence of the 2010's outbreak in Greece has been related to positive anomalies in temperature. Currently available remote sensing time series might provide the temporal and spatial coverage needed to assess this kind of hypothesis. However, the main problem with remotely sensed temperature are the gaps caused by cloud cover. With the objective of testing the former hypothesis, we reconstructed daily MODIS Land Surface Temperature (LST) data and derived several indices that are known or hypothesized to be related to mosquito populations, WNV transmission or risk of disease since they might constitute proxies for favoring or limiting conditions. We present the first results of the comparisons of time series of LST-derived indices among locations with WNV human cases and municipalities with and without reported WNV infection in Greece between 2010 and 2014.

  8. The global surface temperatures of the Moon as measured by the Diviner Lunar Radiometer Experiment

    Science.gov (United States)

    Williams, J.-P.; Paige, D. A.; Greenhagen, B. T.; Sefton-Nash, E.

    2017-02-01

    The Diviner Lunar Radiometer Experiment onboard the Lunar Reconnaissance Orbiter (LRO) has been acquiring solar reflectance and mid-infrared radiance measurements nearly continuously since July of 2009. Diviner is providing the most comprehensive view of how regoliths on airless bodies store and exchange thermal energy with the space environment. Approximately a quarter trillion calibrated radiance measurements of the Moon, acquired over 5.5 years by Diviner, have been compiled into a 0.5° resolution global dataset with a 0.25 h local time resolution. Maps generated with this dataset provide a global perspective of the surface energy balance of the Moon and reveal the complex and extreme nature of the lunar surface thermal environment. Our achievable map resolution, both spatially and temporally, will continue to improve with further data acquisition. Daytime maximum temperatures are sensitive to the albedo of the surface and are ∼387-397 K at the equator, dropping to ∼95 K just before sunrise, though anomalously warm areas characterized by high rock abundances can be > 50 K warmer than the zonal average nighttime temperatures. An asymmetry is observed between the morning and afternoon temperatures due to the thermal inertia of the lunar regolith with the dusk terminator ∼30 K warmer than the dawn terminator at the equator. An increase in albedo with incidence angle is required to explain the observed decrease in temperatures with latitude. At incidence angles exceeding ∼40°, topography and surface roughness influence temperatures resulting in increasing scatter in temperatures and anisothermality between Diviner channels. Nighttime temperatures are sensitive to the thermophysical properties of the regolith. High thermal inertia (TI) materials such as large rocks, remain warmer during the long lunar night and result in anomalously warm nighttime temperatures and anisothermality in the Diviner channels. Anomalous maximum and minimum temperatures are

  9. Predicting East African spring droughts using Pacific and Indian Ocean sea surface temperature indices

    Science.gov (United States)

    Funk, Christopher C.; Hoell, Andrew; Shukla, Shraddhanand; Blade, Ileana; Liebmann, Brant; Roberts, Jason B.; Robertson, Franklin R.

    2014-01-01

    In southern Ethiopia, Eastern Kenya, and southern Somalia poor boreal spring rains in 1999, 2000, 2004, 2007, 2008, 2009 and 2011 contributed to severe food insecurity and high levels of malnutrition. Predicting rainfall deficits in this region on seasonal and decadal time frames can help decision makers support disaster risk reduction while guiding climate-smart adaptation and agricultural development. Building on recent research that links more frequent droughts to a stronger Walker Circulation, warming in the Indo-Pacific warm pool, and an increased western Pacific sea surface temperature (SST) gradient, we explore the dominant modes of East African rainfall variability, links between these modes and sea surface temperatures, and a simple index-based monitoring-prediction system suitable for drought early warning.

  10. Temporal variations in surface air temperature anomaly in urban cities of India

    Science.gov (United States)

    Chelani, Asha B.; Rao, Padma S.

    2013-08-01

    Persistence in surface air temperature anomaly (SATA) time series over 1901-2010 observed at four cities: Nagpur, Pune, Mumbai and Delhi of India is examined using rescaled-range and predictability index. A gap of 40 years is observed in predictability maxima, which is linked with the short-range correlations. Seasonal analysis showed unpredictability of SATA during four seasons at Nagpur, during summers at Pune and Mumbai, and during monsoon and post-monsoon at Mumbai and Delhi. Significant change is observed after 1991 at Delhi, Nagpur and Mumbai with a respective increase of 1.7, 2.2 and 3.3 °C in surface air temperature (SAT) during 1901-2010. The spatial and temporal variations in the SAT in four cities are attributed to their geographic and climatic conditions. The results suggest the utility of the rescaled-range analysis and predictability index in exploring the changes in the climatic variables.

  11. Taste and Temperature in Swallowing Transit Time after Stroke

    Directory of Open Access Journals (Sweden)

    Paula C. Cola

    2012-09-01

    Full Text Available Background: Oropharyngeal dysphagia is common in individuals after stroke. Taste and temperature are used in dysphagia rehabilitation. The influence of stimuli, such as taste and temperature, on swallowing biomechanics has been investigated in both healthy individuals and in individuals with neurological disease. However, some questions still remain unanswered, such as how the sequence of offered stimuli influences the pharyngeal response. The goal of the present study was to determine the influence of the sequence of stimuli, sour taste and cold temperature, on pharyngeal transit time during deglutition in individuals after stroke. Methods: The study included 60 individuals with unilateral ischemic stroke, 29 males and 31 females, aged 41–88 years (mean age: 66.2 years examined 0–50 days after ictus (median: 6 days, with mild to moderate oropharyngeal dysphagia. Exclusion criteria were hemorrhagic stroke patients, patients with decreased level of consciousness, and clinically unstable patients, as confirmed by medical evaluation. The individuals were divided into two groups of 30 individuals each. Group 1 received a nonrandomized sequence of stimuli (i.e. natural, cold, sour, and sour-cold and group 2 received a randomized sequence of stimuli. A videofluoroscopic swallowing study was performed to analyze the pharyngeal transit time. Four different stimuli (natural, cold, sour, and sour-cold were offered. The images were digitalized and specific software was used to measure the pharyngeal transit time. Since the values did not present regular distribution and uniform variances, nonparametric tests were performed. Results: Individuals in group 1 presented a significantly shorter pharyngeal transit time with the sour-cold stimulus than with the other stimuli. Individuals in group 2 did not show a significant difference in pharyngeal transit time between stimuli. Conclusions: The results showed that the sequence of offered stimuli influences

  12. Temperature Measurements On Semi-Permanent Mold Surfaces Using Infrared Thermography

    Science.gov (United States)

    Hurley, Ronald G.

    1983-03-01

    Die surface temperature and internal die thermal balance are critical to the quality of semi-permanent mold die castings. Measurements of the surface temperature are currently made using either hand-held contact temperature probes or optical pyrometers. Neither measurement technique provides a thermal map of the entire die surface. This paper discusses the use of infrared thermography for die surface temperature measurement. Using infrared thermographic techniques, scans were made over the surface of an experimental 302 CID semi-permanent mold cylinder head die during several casting cycles. The results obtained were in reasonable agreement with the temperature measurements made using optical pyrometers and the contact probes. In addition, using gray-level conversion the IR technique provided a measure of the temperature gradient over the surface of the die. Such thermal mapping has not been practical using optical or contact temperature probes.

  13. Effects of temperature and deposition time on the RF- sputtered CdTe films preparation

    OpenAIRE

    E. Camacho-Espinosa; Rosendo, E.; T. Díaz; A. I. Oliva; V. Rejon; Peña, J. L.

    2014-01-01

    In this work, CdTe thin films were deposited by rf-sputtering at different substrate temperatures (room temperature (RT), 100, 150, 200, and 250 °C) and deposition times (30, 60, and 90 min). The applied power and vacuum pressure were maintained fixed for all depositions. A mean value of 18 .5 nm/s on the deposition rate was maintained for films deposition. The surface morphology, rms-roughness, and grain size of the sputtered-films were obtained from atomic force microscopy and scanning elec...

  14. Understanding the effects of the impervious surfaces pattern on land surface temperature in an urban area

    Science.gov (United States)

    Nie, Qin; Xu, Jianhua

    2015-06-01

    It is well known that urban impervious surface (IS) has a warming effect on urban land surface temperature (LST). However, the influence of an IS's structure, components, and spatial distribution on LST has rarely been quantitatively studied within strictly urban areas. Using ETM+ remote sensing images from the downtown area of Shanghai, China in 2010, this study characterized and quantified the influence of the IS spatial pattern on LST by selecting the percent cover of each IS cover feature and ten configuration metrics. The IS fraction was estimated by linear spectral mixture analysis (LSMA), and LST was retrieved using a mono-window algorithm. The results indicate that high fraction IS cover features account for the majority of the study area. The high fraction IS cover features are widely distributed and concentrated in groups, which is similar with that of high temperature zones. Both the percent composition and the configuration of IS cover features greatly affect the magnitude of LST, but the percent composition is a more important factor in determining LST than the configuration of those features. The significances and effects of the given configuration variables on LST vary greatly among IS cover features.

