Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC MELLON in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1978-06-02 to 1978-08-10 (NODC Accession 7800664)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USCGC MELLON in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Coast Guard...

Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC INGHAM in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1974-04-14 to 1974-05-14 (NODC Accession 7400400)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USCGC INGHAM in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by US Coast Guard from...

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1975-11-20 to 1975-12-09 (NODC Accession 7600702)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1970-07-12 to 1972-11-04 (NODC Accession 7500783)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1975-07-27 to 1975-09-05 (NODC Accession 7501077)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the South Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1975-04-07 to 1975-04-19 (NODC Accession 7600703)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Temperature profiles from expendable bathythermograph (XBT) casts from the USNS SILAS BENT in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1977-03-04 to 1977-03-27 (NODC Accession 7700351)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USNS SILAS BENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Navy; Naval...

Temperature profiles from expendable bathythermograph (XBT) casts from the BARTLETT and Other Platforms in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1974-03-14 to 1974-05-04 (NODC Accession 7400432)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the BARTLETT and Other Platforms in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the...

Ocean Data Interoperability Platform (ODIP): using regional data systems for global ocean research

Science.gov (United States)

Schaap, D.; Thijsse, P.; Glaves, H.

2017-12-01

Ocean acidification, loss of coral reefs, sustainable exploitation of the marine environment are just a few of the challenges researchers around the world are currently attempting to understand and address. However, studies of these ecosystem level challenges are impossible unless researchers can discover and re-use the large volumes of interoperable multidisciplinary data that are currently only accessible through regional and global data systems that serve discreet, and often discipline specific, user communities. The plethora of marine data systems currently in existence are also using different standards, technologies and best practices making re-use of the data problematic for those engaged in interdisciplinary marine research. The Ocean Data Interoperability Platform (ODIP) is responding to this growing demand for discoverable, accessible and reusable data by establishing the foundations for a common global framework for marine data management. But creation of such an infrastructure is a major undertaking, and one that needs to be achieved in part by establishing different levels of interoperability across existing regional and global marine e-infrastructures. Workshops organised by ODIP II facilitate dialogue between selected regional and global marine data systems in an effort to identify potential solutions that integrate these marine e-infrastructures. The outcomes of these discussions have formed the basis for a number of prototype development tasks that aim to demonstrate effective sharing of data across multiple data systems, and allow users to access data from more than one system through a single access point. The ODIP II project is currently developing four prototype solutions that are establishing interoperability between selected regional marine data management infrastructures in Europe, the USA, Canada and Australia, and with the global POGO, IODE Ocean Data Portal (ODP) and GEOSS systems. The potential impact of implementing these solutions for

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1971-01-04 to 18 January 197104 January (NODC Accession 7600707)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the North/South Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1972-03-11 to 1974-12-02 (NODC Accession 7500273)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming

Science.gov (United States)

Huang, Ping; Lin, I. -I; Chou, Chia; Huang, Rong-Hui

2015-01-01

Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas. PMID:25982028

Temperature profiles from expendable bathythermograph (XBT) casts from NOAA Ship RAINIER in the Coastal Waters of SE Alaska/British Columbia and North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1978-08-24 to 1978-08-28 (NODC Accession 7800691)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from NOAA Ship RAINIER in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean...

Going with the flow: the role of ocean circulation in global marine ecosystems under a changing climate.

Science.gov (United States)

van Gennip, Simon J; Popova, Ekaterina E; Yool, Andrew; Pecl, Gretta T; Hobday, Alistair J; Sorte, Cascade J B

2017-07-01

Ocean warming, acidification, deoxygenation and reduced productivity are widely considered to be the major stressors to ocean ecosystems induced by emissions of CO 2 . However, an overlooked stressor is the change in ocean circulation in response to climate change. Strong changes in the intensity and position of the western boundary currents have already been observed, and the consequences of such changes for ecosystems are beginning to emerge. In this study, we address climatically induced changes in ocean circulation on a global scale but relevant to propagule dispersal for species inhabiting global shelf ecosystems, using a high-resolution global ocean model run under the IPCC RCP 8.5 scenario. The ¼ degree model resolution allows improved regional realism of the ocean circulation beyond that of available CMIP5-class models. We use a Lagrangian approach forced by modelled ocean circulation to simulate the circulation pathways that disperse planktonic life stages. Based on trajectory backtracking, we identify present-day coastal retention, dominant flow and dispersal range for coastal regions at the global scale. Projecting into the future, we identify areas of the strongest projected circulation change and present regional examples with the most significant modifications in their dominant pathways. Climatically induced changes in ocean circulation should be considered as an additional stressor of marine ecosystems in a similar way to ocean warming or acidification. © 2017 John Wiley & Sons Ltd.

Building a Global Ocean Science Education Network

Science.gov (United States)

Scowcroft, G. A.; Tuddenham, P. T.; Pizziconi, R.

2016-02-01

It is imperative for ocean science education to be closely linked to ocean science research. This is especially important for research that addresses global concerns that cross national boundaries, including climate related issues. The results of research on these critical topics must find its way to the public, educators, and students of all ages around the globe. To facilitate this, opportunities are needed for ocean scientists and educators to convene and identify priorities and strategies for ocean science education. On June 26 and 27, 2015 the first Global Ocean Science Education (GOSE) Workshop was convened in the United States at the University of Rhode Island Graduate School of Oceanography. The workshop, sponsored by the Consortium for Ocean Science Exploration and Engagement (COSEE) and the College of Exploration, had over 75 participants representing 15 nations. The workshop addressed critical global ocean science topics, current ocean science research and education priorities, advanced communication technologies, and leveraging international ocean research technologies. In addition, panels discussed elementary, secondary, undergraduate, graduate, and public education across the ocean basins with emphasis on opportunities for international collaboration. Special presentation topics included advancements in tropical cyclone forecasting, collaborations among Pacific Islands, ocean science for coastal resiliency, and trans-Atlantic collaboration. This presentation will focus on workshop outcomes as well as activities for growing a global ocean science education network. A summary of the workshop report will also be provided. The dates and location for the 2016 GOES Workshop will be announced. See http://www.coexploration.net/gose/index.html

HYbrid Coordinate Ocean Model (HYCOM): Global

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Global HYbrid Coordinate Ocean Model (HYCOM) and U.S. Navy Coupled Ocean Data Assimilation (NCODA) 3-day, daily forecast at approximately 9-km (1/12-degree)...

Global projections of extreme sea levels in view of climate change

Science.gov (United States)

Vousdoukas, M. I.; Feyen, L.; Voukouvalas, E.; Mentaschi, L.; Verlaan, M.; Jevrejeva, S.; Jackson, L. P.

2017-12-01

Global warming is expected to drive increasing extreme sea levels (ESLs) and flood risk along the world's coasts. The present contribution aims to present global ESL projections obtained by combining dynamic simulations of all the major ESL components during the present century, considering the latest CMIP5 projections for RCP4.5 and RCP8.5. Baseline values are obtained combining global re-analyses of tides, waves, and storm surges, including the effects of tropical cyclones. The global average RSLR is projected around 20 and 24 cm by the 2050s under RCP4.5 and RCP8.5, respectively and is projected to reach 46 and 67 cm by the year 2100. The largest increases in MSL are projected along the South Pacific, Australia and West Africa, while the smaller RSLR is projected around East North America, and Europe. Contributions from waves and storm surges show a very weak increasing global trend, which becomes statistically significant only towards the end of the century and under RCP8.5. However, for areas like the East China Sea, Sea of Japan, Alaska, East Bering Sea, as well as the Southern Ocean, climate extremes could increase up to 15%. By the end of this century the 100-year event ESL along the world's coastlines will on average increase by 48 cm for RCP4.5 and 75 cm for RCP8.5. The strongest rise is projected along the Southern Ocean exceeding 1 m under RCP8.5 by the end of the century. Increase exceeding 80 cm is projected for East Asia, West North America, East South America, and the North Indian Ocean. Considering always the business as usual and the year 2100, the lowest increase in ESL100 is projected along the East North America and Europe (below 50 cm). The present findings indicate that, under both RCPs, by the year 2050 the present day 100-year event will occur every 5 years along a large part of the tropics, rendering coastal zones exposed to intermittent flood hazard.

Global Precipitation Climatology Project (GPCP) - Daily, Version 1.2

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Global Precipitation Climatology Project (GPCP) comprises a total of 27 products. The Version 1.2 Daily product covers the period October 1998 to the present,...

Global Precipitation Climatology Project (GPCP) - Pentad, Version 2.2

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Global Precipitation Climatology Project (GPCP) comprises a total of 27 products. The Version 2.2 Pentad product covers the period January 1979 to the present,...

Uncertainty in Indian Ocean Dipole response to global warming: the role of internal variability

Science.gov (United States)

Hui, Chang; Zheng, Xiao-Tong

2018-01-01

The Indian Ocean Dipole (IOD) is one of the leading modes of interannual sea surface temperature (SST) variability in the tropical Indian Ocean (TIO). The response of IOD to global warming is quite uncertain in climate model projections. In this study, the uncertainty in IOD change under global warming, especially that resulting from internal variability, is investigated based on the community earth system model large ensemble (CESM-LE). For the IOD amplitude change, the inter-member uncertainty in CESM-LE is about 50% of the intermodel uncertainty in the phase 5 of the coupled model intercomparison project (CMIP5) multimodel ensemble, indicating the important role of internal variability in IOD future projection. In CESM-LE, both the ensemble mean and spread in mean SST warming show a zonal positive IOD-like (pIOD-like) pattern in the TIO. This pIOD-like mean warming regulates ocean-atmospheric feedbacks of the interannual IOD mode, and weakens the skewness of the interannual variability. However, as the changes in oceanic and atmospheric feedbacks counteract each other, the inter-member variability in IOD amplitude change is not correlated with that of the mean state change. Instead, the ensemble spread in IOD amplitude change is correlated with that in ENSO amplitude change in CESM-LE, reflecting the close inter-basin relationship between the tropical Pacific and Indian Ocean in this model.

Ocean Data Interoperability Platform (ODIP): developing a common framework for marine data management on a global scale

Science.gov (United States)

Schaap, Dick M. A.; Glaves, Helen

2016-04-01

Europe, the USA, and Australia are making significant progress in facilitating the discovery, access and long term stewardship of ocean and marine data through the development, implementation, population and operation of national, regional or international distributed ocean and marine observing and data management infrastructures such as SeaDataNet, EMODnet, IOOS, R2R, and IMOS. All of these developments are resulting in the development of standards and services implemented and used by their regional communities. The Ocean Data Interoperability Platform (ODIP) project is supported by the EU FP7 Research Infrastructures programme, National Science Foundation (USA) and Australian government and has been initiated 1st October 2012. Recently the project has been continued as ODIP II for another 3 years with EU HORIZON 2020 funding. ODIP includes all the major organisations engaged in ocean data management in EU, US, and Australia. ODIP is also supported by the IOC-IODE, closely linking this activity with its Ocean Data Portal (ODP) and Ocean Data Standards Best Practices (ODSBP) projects. The ODIP platform aims to ease interoperability between the regional marine data management infrastructures. Therefore it facilitates an organised dialogue between the key infrastructure representatives by means of publishing best practice, organising a series of international workshops and fostering the development of common standards and interoperability solutions. These are evaluated and tested by means of prototype projects. The presentation will give further background on the ODIP projects and the latest information on the progress of three prototype projects addressing: 1. establishing interoperability between the regional EU, USA and Australia data discovery and access services (SeaDataNet CDI, US NODC, and IMOS MCP) and contributing to the global GEOSS and IODE-ODP portals; 2. establishing interoperability between cruise summary reporting systems in Europe, the USA and

Future habitat suitability for coral reef ecosystems under global warming and ocean acidification

OpenAIRE

Couce, Elena M; Ridgwell, Andy J; Hendy, Erica

2013-01-01

Rising atmospheric CO2 concentrations are placing spatially divergent stresses on the world’s tropical coral reefs through increasing ocean surface temperatures and ocean acidification. We show how these two stressors combine to alter the global habitat suitability for shallow coral reef ecosystems, using statistical Bioclimatic Envelope Models rather than basing projections on any a priori assumptions of physiological tolerances or fixed thresholds. We apply two different modeling approaches...

Variability in global ocean phytoplankton distribution over 1979-2007

Science.gov (United States)

Masotti, I.; Alvain, S.; Moulin, C.; Antoine, D.

2009-04-01

Recently, reanalysis of long-term ocean color data (CZCS and SeaWiFS; Antoine et al., 2005) has shown that world ocean average phytoplankton chlorophyll levels show an increase of 20% over the last two decades. It is however unknown whether this increase is associated with a change in the distribution of phytoplankton groups or if it simply corresponds to an increase of the productivity. Within the framework of the GLOBPHY project, the distribution of the phytoplankton groups was monitored by applying the PHYSAT method (Alvain et al., 2005) to the historical ocean color data series from CZCS, OCTS and SeaWiFS sensors. The PHYSAT algorithm allows identification of several phytoplankton, like nanoeucaryotes, prochlorococcus, synechococcus and diatoms. Because both sensors (OCTS-SeaWiFS) are very similar, OCTS data were processed with the standard PHYSAT algorithm to cover the 1996-1997 period during which a large El Niño event occurred, just before the SeaWiFS era. Our analysis of this dataset (1996-2006) evidences a strong variability in the distribution of phytoplankton groups at both regional and global scales. In the equatorial region (0°-5°S), a three-fold increase of nanoeucaryotes frequency was detected in opposition to a two-fold decrease of synechococcus during the early stages of El Niño conditions (May-June 1997, OCTS). The impact of this El Niño is however not confined to the Equatorial Pacific and has affected the global ocean. The processing of CZCS data with PHYSAT has required several adaptations of this algorithm due to the lower performances and the reduced number of spectral bands of the sensor. Despites higher uncertainties, the phytoplankton groups distribution obtained with CZCS is globally consistent with that of SeaWiFS. A comparison of variability in global phytoplankton distribution between 1979-1982 (CZCS) and 1999-2002 (SeaWiFS) suggests an increase in nanoeucaryotes at high latitudes (>40°) and in the equatorial region (10°S-10�

Exploring the sensitivity of global ocean circulation to future ice loss from Antarctica

Energy Technology Data Exchange (ETDEWEB)

Condron, Alan [Univ. of Massachusetts, Amherst, MA (United States); Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA (United States)

2017-09-30

The sensitivity of the global ocean circulation and climate to large increases in iceberg calving and meltwater discharges from the Antarctic Ice Sheet (AIS) are rarely studied and poorly understood. The requirement to investigate this topic is heightened by growing evidence that the West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse on multidecadal-to-centennial timescales. Observations collected over the last 30 years indicate that the WAIS is now losing mass at an accelerated and that a collapse may have already begun in the Amundsen Sea sector. In addition, some recent future model simulations of the AIS show the potential for rapid ice sheet retreat in the next 50 – 300 years. Such a collapse would be associated with the discharge of enormous volumes of ice and meltwater to the Southern Ocean. This project funds PI Condron to begin assessing the sensitivity of the global ocean circulation to projected increases in meltwater discharge and iceberg calving from the AIS for the next 50 – 100 years. A series of climate model simulations will determine changes in ocean circulation and temperature at the ice sheet grounding line, the role of mesoscale ocean eddies in mixing and transporting freshwater away from the continent to deep water formation regions, and the likely impact on the northward transport of heat to Europe and North America.