  15. Inferring snow pack ripening and melt out from distributed ground surface temperature measurements

    Directory of Open Access Journals (Sweden)

    M.-O. Schmid

    2012-02-01

    Full Text Available The seasonal snow cover and its melting are heterogeneous both in space and time. Describing and modelling this variability are important because it affects divers phenomena such as runoff, ground temperatures or slope movements. This study investigates the derivation of melting characteristics based on spatial clusters of temperature measurements. Results are based on data from Switzerland where ground surface temperatures were measured with miniature loggers (iButtons at 40 locations, referred to as footprints. At each footprint, ten iButtons have been distributed randomly few cm below the ground surface over an area of 10 m × 10 m. Footprints span elevations of 2100–3300 m a.s.l. and slope angles of 0–55°, as well as diverse slope expositions and types of surface cover and ground material. Based on two years of temperature data, the basal ripening date and the melt-out date are determined for each iButton, aggregated to the footprint level and further analysed. The date of melt out could be derived for nearly all iButtons, the ripening date could be extracted for only approximately half of them because it requires ground freezing below the snow pack. The variability within a footprint is often considerable and one to three weeks difference between melting or ripening of the points in one footprint is not uncommon. The correlation of mean annual ground surface temperatures, ripening date and melt-out date is moderate, making them useful intuitive complementary measured for model evaluation.

  16. Pliocene-Pleistocene evolution of sea surface and intermediate water temperatures from the southwest Pacific

    Science.gov (United States)

    McClymont, Erin L.; Elmore, Aurora C.; Kender, Sev; Leng, Melanie J.; Greaves, Mervyn; Elderfield, Henry

    2016-06-01

    Over the last 5 million years, the global climate system has evolved toward a colder mean state, marked by large-amplitude oscillations in continental ice volume. Equatorward expansion of polar waters and strengthening temperature gradients have been detected. However, the response of the mid latitudes and high latitudes of the Southern Hemisphere is not well documented, despite the potential importance for climate feedbacks including sea ice distribution and low-high latitude heat transport. Here we reconstruct the Pliocene-Pleistocene history of both sea surface and Antarctic Intermediate Water (AAIW) temperatures on orbital time scales from Deep Sea Drilling Project Site 593 in the Tasman Sea, southwest Pacific. We confirm overall Pliocene-Pleistocene cooling trends in both the surface ocean and AAIW, although the patterns are complex. The Pliocene is warmer than modern, but our data suggest an equatorward displacement of the subtropical front relative to present and a poleward displacement of the subantarctic front of the Antarctic Circumpolar Current (ACC). Two main intervals of cooling, from ~3 Ma and ~1.5 Ma, are coeval with cooling and ice sheet expansion noted elsewhere and suggest that equatorward expansion of polar water masses also characterized the southwest Pacific through the Pliocene-Pleistocene. However, the observed trends in sea surface temperature and AAIW temperature are not identical despite an underlying link to the ACC, and intervals of unusual surface ocean warmth (~2 Ma) and large-amplitude variability in AAIW temperatures (from ~1 Ma) highlight complex interactions between equatorward displacements of fronts associated with the ACC and/or varying poleward heat transport from the subtropics.

  17. Time-Series Modeling and Prediction of Global Monthly Absolute Temperature for Environmental Decision Making

    Institute of Scientific and Technical Information of China (English)

    YE Liming; YANG Guixia; Eric VAN RANST; TANG Huajun

    2013-01-01

    A generalized,structural,time series modeling framework was developed to analyze the monthly records of absolute surface temperature,one of the most important environmental parameters,using a deterministicstochastic combined (DSC) approach.Although the development of the framework was based on the characterization of the variation patterns of a global dataset,the methodology could be applied to any monthly absolute temperature record.Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal,involving polynomial functions and the Fourier method,respectively,while stochastic processes were employed to account for any remaining patterns in the temperature signal,involving seasonal autoregressive integrated moving average (SARIMA) models.A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years.The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors,suggesting that DSC models,when coupled with other ecoenvironmental models,can be used as a supplemental tool for short-term (~10-year) environmental planning and decision making.

  18. TIME-TEMPERATURE-TRANSFORMATION (TTT) DIAGRAMS FOR FUTURE WASTE COMPOSITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Billings, A.; Edwards, T.

    2010-07-08

    As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the waste form stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (T{sub g}) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The T{sub g} of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP) and in SRNL-STI-2009-00025. Additional phase transformation information exists for other projected compositions, but overall these compositions did not cover composition regions estimated for future waste processing. To develop TTT diagrams for future waste types, the Savannah River National Laboratory (SRNL) fabricated two caches of glass from reagent grade oxides to simulate glass compositions which would be likely processed with and without Al dissolution. These were used for glass transition temperature measurement and TTT diagram development. The glass transition temperatures of both glasses were measured using differential scanning calorimetry (DSC) and were recorded to be 448 C and 452 C. Using the previous TTT diagrams as

  19. Temperature evaluation of dental implant surface irradiated with high-power diode laser.

    Science.gov (United States)

    Rios, F G; Viana, E R; Ribeiro, G M; González, J C; Abelenda, A; Peruzzo, D C

    2016-09-01

    The prevalence of peri-implantitis and the absence of a standard approach for decontamination of the dental implant surface have led to searches for effective therapies. Since the source of diode lasers is portable, has reduced cost, and does not cause damage to the titanium surface of the implant, high-power diode lasers have been used for this purpose. The effect of laser irradiation on the implants is the elevation of the temperature surface. If this elevation exceeds 47 °C, the bone tissue is irreversibly damaged, so for a safety therapy, the laser parameters should be controlled. In this study, a diode laser of GaAsAl was used to irradiate titanium dental implants, for powers 1.32 to 2.64 W (real) or 2.00 to 4.00 W (nominal), in continuous/pulsed mode DC/AC, with exposure time of 5/10 s, with/without air flow for cooling. The elevation of the temperature was monitored in real time in two positions: cervical and apical. The best results for decontamination using a 968-nm diode laser were obtained for a power of 1.65 and 1.98 W (real) for 10 s, in DC or AC mode, with an air flow of 2.5 l/min. In our perspective in this article, we determine a suggested approach for decontamination of the dental implant surface using a 968-nm diode laser.

  20. Time resolved measurements of the CF{sub 2} rotational temperature in pulsed fluorocarbon rf plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, O; Stepanov, S; Pfafferott, M; Meichsner, J [Institute of Physics, University of Greifswald, Domstrasse 10a, D-17498, Greifswald (Germany)

    2006-11-01

    Knowledge of the absolute densities of small radicals like CF, CF{sub 2} and CF{sub 3} in fluorocarbon plasmas is essential for a fundamental understanding of plasma chemical processes and plasma surface interaction. Infrared absorption spectroscopy by means of tunable diode lasers (IR-TDLAS) was established and widely used for density measurements in the last decade. The often unknown parameter in the calculation of absolute radical densities from a measured absorption of a single line is the rotational temperature. In particular, a strong dependence of the line strength on rotational temperature has a significant influence on density calculation. In this paper we report on measurements of the CF{sub 2} rotational temperature in capacitively coupled CF{sub 4}/H{sub 2} plasmas (CCP) with rf (13.56 MHz) powers up to 200 W. Rotational temperatures in continuous and pulsed modes of the discharge were found to be between 300 and 450 K. Furthermore, first measurements of the time dependence of the rotational temperature in pulsed rf plasma are presented. The rotational temperature rises in the plasma phase within 0.1 s and goes down again to the temperature of the background gas in the plasma pause within 0.5 s. It is also shown that accurate density measurements of the radicals by means of single line absorption need correct information about the rotational temperature and careful selection of a suitable absorption line.

  1. Spatial and Temporal Variations in Titan's Surface Temperatures from Cassini CIRS Observations

    Science.gov (United States)

    Cottini, V.; Nixon, C. A.; Jennings, D. E.; deKok, R.; Teanby, N. A.; Irwin, P. G. J.; Flasar, F. M.

    2012-01-01

    We report a wide-ranging study of Titan's surface temperatures by analysis of the Moon's outgoing radiance through a spectral window in the thermal infrared at 19 mm (530/cm) characterized by lower atmospheric opacity. We begin by modeling Cassini Composite Infrared Spectrometer (CIRS) far infrared spectra collected in the period 2004-2010, using a radiative transfer forward model combined with a non-linear optimal estimation inversion method. At low-latitudes, we agree with the HASI near-surface temperature of about 94 K at 101S (Fulchignoni et al., 2005). We find a systematic decrease from the equator toward the poles, hemispherically asymmetric, of approx. 1 K at 60 deg. south and approx. 3 K at 60 deg. north, in general agreement with a previous analysis of CIRS data and with Voyager results from the previous northern winter. Subdividing the available database, corresponding to about one Titan season, into 3 consecutive periods, small seasonal changes of up to 2 K at 60 deg N became noticeable in the results. In addition, clear evidence of diurnal variations of the surface temperatures near the equator are observed for the first time: we find a trend of slowly increasing temperature from the morning to the early afternoon and a faster decrease during the night. The diurnal change is approx. 1.5 K, in agreement with model predictions for a surface with a thermal inertia between 300 and 600 J/ sq. m s (exp -1/2) / K. These results provide important constraints on coupled surface-atmosphere models of Titan's meteorology and atmospheric dynamic.

  2. An energy dispersive time resolved liquid surface reflectometer

    CERN Document Server

    Garrett, R F; King, D J; Dowling, T L; Fullagar, W

    2001-01-01

    Two designs are presented for an energy dispersive liquid surface reflectometer with time resolution in the milli-second domain. The designs utilise rotating crystal and Laue analyser optics respectively to energy analyse a pink synchrotron X-ray beam after reflection from a liquid surface. Some performance estimates are presented, along with results of a test experiment using a laboratory source and solid state detector.

  3. Rooftop Surface Temperature Analysis in an Urban Residential Environment

    Directory of Open Access Journals (Sweden)

    Qunshan Zhao

    2015-09-01

    Full Text Available The urban heat island (UHI phenomenon is a significant worldwide problem caused by rapid population growth and associated urbanization. The UHI effect exacerbates heat waves during the summer, increases energy and water consumption, and causes the high risk of heat-related morbidity and mortality. UHI mitigation efforts have increasingly relied on wisely designing the urban residential environment such as using high albedo rooftops, green rooftops, and planting trees and shrubs to provide canopy coverage and shading. Thus, strategically designed residential rooftops and their surrounding landscaping have the potential to translate into significant energy, long-term cost savings, and health benefits. Rooftop albedo, material, color, area, slope, height, aspect and nearby landscaping are factors that potentially contribute. To extract, derive, and analyze these rooftop parameters and outdoor landscaping information, high resolution optical satellite imagery, LIDAR (light detection and ranging point clouds and thermal imagery are necessary. Using data from the City of Tempe AZ (a 2010 population of 160,000 people, we extracted residential rooftop footprints and rooftop configuration parameters from airborne LIDAR point clouds and QuickBird satellite imagery (2.4 m spatial resolution imagery. Those parameters were analyzed against surface temperature data from the MODIS/ASTER airborne simulator (MASTER. MASTER images provided fine resolution (7 m surface temperature data for residential areas during daytime and night time. Utilizing these data, ordinary least squares (OLS regression was used to evaluate the relationships between residential building rooftops and their surface temperature in urban environment. The results showed that daytime rooftop temperature was closely related to rooftop spectral attributes, aspect, slope, and surrounding trees. Night time temperature was only influenced by rooftop spectral attributes and slope.

  4. Evaluation of Land Surface Temperature Operationally Retrieved from Korean Geostationary Satellite (COMS Data

    Directory of Open Access Journals (Sweden)

    A-Ra Cho

    2013-08-01

    Full Text Available We evaluated the precision of land surface temperature (LST operationally retrieved from the Korean multipurpose geostationary satellite, Communication, Ocean and Meteorological Satellite (COMS. The split-window (SW-type retrieval algorithm was developed through radiative transfer model simulations under various atmospheric profiles, satellite zenith angles, surface emissivity values and surface lapse rate conditions using Moderate Resolution Atmospheric Transmission version 4 (MODTRAN4. The estimation capabilities of the COMS SW (CSW LST algorithm were evaluated for various impacting factors, and the retrieval accuracy of COMS LST data was evaluated with collocated Moderate Resolution Imaging Spectroradiometer (MODIS LST data. The surface emissivity values for two SW channels were generated using a vegetation cover method. The CSW algorithm estimated the LST distribution reasonably well (averaged bias = 0.00 K, Root Mean Square Error (RMSE = 1.41 K, correlation coefficient = 0.99; however, the estimation capabilities of the CSW algorithm were significantly impacted by large brightness temperature differences and surface lapse rates. The CSW algorithm reproduced spatiotemporal variations of LST comparing well to MODIS LST data, irrespective of what month or time of day the data were collected from. The one-year evaluation results with MODIS LST data showed that the annual mean bias, RMSE and correlation coefficient for the CSW algorithm were −1.009 K, 2.613 K and 0.988, respectively.

  5. Climate Variability in Coastal Ecosystems - Use of MODIS Land Surface and Sea Surface Temperature Observations

    Science.gov (United States)

    Chintalapati, S.; Lakshmi, V.

    2007-12-01

    The intertidal zone, with its complex blend of marine and terrestrial environments, is one of the intensively studied ecosystems, in understanding the effects of climate change on species abundance and distribution. As climatic conditions change, the geographic limits of the intertidal species will likely move towards more tolerable coastal conditions. Traditionally, understanding climate change effects through species physiologic response have involved use of in situ measurements and thermal engineering models. But these approaches are constrained by their data intensive requirements and may not be suitable for predicting change patterns relevant to large scale species distributions. Satellite remote sensing provides an alternate approach, given the regular global coverage at moderate spatial resolutions. The present study uses six years of land surface temperature (LST) and sea surface temperature (SST) data from MODIS/Terra instrument along various coastlines around the globe - East and West Coast US, Southern Africa, Northern Japan and New Zealand. Apart from the dominant annual cycle in LST and SST, the other seasonal cycles vary from dominant semi-annual cycles in lower latitudes to 1.5 and 2 year cycles at higher latitudes. The monthly anomalies show strong spatial structure at lower latitudes when compared to higher latitudes, with the exception of US east coast, where the spatial structure extended almost along the whole coastline, indicating strong regulation from the Gulf Stream. The patterns along different coast lines are consistent with the atmospheric and ocean circulation patterns existing at those regions. These results suggest that the climatology at the coastal regions can be adequately represented using satellite-based temperature data, thus enabling further research in understanding the effects of climate change on species abundance and distribution at larger scales.

  6. Real Time Land-Surface Hydrologic Modeling Over Continental US

    Science.gov (United States)

    Houser, Paul R.

    1998-01-01

    The land surface component of the hydrological cycle is fundamental to the overall functioning of the atmospheric and climate processes. Spatially and temporally variable rainfall and available energy, combined with land surface heterogeneity cause complex variations in all processes related to surface hydrology. The characterization of the spatial and temporal variability of water and energy cycles are critical to improve our understanding of land surface-atmosphere interaction and the impact of land surface processes on climate extremes. Because the accurate knowledge of these processes and their variability is important for climate predictions, most Numerical Weather Prediction (NWP) centers have incorporated land surface schemes in their models. However, errors in the NWP forcing accumulate in the surface and energy stores, leading to incorrect surface water and energy partitioning and related processes. This has motivated the NWP to impose ad hoc corrections to the land surface states to prevent this drift. A proposed methodology is to develop Land Data Assimilation schemes (LDAS), which are uncoupled models forced with observations, and not affected by NWP forcing biases. The proposed research is being implemented as a real time operation using an existing Surface Vegetation Atmosphere Transfer Scheme (SVATS) model at a 40 km degree resolution across the United States to evaluate these critical science questions. The model will be forced with real time output from numerical prediction models, satellite data, and radar precipitation measurements. Model parameters will be derived from the existing GIS vegetation and soil coverages. The model results will be aggregated to various scales to assess water and energy balances and these will be validated with various in-situ observations.