Improved Global Ocean Color Using Polymer Algorithm

Science.gov (United States)

Steinmetz, Francois; Ramon, Didier; Deschamps, ierre-Yves; Stum, Jacques

2010-12-01

A global ocean color product has been developed based on the use of the POLYMER algorithm to correct atmospheric scattering and sun glint and to process the data to a Level 2 ocean color product. Thanks to the use of this algorithm, the coverage and accuracy of the MERIS ocean color product have been significantly improved when compared to the standard product, therefore increasing its usefulness for global ocean monitor- ing applications like GLOBCOLOUR. We will present the latest developments of the algorithm, its first application to MODIS data and its validation against in-situ data from the MERMAID database. Examples will be shown of global NRT chlorophyll maps produced by CLS with POLYMER for operational applications like fishing or oil and gas industry, as well as its use by Scripps for a NASA study of the Beaufort and Chukchi seas.

Observationally-based Metrics of Ocean Carbon and Biogeochemical Variables are Essential for Evaluating Earth System Model Projections

Science.gov (United States)

Russell, J. L.; Sarmiento, J. L.

2017-12-01

The Southern Ocean is central to the climate's response to increasing levels of atmospheric greenhouse gases as it ventilates a large fraction of the global ocean volume. Global coupled climate models and earth system models, however, vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic forcing. Due to its complex water-mass structure and dynamics, Southern Ocean carbon and heat uptake depend on a combination of winds, eddies, mixing, buoyancy fluxes and topography. Understanding how the ocean carries heat and carbon into its interior and how the observed wind changes are affecting this uptake is essential to accurately projecting transient climate sensitivity. Observationally-based metrics are critical for discerning processes and mechanisms, and for validating and comparing climate models. As the community shifts toward Earth system models with explicit carbon simulations, more direct observations of important biogeochemical parameters, like those obtained from the biogeochemically-sensored floats that are part of the Southern Ocean Carbon and Climate Observations and Modeling project, are essential. One goal of future observing systems should be to create observationally-based benchmarks that will lead to reducing uncertainties in climate projections, and especially uncertainties related to oceanic heat and carbon uptake.

Decadal Changes in Global Ocean Annual Primary Production

Science.gov (United States)

Gregg, Watson; Conkright, Margarita E.; Behrenfeld, Michael J.; Ginoux, Paul; Casey, Nancy W.; Koblinsky, Chester J. (Technical Monitor)

2002-01-01

The Sea-viewing Wide Field-of-View Sensor (SeaWiFS) has produced the first multi-year time series of global ocean chlorophyll observations since the demise of the Coastal Zone Color Scanner (CZCS) in 1986. Global observations from 1997-present from SeaWiFS combined with observations from 1979-1986 from the CZCS should in principle provide an opportunity to observe decadal changes in global ocean annual primary production, since chlorophyll is the primary driver for estimates of primary production. However, incompatibilities between algorithms have so far precluded quantitative analysis. We have developed and applied compatible processing methods for the CZCS, using modern advances in atmospheric correction and consistent bio-optical algorithms to advance the CZCS archive to comparable quality with SeaWiFS. We applied blending methodologies, where in situ data observations are incorporated into the CZCS and SeaWiFS data records, to provide improvement of the residuals. These re-analyzed, blended data records provide maximum compatibility and permit, for the first time, a quantitative analysis of the changes in global ocean primary production in the early-to-mid 1980's and the present, using synoptic satellite observations. An intercomparison of the global and regional primary production from these blended satellite observations is important to understand global climate change and the effects on ocean biota. Photosynthesis by chlorophyll-containing phytoplankton is responsible for biotic uptake of carbon in the oceans and potentially ultimately from the atmosphere. Global ocean annual primary decreased from the CZCS record to SeaWiFS, by nearly 6% from the early 1980s to the present. Annual primary production in the high latitudes was responsible for most of the decadal change. Conversely, primary production in the low latitudes generally increased, with the exception of the tropical Pacific. The differences and similarities of the two data records provide evidence

Temperature profiles from expendable bathythermograph (XBT) casts from NOAA Ship RAINIER in the Coastal Waters of California in support of the Integrated Global Ocean Services System (IGOSS) project from 1975-09-12 to 1975-09-15 (NODC Accession 7500938)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from NOAA Ship RAINIER in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean...

Isolating Tracers of Phytoplankton with Allometric Zooplankton (TOPAZ) from Modular Ocean Model (MOM5) to Couple it with a Global Ocean Model

Science.gov (United States)

Jung, H. C.; Moon, B. K.; Wie, J.; Park, H. S.; Kim, K. Y.; Lee, J.; Byun, Y. H.

2017-12-01

This research is motivated by a need to develop a new coupled ocean-biogeochemistry model, a key tool for climate projections. The Modular Ocean Model (MOM5) is a global ocean/ice model developed by the Geophysical Fluid Dynamics Laboratory (GFDL) in the US, and it incorporates Tracers of Phytoplankton with Allometric Zooplankton (TOPAZ), which simulates the marine biota associated with carbon cycles. We isolated TOPAZ from MOM5 into a stand-alone version (TOPAZ-SA), and had it receive initial data and ocean physical fields required. Then, its reliability was verified by comparing the simulation results from the TOPAZ-SA with the MOM5/TOPAZ. This stand-alone version of TOPAZ is to be coupled to the Nucleus for European Modelling of the Ocean (NEMO). Here we present the preliminary results. Acknowledgements This research was supported by the project "Research and Development for KMA Weather, Climate, and Earth system Services" (NIMS-2016-3100) of the National Institute of Meteorological Sciences/Korea Meteorological Administration.

Benchmarking the mesoscale variability in global ocean eddy-permitting numerical systems

Science.gov (United States)

Cipollone, Andrea; Masina, Simona; Storto, Andrea; Iovino, Doroteaciro

2017-10-01

The role of data assimilation procedures on representing ocean mesoscale variability is assessed by applying eddy statistics to a state-of-the-art global ocean reanalysis (C-GLORS), a free global ocean simulation (performed with the NEMO system) and an observation-based dataset (ARMOR3D) used as an independent benchmark. Numerical results are computed on a 1/4 ∘ horizontal grid (ORCA025) and share the same resolution with ARMOR3D dataset. This "eddy-permitting" resolution is sufficient to allow ocean eddies to form. Further to assessing the eddy statistics from three different datasets, a global three-dimensional eddy detection system is implemented in order to bypass the need of regional-dependent definition of thresholds, typical of commonly adopted eddy detection algorithms. It thus provides full three-dimensional eddy statistics segmenting vertical profiles from local rotational velocities. This criterion is crucial for discerning real eddies from transient surface noise that inevitably affects any two-dimensional algorithm. Data assimilation enhances and corrects mesoscale variability on a wide range of features that cannot be well reproduced otherwise. The free simulation fairly reproduces eddies emerging from western boundary currents and deep baroclinic instabilities, while underestimates shallower vortexes that populate the full basin. The ocean reanalysis recovers most of the missing turbulence, shown by satellite products , that is not generated by the model itself and consistently projects surface variability deep into the water column. The comparison with the statistically reconstructed vertical profiles from ARMOR3D show that ocean data assimilation is able to embed variability into the model dynamics, constraining eddies with in situ and altimetry observation and generating them consistently with local environment.

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the East Coast - US/Canada in support of the Integrated Global Ocean Services System (IGOSS) project for 1969-07-10 (NODC Accession 7600701)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Enhanced deep ocean ventilation and oxygenation with global warming

Science.gov (United States)

Froelicher, T. L.; Jaccard, S.; Dunne, J. P.; Paynter, D.; Gruber, N.

2014-12-01

Twenty-first century coupled climate model simulations, observations from the recent past, and theoretical arguments suggest a consistent trend towards warmer ocean temperatures and fresher polar surface oceans in response to increased radiative forcing resulting in increased upper ocean stratification and reduced ventilation and oxygenation of the deep ocean. Paleo-proxy records of the warming at the end of the last ice age, however, suggests a different outcome, namely a better ventilated and oxygenated deep ocean with global warming. Here we use a four thousand year global warming simulation from a comprehensive Earth System Model (GFDL ESM2M) to show that this conundrum is a consequence of different rates of warming and that the deep ocean is actually better ventilated and oxygenated in a future warmer equilibrated climate consistent with paleo-proxy records. The enhanced deep ocean ventilation in the Southern Ocean occurs in spite of increased positive surface buoyancy fluxes and a constancy of the Southern Hemisphere westerly winds - circumstances that would otherwise be expected to lead to a reduction in deep ocean ventilation. This ventilation recovery occurs through a global scale interaction of the Atlantic Meridional Overturning Circulation undergoing a multi-centennial recovery after an initial century of transient decrease and transports salinity-rich waters inform the subtropical surface ocean to the Southern Ocean interior on multi-century timescales. The subsequent upwelling of salinity-rich waters in the Southern Ocean strips away the freshwater cap that maintains vertical stability and increases open ocean convection and the formation of Antarctic Bottom Waters. As a result, the global ocean oxygen content and the nutrient supply from the deep ocean to the surface are higher in a warmer ocean. The implications for past and future changes in ocean heat and carbon storage will be discussed.

Global oceanic production of nitrous oxide

Science.gov (United States)

Freing, Alina; Wallace, Douglas W. R.; Bange, Hermann W.

2012-01-01

We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N2O) to estimate the concentration of biologically produced N2O and N2O production rates in the ocean on a global scale. Our approach to estimate the N2O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N2O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N2O are not taken into account in our study. The largest amount of subsurface N2O is produced in the upper 500 m of the water column. The estimated global annual subsurface N2O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr−1. This is in agreement with estimates of the global N2O emissions to the atmosphere and indicates that a N2O source in the mixed layer is unlikely. The potential future development of the oceanic N2O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed. PMID:22451110

Global oceanic production of nitrous oxide.

Science.gov (United States)

Freing, Alina; Wallace, Douglas W R; Bange, Hermann W

2012-05-05

We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N(2)O) to estimate the concentration of biologically produced N(2)O and N(2)O production rates in the ocean on a global scale. Our approach to estimate the N(2)O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N(2)O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N(2)O are not taken into account in our study. The largest amount of subsurface N(2)O is produced in the upper 500 m of the water column. The estimated global annual subsurface N(2)O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr(-1). This is in agreement with estimates of the global N(2)O emissions to the atmosphere and indicates that a N(2)O source in the mixed layer is unlikely. The potential future development of the oceanic N(2)O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed.

State of Climate 2011 - Global Ocean Phytoplankton

Science.gov (United States)

Siegel, D. A.; Antoine, D.; Behrenfeld, M. J.; d'Andon, O. H. Fanton; Fields, E.; Franz, B. A.; Goryl, P.; Maritorena, S.; McClain, C. R.; Wang, M.;

Global Ocean Currents Database (GOCD) (NCEI Accession 0093183)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Global Ocean Currents Database (GOCD) is a collection of quality controlled ocean current measurements such as observed current direction and speed obtained from...

An overview of the SeaWiFS project and strategies for producing a climate research quality global ocean bio-optical time series

Science.gov (United States)

McClain, Charles R.; Feldman, Gene C.; Hooker, Stanford B.

2004-01-01

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Project Office was formally initiated at the NASA Goddard Space Flight Center in 1990. Seven years later, the sensor was launched by Orbital Sciences Corporation under a data-buy contract to provide 5 years of science quality data for global ocean biogeochemistry research. To date, the SeaWiFS program has greatly exceeded the mission goals established over a decade ago in terms of data quality, data accessibility and usability, ocean community infrastructure development, cost efficiency, and community service. The SeaWiFS Project Office and its collaborators in the scientific community have made substantial contributions in the areas of satellite calibration, product validation, near-real time data access, field data collection, protocol development, in situ instrumentation technology, operational data system development, and desktop level-0 to level-3 processing software. One important aspect of the SeaWiFS program is the high level of science community cooperation and participation. This article summarizes the key activities and approaches the SeaWiFS Project Office pursued to define, achieve, and maintain the mission objectives. These achievements have enabled the user community to publish a large and growing volume of research such as those contributed to this special volume of Deep-Sea Research. Finally, some examples of major geophysical events (oceanic, atmospheric, and terrestrial) captured by SeaWiFS are presented to demonstrate the versatility of the sensor.

Global warming-induced upper-ocean freshening and the intensification of super typhoons.

Science.gov (United States)

Balaguru, Karthik; Foltz, Gregory R; Leung, L Ruby; Emanuel, Kerry A

2016-11-25

Super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards globally. The violent winds of these storms induce deep mixing of the upper ocean, resulting in strong sea surface cooling and making STYs highly sensitive to ocean density stratification. Although a few studies examined the potential impacts of changes in ocean thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper ocean, caused by greater rainfall in places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper ocean. We further demonstrate that the strengthening effect of this freshening over the period 1961-2008 is ∼53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of ocean temperature changes.

The growth of finfish in global open-ocean aquaculture under climate change.

Science.gov (United States)

Klinger, Dane H; Levin, Simon A; Watson, James R

2017-10-11

Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds-Atlantic salmon ( Salmo salar ), gilthead seabream ( Sparus aurata ) and cobia ( Rachycentron canadum )-is compared across species and regions and with climate change, based on outputs of a high-resolution global climate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses. © 2017 The Author(s).

How does ocean ventilation change under global warming?

Directory of Open Access Journals (Sweden)

A. Gnanadesikan

2007-01-01

Full Text Available Since the upper ocean takes up much of the heat added to the earth system by anthropogenic global warming, one would expect that global warming would lead to an increase in stratification and a decrease in the ventilation of the ocean interior. However, multiple simulations in global coupled climate models using an ideal age tracer which is set to zero in the mixed layer and ages at 1 yr/yr outside this layer show that the intermediate depths in the low latitudes, Northwest Atlantic, and parts of the Arctic Ocean become younger under global warming. This paper reconciles these apparently contradictory trends, showing that the decreases result from changes in the relative contributions of old deep waters and younger surface waters. Implications for the tropical oxygen minimum zones, which play a critical role in global biogeochemical cycling are considered in detail.

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the Caribbean Sea in support of the Integrated Global Ocean Services System (IGOSS) project from 1975-04-28 to 1975-05-08 (NODC Accession 7600704)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

An updated climatology of surface dimethlysulfide concentrations and emission fluxes in the global ocean

Science.gov (United States)

Lana, A.; Bell, T. G.; Simó, R.; Vallina, S. M.; Ballabrera-Poy, J.; Kettle, A. J.; Dachs, J.; Bopp, L.; Saltzman, E. S.; Stefels, J.; Johnson, J. E.; Liss, P. S.

2011-03-01

The potentially significant role of the biogenic trace gas dimethylsulfide (DMS) in determining the Earth's radiation budget makes it necessary to accurately reproduce seawater DMS distribution and quantify its global flux across the sea/air interface. Following a threefold increase of data (from 15,000 to over 47,000) in the global surface ocean DMS database over the last decade, new global monthly climatologies of surface ocean DMS concentration and sea-to-air emission flux are presented as updates of those constructed 10 years ago. Interpolation/extrapolation techniques were applied to project the discrete concentration data onto a first guess field based on Longhurst's biogeographic provinces. Further objective analysis allowed us to obtain the final monthly maps. The new climatology projects DMS concentrations typically in the range of 1-7 nM, with higher levels occurring in the high latitudes, and with a general trend toward increasing concentration in summer. The increased size and distribution of the observations in the DMS database have produced in the new climatology substantially lower DMS concentrations in the polar latitudes and generally higher DMS concentrations in regions that were severely undersampled 10 years ago, such as the southern Indian Ocean. Using the new DMS concentration climatology in conjunction with state-of-the-art parameterizations for the sea/air gas transfer velocity and climatological wind fields, we estimate that 28.1 (17.6-34.4) Tg of sulfur are transferred from the oceans into the atmosphere annually in the form of DMS. This represents a global emission increase of 17% with respect to the equivalent calculation using the previous climatology. This new DMS climatology represents a valuable tool for atmospheric chemistry, climate, and Earth System models.

Global Precipitation Climatology Project (GPCP) Climate Data Record (CDR), Version 2.3 (Monthly)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Global Precipitation Climatology Project (GPCP) consists of monthly satellite-gauge and associated precipitation error estimates and covers the period January...

Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC RUSH in the Coastal Waters of California in support of the Integrated Global Ocean Services System (IGOSS) project from 1973-12-14 to 1973-12-19 (NODC Accession 7400077)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the USCGC RUSH in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Coast Guard...

Sharing Data in the Global Ocean Observing System (Invited)

Science.gov (United States)

Lindstrom, E. J.; McCurdy, A.; Young, J.; Fischer, A. S.

2010-12-01

We examine the evolution of data sharing in the field of physical oceanography to highlight the challenges now before us. Synoptic global observation of the ocean from space and in situ platforms has significantly matured over the last two decades. In the early 1990’s the community data sharing challenges facing the World Ocean Circulation Experiment (WOCE) largely focused on the behavior of individual scientists. Satellite data sharing depended on the policy of individual agencies. Global data sets were delivered with considerable delay and with enormous personal sacrifice. In the 2000’s the requirements for global data sets and sustained observations from the likes of the U.N. Framework Convention on Climate Change have led to data sharing and cooperation at a grander level. It is more effective and certainly more efficient. The Joint WMO/IOC Technical Commission on Oceanography and Marine Meteorology (JCOMM) provided the means to organize many aspects of data collection and data dissemination globally, for the common good. In response the Committee on Earth Observing Satellites organized Virtual Constellations to enable the assembly and sharing of like kinds of satellite data (e.g., sea surface topography, ocean vector winds, and ocean color). Individuals in physical oceanography have largely adapted to the new rigors of sharing data for the common good, and as a result of this revolution new science has been enabled. Primary obstacles to sharing have shifted from the individual level to the national level. As we enter into the 2010’s the demands for ocean data continue to evolve with an expanded requirement for more real-time reporting and broader disciplinary coverage, to answer key scientific and societal questions. We are also seeing the development of more numerous national contributions to the global observing system. The drivers for the establishment of global ocean observing systems are expanding beyond climate to include biological and

Temperature profiles from expendable bathythermograph (XBT) casts from NOAA Ship RAINIER and other platforms in a World-wide distribution in support of the Integrated Global Ocean Services System (IGOSS) project from 1982-10-02 to 1983-03-16 (NODC Accession 8300044)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from NOAA Ship RAINIER and other platforms in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by...

Future habitat suitability for coral reef ecosystems under global warming and ocean acidification.

Science.gov (United States)

Couce, Elena; Ridgwell, Andy; Hendy, Erica J

2013-12-01

Rising atmospheric CO2 concentrations are placing spatially divergent stresses on the world's tropical coral reefs through increasing ocean surface temperatures and ocean acidification. We show how these two stressors combine to alter the global habitat suitability for shallow coral reef ecosystems, using statistical Bioclimatic Envelope Models rather than basing projections on any a priori assumptions of physiological tolerances or fixed thresholds. We apply two different modeling approaches (Maximum Entropy and Boosted Regression Trees) with two levels of complexity (one a simplified and reduced environmental variable version of the other). Our models project a marked temperature-driven decline in habitat suitability for many of the most significant and bio-diverse tropical coral regions, particularly in the central Indo-Pacific. This is accompanied by a temperature-driven poleward range expansion of favorable conditions accelerating up to 40-70 km per decade by 2070. We find that ocean acidification is less influential for determining future habitat suitability than warming, and its deleterious effects are centered evenly in both hemispheres between 5° and 20° latitude. Contrary to expectations, the combined impact of ocean surface temperature rise and acidification leads to little, if any, degradation in future habitat suitability across much of the Atlantic and areas currently considered 'marginal' for tropical corals, such as the eastern Equatorial Pacific. These results are consistent with fossil evidence of range expansions during past warm periods. In addition, the simplified models are particularly sensitive to short-term temperature variations and their projections correlate well with reported locations of bleaching events. Our approach offers new insights into the relative impact of two global environmental pressures associated with rising atmospheric CO2 on potential future habitats, but greater understanding of past and current controls on coral

Temperature profiles from expendable bathythermograph (XBT) casts from the R/V TRIDENT in the East Coast - US/Canada in support of the Integrated Global Ocean Services System (IGOSS) project from 1975-05-25 to 1975-07-10 (NODC Accession 7500782)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R/V TRIDENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the University of...

Downscaling the climate change for oceans around Australia

Directory of Open Access Journals (Sweden)

M. A. Chamberlain

2012-09-01

Full Text Available At present, global climate models used to project changes in climate poorly resolve mesoscale ocean features such as boundary currents and eddies. These missing features may be important to realistically project the marine impacts of climate change. Here we present a framework for dynamically downscaling coarse climate change projections utilising a near-global ocean model that resolves these features in the Australasian region, with coarser resolution elsewhere.

A time-slice projection for a 2060s ocean was obtained by adding climate change anomalies to initial conditions and surface fluxes of a near-global eddy-resolving ocean model. Climate change anomalies are derived from the differences between present and projected climates from a coarse global climate model. These anomalies are added to observed fields, thereby reducing the effect of model bias from the climate model.

The downscaling model used here is ocean-only and does not include the effects that changes in the ocean state will have on the atmosphere and air–sea fluxes. We use restoring of the sea surface temperature and salinity to approximate real-ocean feedback on heat flux and to keep the salinity stable. Extra experiments with different feedback parameterisations are run to test the sensitivity of the projection. Consistent spatial differences emerge in sea surface temperature, salinity, stratification and transport between the downscaled projections and those of the climate model. Also, the spatial differences become established rapidly (< 3 yr, indicating the importance of mesoscale resolution. However, the differences in the magnitude of the difference between experiments show that feedback of the ocean onto the air–sea fluxes is still important in determining the state of the ocean in these projections.

Until such a time when it is feasible to regularly run a global climate model with eddy resolution, our framework for ocean climate change

A Southern Ocean variability study using the Argo-based Model for Investigation of the Global Ocean (AMIGO)

Science.gov (United States)

Lebedev, Konstantin

2017-04-01

The era of satellite observations of the ocean surface that started at the end of the 20th century and the development of the Argo project in the first years of the 21st century, designed to collect information of the upper 2000 m of the ocean using satellites, provides unique opportunities for continuous monitoring of the Global Ocean state. Starting from 2005, measurements with the Argo floats have been performed over the majority of the World Ocean. In November 2007, the Argo program reached coverage of 3000 simultaneously operating floats (one float in a three-degree square) planned during the development of the program. Currently, 4000 Argo floats autonomously profile the upper 2000-m water column of the ocean from Antarctica to Spitsbergen increasing World Ocean temperature and salinity databases by 12000 profiles per month. This makes it possible to solve problems on reconstructing and monitoring the ocean state on an almost real-time basis, study the ocean dynamics, obtain reasonable estimates of the climatic state of the ocean in the last decade and estimate existing intraclimatic trends. We present the newly developed Argo-Based Model for Investigation of the Global Ocean (AMIGO), which consists of a block for variational interpolation of the profiles of drifting Argo floats to a regular grid and a block for model hydrodynamic adjustment of variationally interpolated fields. Such a method makes it possible to obtain a full set of oceanographic characteristics - temperature, salinity, density, and current velocity - using irregularly located Argo measurements (the principle of the variational interpolation technique entails minimization of the misfit between the interpolated fields defined on the regular grid and irregularly distributed data; hence the optimal solution passes as close to the data as possible). The simulations were performed for the entire globe limited in the north by 85.5° N using 1° grid spacing in both longitude and latitude. At the

Distribution of mesozooplankton biomass in the global ocean

Directory of Open Access Journals (Sweden)

R. Moriarty

2013-02-01

Full Text Available Mesozooplankton are cosmopolitan within the sunlit layers of the global ocean. They are important in the pelagic food web, having a significant feedback to primary production through their consumption of phytoplankton and microzooplankton. In many regions of the global ocean, they are also the primary contributors to vertical particle flux in the oceans. Through both they affect the biogeochemical cycling of carbon and other nutrients in the oceans. Little, however, is known about their global distribution and biomass. While global maps of mesozooplankton biomass do exist in the literature, they are usually in the form of hand-drawn maps for which the original data associated with these maps are not readily available. The dataset presented in this synthesis has been in development since the late 1990s, is an integral part of the Coastal and Oceanic Plankton Ecology, Production, and Observation Database (COPEPOD, and is now also part of a wider community effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. A total of 153 163 biomass values were collected, from a variety of sources, for mesozooplankton. Of those 2% were originally recorded as dry mass, 26% as wet mass, 5% as settled volume, and 68% as displacement volume. Using a variety of non-linear biomass conversions from the literature, the data have been converted from their original units to carbon biomass. Depth-integrated values were then used to calculate an estimate of mesozooplankton global biomass. Global epipelagic mesozooplankton biomass, to a depth of 200 m, had a mean of 5.9 μg C L−1, median of 2.7 μg C L−1 and a standard deviation of 10.6 μg C L−1. The global annual average estimate of mesozooplankton in the top 200 m, based on the median value, was 0.19 Pg C. Biomass was highest in the Northern Hemisphere, and there were slight decreases from polar oceans (40�

Bacteria in the greenhouse: Modeling the role of oceanic plankton in the global carbon cycle

International Nuclear Information System (INIS)

Ducklow, H.W.; Fasham, M.J.R.

1992-01-01

To plan effectively to deal with the greenhouse effect, a fundamental understanding is needed of the biogeochemical and physical machinery that cycles carbon in the global system; in addition, models are needed of the carbon cycle to project the effects of increasing carbon dioxide. In this chapter, a description is given of efforts to simulate the cycling of carbon and nitrogen in the upper ocean, concentrating on the model's treatment of marine phytoplankton, and what it reveals of their role in the biogeochemical cycling of carbon between the ocean and atmosphere. The focus is on the upper ocean because oceanic uptake appears to regulate the level of carbon dioxide in the atmosphere

Experimental strategies to assess the biological ramifications of multiple drivers of global ocean change-A review.

Science.gov (United States)

Boyd, Philip W; Collins, Sinead; Dupont, Sam; Fabricius, Katharina; Gattuso, Jean-Pierre; Havenhand, Jonathan; Hutchins, David A; Riebesell, Ulf; Rintoul, Max S; Vichi, Marcello; Biswas, Haimanti; Ciotti, Aurea; Gao, Kunshan; Gehlen, Marion; Hurd, Catriona L; Kurihara, Haruko; McGraw, Christina M; Navarro, Jorge M; Nilsson, Göran E; Passow, Uta; Pörtner, Hans-Otto

2018-06-01

Marine life is controlled by multiple physical and chemical drivers and by diverse ecological processes. Many of these oceanic properties are being altered by climate change and other anthropogenic pressures. Hence, identifying the influences of multifaceted ocean change, from local to global scales, is a complex task. To guide policy-making and make projections of the future of the marine biosphere, it is essential to understand biological responses at physiological, evolutionary and ecological levels. Here, we contrast and compare different approaches to multiple driver experiments that aim to elucidate biological responses to a complex matrix of ocean global change. We present the benefits and the challenges of each approach with a focus on marine research, and guidelines to navigate through these different categories to help identify strategies that might best address research questions in fundamental physiology, experimental evolutionary biology and community ecology. Our review reveals that the field of multiple driver research is being pulled in complementary directions: the need for reductionist approaches to obtain process-oriented, mechanistic understanding and a requirement to quantify responses to projected future scenarios of ocean change. We conclude the review with recommendations on how best to align different experimental approaches to contribute fundamental information needed for science-based policy formulation. © 2018 John Wiley & Sons Ltd.

The Sun is the climate pacemaker II. Global ocean temperatures

Energy Technology Data Exchange (ETDEWEB)

Douglass, David H., E-mail: douglass@pas.rochester.edu; Knox, Robert S.

2015-04-17

In part I, equatorial Pacific Ocean temperature index SST3.4 was found to have segments during 1990–2014 showing a phase-locked annual signal and phase-locked signals of 2- or 3-year periods. Phase locking is to an inferred solar forcing of 1.0 cycle/yr. Here the study extends to the global ocean, from surface to 700 and 2000 m. The same phase-locking phenomena are found. The El Niño/La Niña effect diffuses into the world oceans with a delay of about two months. - Highlights: • Global ocean temperatures at depths 0–700 m and 0–2000 m from 1990 to 2014 are studied. • The same phase-locked phenomena reported in Paper I are observed. • El Niño/La Niña effects diffuse to the global oceans with a two month delay. • Ocean heat content trends during phase-locked time segments are consistent with zero.