  7. Souring in low-temperature surface facilities of two high-temperature Argentinian oil fields.

    Science.gov (United States)

    Agrawal, Akhil; An, Dongshan; Cavallaro, Adriana; Voordouw, Gerrit

    2014-09-01

    Produced waters from the Barrancas and Chihuido de la Salina (CHLS) fields in Argentina had higher concentrations of sulfate than were found in the injection waters, suggesting that the formation waters in these reservoirs had a high sulfate concentration and that sulfate-reducing bacteria were inactive downhole. Incubation of produced waters with produced oil gave rapid reduction of sulfate to sulfide (souring) at 37 °C, some at 60 °C, but none at 80 °C. Alkylbenzenes and alkanes served as electron donor, especially in incubations with CHLS oil. Dilution with water to decrease the ionic strength or addition of inorganic phosphate did not increase souring at 37 or 60 °C. These results indicate that souring in these reservoirs is limited by the reservoir temperature (80 °C for the Barrancas and 65-70 °C for the CHLS field) and that souring may accelerate in surface facilities where the oil-water mixture cools. As a result, significant sulfide concentrations are present in these surface facilities. The activity and presence of chemolithotrophic Gammaproteobacteria of the genus Thiomicrospira, which represented 85% of the microbial community in a water plant in the Barrancas field, indicated reoxidation of sulfide and sulfur to sulfate. The presence of these bacteria offers potential for souring control by microbial oxidation in aboveground facilities, provided that formation of corrosive sulfur can be avoided.

  8. Study on the effect of subcooling on vapor film collapse on high temperature particle surface

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yutaka; Tochio, Daisuke; Yanagida, Hiroshi [Department of Mechanical Systems Engineering, Yamagata Univ., Yonezawa, Yamagata (Japan)

    2000-11-01

    Thermal detonation model is proposed to describe vapor explosion. According to this model, vapor film on pre-mixed high temperature droplet surface is needed to be collapsed for the trigger of the vapor explosion. It is pointed out that the vapor film collapse behavior is significantly affected by the subcooling of low temperature liquid. However, the effect of subcooling on micro-mechanism of vapor film collapse behavior is not experimentally well identified. The objective of the present research is to experimentally investigate the effect of subcooling on micro-mechanism of film boiling collapse behavior. As the results, it is experimentally clarified that the vapor film collapse behavior in low subcooling condition is qualitatively different from the vapor film collapse behavior in high subcooling condition. In case of vapor film collapse by pressure pulse, homogeneous vapor generation occurred all over the surface of steel particle in low subcooling condition. On the other hand, heterogeneous vapor generation was observed for higher subcooling condition. In case of vapor film collapse spontaneously, fluctuation of the gas-liquid interface after quenching propagated from bottom to top of the steel particle heterogeneously in low subcooling condition. On the other hand, simultaneous vapor generation occurred for higher subcooling condition. And the time transient of pressure, particle surface temperature, water temperature and visual information were simultaneously measured in the vapor film collapse experiment by external pressure pulse. Film thickness was estimated by visual data processing technique with the pictures taken by the high-speed video camera. Temperature and heat flux at the vapor-liquid interface were estimated by solving the heat condition equation with the measured pressure, liquid temperature and vapor film thickness as boundary conditions. Movement of the vapor-liquid interface were estimated with the PIV technique with the visual observation

  9. Effect of blanching temperature and dipping time on drying time of broccoli.

    Science.gov (United States)

    Doymaz, Ibrahim

    2014-03-01

    Drying characteristics of broccoli was experimentally studied in cabinet-type convective dryer. Experiments were conducted using constant air velocity of 2 m/s and air temperature of 60 . Drying rate increased with increasing blanching temperature and thus reduced the drying time. The experimental drying data were used to fit twelve drying models and drying rate constants and coefficients of the models were determined by non-linear regression analysis. Estimations by the Midilli et al. model were in good agreement with the experimental data obtained. Fick's second law was used to calculate the effective moisture diffusivity, which varied from 1.987 to 3.577 × 10(-8) m(2)/s for the given blanching temperature range. The rehydration ratio was observed to increase with increasing blanching temperature.

  10. Retrieval of sea surface air temperature from satellite data over Indian Ocean: An empirical approach

    Digital Repository Service at National Institute of Oceanography (India)

    Sathe, P.V.; Muraleedharan, P.M.

    the surface air temperature and surface humidity is analysed by fitting a polynomial between the two for different regions of the Indian Ocean in different seasons. Taking into account the variation in surface air temperatures, the Indian Ocean is split in 14...

  11. A long time low drift integrator with temperature control

    Science.gov (United States)

    Zhang, Donglai; Yan, Xiaolan; Zhang, Enchao; Pan, Shimin

    2016-10-01

    The output of an operational amplifier always contains signals that could not have been predicted, even with knowledge of the input and an accurately determined closed-loop transfer function. These signals lead to integrator zero-drift over time. A new type of integrator system with a long-term low-drift characteristic has therefore been designed. The integrator system is composed of a temperature control module and an integrator module. The aluminum printed circuit board of the integrator is glued to a thermoelectric cooler to maintain the electronic components at a stable temperature. The integration drift is automatically compensated using an analog-to-digital converter/proportional integration/digital-to-analog converter control circuit. Performance testing in a standard magnet shows that the proposed integrator, which has an integration time constant of 10 ms, has a low integration drift (<5 mV) over 1000 s after repeated measurements. The integrator can be used for magnetic flux measurements in most tokamaks and in the wire rope nondestructive test.

  12. Validation of the MODIS "Clear-Sky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Koenig, L. S.; DiGirolamo, N. E.; Comiso, J.; Shuman, C. A.

    2011-01-01

    Surface temperatures on the Greenland Ice Sheet have been studied on the ground, using automatic weather station (AWS) data from the Greenland-Climate Network (GC-Net), and from analysis of satellite sensor data. Using Advanced Very High Frequency Radiometer (AVHRR) weekly surface temperature maps, warming of the surface of the Greenland Ice Sheet has been documented from 1981 to present. We extend and refine this record using higher-resolution Moderate-Resolution Imaging Spectroradiometer (MODIS) data from March 2000 to the present. To permit changes to be observed over time, we are developing a well-characterized monthly climate-data record (CDR) of the "clear-sky" surface temperature of the Greenland Ice Sheet using data from both the Terra and Aqua satellites. We use the MODIS ice-surface temperature (IST) algorithm. Validation of the CDR consists of several facets: 1) comparisons between the Terra and Aqua IST maps; 2) comparisons between ISTs and in-situ measurements; 3) comparisons between ISTs and AWS data; and 4) comparisons of ISTs with surface temperatures derived from other satellite instruments such as the Thermal Emission and Reflection Radiometer. In this work, we focus on 1) and 2) above. Surface temperatures on the Greenland Ice Sheet have been studied on the ground, using automatic weather station (AWS) data from the Greenland-Climate Network (GC-Net), and from analysis of satellite sensor data. Using Advanced Very High Frequency Radiometer (AVHRR) weekly surface temperature maps, warming of the surface of the Greenland Ice Sheet has been documented from 1981 to present. We extend and refine this record using higher-resolution Moderate-Resolution Imaging Spectroradiometer (MODIS) data from March 2000 to the present. To permit changes to be observed over time, we are developing a well-characterized monthly climate-data record (CDR) of the "clear-sky" surface temperature of the Greenland Ice Sheet using data from both the Terra and Aqua satellites

  13. Statistical analysis of global surface air temperature and sea level using cointegration methods

    DEFF Research Database (Denmark)

    Schmith, Torben; Johansen, Søren; Thejll, Peter

    Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to physically-based models being unable to simulate observed sea level trends, semi-empirical models have been applied as an alternative for projecting...... of future sea levels. There is in this, however, potential pitfalls due to the trending nature of the time series. We apply a statistical method called cointegration analysis to observed global sea level and surface air temperature, capable of handling such peculiarities. We find a relationship between sea...... level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean. We further find that the warming episode in the 1940s is exceptional in the sense that sea level and warming deviates from the expected...

  14. Statistical analysis of global surface temperature and sea level using cointegration methods

    DEFF Research Database (Denmark)

    Schmidt, Torben; Johansen, Søren; Thejll, Peter

    2012-01-01

    Global sea levels are rising which is widely understood as a consequence of thermal expansion and melting of glaciers and land-based ice caps. Due to the lack of representation of ice-sheet dynamics in present-day physically-based climate models being unable to simulate observed sea level trends......, semi-empirical models have been applied as an alternative for projecting of future sea levels. There is in this, however, potential pitfalls due to the trending nature of the time series. We apply a statistical method called cointegration analysis to observed global sea level and land-ocean surface air...... temperature, capable of handling such peculiarities. We find a relationship between sea level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean. We further find that the warming episode in the 1940s...