NOAA's Role in Sustaining Global Ocean Observations: Future Plans for OAR's Ocean Observing and Monitoring Division

Science.gov (United States)

Todd, James; Legler, David; Piotrowicz, Stephen; Raymond, Megan; Smith, Emily; Tedesco, Kathy; Thurston, Sidney

2017-04-01

The Ocean Observing and Monitoring Division (OOMD, formerly the Climate Observation Division) of the National Oceanic and Atmospheric Administration (NOAA) Climate Program Office provides long-term, high-quality global observations, climate information and products for researchers, forecasters, assessments and other users of environmental information. In this context, OOMD-supported activities serve a foundational role in an enterprise that aims to advance 1) scientific understanding, 2) monitoring and prediction of climate and 3) understanding of potential impacts to enable a climate resilient society. Leveraging approximately 50% of the Global Ocean Observing System, OOMD employs an internationally-coordinated, multi-institution global strategy that brings together data from multiple platforms including surface drifting buoys, Argo profiling floats, flux/transport moorings (RAMA, PIRATA, OceanSITES), GLOSS tide gauges, SOOP-XBT and SOOP-CO2, ocean gliders and repeat hydrographic sections (GO-SHIP). OOMD also engages in outreach, education and capacity development activities to deliver training on the social-economic applications of ocean data. This presentation will highlight recent activities and plans for 2017 and beyond.

Practical global oceanic state estimation

Science.gov (United States)

Wunsch, Carl; Heimbach, Patrick

2007-06-01

The problem of oceanographic state estimation, by means of an ocean general circulation model (GCM) and a multitude of observations, is described and contrasted with the meteorological process of data assimilation. In practice, all such methods reduce, on the computer, to forms of least-squares. The global oceanographic problem is at the present time focussed primarily on smoothing, rather than forecasting, and the data types are unlike meteorological ones. As formulated in the consortium Estimating the Circulation and Climate of the Ocean (ECCO), an automatic differentiation tool is used to calculate the so-called adjoint code of the GCM, and the method of Lagrange multipliers used to render the problem one of unconstrained least-squares minimization. Major problems today lie less with the numerical algorithms (least-squares problems can be solved by many means) than with the issues of data and model error. Results of ongoing calculations covering the period of the World Ocean Circulation Experiment, and including among other data, satellite altimetry from TOPEX/POSEIDON, Jason-1, ERS- 1/2, ENVISAT, and GFO, a global array of profiling floats from the Argo program, and satellite gravity data from the GRACE mission, suggest that the solutions are now useful for scientific purposes. Both methodology and applications are developing in a number of different directions.

Global Modeling Study of the Bioavailable Atmospheric Iron Supply to the Global Ocean

Science.gov (United States)

Myriokefalitakis, S.; Krol, M. C.; van Noije, T.; Le Sager, P.

2017-12-01

Atmospheric deposition of trace constituents acts as a nutrient source to the open ocean and affect marine ecosystem. Dust is known as a major source of nutrients to the global ocean, but only a fraction of these nutrients is released in a bioavailable form that can be assimilated by the marine biota. Iron (Fe) is a key micronutrient that significantly modulates gross primary production in the High-Nutrient-Low-Chlorophyll (HNLC) oceans, where macronutrients like nitrate are abundant, but primary production is limited by Fe scarcity. The global atmospheric Fe cycle is here parameterized in the state-of-the-art global Earth System Model EC-Earth. The model takes into account the primary emissions of both insoluble and soluble Fe forms, associated with mineral dust and combustion aerosols. The impact of atmospheric acidity and organic ligands on mineral dissolution processes, is parameterized based on updated experimental and theoretical findings. Model results are also evaluated against available observations. Overall, the link between the labile Fe atmospheric deposition and atmospheric composition changes is here demonstrated and quantified. This work has been financed by the Marie-Curie H2020-MSCA-IF-2015 grant (ID 705652) ODEON (Online DEposition over OceaNs; modeling the effect of air pollution on ocean bio-geochemistry in an Earth System Model).

Role of coral reefs in global ocean production

Energy Technology Data Exchange (ETDEWEB)

Crossland, C J; Hatcher, B G; Smith, S V [CSIRO Institute of Natural Resources and Environment, Dickson, ACT (Australia)

1991-01-01

Coral reefs cover some 600 thousand square kilometres of the earth's surface (0.17% of the ocean surface). First order estimates show coral reefs to contribute about 0.05% of the estimated net CO{sub 2} fixation rate of the global oceans. Gross CO{sub 2} fixation is relatively high (of the order 700 x 10{sup 12}g C year{sup -1}), but most of this material is recycled within the reefs. Excess (net) production of organic material (E) is much smaller, of the order 20 x 10{sup 12}g C year{sup -1}. 75% of E is available for export from coral reefs to adjacent areas. Comparison of estimates for net production by reefs and their surrounding oceans indicates that the excess production by coral reefs is similar to new production in the photic zone of oligotrophic oceans. Consequently, estimates for global ocean production should as a first approximation include reefal areas with the surrounding ocean when assigning average net production rates. It can be concluded that organic production by reefs plays a relatively minor role in the global scale of fluxes and storage of elements. In comparison, the companion process of biologically-mediated inorganic carbon precipitation represents a major role for reefs. While reef production does respond on local scales to variation in ocean climate, neither the absolute rates nor the amount accumulated into organic pools appear to be either sensitive indicators or accurate recorders of climatic change in most reef systems. Similarly, the productivity of most reefs should be little affected by currently predicted environmental changes resulting from the greenhouse effect. 86 refs., 2 figs., 1 tab.

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses.

Science.gov (United States)

Roux, Simon; Brum, Jennifer R; Dutilh, Bas E; Sunagawa, Shinichi; Duhaime, Melissa B; Loy, Alexander; Poulos, Bonnie T; Solonenko, Natalie; Lara, Elena; Poulain, Julie; Pesant, Stéphane; Kandels-Lewis, Stefanie; Dimier, Céline; Picheral, Marc; Searson, Sarah; Cruaud, Corinne; Alberti, Adriana; Duarte, Carlos M; Gasol, Josep M; Vaqué, Dolors; Bork, Peer; Acinas, Silvia G; Wincker, Patrick; Sullivan, Matthew B

2016-09-29

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface- and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting 'global ocean virome' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they

Satellite based Ocean Forecasting, the SOFT project

Science.gov (United States)

Stemmann, L.; Tintoré, J.; Moneris, S.

2003-04-01

The knowledge of future oceanic conditions would have enormous impact on human marine related areas. For such reasons, a number of international efforts are being carried out to obtain reliable and manageable ocean forecasting systems. Among the possible techniques that can be used to estimate the near future states of the ocean, an ocean forecasting system based on satellite imagery is developped through the Satelitte based Ocean ForecasTing project (SOFT). SOFT, established by the European Commission, considers the development of a forecasting system of the ocean space-time variability based on satellite data by using Artificial Intelligence techniques. This system will be merged with numerical simulation approaches, via assimilation techniques, to get a hybrid SOFT-numerical forecasting system of improved performance. The results of the project will provide efficient forecasting of sea-surface temperature structures, currents, dynamic height, and biological activity associated to chlorophyll fields. All these quantities could give valuable information on the planning and management of human activities in marine environments such as navigation, fisheries, pollution control, or coastal management. A detailed identification of present or new needs and potential end-users concerned by such an operational tool is being performed. The project would study solutions adapted to these specific needs.

Temperature profiles from expendable bathythermograph (XBT) casts from the USS R.A. OWENS and other platforms in a world-wide distribution in support of the Integrated Global Ocean Services System (IGOSS) project from 1968-08-09 to 1974-08-01 (NODC Accession 7500699)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT data were collected from the R.A. OWENS and other platforms in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the...

Coordination and Integration of Global Ocean Observing through JCOMM

Science.gov (United States)

Legler, D. M.; Meldrum, D. T.; Hill, K. L.; Charpentier, E.

2016-02-01

The primary objective of the JCOMM Observations Coordination Group (OCG) is to provide technical coordination to implement fully integrated ocean observing system across the entire marine meteorology and oceanographic community. JCOMM OCG works in partnership with the Global Ocean Observing System, , which focusses on setting observing system requirements and conducting evalutions. JCOMM OCG initially focused on major global observing networks (e.g. Argo profiling floats, moored buoys, ship based observations, sea level stations, reference sites, etc), and is now expanding its horizon in recognition of new observing needs and new technologies/networks (e.g. ocean gliders). Over the next five years the JCOMM OCG is focusing its attention on integration and coordination in four major areas: observing network implementation particularly in response to integrated ocean observing requirements; observing system monitoring and metrics; standards and best practices; and improving integrated data management and access. This presentation will describe the scope and mission of JCOMM OCG; summarize the state of the global ocean observing system; highlight recent successes and resources for the research, prediction, and assessment communities; summarize our plans for the next several years; and suggest engagement opportunities.

Future Projection of Ocean Wave Climate: Analysis of SST Impacts on Wave Climate Changes in the Western North Pacific

OpenAIRE

Shimura, Tomoya; Mori, Nobuhito; Mase, Hajime

2015-01-01

Changes in ocean surface waves elicit a variety of impacts on coastal environments. To assess the future changes in the ocean surface wave climate, several future projections of global wave climate have been simulated in previous studies. However, previously there has been little discussion about the causes behind changes in the future wave climate and the differences between projections. The objective of this study is to estimate the future changes in mean wave climate and the sensitivity of...

Teaching supply chain management through global projects with global project teams

NARCIS (Netherlands)

Kopczak, L.R.; Fransoo, J.C.

2000-01-01

In this article, we describe the Global Project Coordination Course, a course in which project teams composed of three students from each of two overseas universities execute company-sponsored projects dealing with global supply chain management issues. The $75,000 to $100,00 contributed in total by

The Global Ocean Observing System (GOOS): New developments

International Nuclear Information System (INIS)

Summerhayes, C.P.

1999-01-01

GOOS will provide information about the present and future states of seas and oceans and their living resources, and on the role of the oceans in climate change. Among other things, it will include monitoring the extent to which the sea is polluted, and applying models enabling the behaviour of polluted environments to be forecast given a variety of forcing conditions including anthropogenic and natural changes. Implementation has begun through integration of previously separate existing observing systems into a GOOS Initial Observing System, and through the development of Pilot Projects, most notably in the coastal seas of Europe and North-east Asia. Although the present emphasis is on the measurement of physical properties, plans are underway for increasing the observation of chemical and biological parameters. The main biological thrust at present comes through the Global Coral Reef Monitoring Network (GCRMN). Consideration needs to be given to incorporation into the GOOS Initial Observing System of present national, international and global chemical and biological monitoring systems, and the development and implementation of new chemical and biological monitoring subsystems, especially in coastal seas for monitoring the health of those environments. GOOS will offer marine scientists and other users a scheme of continuing measurements on a scale larger in time and space than can be accomplished by individuals for their own applications, and a vastly improved store of basic marine environmental data for a multitude of purposes. For GOOS news see the GOOS Homepage at http://ioc.unesco.org/GOOS/. (author)

OceanSITES format and Ocean Observatory Output harmonisation: past, present and future

Science.gov (United States)

Pagnani, Maureen; Galbraith, Nan; Diggs, Stephen; Lankhorst, Matthias; Hidas, Marton; Lampitt, Richard

2015-04-01

The Global Ocean Observing System (GOOS) initiative was launched in 1991, and was the first step in creating a global view of ocean observations. In 1999 oceanographers at the OceanObs conference envisioned a 'global system of eulerian observatories' which evolved into the OceanSITES project. OceanSITES has been generously supported by individual oceanographic institutes and agencies across the globe, as well as by the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology (under JCOMMOPS). The project is directed by the needs of research scientists, but has a strong data management component, with an international team developing content standards, metadata specifications, and NetCDF templates for many types of in situ oceanographic data. The OceanSITES NetCDF format specification is intended as a robust data exchange and archive format specifically for time-series observatory data from the deep ocean. First released in February 2006, it has evolved to build on and extend internationally recognised standards such as the Climate and Forecast (CF) standard, BODC vocabularies, ISO formats and vocabularies, and in version 1.3, released in 2014, ACDD (Attribute Convention for Dataset Discovery). The success of the OceanSITES format has inspired other observational groups, such as autonomous vehicles and ships of opportunity, to also use the format and today it is fulfilling the original concept of providing a coherent set of data from eurerian observatories. Data in the OceanSITES format is served by 2 Global Data Assembly Centres (GDACs), one at Coriolis, in France, at ftp://ftp.ifremer.fr/ifremer/oceansites/ and one at the US NDBC, at ftp://data.ndbc.noaa.gov/data/oceansites/. These two centres serve over 26,800 OceanSITES format data files from 93 moorings. The use of standardised and controlled features enables the files held at the OceanSITES GDACs to be electronically discoverable and ensures the widest access to the data. The Ocean

Global ocean carbon uptake: magnitude, variability and trends

Directory of Open Access Journals (Sweden)

R. Wanninkhof

2013-03-01

Full Text Available The globally integrated sea–air anthropogenic carbon dioxide (CO2 flux from 1990 to 2009 is determined from models and data-based approaches as part of the Regional Carbon Cycle Assessment and Processes (RECCAP project. Numerical methods include ocean inverse models, atmospheric inverse models, and ocean general circulation models with parameterized biogeochemistry (OBGCMs. The median value of different approaches shows good agreement in average uptake. The best estimate of anthropogenic CO2 uptake for the time period based on a compilation of approaches is −2.0 Pg C yr−1. The interannual variability in the sea–air flux is largely driven by large-scale climate re-organizations and is estimated at 0.2 Pg C yr−1 for the two decades with some systematic differences between approaches. The largest differences between approaches are seen in the decadal trends. The trends range from −0.13 (Pg C yr−1 decade−1 to −0.50 (Pg C yr−1 decade−1 for the two decades under investigation. The OBGCMs and the data-based sea–air CO2 flux estimates show appreciably smaller decadal trends than estimates based on changes in carbon inventory suggesting that methods capable of resolving shorter timescales are showing a slowing of the rate of ocean CO2 uptake. RECCAP model outputs for five decades show similar differences in trends between approaches.

Global and regional ocean carbon uptake and climate change: sensitivity to a substantial mitigation scenario

Energy Technology Data Exchange (ETDEWEB)

Vichi, Marcello; Masina, Simona; Navarra, Antonio [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy); Manzini, Elisa [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy); Max Planck Institute for Meteorology, Hamburg (Germany); Fogli, Pier Giuseppe [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Alessandri, Andrea [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); ENEA, Rome (Italy); Patara, Lavinia [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Leibniz Institute of Marine Sciences (IFM-GEOMAR), Kiel (Germany); Scoccimarro, Enrico [Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy)

2011-11-15

Under future scenarios of business-as-usual emissions, the ocean storage of anthropogenic carbon is anticipated to decrease because of ocean chemistry constraints and positive feedbacks in the carbon-climate dynamics, whereas it is still unknown how the oceanic carbon cycle will respond to more substantial mitigation scenarios. To evaluate the natural system response to prescribed atmospheric ''target'' concentrations and assess the response of the ocean carbon pool to these values, 2 centennial projection simulations have been performed with an Earth System Model that includes a fully coupled carbon cycle, forced in one case with a mitigation scenario and the other with the SRES A1B scenario. End of century ocean uptake with the mitigation scenario is projected to return to the same magnitude of carbon fluxes as simulated in 1960 in the Pacific Ocean and to lower values in the Atlantic. With A1B, the major ocean basins are instead projected to decrease the capacity for carbon uptake globally as found with simpler carbon cycle models, while at the regional level the response is contrasting. The model indicates that the equatorial Pacific may increase the carbon uptake rates in both scenarios, owing to enhancement of the biological carbon pump evidenced by an increase in Net Community Production (NCP) following changes in the subsurface equatorial circulation and enhanced iron availability from extratropical regions. NCP is a proxy of the bulk organic carbon made available to the higher trophic levels and potentially exportable from the surface layers. The model results indicate that, besides the localized increase in the equatorial Pacific, the NCP of lower trophic levels in the northern Pacific and Atlantic oceans is projected to be halved with respect to the current climate under a substantial mitigation scenario at the end of the twenty-first century. It is thus suggested that changes due to cumulative carbon emissions up to present and the

Global multi-decadal ocean climate and small-pelagic fish population

International Nuclear Information System (INIS)

Tourre, Yves M; Lluch-Cota, Salvador E; White, Warren B

2007-01-01

Ocean climate, environmental and biological conditions vary on several spatio-temporal scales. Besides climate change associated with anthropogenic activity, there is growing evidence of a natural global multi-decadal climate signal in the ocean-atmosphere-biosphere climate system. The spatio-temporal evolution of this signal is thus analyzed during the 20th century and compared to the variability of small-pelagic fish landings. It is argued that the low-frequency global ocean environment and plankton ecosystems must be modified such that small-pelagic populations vary accordingly. A small-pelagic global index or fishing 'regime indicator series' (RIS) (i.e. a small-pelagic abundance indicator) is used. RIS is derived from fish landings data in the four main fishing areas in the Pacific and Atlantic oceans. Global RIS changes phase (from positive to negative values) when SST multi-decadal anomalies are out-of-phase between the eastern Pacific and southern Atlantic. RIS also displays maxima during the mid-30s to early-40s and the late-70s to early-80s when the multi-decadal signal was approximately changing phases (Tourre and White 2006 Geophys. Res. Lett. 33 L06716). It is recognized that other factors may modulate fish stocks, including anthropogenic predation. Nevertheless it is proposed that variable climate and environment, and the low-frequency 'global synchrony' of small-pelagic landings (Schwartzlose et al 1999 S. Afr. J. Mar. Sci. 21 289-347), could be associated with the multi-decadal changes in global ocean climate conditions

Global Earth Response to Loading by Ocean Tide Models

Science.gov (United States)

Estes, R. H.; Strayer, J. M.

1979-01-01

Mathematical and programming techniques to numerically calculate Earth response to global semidiurnal and diurnal ocean tide models were developed. Global vertical crustal deformations were evaluated for M sub 2, S sub 2, N sub 2, K sub 2, K sub 1, O sub 1, and P sub 1 ocean tide loading, while horizontal deformations were evaluated for the M sub 2 tidal load. Tidal gravity calculations were performed for M sub 2 tidal loads, and strain tensor elements were evaluated for M sub 2 loads. The M sub 2 solution used for the ocean tide included the effects of self-gravitation and crustal loading.

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses

KAUST Repository

Roux, Simon

2016-05-12

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface-and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting â global ocean virome\\' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses

KAUST Repository

Roux, Simon; Brum, Jennifer R; Dutilh, Bas E.; Sunagawa, Shinichi; Duhaime, Melissa B; Loy, Alexander; Poulos, Bonnie T; Solonenko, Natalie; Lara, Elena; Poulain, Julie; Pesant, Stephane; Kandels-Lewis, Stefanie; Dimier, Celine; Picheral, Marc; Searson, Sarah; Cruaud, Corinne; Alberti, Adriana; Duarte, Carlos M.; Gasol, Josep M M; Vaque, Dolors; Bork, Peer; Acinas, Silvia G; Wincker, Patrick; Sullivan, Matthew B

2016-01-01

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface-and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting â global ocean virome' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they

Energetics of global ocean tides from Geosat altimetry

Science.gov (United States)

Cartwright, David E.; Ray, Richard D.

1991-01-01

The present paper focuses on resonance and energetics of the daily tides, especially in the southern ocean, the distribution of gravitational power input of daily and half-daily tides, and comparison with other estimates of global dissipation rates. The present global tidal maps, derived from Geosat altimetry, compare favorably with ground truth data at about the same rms level as the models of Schwiderski (1983), and are slightly better in lunar than in solar tides. Diurnal admittances clearly show Kelvin wave structure in the southern ocean and confirm the resonant mode of Platzman (1984) at 28.5 + or - 0.1 hr with an apparent Q of about 4. Driving energy is found to enter dominantly in the North Pacific for the daily tides and is strongly peaked in the tropical oceans for the half-daily tides. Global rates of working on all major tide constituents except S2 agree well with independent results from analyses of gravity through satellite tracking. Comparison at S2 is improved by allowing for the air tide in gravitational results but suggests deficiencies in all solar tide models.

Recent Trends in Global Ocean Chlorophyll

Science.gov (United States)

Gregg, Watson; Casey, Nancy

2004-01-01

Recent analyses of SeaWiFS data have shown that global ocean chlorophyll has increased more than 5% since 1998. The North Pacific ocean basin has increased nearly 19%. To understand the causes of these trends we have applied the newly developed NASA Ocean Biogeochemical Assimilation Model (OBAM), which is driven in mechanistic fashion by surface winds, sea surface temperature, atmospheric iron deposition, sea ice, and surface irradiance. The mode1 utilizes chlorophyll from SeaWiFS in a daily assimilation. The model has in place many of the climatic variables that can be expected to produce the changes observed in SeaWiFS data. Ths enables us to diagnose the model performance, the assimilation performance, and possible causes for the increase in chlorophyll.

Seafloor 2030 - Building a Global Ocean Map through International Collaboration

Science.gov (United States)

Ferrini, V. L.; Wigley, R. A.; Falconer, R. K. H.; Jakobsson, M.; Allen, G.; Mayer, L. A.; Schmitt, T.; Rovere, M.; Weatherall, P.; Marks, K. M.

2016-12-01

With more than 85% of the ocean floor unmapped, a huge proportion of our planet remains unexplored. Creating a comprehensive map of seafloor bathymetry remains a true global challenge that can only be accomplished through collaboration and partnership between governments, industry, academia, research organizations and non-government organizations. The objective of Seafloor 2030 is to comprehensively map the global ocean floor to resolutions that enable exploration and improved understanding of ocean processes, while informing maritime policy and supporting the management of natural marine resources for a sustainable Blue Economy. Seafloor 2030 is the outcome of the Forum for Future of Ocean Floor Mapping held in Monaco in June 2016, which was held under the auspices of GEBCO and the Nippon Foundation of Japan. GEBCO is the only international organization mandated to map the global ocean floor and is guided by the International Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission of UNESCO. The task of completely mapping the ocean floor will require new global coordination to ensure that both existing data are identified and that new mapping efforts are coordinated to help efficiently "map the gaps." Fundamental to achieving Seafloor 2030 will be greater access to data, tools and technology, particularly for developing and coastal nations. This includes bathymetric post-processing and analysis software, database technology, computing infrastructure and gridding techniques as well as the latest developments in seafloor mapping methods and emerging crowd-sourced bathymetry initiatives. The key to achieving this global bathymetric map is capacity building and education - including greater coordination between scientific research and industry and the effective engagement of international organizations such as the United Nations.

A mechanism for land-ocean contrasts in global monsoon trends in a warming climate

Energy Technology Data Exchange (ETDEWEB)

Fasullo, J. [National Center for Atmospheric Research, CAS/NCAR, Boulder, CO (United States)

2012-09-15

A central paradox of the global monsoon record involves reported decreases in rainfall over land during an era in which the global hydrologic cycle is both expected and observed to intensify. It is within this context that this work develops a physical basis for both interpreting the observed record and anticipating changes in the monsoons in a warming climate while bolstering the concept of the global monsoon in the context of shared feedbacks. The global-land monsoon record across multiple reanalyses is first assessed. Trends that in other studies have been taken as real are shown to likely be spurious as a result of changes in the assimilated data streams both prior to and during the satellite era. Nonetheless, based on satellite estimates, robust increases in monsoon rainfall over ocean do exist and a physical basis for this land-ocean contrast remains lacking. To address the contrast's causes, simulated trends are therefore assessed. While projections of total rainfall are inconsistent across models, the robust land-ocean contrast identified in observations is confirmed. A feedback mechanism is proposed rooted in the facts that land areas warm disproportionately relative to ocean, and onshore flow is the chief source of monsoonal moisture. Reductions in lower tropospheric relative humidity over land domains are therefore inevitable and these have direct consequences for the monsoonal convective environment including an increase in the lifting condensation level and a shift in the distribution of convection generally towards less frequent and potentially more intense events. The mechanism is interpreted as an important modulating influence on the ''rich-get-richer'' mechanism. Caveats for regional monsoons exist and are discussed. (orig.)

Monitoring of ocean storage projects

Energy Technology Data Exchange (ETDEWEB)

Caldeira, K. [Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA (United States)

2003-02-01

It has been proposed that atmospheric CO2 accumulation could be slowed by capture of CO2 from point sources and subsequent storage of that CO2 in the ocean. If applied, such sequestration efforts would need to be monitored for compliance, effectiveness, and unintended consequences. Aboveground inspection and monitoring of facilities and practices, combined with ocean observations, could assure compliance with ocean sequestration guidelines and regulations. Ocean observations could be made using a variety of sensors mounted on moorings or underwater gliders. Long-term effectiveness and leakage to the atmosphere must be estimated from models, since on large spatial scales it will be impossible to observationally distinguish carbon stored by a project from variable concentrations of background carbon. Furthermore, the ocean naturally would absorb roughly 80% of fossil fuel CO2 released to the atmosphere within a millennium. This means that most of the CO2 sequestered in the ocean that leaks out to the atmosphere will be reabsorbed by the ocean. However, there is no observational way to distinguish remaining carbon from reabsorbed carbon. The science of monitoring unintended consequences in the deep ocean interior is at a primitive state. Little is understood about ecosystems of the deep ocean interior; and even less is understood about how those ecosystems would respond to added CO2. High priority research objectives should be (1) to improve our understanding of the natural ecosystems of the deep ocean, and (2) to improve our understanding of the response of these ecosystems to increased oceanic CO2 concentrations and decreased ocean pH.

Ocean plankton. Structure and function of the global ocean microbiome.

Science.gov (United States)

Sunagawa, Shinichi; Coelho, Luis Pedro; Chaffron, Samuel; Kultima, Jens Roat; Labadie, Karine; Salazar, Guillem; Djahanschiri, Bardya; Zeller, Georg; Mende, Daniel R; Alberti, Adriana; Cornejo-Castillo, Francisco M; Costea, Paul I; Cruaud, Corinne; d'Ovidio, Francesco; Engelen, Stefan; Ferrera, Isabel; Gasol, Josep M; Guidi, Lionel; Hildebrand, Falk; Kokoszka, Florian; Lepoivre, Cyrille; Lima-Mendez, Gipsi; Poulain, Julie; Poulos, Bonnie T; Royo-Llonch, Marta; Sarmento, Hugo; Vieira-Silva, Sara; Dimier, Céline; Picheral, Marc; Searson, Sarah; Kandels-Lewis, Stefanie; Bowler, Chris; de Vargas, Colomban; Gorsky, Gabriel; Grimsley, Nigel; Hingamp, Pascal; Iudicone, Daniele; Jaillon, Olivier; Not, Fabrice; Ogata, Hiroyuki; Pesant, Stephane; Speich, Sabrina; Stemmann, Lars; Sullivan, Matthew B; Weissenbach, Jean; Wincker, Patrick; Karsenti, Eric; Raes, Jeroen; Acinas, Silvia G; Bork, Peer

2015-05-22

Microbes are dominant drivers of biogeochemical processes, yet drawing a global picture of functional diversity, microbial community structure, and their ecological determinants remains a grand challenge. We analyzed 7.2 terabases of metagenomic data from 243 Tara Oceans samples from 68 locations in epipelagic and mesopelagic waters across the globe to generate an ocean microbial reference gene catalog with >40 million nonredundant, mostly novel sequences from viruses, prokaryotes, and picoeukaryotes. Using 139 prokaryote-enriched samples, containing >35,000 species, we show vertical stratification with epipelagic community composition mostly driven by temperature rather than other environmental factors or geography. We identify ocean microbial core functionality and reveal that >73% of its abundance is shared with the human gut microbiome despite the physicochemical differences between these two ecosystems. Copyright © 2015, American Association for the Advancement of Science.

The Oceans 2015 Initiative, Part I - An updated synthesis of the observed and projected impacts of climate change on physical and biological processes in the oceans

International Nuclear Information System (INIS)

Howes, Ella L.; Joos, Fortunat; Eakin, Mark; Gattuso, Jean-Pierre

2015-01-01

The oceans have absorbed approximately 93% of the excess heat caused by global warming. Warming increases stratification, limiting the circulation of nutrients from deep waters to the surface. There is evidence that enhanced stratification and increasing temperature are causing a decline in dissolved oxygen concentration and expanding existing oxygen minimum zones (OMZs). Approximately 26% of anthropogenic CO 2 is absorbed by the oceans, resulting in a reduction in pH and carbonate ion concentration, termed ocean acidification. Anthropogenic CO 2 has caused global ocean pH to decrease by 0.1 units since the start of the Industrial Revolution. The ocean ecosystems are responding to the changing environment, but at different rates and magnitudes and with interspecific and geographic variation in responses. Warming causes shifts in species' geographic distribution, abundance, migration patterns and phenology. Organisms that produce shells and skeletons from calcium carbonate are at most risk from ocean acidification as it lowers the saturation state of the mineral, favouring a dissolution reaction. To date, there are few observations of ocean acidification effects in natural communities; however, experimental evidence suggests that the risk to ecosystems will increase over the coming decades. Decreasing dissolved oxygen concentrations and expanding OMZs will favour anaerobic metabolisers such as bacteria and small microbes whilst reducing habitat for larger, oxygen dependent organisms. The interaction of multiple drivers can amplify or alleviate each other's effects. It is likely that marine organisms will experience a combination of warming, acidification and declining oxygen concentrations as well as regionally specific local stressors. This makes it difficult to predict the responses of individual species to multiple drivers, and species interactions make ecosystem- based projections challenging. Using the available evidence, projections have been

The global marine phosphorus cycle: sensitivity to oceanic circulation

Directory of Open Access Journals (Sweden)

C. P. Slomp

2007-01-01

Full Text Available A new mass balance model for the coupled marine cycles of phosphorus (P and carbon (C is used to examine the relationships between oceanic circulation, primary productivity, and sedimentary burial of reactive P and particulate organic C (POC, on geological time scales. The model explicitly represents the exchanges of water and particulate matter between the continental shelves and the open ocean, and it accounts for the redox-dependent burial of POC and the various forms of reactive P (iron(III-bound P, particulate organic P (POP, authigenic calcium phosphate, and fish debris. Steady state and transient simulations indicate that a slowing down of global ocean circulation decreases primary production in the open ocean, but increases that in the coastal ocean. The latter is due to increased transfer of soluble P from deep ocean water to the shelves, where it fuels primary production and causes increased reactive P burial. While authigenic calcium phosphate accounts for most reactive P burial ocean-wide, enhanced preservation of fish debris may become an important reactive P sink in deep-sea sediments during periods of ocean anoxia. Slower ocean circulation globally increases POC burial, because of enhanced POC preservation under anoxia in deep-sea depositional environments and higher primary productivity along the continental margins. In accordance with geological evidence, the model predicts increased accumulation of reactive P on the continental shelves during and following periods of ocean anoxia.