  15. Simulations on the influence of lunar surface temperature profiles on CE-1 lunar microwave sounder brightness temperature

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Surface temperature profile is an important parameter in lunar microwave remote sensing. Based on the analysis of physical properties of the lunar samples brought back by the Apollo and Luna missions, we modeled temporal and spatial variation of lunar surface temperature with the heat conduction equation, and produced temperature distribution in top 6.0 m of lunar regolith of the whole Moon surface. Our simulation results show that the profile of lunar surface temperature varies mainly within the top 20 cm, except at the lunar polar regions where the changes can reach to about 1.0 m depth. The temperature is stable beyond that depth. The variations of lunar surface temperature lead to main changes in brightness temperature (TB) at different channels of the lunar microwave sounder (CELMS) on Chang’E-1 (CE-1). The results of this paper show that the temperature profile influenced CELMS TB, which provides strong validation on the CELMS data, and lays a solid basis for future interpretation and utilization of the CELMS data.

  16. Prediction of daily sea surface temperature using efficient neural networks

    Science.gov (United States)

    Patil, Kalpesh; Deo, Makaranad Chintamani

    2017-04-01

    Short-term prediction of sea surface temperature (SST) is commonly achieved through numerical models. Numerical approaches are more suitable for use over a large spatial domain than in a specific site because of the difficulties involved in resolving various physical sub-processes at local levels. Therefore, for a given location, a data-driven approach such as neural networks may provide a better alternative. The application of neural networks, however, needs a large experimentation in their architecture, training methods, and formation of appropriate input-output pairs. A network trained in this manner can provide more attractive results if the advances in network architecture are additionally considered. With this in mind, we propose the use of wavelet neural networks (WNNs) for prediction of daily SST values. The prediction of daily SST values was carried out using WNN over 5 days into the future at six different locations in the Indian Ocean. First, the accuracy of site-specific SST values predicted by a numerical model, ROMS, was assessed against the in situ records. The result pointed out the necessity for alternative approaches. First, traditional networks were tried and after noticing their poor performance, WNN was used. This approach produced attractive forecasts when judged through various error statistics. When all locations were viewed together, the mean absolute error was within 0.18 to 0.32 °C for a 5-day-ahead forecast. The WNN approach was thus found to add value to the numerical method of SST prediction when location-specific information is desired.

  17. Prediction of daily sea surface temperature using efficient neural networks

    Science.gov (United States)

    Patil, Kalpesh; Deo, Makaranad Chintamani

    2017-02-01

    Short-term prediction of sea surface temperature (SST) is commonly achieved through numerical models. Numerical approaches are more suitable for use over a large spatial domain than in a specific site because of the difficulties involved in resolving various physical sub-processes at local levels. Therefore, for a given location, a data-driven approach such as neural networks may provide a better alternative. The application of neural networks, however, needs a large experimentation in their architecture, training methods, and formation of appropriate input-output pairs. A network trained in this manner can provide more attractive results if the advances in network architecture are additionally considered. With this in mind, we propose the use of wavelet neural networks (WNNs) for prediction of daily SST values. The prediction of daily SST values was carried out using WNN over 5 days into the future at six different locations in the Indian Ocean. First, the accuracy of site-specific SST values predicted by a numerical model, ROMS, was assessed against the in situ records. The result pointed out the necessity for alternative approaches. First, traditional networks were tried and after noticing their poor performance, WNN was used. This approach produced attractive forecasts when judged through various error statistics. When all locations were viewed together, the mean absolute error was within 0.18 to 0.32 °C for a 5-day-ahead forecast. The WNN approach was thus found to add value to the numerical method of SST prediction when location-specific information is desired.

  18. Evaluation and Monitoring of Jpss Land Surface Temperature Data

    Science.gov (United States)

    Yu, Y.; Yu, P.; Liu, Y.; Csiszar, I. A.

    2016-12-01

    Land Surface Temperature (LST) is one of environmental data records (EDRs) produced operationally through the U.S. Joint Polar Satellite System (JPSS) mission. LST is an important parameter for understanding climate change, modeling the hydrological and biogeochemical cycles, and is a prime candidate for Numerical Weather Prediction (NWP) assimilation models. Recently, the international LST and Emissivity Working Ggroup (ILSTE-WG) is promoting to the inclusion of the LST as essential climate variable (ECV) in the Global Climate Observation System (GCOS) of the Word Meteorological Organization (WMO). At the Center for Satellite Applications and Research (STAR) of National Atmospheric and Oceanic Administration (NOAA), we, are as a science team, are responsible to for the science of JPSS LST production. In this work, we present our activities and accomplishments on the JPSS LST evaluation and monitoring since the launch of the first JPSS satellite, i.e. S-NPP, satellite. Beta version, provisional version, and validated stage 1 version of the S-NPP LST products which were announced in May 2013, July 2014, and March 2015, respectively. Evaluation of the LST products have been performed versus ground measurements and other polar-orbiting satellite LST data (e,g. MODIS LSTs); some results will be illustrated. A daily monitoring system of the JPSS LST production has been developed, which presents daily, weekly and monthly global LST maps and inter-comparison results on the STAR JPSS program website. Further, evaluation of the enterprise LST algorithm for JPSS mission which is in development at STAR currently are presented in this work. Finally, evaluation and monitoring plan of the LST production for the JPSS-1 satellite are also presented.

  19. A new algorithm for microwave radiometer remote sensing of sea surface salinity and temperature

    Institute of Scientific and Technical Information of China (English)

    YIN; Xiaobin; LIU; Yuguang; WANG; Zhenzhan

    2006-01-01

    The microwave radiation of the sea surface, which is denoted by the sea surface brightness temperature, is not only related with sea surface salinity (SSS) and temperature (SST), but also influenced by sea surface wind. The errors of wind detected by satellite sensor have significant influences on the accuracy of SSS and SST retrieval. The effects of sea surface wind on sea surface brightness temperature, i.e. △Th,v, and the relations among △Th,v, wind speed, sea surface temperature, sea surface salinity and incidence angle of observation are investigated. Based on the investigations, a new algorithm depending on the design of a single radiometer with double polarizations and multi-incidence angles is proposed. The algorithm excludes the influence of sea surface wind on SSS and SST retrieval, and provides a new method for remote sensing of SSS and SST.

  20. Temperature variation on root surface with three root-end cavity preparation techniques

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2013-01-01

    Full Text Available Introduction. Thermal changes can occur on the external root surface when root-end cavity preparation is performed, which may damage periodontal ligament cells and alveolar bone. Objective. The purpose of this study was to evaluate the temperature changes during preparation of the root-end cavities at 1 and 3 mm to the sectioned apical root surfaces when either tungsten carbide round bur, diamond round bur or ultrasonic diamond tip was used. Methods. Root-end resection was performed at 90° to the long axis of the root, 3 mm from the apex. Specimens were randomly divided into three groups of 12 teeth each for three different root-end cavity preparation techniques to be used, i.e. tungsten carbide bur, diamond bur and ultrasonic diamond retro tip. Thermocouples were used to measure temperature changes at 1 mm (T1 and 3 mm (T2 to the cutting plane during the preparations. Results. For T1, the lowest and the highest mean temperature increases of 3.53°C and 4.34°C were recorded for the carbide and diamond burs, respectively. For T2, the lowest and the highest mean temperature increases of 2.62°C and 4.39°C where recorded for the carbide and diamond burs, respectively. The mean temperatures with the ultrasonic tip were 3.68 and 3.04 ºC at T1 and T2 region, respectively. For root-end preparation, the ultrasonic preparation technique took the shortest preparation time (10.25 sec and the diamond bur took the longest time (28.17 sec. Conclusion. Ultrasonic retro tips and burs caused temperature to rise from 2.62° to 4.39°C, and these rises were within safety levels.

  1. Clouds, radiation, and the diurnal cycle of sea surface temperature in the tropical Western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Webster, P.J.; Clayson, C.A.; Curry, J.A. [Univ. of Colorado, Boulder, CO (United States)

    1996-04-01

    In the tropical Western Pacific (TWP) Ocean, the clouds and the cloud-radiation feedback can only be understood in the context of air/sea interactions and the ocean mixed layer. Considerable interest has been shown in attempting to explain why sea surface temperature (SST) rarely rises above 30{degrees}C, and gradients of the SST. For the most part, observational studies that address this issue have been conducted using monthly cloud and SST data, and the focus has been on intraseasonal and interannual time scales. For the unstable tropical atmosphere, using monthly averaged data misses a key feedback between clouds and SST that occurs on the cloud-SST coupling time scale, which was estimated to be 3-6 days for the unstable tropical atmosphere. This time scale is the time needed for a change in cloud properties, due to the change of ocean surface evaporation caused by SST variation, to feed back to the SST variation, to feed back to the SST through its effect on the surface heat flux. This paper addresses the relationship between clouds, surface radiation flux and SST of the TWP ocean over the diurnal cycle.