Ice-dynamic projections of the Greenland ice sheet in response to atmospheric and oceanic warming

Directory of Open Access Journals (Sweden)

J. J. Fürst

2015-05-01

Full Text Available Continuing global warming will have a strong impact on the Greenland ice sheet in the coming centuries. During the last decade (2000–2010, both increased melt-water runoff and enhanced ice discharge from calving glaciers have contributed 0.6 ± 0.1 mm yr−1 to global sea-level rise, with a relative contribution of 60 and 40% respectively. Here we use a higher-order ice flow model, spun up to present day, to simulate future ice volume changes driven by both atmospheric and oceanic temperature changes. For these projections, the flow model accounts for runoff-induced basal lubrication and ocean warming-induced discharge increase at the marine margins. For a suite of 10 atmosphere and ocean general circulation models and four representative concentration pathway scenarios, the projected sea-level rise between 2000 and 2100 lies in the range of +1.4 to +16.6 cm. For two low emission scenarios, the projections are conducted up to 2300. Ice loss rates are found to abate for the most favourable scenario where the warming peaks in this century, allowing the ice sheet to maintain a geometry close to the present-day state. For the other moderate scenario, loss rates remain at a constant level over 300 years. In any scenario, volume loss is predominantly caused by increased surface melting as the contribution from enhanced ice discharge decreases over time and is self-limited by thinning and retreat of the marine margin, reducing the ice–ocean contact area. As confirmed by other studies, we find that the effect of enhanced basal lubrication on the volume evolution is negligible on centennial timescales. Our projections show that the observed rates of volume change over the last decades cannot simply be extrapolated over the 21st century on account of a different balance of processes causing ice loss over time. Our results also indicate that the largest source of uncertainty arises from the surface mass balance and the underlying climate change

Realistic Paleobathymetry of the Cenomanian–Turonian (94 Ma Boundary Global Ocean

Directory of Open Access Journals (Sweden)

Arghya Goswami

2018-01-01

Full Text Available At present, global paleoclimate simulations are prepared with bathtub-like, flat, featureless and steep walled ocean bathymetry, which is neither realistic nor suitable. In this article, we present the first enhanced version of a reconstructed paleobathymetry for Cenomanian–Turonian (94 Ma time in a 0.1° × 0.1° resolution, that is both realistic and suitable for use in paleo-climate studies. This reconstruction is an extrapolation of a parameterized modern ocean bathymetry that combines simple geophysical models (standard plate cooling model for the oceanic lithosphere based on ocean crustal age, global modern oceanic sediment thicknesses, and generalized shelf-slope-rise structures calibrated from a published global relief model of the modern world (ETOPO1 at active and passive continental margins. The base version of this Cenomanian–Turonian paleobathymetry reconstruction is then updated with known submarine large igneous provinces, plateaus, and seamounts to minimize the difference between the reconstructed paleobathymetry and the real bathymetry that once existed.

Collaborative project. Ocean-atmosphere interaction from meso-to planetary-scale. Mechanisms, parameterization, and variability

Energy Technology Data Exchange (ETDEWEB)

Small, Richard [National Center for Atmospheric Research, Boulder, CO (United States); Bryan, Frank [National Center for Atmospheric Research, Boulder, CO (United States); Tribbia, Joseph [National Center for Atmospheric Research, Boulder, CO (United States); Park, Sungsu [National Center for Atmospheric Research, Boulder, CO (United States); Dennis, John [National Center for Atmospheric Research, Boulder, CO (United States); Saravanan, R. [National Center for Atmospheric Research, Boulder, CO (United States); Schneider, Niklas [National Center for Atmospheric Research, Boulder, CO (United States); Kwon, Young-Oh [National Center for Atmospheric Research, Boulder, CO (United States)

2015-06-11

This project aims to improve long term global climate simulations by resolving ocean mesoscale activity and the corresponding response in the atmosphere. The main computational objectives are; i) to perform and assess Community Earth System Model (CESM) simulations with the new Community Atmospheric Model (CAM) spectral element dynamical core; ii) use static mesh refinement to focus on oceanic fronts; iii) develop a new Earth System Modeling tool to investigate the atmospheric response to fronts by selectively filtering surface flux fields in the CESM coupler. The climate research objectives are 1) to improve the coupling of ocean fronts and the atmospheric boundary layer via investigations of dependency on model resolution and stability functions: 2) to understand and simulate the ensuing tropospheric response that has recently been documented in observations: and 3) to investigate the relationship of ocean frontal variability to low frequency climate variability and the accompanying storm tracks and extremes in high resolution simulations. This is a collaborative multi-institution project consisting of computational scientists, climate scientists and climate model developers. It specifically aims at DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

Leading global projects for professional and accidental project leaders

CERN Document Server

Moran, Robert T

2008-01-01

This book is a must-read for anyone responsible for projects and initiatives that span functional and geographical divides. Authors Moran and Youngdahl bring extensive experience and learning from industry practice to present a clear and straightforward treatment of the leadership skills and knowledge required to lead projects that are global in nature. They have written the first book of its kind to address the three essential skills of global project leaders - strategic project management, project leadership, and cross-cultural leadership. The authors argue that global project leadership is an essential skill in our project-based world and that we are all either intentional or accidental project leaders. Intentional project leaders pursue formal project management education and even certification whereas accidental project leaders find themselves leading global projects and initiatives as a result of a special assignment or promotion. Moran and Youndahl have found that the vast majority of global projects ...

The timescales of global surface-ocean connectivity.

Science.gov (United States)

Jönsson, Bror F; Watson, James R

2016-04-19

Planktonic communities are shaped through a balance of local evolutionary adaptation and ecological succession driven in large part by migration. The timescales over which these processes operate are still largely unresolved. Here we use Lagrangian particle tracking and network theory to quantify the timescale over which surface currents connect different regions of the global ocean. We find that the fastest path between two patches--each randomly located anywhere in the surface ocean--is, on average, less than a decade. These results suggest that marine planktonic communities may keep pace with climate change--increasing temperatures, ocean acidification and changes in stratification over decadal timescales--through the advection of resilient types.

Potential Increasing Dominance of Heterotrophy in the Global Ocean

Science.gov (United States)

Kvale, K.; Meissner, K. J.; Keller, D. P.

2016-02-01

Autotrophs are largely limited by resources in the modern ocean. However, standard metabolic theory suggests continued ocean warming could globally benefit heterotrophs, thereby reducing autotrophic nutrient limitation. The paleo record as well as modern observations offer evidence this has happened in the past and could happen again. Increasing dominance of heterotrophs would result in strong nutrient recycling in the upper ocean and high rates of net primary production (NPP), yet low carbon export to the deep ocean and sediments. We describe the transition towards such a state in the early 22nd century as a response to business-as-usual Representative Concentration Pathway forcing (RCP8.5) in an intermediate complexity Earth system model in three configurations: with and without an explicit calcifier phytoplankton class and calcite ballast model. In all models nutrient regeneration in the near surface becomes an increasingly important driver of primary production. The near-linear relationship between changes in NPP and global sea surface temperature (SST) found over the 21st century becomes exponential above a 2-4 °C global mean SST change. This transition to a more heterotrophic ocean agrees roughly with metabolic theory. Inclusion of small phytoplankton and calcifiers increase the model NPP:SST sensitivity because of their relatively higher nutrient affinity than general phytoplankton. Accounting for organic carbon "protected" from remineralization by carbonate ballast mitigates the exponential increase in NPP and provides an increasingly important pathway for deep carbon export with higher SST changes, despite simultaneous increasing carbonate dissolution rates due to ocean acidification.

Ocean Thermal Extractable Energy Visualization

Energy Technology Data Exchange (ETDEWEB)

Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)

2012-10-28

The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

Ocean response to volcanic eruptions in Coupled Model Intercomparison Project 5 simulations

KAUST Repository

Ding, Yanni

2014-09-01

We examine the oceanic impact of large tropical volcanic eruptions as they appear in ensembles of historical simulations from eight Coupled Model Intercomparison Project Phase 5 models. These models show a response that includes lowering of global average sea surface temperature by 0.1–0.3 K, comparable to the observations. They show enhancement of Arctic ice cover in the years following major volcanic eruptions, with long-lived temperature anomalies extending to the middepth and deep ocean on decadal to centennial timescales. Regional ocean responses vary, although there is some consistent hemispheric asymmetry associated with the hemisphere in which the eruption occurs. Temperature decreases and salinity increases contribute to an increase in the density of surface water and an enhancement in the overturning circulation of the North Atlantic Ocean following these eruptions. The strength of this overturning increase varies considerably from model to model and is correlated with the background variability of overturning in each model. Any cause/effect relationship between eruptions and the phase of El Niño is weak.

Satellite-detected fluorescence reveals global physiology of ocean phytoplankton

Directory of Open Access Journals (Sweden)

M. J. Behrenfeld

2009-05-01

Full Text Available Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of quenching-corrected fluorescence quantum yields reveal a striking consistency with anticipated patterns of iron availability. High fluorescence quantum yields are typically found in low iron waters, while low quantum yields dominate regions where other environmental factors are most limiting to phytoplankton growth. Specific properties of photosynthetic membranes are discussed that provide a mechanistic view linking iron stress to satellite-detected fluorescence. Our results present satellite-based fluorescence as a valuable tool for evaluating nutrient stress predictions in ocean ecosystem models and give the first synoptic observational evidence that iron plays an important role in seasonal phytoplankton dynamics of the Indian Ocean. Satellite fluorescence may also provide a path for monitoring climate-phytoplankton physiology interactions and improving descriptions of phytoplankton light use efficiencies in ocean productivity models.

Scientific advances of the MyOcean projects underpinning the transition towards the Marine Copernicus service

Science.gov (United States)

Brasseur, Pierre

2015-04-01

The MyOcean projects supported by the European Commission period have been developed during the 2008-2015 period to build an operational service of ocean physical state and ecosystem information to intermediate and downstream users in the areas of marine safety, marine resources, marine and coastal environment and weather, climate and seasonal forecasting. The "core" information provided to users is obtained through the combination of satellite and in situ observations, eddy-resolving modelling of the global ocean and regional european seas, biochemistry, ecosystem and sea-ice modelling, and data assimilation for global to basin scale circulation. A comprehensive R&D plan was established in 2010 to ensure the collection and provision of information of best possible quality for daily estimates of the ocean state (real-time), its short-term evolution, and its history over the past (reanalyses). A service validation methodology was further developed to ensure proper scientific evaluation and routine monitoring of the accuracy of MyOcean products. In this presentation, we will present an overview of the main scientific advances achieved in MyOcean using the NEMO modelling platform, ensemble-based assimilation schemes, coupled circulation-ecosystem, sea-ice assimilative models and probabilistic methodologies for ensemble validation. We will further highlight the key areas that will require additional innovation effort to support the Marine Copernicus service evolution.

Tsunami Speed Variations in Density-stratified Compressible Global Oceans

Science.gov (United States)

Watada, S.

2013-12-01

Recent tsunami observations in the deep ocean have accumulated unequivocal evidence that tsunami traveltime delays compared with the linear long-wave tsunami simulations occur during tsunami propagation in the deep ocean. The delay is up to 2% of the tsunami traveltime. Watada et al. [2013] investigated the cause of the delay using the normal mode theory of tsunamis and attributed the delay to the compressibility of seawater, the elasticity of the solid earth, and the gravitational potential change associated with mass motion during the passage of tsunamis. Tsunami speed variations in the deep ocean caused by seawater density stratification is investigated using a newly developed propagator matrix method that is applicable to seawater with depth-variable sound speeds and density gradients. For a 4-km deep ocean, the total tsunami speed reduction is 0.45% compared with incompressible homogeneous seawater; two thirds of the reduction is due to elastic energy stored in the water and one third is due to water density stratification mainly by hydrostatic compression. Tsunami speeds are computed for global ocean density and sound speed profiles and characteristic structures are discussed. Tsunami speed reductions are proportional to ocean depth with small variations, except for in warm Mediterranean seas. The impacts of seawater compressibility and the elasticity effect of the solid earth on tsunami traveltime should be included for precise modeling of trans-oceanic tsunamis. Data locations where a vertical ocean profile deeper than 2500 m is available in World Ocean Atlas 2009. The dark gray area indicates the Pacific Ocean defined in WOA09. a) Tsunami speed variations. Red, gray and black bars represent global, Pacific, and Mediterranean Sea, respectively. b) Regression lines of the tsunami velocity reduction for all oceans. c)Vertical ocean profiles at grid points indicated by the stars in Figure 1.

Opposite latitudinal gradients in projected ocean acidification and bleaching impacts on coral reefs.

Science.gov (United States)

van Hooidonk, Ruben; Maynard, Jeffrey Allen; Manzello, Derek; Planes, Serge

2014-01-01

Coral reefs and the services they provide are seriously threatened by ocean acidification and climate change impacts like coral bleaching. Here, we present updated global projections for these key threats to coral reefs based on ensembles of IPCC AR5 climate models using the new Representative Concentration Pathway (RCP) experiments. For all tropical reef locations, we project absolute and percentage changes in aragonite saturation state (Ωarag) for the period between 2006 and the onset of annual severe bleaching (thermal stress >8 degree heating weeks); a point at which it is difficult to believe reefs can persist as we know them. Severe annual bleaching is projected to start 10-15 years later at high-latitude reefs than for reefs in low latitudes under RCP8.5. In these 10-15 years, Ωarag keeps declining and thus any benefits for high-latitude reefs of later onset of annual bleaching may be negated by the effects of acidification. There are no long-term refugia from the effects of both acidification and bleaching. Of all reef locations, 90% are projected to experience severe bleaching annually by 2055. Furthermore, 5% declines in calcification are projected for all reef locations by 2034 under RCP8.5, assuming a 15% decline in calcification per unit of Ωarag. Drastic emissions cuts, such as those represented by RCP6.0, result in an average year for the onset of annual severe bleaching that is ~20 years later (2062 vs. 2044). However, global emissions are tracking above the current worst-case scenario devised by the scientific community, as has happened in previous generations of emission scenarios. The projections here for conditions on coral reefs are dire, but provide the most up-to-date assessment of what the changing climate and ocean acidification mean for the persistence of coral reefs. © 2013 John Wiley & Sons Ltd.

Global ocean conveyor lowers extinction risk in the deep sea

Science.gov (United States)

Henry, Lea-Anne; Frank, Norbert; Hebbeln, Dierk; Wienberg, Claudia; Robinson, Laura; van de Flierdt, Tina; Dahl, Mikael; Douarin, Mélanie; Morrison, Cheryl L.; López Correa, Matthias; Rogers, Alex D.; Ruckelshausen, Mario; Roberts, J. Murray

2014-06-01

General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth's largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium-thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6 kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500 km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

The role of clouds and oceans in global greenhouse warming

International Nuclear Information System (INIS)

Hoffert, M.I.

1992-12-01

During the past three years we have conducted several studies using models and a combination of satellite data, in situ meteorological and oceanic data, and paleoclimate reconstructions, under the DoE program, ''Quantifying the Link Between Change in Radiative Balance and Atmospheric Temperature''. Our goals were to investigate effects of global cloudiness variations on global climate and their implications for cloud feedback and continue development and application of NYU transient climate/ocean models, with emphasis on coupled effects of greenhouse warming and feedbacks by both the clouds and oceans. Our original research plan emphasized the use of cloud, surface temperature and ocean data sets interpreted by focused climate/ocean models to develop a cloud radiative forcing scenario for the past 100 years and to assess the transient climate response; to narrow key uncertainties in the system; and to identify those aspects of the climate system most likely to be affected by greenhouse warming over short, medium and long time scales

Combined constraints on global ocean primary production using observations and models

Science.gov (United States)

Buitenhuis, Erik T.; Hashioka, Taketo; Quéré, Corinne Le

2013-09-01

production is at the base of the marine food web and plays a central role for global biogeochemical cycles. Yet global ocean primary production is known to only a factor of 2, with previous estimates ranging from 38 to 65 Pg C yr-1 and no formal uncertainty analysis. Here, we present an improved global ocean biogeochemistry model that includes a mechanistic representation of photosynthesis and a new observational database of net primary production (NPP) in the ocean. We combine the model and observations to constrain particulate NPP in the ocean with statistical metrics. The PlankTOM5.3 model includes a new photosynthesis formulation with a dynamic representation of iron-light colimitation, which leads to a considerable improvement of the interannual variability of surface chlorophyll. The database includes a consistent set of 50,050 measurements of 14C primary production. The model best reproduces observations when global NPP is 58 ± 7 Pg C yr-1, with a most probable value of 56 Pg C yr-1. The most probable value is robust to the model used. The uncertainty represents 95% confidence intervals. It considers all random errors in the model and observations, but not potential biases in the observations. We show that tropical regions (23°S-23°N) contribute half of the global NPP, while NPPs in the Northern and Southern Hemispheres are approximately equal in spite of the larger ocean area in the South.

Trends in the Indian Ocean Climatology due to anthropogenic induced global warming

CSIR Research Space (South Africa)

Meyer, AA

2009-09-01

Full Text Available clearly show that due to global warming the South West Indian Ocean Climatology has been changing and that this changing trend will continue into the future as global warming continues. The impacts of regional oceanic climate change on the regions coastal...

Spiraling pathways of global deep waters to the surface of the Southern Ocean

OpenAIRE

Tamsitt, Veronica; Drake, Henri F.; Morrison, Adele K.; Talley, Lynne D.; Dufour, Carolina O.; Gray, Alison R.; Griffies, Stephen M.; Mazloff, Matthew R.; Sarmiento, Jorge L.; Wang, Jinbo; Weijer, Wilbert

2017-01-01

Upwelling of global deep waters to the sea surface in the Southern Ocean closes the global overturning circulation and is fundamentally important for oceanic uptake of carbon and heat, nutrient resupply for sustaining oceanic biological production, and the melt rate of ice shelves. However, the exact pathways and role of topography in Southern Ocean upwelling remain largely unknown. Here we show detailed upwelling pathways in three dimensions, using hydrographic observations and particle trac...

Global variations in gravity-derived oceanic crustal thickness: Implications on oceanic crustal accretion and hotspot-lithosphere interactions

Science.gov (United States)

Lin, J.; Zhu, J.

2012-12-01

We present a new global model of oceanic crustal thickness based on inversion of global oceanic gravity anomaly with constrains from seismic crustal thickness profiles. We first removed from the observed marine free-air gravity anomaly all gravitational effects that can be estimated and removed using independent constraints, including the effects of seafloor topography, marine sediment thickness, and the age-dependent thermal structure of the oceanic lithosphere. We then calculated models of gravity-derived crustal thickness through inversion of the residual mantle Bouguer anomaly using best-fitting gravity-modeling parameters obtained from comparison with seismically determined crustal thickness profiles. Modeling results show that about 5% of the global crustal volume (or 9% of the global oceanic surface area) is associated with model crustal thickness 8.6 km and is interpreted to have been affected by excess magmatism. The percentage of oceanic crustal volume that is associated with thick crustal thickness (>8.6 km) varies greatly among tectonic plates: Pacific (33%), Africa (50%), Antarctic (33%), Australia (30%), South America (34%), Nazca (23%), North America (47%), India (74%), Eurasia (68%), Cocos (20%), Philippine (26%), Scotia (41%), Caribbean (89%), Arabian (82%), and Juan de Fuca (21%). We also found that distribution of thickened oceanic crust (>8.6 km) seems to depend on spreading rate and lithospheric age: (1) On ocean basins younger than 5 Ma, regions of thickened crust are predominantly associated with slow and ultraslow spreading ridges. The relatively strong lithospheric plate at slow and ultraslow ridges might facilitate the loading of large magmatic emplacements on the plate. (2) In contrast, crustal thickness near fast and intermediately fast spreading ridges typically does not exceed 7-8 km. The relatively weak lithosphere at fast and intermediately fast ridges might make it harder for excess magmatism to accrete. We further speculate that

The role stratification on Indian ocean mixing under global warming

Science.gov (United States)

Praveen, V.; Valsala, V.; Ravindran, A. M.

2017-12-01

The impact of changes in Indian ocean stratification on mixing under global warming is examined. Previous studies on global warming and associated weakening of winds reported to increase the stratification of the world ocean leading to a reduction in mixing, increased acidity, reduced oxygen and there by a reduction in productivity. However this processes is not uniform and are also modulated by changes in wind pattern of the future. Our study evaluate the role of stratification and surface fluxes on mixing focusing northern Indian ocean. A dynamical downscaling study using Regional ocean Modelling system (ROMS) forced with stratification and surface fluxes from selected CMIP5 models are presented. Results from an extensive set of historical and Representative Concentration Pathways 8.5 (rcp8.5) scenario simulations are used to quantify the distinctive role of stratification on mixing.

Mapping Global Ocean Surface Albedo from Satellite Observations: Models, Algorithms, and Datasets

Science.gov (United States)

Li, X.; Fan, X.; Yan, H.; Li, A.; Wang, M.; Qu, Y.

2018-04-01

Ocean surface albedo (OSA) is one of the important parameters in surface radiation budget (SRB). It is usually considered as a controlling factor of the heat exchange among the atmosphere and ocean. The temporal and spatial dynamics of OSA determine the energy absorption of upper level ocean water, and have influences on the oceanic currents, atmospheric circulations, and transportation of material and energy of hydrosphere. Therefore, various parameterizations and models have been developed for describing the dynamics of OSA. However, it has been demonstrated that the currently available OSA datasets cannot full fill the requirement of global climate change studies. In this study, we present a literature review on mapping global OSA from satellite observations. The models (parameterizations, the coupled ocean-atmosphere radiative transfer (COART), and the three component ocean water albedo (TCOWA)), algorithms (the estimation method based on reanalysis data, and the direct-estimation algorithm), and datasets (the cloud, albedo and radiation (CLARA) surface albedo product, dataset derived by the TCOWA model, and the global land surface satellite (GLASS) phase-2 surface broadband albedo product) of OSA have been discussed, separately.

Projected Impact of Climate Change on the Water and Salt Budgets of the Arctic Ocean by a Global Climate Model

Science.gov (United States)

Miller, James R.; Russell, Gary L.

1996-01-01

The annual flux of freshwater into the Arctic Ocean by the atmosphere and rivers is balanced by the export of sea ice and oceanic freshwater. Two 150-year simulations of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. Relative to the control, the last 50-year period of the GHG experiment indicates that the total inflow of water from the atmosphere and rivers increases by 10% primarily due to an increase in river discharge, the annual sea-ice export decreases by about half, the oceanic liquid water export increases, salinity decreases, sea-ice cover decreases, and the total mass and sea-surface height of the Arctic Ocean increase. The closed, compact, and multi-phased nature of the hydrologic cycle in the Arctic Ocean makes it an ideal test of water budgets that could be included in model intercomparisons.

Euro-Argo: The European contribution to the global Argo ocean observations network

Science.gov (United States)

Gourcuff, Claire

2017-04-01

The international Argo programme is a major element of the global in-situ ocean observing system. More than 3900 floats are now globally measuring temperature and salinity throughout the global oceans, down to 2,000 meters depth and delivering data both in real time for operational users and after careful scientific quality control for climate change research and monitoring. Argo is the single most important in-situ observing system for the Copernicus Marine Service. The Euro-Argo research infrastructure organizes and federates European contribution to Argo. A legal and governance framework (Euro-Argo ERIC) was set up in May 2014; it allows European countries to consolidate and improve their contribution to Argo international. We will provide an overview of the development of Euro-Argo over the past years and present the now agreed Euro-Argo long term organization. The capability of the Euro-Argo infrastructure to organize Argo floats procurement, deployment and processing at European level and to conduct R&D driven by Copernicus needs will be highlighted. During the recent years, within the H2020 E-AIMS project, Euro-Argo carried R&D activities on new Argo floats, equipped with biogeochemical sensors or able to dive up to 4000m, from the floats design up to the analysis of their measurements. European Argo data centers were adapted so that they can handle the new data. Observing System Evaluations and Simulation Experiments were also conducted to provide robust recommendations for the next phase of Argo. One of the main challenges for Euro-Argo is now to implement the next phase of Argo with an extension towards biogeochemistry (e.g. oxygen, biology), the polar oceans, the marginal seas and the deep ocean. Meeting such challenges is essential for the long term sustainability and evolution of the Copernicus Marine Service. We will present Euro-Argo strategy and provide some highlights on the implementation-plan for the years to come and the Argo extensions for the

Twenty-first century wave climate projections for Ireland and surface winds in the North Atlantic Ocean

Science.gov (United States)

Gallagher, Sarah; Gleeson, Emily; Tiron, Roxana; McGrath, Ray; Dias, Frédéric

2016-04-01

Ireland has a highly energetic wave and wind climate, and is therefore uniquely placed in terms of its ocean renewable energy resource. The socio-economic importance of the marine resource to Ireland makes it critical to quantify how the wave and wind climate may change in the future due to global climate change. Projected changes in winds, ocean waves and the frequency and severity of extreme weather events should be carefully assessed for long-term marine and coastal planning. We derived an ensemble of future wave climate projections for Ireland using the EC-Earth global climate model and the WAVEWATCH III® wave model, by comparing the future 30-year period 2070-2099 to the period 1980-2009 for the RCP4.5 and the RCP8.5 forcing scenarios. This dataset is currently the highest resolution wave projection dataset available for Ireland. The EC-Earth ensemble predicts decreases in mean (up to 2 % for RCP4.5 and up to 3.5 % for RCP8.5) 10 m wind speeds over the North Atlantic Ocean (5-75° N, 0-80° W) by the end of the century, which will consequently affect swell generation for the Irish wave climate. The WAVEWATCH III® model predicts an overall decrease in annual and seasonal mean significant wave heights around Ireland, with the largest decreases in summer (up to 15 %) and winter (up to 10 %) for RCP8.5. Projected decreases in mean significant wave heights for spring and autumn were found to be small for both forcing scenarios (less than 5 %), with no significant decrease found for RCP4.5 off the west coast in those seasons.

From global to regional and back again: common climate stressors of marine ecosystems relevant for adaptation across five ocean warming hotspots.

Science.gov (United States)

Popova, Ekaterina; Yool, Andrew; Byfield, Valborg; Cochrane, Kevern; Coward, Andrew C; Salim, Shyam S; Gasalla, Maria A; Henson, Stephanie A; Hobday, Alistair J; Pecl, Gretta T; Sauer, Warwick H; Roberts, Michael J

2016-06-01

Ocean warming 'hotspots' are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2 -driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future

A Canonical Response in Rainfall Characteristics to Global Warming: Projections by IPCC CMIP5 Models

Science.gov (United States)

Lau, William K. M.; Wu, H. T.; Kim, K. M.

2012-01-01

Changes in rainfall characteristics induced by global warming are examined based on probability distribution function (PDF) analysis, from outputs of 14 IPCC (Intergovernmental Panel on Climate Change), CMIP (5th Coupled Model Intercomparison Project) models under various scenarios of increased CO2 emissions. Results show that collectively CMIP5 models project a robust and consistent global and regional rainfall response to CO2 warming. Globally, the models show a 1-3% increase in rainfall per degree rise in temperature, with a canonical response featuring large increase (100-250 %) in frequency of occurrence of very heavy rain, a reduction (5-10%) of moderate rain, and an increase (10-15%) of light rain events. Regionally, even though details vary among models, a majority of the models (>10 out of 14) project a consistent large scale response with more heavy rain events in climatologically wet regions, most pronounced in the Pacific ITCZ and the Asian monsoon. Moderate rain events are found to decrease over extensive regions of the subtropical and extratropical oceans, but increases over the extratropical land regions, and the Southern Oceans. The spatial distribution of light rain resembles that of moderate rain, but mostly with opposite polarity. The majority of the models also show increase in the number of dry events (absence or only trace amount of rain) over subtropical and tropical land regions in both hemispheres. These results suggest that rainfall characteristics are changing and that increased extreme rainfall events and droughts occurrences are connected, as a consequent of a global adjustment of the large scale circulation to global warming.

Spacebased Observation of Water Balance Over Global Oceans

Science.gov (United States)

Liu, W.; Xie, X.