  2. Alpha surfaces for complex space-times with torsion

    CERN Document Server

    Esposito, G

    1993-01-01

    This paper studies necessary conditions for the existence of alpha-surfaces in complex space-time manifolds with nonvanishing torsion. For these manifolds, Lie brackets of vector fields and spinor Ricci identities contain explicitly the effects of torsion. This leads to an integrability condition for alpha-surfaces which does not involve just the self-dual Weyl spinor, as in complex general relativity, but also the torsion spinor, in a nonlinear way, and its covariant derivative. Interestingly, a particular solution of the integrability condition is given by conformally right-flat and right-torsion-free space-times.

  3. Protein sequences bound to mineral surfaces persist into deep time

    DEFF Research Database (Denmark)

    Demarchi, Beatrice; Hall, Shaun; Roncal-Herrero, Teresa;

    2016-01-01

    of Laetoli (3.8 Ma) and Olduvai Gorge (1.3 Ma) in Tanzania. By tracking protein diagenesis back in time we find consistent patterns of preservation, demonstrating authenticity of the surviving sequences. Molecular dynamics simulations of struthiocalcin-1 and -2, the dominant proteins within the eggshell......, reveal that distinct domains bind to the mineral surface. It is the domain with the strongest calculated binding energy to the calcite surface that is selectively preserved. Thermal age calculations demonstrate that the Laetoli and Olduvai peptides are 50 times older than any previously authenticated...... sequence (equivalent to ~16 Ma at a constant 10°C)....

  4. Effects of Slope and Aspect Variations on Satellite Surface Temperature Retrievals and Mesoscale Analysis in Mountainous Terrain.

    Science.gov (United States)

    Lipton, Alan E.

    1992-03-01

    Surface temperature retrieval in mountainous areas is complicated by the high variability of temperatures that can occur within a single satellite field of view. Temperatures depend in part on slope orientation relative to the sun, which can vary radically over very short distances. The surface temperature detected by a satellite is biased toward the temperatures of the sub-field-of-view terrain elements that most directly face the satellite. Numerical simulations were conducted to estimate the effects of satellite viewing geometry on surface temperature retrievals for a section of central Colorado. Surface temperatures were computed using a mesoscale model with a parameterization of subgrid variations in slope and aspect angles.The simulations indicate that the slope-aspect effect can lead to local surface temperature variations up to 30°C for autumn conditions in the Colorado mountains. For realistic satellite viewing conditions, these variations can give rise to biases in retrieved surface temperatures of about 3°C. Relative biases between retrievals from two satellites with different viewing angles can be over 6°C, which could lead to confusion when merging datasets. The bias computations were limited by the resolution of the available terrain height data (90 m). The results suggest that the biases would be significantly larger if the data resolution was fine enough to represent every detail of the real Colorado terrain or if retrievals were made in mountain areas that have a larger proportion of steep slopes than the Colorado Rockies. The computed bias gradients across the Colorado domain were not large enough to significantly alter the forcing of the diurnal upslope-downslope circulations, according to simulations in which surface temperature retrievals with view-dependent biases were assimilated into time-continuous analyses. View-dependent retrieval biases may be relevant to climatological analysts that rely on remotely sensed data, given that bias

  5. Constant pressure and temperature discrete-time Langevin molecular dynamics.

    Science.gov (United States)

    Grønbech-Jensen, Niels; Farago, Oded

    2014-11-21

    We present a new and improved method for simultaneous control of temperature and pressure in molecular dynamics simulations with periodic boundary conditions. The thermostat-barostat equations are built on our previously developed stochastic thermostat, which has been shown to provide correct statistical configurational sampling for any time step that yields stable trajectories. Here, we extend the method and develop a set of discrete-time equations of motion for both particle dynamics and system volume in order to seek pressure control that is insensitive to the choice of the numerical time step. The resulting method is simple, practical, and efficient. The method is demonstrated through direct numerical simulations of two characteristic model systems-a one-dimensional particle chain for which exact statistical results can be obtained and used as benchmarks, and a three-dimensional system of Lennard-Jones interacting particles simulated in both solid and liquid phases. The results, which are compared against the method of Kolb and Dünweg [J. Chem. Phys. 111, 4453 (1999)], show that the new method behaves according to the objective, namely that acquired statistical averages and fluctuations of configurational measures are accurate and robust against the chosen time step applied to the simulation.

  6. Estimation of Daily Air Temperature Based on MODIS Land Surface Temperature Products over the Corn Belt in the US

    Directory of Open Access Journals (Sweden)

    Linglin Zeng

    2015-01-01

    Full Text Available Air temperature (Ta is a key input in a wide range of agroclimatic applications. Moderate Resolution Imaging Spectroradiometer (MODIS Ts (Land Surface Temperature (LST products are widely used to estimate daily Ta. However, only daytime LST (Ts-day or nighttime LST (Ts-night data have been used to estimate Tmax/Tmin (daily maximum or minimum air temperature, respectively. The relationship between Tmax and Ts-night, and the one between Tmin and Ts-day has not been studied. In this study, both the ability of Ts-night data to estimate Tmax and the ability of Ts-day data to estimate Tmin were tested and studied in the Corn Belt during the growing season (May–September from 2008 to 2012, using MODIS daily LST products from both Terra and Aqua. The results show that using Ts-night for estimating Tmax could result in a higher accuracy than using Ts-day for a similar estimate. Combining Ts-day and Ts-night, the estimation of Tmax was improved by 0.19–1.85, 0.37–1.12 and 0.26–0.93 °C for crops, deciduous forest and developed areas, respectively, when compared with using only Ts-day or Ts-night data. The main factors influencing the Ta estimation errors spatially and temporally were analyzed and discussed, such as satellite overpassing time, air masses, irrigation, etc.

  7. The Response of Snow on Tibetan Plateau in Winter to Indian Ocean Sea Surface Temperature Anomaly

    Science.gov (United States)

    Jia, Lha; Xiao, Tiangui; Wang, Chao; Du, Jun; Zhou, Xiaoli

    2017-04-01

    By using the daily snow depth and snow cover days data at 100 meteorological stations in Tibetan Plateau during 1979-2013, the methods of EOF, REOF and SVD were used to analyze the distribution characteristic and time series variation of snow in Tibetan Plateau. The coupling relationship between snow in Tibetan Plateau in winter and Indian Ocean sea surface temperature in winter, and the lag response of the snow in Tibetan Plateau in winter to Indian Ocean sea surface temperature were also studied. Main conclusions are as follows: 1.Snow depth and snow cover reaches the maximum value in January and reaches the minimum value in July; accumulated snow depth and snow cover days shows an increasing tendency during 1980s to 1990s and has a decreasing tendency since then. The accumulated snow depth and snow cover days decrease in summer and increase in autumn. 2. There were 4 high-frequency centers of snow cover days and accumulated snow depth: the southern Himalayas area, the area between the Tanggula Mountains and the Nyainqentanglha Mountains, the area around Bayankela Mountains and the area around Qilian Mountains. 3. The first pattern of SVD between snow in Tibetan Plateau in winter and Indian Ocean sea surface temperature in winter has the feature that Indian Ocean sea surface temperature increase in the whole area and snow has an opposite trend in the western and southeastern Plateau and the northern and southern Plateau. The second pattern shows that Indian Ocean sea surface temperature has an opposite trend in the western ocean and the eastern ocean and snow has an opposite trend in the western Plateau and the southeastern Plateau. There is a significant negative correlation between Indian Ocean sea surface temperature in June and July and snow in Tibetan Plateau in winter. Key words: Tibetan Plateau; snow; Indian Ocean; SVD Acknowledgements This study was supported by National Natural Science Foundation of China Fund Project (91337215, 41575066),National Key

  8. Long-term evolution of tidal heating and surface temperature on extrasolar planets

    Science.gov (United States)

    Kanova, Michaela; Behounkova, Marie

    2015-04-01

    Increasing number of detected extrasolar planets provides a unique statistical set that may help us to improve our knowledge about planetary evolution. Indirect detection methods employed in search for exoplanets are most sensitive to objects orbiting close to their host star and this criterion gets particularly important in the case of low-mass terrestrial planets. Here, we focus on long-term orbital and thermal evolution of a single planet subjected to stellar tides. Our approach combines evaluation of surface temperature as well as numerical computation of tidal effects on planetary orbit and internal heating. By calculating the tidal evolution of the orbit [1], we analyze the effect of initial orbital parameters (eccentricity, semi-major axis and rotational frequency) on secular changes in surface temperature and tidal dissipation. The maximum surface temperature and temperature gradient is computed during the process and it evolves together with the semi-major axis, the eccentricity and the ratio of spin and orbital frequency. Significant increase in the surface temperature is observed when the planet encounters a spin-orbit resonance. We solve the heat diffusion equation numerically for both 1D and 3D geometry in a thin spherical shell corresponding to a subsurface layer (see e.g. [2]), where the upper boundary condition is given by energy equilibrium and is strongly non-linear in temperature due to Stefan-Boltzmann law. Additionally, we solve the viscoelastic response to the tidal loading during orbital evolution. Following the method of [3,4], the tidal heating is evaluated for Maxwell or Andrade rheology in the time domain. We study disturbing potential caused by the body's deformation, the time dependence of phase lag and time lag during one orbit and compare our results with traditionally used constant tidal lag models (e.g. [1,5]). The effect of a 3D internal structure on the disturbing potential is investigated as well. This study is our first step

  9. Seasonal trends in precipitation and surface air temperature extremes in mainland Portugal, 1941-2007

    Science.gov (United States)

    de Lima, M. I. P.; Santo, F. E.; Ramos, A. M.

    2012-04-01

    Several climate models predict, on a global scale, modifications in climate variables that are expected to have impact on society and the environment. The concern is on changes in the variability of processes, the mean and extreme events (maximum and minimum). To explore recent changes in precipitation and near surface air temperature extremes in mainland Portugal, we have inspected trends in time series of specific indices defined for daily data. These indices were recommended by the Commission for Climatology/Climate Variability and Predictability (CCl/CLIVAR) Working Group on Climate Change Detection, and include threshold indices, probability indices, duration indices and other indices. The precipitation and air temperature data used in this study are from, respectively, 57 and 23 measuring stations scattered across mainland Portugal, and cover the periods 1941-2007, for precipitation, and 1941-2006, for temperature. The study focuses on changes at the seasonal scale. Strong seasonality is one of the main features of climate in mainland Portugal. Intensification of the seasonality signal across the territory, particularly in the more sensitive regions, might contribute to endanger already fragile soil and water resources and ecosystems, and the local environmental and economic sustainability. Thus, the understanding of variations in the intensity, frequency and duration of extreme precipitation and air temperature events at the intra-annual scale is particularly important in this geographical area. Trend analyses were conducted over the full period of the records and for sub-periods, exploring patterns of change. Results show, on the one hand, regional differences in the tendency observed in the time series analysed; and, on the other hand, that although trends in annual indices are in general not statistically significant, there are sometimes significant changes over time in the data at the seasonal scale that point out to an increase in the already existing

  10. Effects of temperature and surface contamination on D retention in ultrathin Li films on TZM

    Energy Technology Data Exchange (ETDEWEB)

    Capece, A.M., E-mail: acapece@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Roszell, J.P. [Princeton University, Department of Chemical and Biological Engineering, Princeton, NJ (United States); Skinner, C.H. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Koel, B.E. [Princeton University, Department of Chemical and Biological Engineering, Princeton, NJ (United States)

    2015-08-15

    In this work, we investigate deuterium retention at the Mo–Li interface by studying thin Li films three monolayers thick on a TZM Mo alloy. Li films at temperatures between 315 and 460 K were exposed to a deuterium ion beam and D retention was measured using temperature programmed desorption. In the absence of oxygen, D is retained as LiD, and the relative amount of retained D decreases with increasing substrate temperature. In three-monolayer thick lithium oxide films, the amount of D retained was 2.5 times higher than the amount retained as LiD in the metallic Li film. However, oxygen reduces the thermal stability of D in the film, causing D{sub 2}O and D{sub 2} to be released from the surface at temperatures 150–200 K below the LiD decomposition temperature. These results highlight the importance of maintaining a metallic Li layer for high D retention in Li films on TZM at elevated temperatures.

  11. Benchmarking the performance of pairwise homogenization of surface temperatures in the United States

    Science.gov (United States)

    Menne, M. J.; Williams, C. N.; Thorne, P. W.

    2013-09-01

    Changes in the circumstances behind in situ temperature measurements often lead to shifts in individual station records that can lead to over or under-estimates of the local and regional temperature trends. Since these shifts are comparable in magnitude to climate change signals, homogeneity "corrections" are necessary to make the records suitable for climate analysis. To quantify the effectiveness of surface temperature homogenization in the United States, a randomized perturbed ensemble of the pairwise homogenization algorithm was run against a suite of benchmark analogs to real monthly temperature data from the United States Cooperative Observer Program, which includes the subset of stations known as the United States Historical Climatology Network (USHCN). Results indicate that all randomized versions of the algorithm consistently produce homogenized data closer to the true climate signal in the presence of widespread systematic shifts in the data. When applied to the real-world observations, the randomized ensemble reinforces previous understanding that the two dominant sources of shifts in the U.S. temperature records are caused by changes to time of observation (spurious cooling in minimum and maximum) and conversion to electronic resistance thermometers (spurious cooling in maximum and warming in minimum). Trend bounds defined by the ensemble output indicate that maximum temperature trends are positive for the past 30, 50 and 100 years, and that these maximums contain pervasive negative shifts that cause the unhomogenized (raw) trends to fall below the lowest of the ensemble of homogenized trends. Moreover, because the residual impact of undetected/uncorrected shifts in the homogenized analogs is one-tailed when the imposed shifts have a positive or negative sign preference, it is likely that maximum temperature trends have been underestimated in the real-world homogenized temperature data from the USHCN. Trends for minimum temperature are also positive

  12. Vegetation, land surface brightness, and temperature dynamics after aspen forest die-off

    Science.gov (United States)

    Huang, Cho-ying; Anderegg, William R. L.

    2014-07-01

    Forest dynamics following drought-induced tree mortality can affect regional climate through biophysical surface properties. These dynamics have not been well quantified, particularly at the regional scale, and are a large uncertainty in ecosystem-climate feedback. We investigated regional biophysical characteristics through time (1995-2011) in drought-impacted (2001-2003), trembling aspen (Populus tremuloides Michx.) forests by utilizing Landsat time series green and brown vegetation cover, surface brightness (total shortwave albedo), and daytime land surface temperature. We quantified the temporal dynamics and postdrought recovery of these characteristics for aspen forests experiencing severe drought-induced mortality in the San Juan National Forest in southwestern Colorado, USA. We partitioned forests into three categories from healthy to severe mortality (Healthy, Intermediate, and Die-off) by referring to field observations of aspen canopy mortality and live aboveground biomass losses. The vegetation cover of die-off areas in 2011 (26.9% of the aspen forest) was significantly different compared to predrought conditions (decrease of 7.4% of the green vegetation cover and increase of 12.1% of the brown vegetation cover compared to 1999). The surface brightness of the study region 9 years after drought however was comparable to predrought estimates (12.7-13.7%). Postdrought brightness was potentially influenced by understory shrubs, since they became the top layer green canopies in disturbed sites from a satellite's point of view. Satellite evidence also showed that the differences of land surface temperature among the three groups increased substantially (≥45%) after drought, possibly due to the reduction of plant evapotranspiration in the Intermediate and Die-off sites. Our results suggest that the mortality-affected systems have not recovered in terms of the surface biophysical properties. We also find that the temporal dynamics of vegetation cover holds

  13. Using SMOS brightness temperature and derived surface-soil moisture to characterize surface conditions and validate land surface models.

    Science.gov (United States)

    Polcher, Jan; Barella-Ortiz, Anaïs; Piles, Maria; Gelati, Emiliano; de Rosnay, Patricia

    2017-04-01

    The SMOS satellite, operated by ESA, observes the surface in the L-band. On continental surface these observations are sensitive to moisture and in particular surface-soil moisture (SSM). In this presentation we will explore how the observations of this satellite can be exploited over the Iberian Peninsula by comparing its results with two land surface models : ORCHIDEE and HTESSEL. Measured and modelled brightness temperatures show a good agreement in their temporal evolution, but their spatial structures are not consistent. An empirical orthogonal function analysis of the brightness temperature's error identifies a dominant structure over the south-west of the Iberian Peninsula which evolves during the year and is maximum in autumn and winter. Hypotheses concerning forcing-induced biases and assumptions made in the radiative transfer model are analysed to explain this inconsistency, but no candidate is found to be responsible for the weak spatial correlations. The analysis of spatial inconsistencies between modelled and measured TBs is important, as these can affect the estimation of geophysical variables and TB assimilation in operational models, as well as result in misleading validation studies. When comparing the surface-soil moisture of the models with the product derived operationally by ESA from SMOS observations similar results are found. The spatial correlation over the IP between SMOS and ORCHIDEE SSM estimates is poor (ρ 0.3). A single value decomposition (SVD) analysis of rainfall and SSM shows that the co-varying patterns of these variables are in reasonable agreement between both products. Moreover the first three SVD soil moisture patterns explain over 80% of the SSM variance simulated by the model while the explained fraction is only 52% of the remotely sensed values. These results suggest that the rainfall-driven soil moisture variability may not account for the poor spatial correlation between SMOS and ORCHIDEE products. Other reasons have to

  14. Seemingly divergent sea surface temperature proxy records in the central Mediterranean during the last deglaciation

    Directory of Open Access Journals (Sweden)

    M.-A. Sicre

    2013-06-01

    Full Text Available Sea surface temperatures (SSTs were reconstructed over the last 25 000 yr using alkenone paleothermometry and planktonic foraminifera assemblages from two cores of the central Mediterranean Sea: the MD04-2797 core (Siculo–Tunisian channel and the MD90-917 core (South Adriatic Sea. Comparison of the centennial scale structure of the two temperature signals during the last deglaciation period reveals significant differences in timing and amplitude. We suggest that seasonal changes likely account for seemingly proxy record divergences during abrupt transitions from glacial to interglacial climates and for the apparent short duration of the Younger Dryas (YD depicted by the alkenone time series, a feature that has already been stressed in earlier studies on the Mediterranean deglaciation.

  15. Simulation of land surface temperatures: comparison of two climate models and satellite retrievals

    Directory of Open Access Journals (Sweden)

    J. M. Edwards

    2009-03-01

    Full Text Available Recently there has been significant progress in the retrieval of land surface temperature from satellite observations. Satellite retrievals of surface temperature offer several advantages, including broad spatial coverage, and such data are potentially of great value in assessing general circulation models of the atmosphere. Here, retrievals of the land surface temperature over the contiguous United States are compared with simulations from two climate models. The models generally simulate the diurnal range realistically, but show significant warm biases during the summer. The models' diurnal cycle of surface temperature is related to their surface flux budgets. Differences in the diurnal cycle of the surface flux budget between the models are found to be more pronounced than those in the diurnal cycle of surface temperature.

  16. Effect of treatment temperature on surface wettability of methylcyclosiloxane layer formed by chemical vapor deposition

    Science.gov (United States)

    Ishizaki, Takahiro; Sasagawa, Keisuke; Furukawa, Takuya; Kumagai, Sou; Yamamoto, Erina; Chiba, Satoshi; Kamiyama, Naosumi; Kiguchi, Takayoshi

    2016-08-01

    The surface wettability of the native Si oxide surfaces were tuned by chemical adsorption of 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) molecules through thermal CVD method at different temperature. Water contact angle measurements revealed that the water contact angles of the TMCTS-modified Si oxide surfaces at the temperature of 333-373 K were found to be in the range of 92 ± 2-102 ± 2°. The advancing and receding water contact angle of the surface prepared at 333 K were found to be 97 ± 2/92 ± 2°, showing low contact angle hysteresis surface. The water contact angles of the surfaces prepared at the temperature of 373-413 K increased with an increase in the treatment temperature. When the treatment temperature was more than 423 K, the water contact angles of TMCTS-modified surfaces were found to become more than 150°, showing superhydrophobic surface. AFM study revealed that the surface roughness of the TMCTS-modified surface increased with an increase in the treatment temperature. This geometric morphology enhanced the surface hydrophobicity. The surface roughness could be fabricated due to the hydrolysis/condensation reactions in the gas phase during CVD process. The effect of the treatment temperature on the reactivity of the TMCTS molecules were also investigated using a thermogravimetric analyzer.

  17. Influence of particle flux density and temperature on surface modifications of tungsten and deuterium retention

    Energy Technology Data Exchange (ETDEWEB)

    Buzi, Luxherta, E-mail: l.buzi@fz-juelich.de [Ghent University, Department of Applied Physics, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Institut für Energie und Klimaforschung – Plasmaphysik, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany); Université de Lorraine, Institut Jean Lamour, CNRS UMR 7198, Bvd. des Aiguillettes, F-54506 Vandoeuvre (France); Temmerman, Greg De [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Unterberg, Bernhard; Reinhart, Michael; Litnovsky, Andrey; Philipps, Volker [Institut für Energie und Klimaforschung – Plasmaphysik, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany); Oost, Guido Van [Ghent University, Department of Applied Physics, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); Möller, Sören [Institut für Energie und Klimaforschung – Plasmaphysik, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany)

    2014-12-15

    Systematic study of deuterium irradiation effects on tungsten was done under ITER – relevant high particle flux density, scanning a broad surface temperature range. Polycrystalline ITER – like grade tungsten samples were exposed in linear plasma devices to two different ranges of deuterium ion flux densities (high: 3.5–7 · 10{sup 23} D{sup +}/m{sup 2} s and low: 9 · 10{sup 21} D{sup +}/m{sup 2} s). Particle fluence and ion energy, respectively 10{sup 26} D{sup +}/m{sup 2} and ∼38 eV were kept constant in all cases. The experiments were performed at three different surface temperatures 530 K, 630 K and 870 K. Experimental results concerning the deuterium retention and surface modifications of low flux exposure confirmed previous investigations. At temperatures 530 K and 630 K, deuterium retention was higher at lower flux density due to the longer exposure time (steady state plasma operation) and a consequently deeper diffusion range. At 870 K, deuterium retention was found to be higher at high flux density according to the thermal desorption spectroscopy (TDS) measurements. While blisters were completely absent at low flux density, small blisters of about 40–50 nm were formed at high flux density exposure. At the given conditions, a relation between deuterium retention and blister formation has been found which has to be considered in addition to deuterium trapping in defects populated by diffusion.

  18. Multiyear predictability of Northern Hemisphere surface air temperature in the Kiel Climate Model

    Science.gov (United States)

    Wu, Y.; Latif, M.; Park, W.

    2016-08-01

    The multiyear predictability of Northern Hemisphere surface air temperature (SAT) is examined in a multi-millennial control integration of the Kiel Climate Model, a coupled ocean-atmosphere-sea ice general circulation model. A statistical method maximizing average predictability time (APT) is used to identify the most predictable SAT patterns in the model. The two leading APT modes are much localized and the physics are discussed that give rise to the enhanced predictability of SAT in these limited regions. Multiyear SAT predictability exists near the sea ice margin in the North Atlantic and mid-latitude North Pacific sector. Enhanced predictability in the North Atlantic is linked to the Atlantic Multidecadal Oscillation and to the sea ice changes. In the North Pacific, the most predictable SAT pattern is characterized by a zonal band in the western and central mid-latitude Pacific. This pattern is linked to the Pacific Decadal Oscillation, which drives sea surface temperature anomalies. The temperature anomalies subduct into deeper ocean layers and re-emerge at the sea surface during the following winters, providing multiyear memory. Results obtained from the Coupled Model Intercomparison Project Phase 5 ensemble yield similar APT modes. Overall, the results stress the importance of ocean dynamics in enhancing predictability in the atmosphere.

  19. The magnitudes and timescales of global mean surface temperature feedbacks in climate models

    Directory of Open Access Journals (Sweden)

    A. Jarvis

    2011-12-01

    Full Text Available Because of the fundamental role feedbacks play in determining the response of surface temperature to perturbations in radiative forcing, it is important we understand the dynamic characteristics of these feedbacks. Rather than attribute the aggregate surface temperature feedback to particular physical processes, this paper adopts a linear systems approach to investigate the partitioning with respect to the timescale of the feedbacks regulating global mean surface temperature in climate models. The analysis reveals that there is a dominant net negative feedback realised on an annual timescale and that this is partially attenuated by a spectrum of positive feedbacks with characteristic timescales in the range 10 to 1000 yr. This attenuation was composed of two discrete phases which are attributed to the equilibration of "diffusive – mixed layer" and "circulatory – deep ocean" ocean heat uptake. The diffusive equilibration was associated with time constants on the decadal timescale and accounted for approximately 75 to 80 percent of the overall ocean heat feedback, whilst the circulatory equilibration operated on a centennial timescale and accounted for the remaining 20 to 25 percent of the response. This suggests that the dynamics of the transient ocean heat uptake feedback first discussed by Baker and Roe (2009 tends to be dominated by loss of diffusive heat uptake in climate models, rather than circulatory deep ocean heat equilibration.

  20. GHRSST Level 2P Global skin Sea Surface Temperature from the Infrared Atmospheric Sounding Interferometer (IASI) on the Metop-B satellite (GDS V2) produced by OSI SAF (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in real-time...