2008-12-01

We demonstrated that ocean surface fresh water flux less the water discharge into the ocean from river and ice melt balances the mass loss in the ocean both in magnitude and in the phase of annual variation. The surface water flux was computed from the divergence of the water transport integrated over the depth of the atmosphere. The atmospheric water transport is estimated from the precipitable water measured by Special Sensor Microwave Imager, the surface wind vector by QuikSCAT, and the NOAA cloud drift wind through a statistical model. The transport has been extensively validated using global radiosonde and data and operational numerical weather prediction results. Its divergence has been shown to agree with the difference between evaporation estimated from the Advanced Microwave Scanning Radiometer data and the precipitation measured by Tropical Rain Measuring Mission over the global tropical and subtropical oceans both in magnitude and geographical distribution for temporal scales ranging from intraseasonal to interannual. The water loss rate in the ocean is estimated by two methods, one is from Gravity Recovery and Climate Experiment and the other is by subtracting the climatological steric change from the sea level change measured by radar altimeter on Jason. Only climatological river discharge and ice melt from in situ measurements are available and the lack of temporal variation may contribute to discrepancies in the balance. We have successfully used the spacebased surface fluxes to estimate to climatological mean heat transport in the Atlantic ocean and is attempting to estimate the meridional fresh water (or salt) transport from the surface flux. The approximate closure of the water balance gives a powerful indirect validation of the spacebased products.

Remote sensing for global change, climate change and atmosphere and ocean forecasting. Volume 1

International Nuclear Information System (INIS)

1992-01-01

This volume is separated in three sessions. First part is on remote sensing for global change (with global modelling, land cover change on global scale, ocean colour studies of marine biosphere, biological and hydrological interactions and large scale experiments). Second part is on remote sensing for climate change (with earth radiation and clouds, sea ice, global climate research programme). Third part is on remote sensing for atmosphere and ocean forecasting (with temperatures and humidity, winds, data assimilation, cloud imagery, sea surface temperature, ocean waves and topography). (A.B.). refs., figs., tabs

Bioavailable atmospheric phosphorous supply to the global ocean: a 3-D global modeling study

Science.gov (United States)

Myriokefalitakis, Stelios; Nenes, Athanasios; Baker, Alex R.; Mihalopoulos, Nikolaos; Kanakidou, Maria

2016-12-01

The atmospheric cycle of phosphorus (P) is parameterized here in a state-of-the-art global 3-D chemistry transport model, taking into account primary emissions of total P (TP) and soluble P (DP) associated with mineral dust, combustion particles from natural and anthropogenic sources, bioaerosols, sea spray and volcanic aerosols. For the present day, global TP emissions are calculated to be roughly 1.33 Tg-P yr-1, with the mineral sources contributing more than 80 % to these emissions. The P solubilization from mineral dust under acidic atmospheric conditions is also parameterized in the model and is calculated to contribute about one-third (0.14 Tg-P yr-1) of the global DP atmospheric source. To our knowledge, a unique aspect of our global study is the explicit modeling of the evolution of phosphorus speciation in the atmosphere. The simulated present-day global annual DP deposition flux is 0.45 Tg-P yr-1 (about 40 % over oceans), showing a strong spatial and temporal variability. Present-day simulations of atmospheric P aerosol concentrations and deposition fluxes are satisfactory compared with available observations, indicating however an underestimate of about 70 % on current knowledge of the sources that drive the P atmospheric cycle. Sensitivity simulations using preindustrial (year 1850) anthropogenic and biomass burning emission scenarios showed a present-day increase of 75 % in the P solubilization flux from mineral dust, i.e., the rate at which P is converted into soluble forms, compared to preindustrial times, due to increasing atmospheric acidity over the last 150 years. Future reductions in air pollutants due to the implementation of air-quality regulations are expected to decrease the P solubilization flux from mineral dust by about 30 % in the year 2100 compared to the present day. Considering, however, that all the P contained in bioaerosols is readily available for uptake by marine organisms, and also accounting for all other DP sources, a total

AFSC/ABL: Global Ocean Ecosystems Dynamics (GLOBEC) fish and oceanography data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Understanding the processes that regulate early marine survival of salmon is a major goal of the Global Ocean Ecosystems Dynamics (GLOBEC) Northeast Pacific (NEP)...

Aquantis C-Plane Ocean Current Turbine Project

Energy Technology Data Exchange (ETDEWEB)

Fleming, Alex [Dehlsen Associates, LLC, Santa Barbara, CA (United States)

2015-09-16

The Aquantis 2.5 MW Ocean Current Generation Device technology developed by Dehlsen Associates, LLC (DA) is a derivation of wind power generating technology (a means of harnessing a slow moving fluid) adapted to the ocean environment. The Aquantis Project provides an opportunity for accelerated technological development and early commercialization, since it involves the joining of two mature disciplines: ocean engineering and wind turbine design. The Aquantis Current Plane (C-Plane) technology is an ocean current turbine designed to extract kinetic energy from a current flow. The technology is capable of achieving competitively priced, continuous, base-load, and reliable power generation from a source of renewable energy not before possible in this scale or form.

The influence of Southern Ocean surface buoyancy forcing on glacial-interglacial changes in the global deep ocean stratification

OpenAIRE

Sun, S; Eisenman, I; Stewart, AL

2016-01-01

©2016. American Geophysical Union. All Rights Reserved. Previous studies have suggested that the global ocean density stratification below ∼3000 m is approximately set by its direct connection to the Southern Ocean surface density, which in turn is constrained by the atmosphere. Here the role of Southern Ocean surface forcing in glacial-interglacial stratification changes is investigated using a comprehensive climate model and an idealized conceptual model. Southern Ocean surface forcing is f...

GLOBEC: Global Ocean Ecosystems Dynamics: A component of the US Global Change Research Program

Science.gov (United States)

1991-01-01

GLOBEC (GLOBal ocean ECosystems dynamics) is a research initiative proposed by the oceanographic and fisheries communities to address the question of how changes in global environment are expected to affect the abundance and production of animals in the sea. The approach to this problem is to develop a fundamental understanding of the mechanisms that determine both the abundance of key marine animal populations and their variances in space and time. The assumption is that the physical environment is a major contributor to patterns of abundance and production of marine animals, in large part because the planktonic life stages typical of most marine animals are intrinsically at the mercy of the fluid motions of the medium in which they live. Consequently, the authors reason that a logical approach to predicting the potential impact of a globally changing environment is to understand how the physical environment, both directly and indirectly, contributes to animal abundance and its variability in marine ecosystems. The plans for this coordinated study of of the potential impact of global change on ocean ecosystems dynamics are discussed.

Assessment of Global Forecast Ocean Assimilation Model (FOAM) using new satellite SST data

Science.gov (United States)

Ascione Kenov, Isabella; Sykes, Peter; Fiedler, Emma; McConnell, Niall; Ryan, Andrew; Maksymczuk, Jan

2016-04-01

There is an increased demand for accurate ocean weather information for applications in the field of marine safety and navigation, water quality, offshore commercial operations, monitoring of oil spills and pollutants, among others. The Met Office, UK, provides ocean forecasts to customers from governmental, commercial and ecological sectors using the Global Forecast Ocean Assimilation Model (FOAM), an operational modelling system which covers the global ocean and runs daily, using the NEMO (Nucleus for European Modelling of the Ocean) ocean model with horizontal resolution of 1/4° and 75 vertical levels. The system assimilates salinity and temperature profiles, sea surface temperature (SST), sea surface height (SSH), and sea ice concentration observations on a daily basis. In this study, the FOAM system is updated to assimilate Advanced Microwave Scanning Radiometer 2 (AMSR2) and the Spinning Enhanced Visible and Infrared Imager (SEVIRI) SST data. Model results from one month trials are assessed against observations using verification tools which provide a quantitative description of model performance and error, based on statistical metrics, including mean error, root mean square error (RMSE), correlation coefficient, and Taylor diagrams. A series of hindcast experiments is used to run the FOAM system with AMSR2 and SEVIRI SST data, using a control run for comparison. Results show that all trials perform well on the global ocean and that largest SST mean errors were found in the Southern hemisphere. The geographic distribution of the model error for SST and temperature profiles are discussed using statistical metrics evaluated over sub-regions of the global ocean.

Vertical eddy diffusion as a key mechanism for removing perfluorooctanoic acid (PFOA) from the global surface oceans

International Nuclear Information System (INIS)

Lohmann, Rainer; Jurado, Elena; Dijkstra, Henk A.; Dachs, Jordi

2013-01-01

Here we estimate the importance of vertical eddy diffusion in removing perfluorooctanoic acid (PFOA) from the surface Ocean and assess its importance as a global sink. Measured water column profiles of PFOA were reproduced by assuming that vertical eddy diffusion in a 3-layer ocean model is the sole cause for the transport of PFOA to depth. The global oceanic sink due to eddy diffusion for PFOA is high, with accumulated removal fluxes over the last 40 years of 660 t, with the Atlantic Ocean accounting for 70% of the global oceanic sink. The global oceans have removed 13% of all PFOA produced to a depth greater than 100 m via vertical eddy diffusion; an additional 4% has been removed via deep water formation. The top 100 m of the surface oceans store another 21% of all PFOA produced (∼1100 t). Highlights: •Eddy diffusion has removed ∼660 t of PFOA from surface oceans over the last 40 years. •Atlantic Ocean accounts for 70% of the global oceanic sink of PFOA. •Vertical eddy diffusion has moved ∼13% of PFOA to oceans deeper than 100 m. •Around 4% of PFOA has been removed via deep water formation. •The top 100 m of global oceans contain ∼21% of historical PFOA production. -- Vertical eddy diffusion is an important removal process for hydrophilic organic pollutants such as PFOA from the surface ocean

Log-Normal Turbulence Dissipation in Global Ocean Models

Science.gov (United States)

Pearson, Brodie; Fox-Kemper, Baylor

2018-03-01

Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly log-normal distribution even at large horizontal scales O (10 km ) . As the horizontal scales of resolved turbulence are larger than the ocean is deep, the Kolmogorov-Yaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply; instead, the down-scale potential enstrophy cascade of quasigeostrophic turbulence should. Yet, energy dissipation obeys approximate log-normality—robustly across depths, seasons, regions, and subgrid schemes. The distribution parameters, skewness and kurtosis, show small systematic departures from log-normality with depth and subgrid friction schemes. Log-normality suggests that a few high-dissipation locations dominate the integrated energy and enstrophy budgets, which should be taken into account when making inferences from simplified models and inferring global energy budgets from sparse observations.

Global equivalent magnetization of the oceanic lithosphere

Science.gov (United States)

Dyment, J.; Choi, Y.; Hamoudi, M.; Lesur, V.; Thebault, E.

2015-11-01

As a by-product of the construction of a new World Digital Magnetic Anomaly Map over oceanic areas, we use an original approach based on the global forward modeling of seafloor spreading magnetic anomalies and their comparison to the available marine magnetic data to derive the first map of the equivalent magnetization over the World's ocean. This map reveals consistent patterns related to the age of the oceanic lithosphere, the spreading rate at which it was formed, and the presence of mantle thermal anomalies which affects seafloor spreading and the resulting lithosphere. As for the age, the equivalent magnetization decreases significantly during the first 10-15 Myr after its formation, probably due to the alteration of crustal magnetic minerals under pervasive hydrothermal alteration, then increases regularly between 20 and 70 Ma, reflecting variations in the field strength or source effects such as the acquisition of a secondary magnetization. As for the spreading rate, the equivalent magnetization is twice as strong in areas formed at fast rate than in those formed at slow rate, with a threshold at ∼40 km/Myr, in agreement with an independent global analysis of the amplitude of Anomaly 25. This result, combined with those from the study of the anomalous skewness of marine magnetic anomalies, allows building a unified model for the magnetic structure of normal oceanic lithosphere as a function of spreading rate. Finally, specific areas affected by thermal mantle anomalies at the time of their formation exhibit peculiar equivalent magnetization signatures, such as the cold Australian-Antarctic Discordance, marked by a lower magnetization, and several hotspots, marked by a high magnetization.

Ocean heat content and ocean energy budget: make better use of historical global subsurface temperature dataset

Science.gov (United States)

Cheng, L.; Zhu, J.

2016-02-01

Ocean heat content (OHC) change contributes substantially to global sea level rise, also is a key metric of the ocean/global energy budget, so it is a vital task for the climate research community to estimate historical OHC. While there are large uncertainties regarding its value, here we review the OHC calculation by using the historical global subsurface temperature dataset, and discuss the sources of its uncertainty. The presentation briefly introduces how to correct to the systematic biases in expendable bathythermograph (XBT) data, a alternative way of filling data gaps (which is main focus of this talk), and how to choose a proper climatology. A new reconstruction of historical upper (0-700 m) OHC change will be presented, which is the Institute of Atmospheric Physics (IAP) version of historical upper OHC assessment. The authors also want to highlight the impact of observation system change on OHC calculation, which could lead to bias in OHC estimates. Furthermore, we will compare the updated observational-based estimates on ocean heat content change since 1970s with CMIP5 results. This comparison shows good agreement, increasing the confidence of the climate models in representing the climate history.

Penetration of UV-visible solar radiation in the global oceans: Insights from ocean color remote sensing

Science.gov (United States)

Lee, Zhongping; Hu, Chuanmin; Shang, Shaoling; Du, Keping; Lewis, Marlon; Arnone, Robert; Brewin, Robert

2013-09-01

Penetration of solar radiation in the ocean is determined by the attenuation coefficient (Kd(λ)). Following radiative transfer theory, Kd is a function of angular distribution of incident light and water's absorption and backscattering coefficients. Because these optical products are now generated routinely from satellite measurements, it is logical to evolve the empirical Kd to a semianalytical Kd that is not only spectrally flexible, but also the sun-angle effect is accounted for explicitly. Here, the semianalytical model developed in Lee et al. (2005b) is revised to account for the shift of phase function between molecular and particulate scattering from the short to long wavelengths. Further, using field data collected independently from oligotrophic ocean to coastal waters covering >99% of the Kd range for the global oceans, the semianalytically derived Kd was evaluated and found to agree with measured data within ˜7-26%. The updated processing system was applied to MODIS measurements to reveal the penetration of UVA-visible radiation in the global oceans, where an empirical procedure to correct Raman effect was also included. The results indicated that the penetration of the blue-green radiation for most oceanic waters is ˜30-40% deeper than the commonly used euphotic zone depth; and confirmed that at a depth of 50-70 m there is still ˜10% of the surface UVA radiation (at 360 nm) in most oligotrophic waters. The results suggest a necessity to modify or expand the light attenuation product from satellite ocean-color measurements in order to be more applicable for studies of ocean physics and biogeochemistry.

Retrieving Temperature Anomaly in the Global Subsurface and Deeper Ocean From Satellite Observations

Science.gov (United States)

Su, Hua; Li, Wene; Yan, Xiao-Hai

2018-01-01

Retrieving the subsurface and deeper ocean (SDO) dynamic parameters from satellite observations is crucial for effectively understanding ocean interior anomalies and dynamic processes, but it is challenging to accurately estimate the subsurface thermal structure over the global scale from sea surface parameters. This study proposes a new approach based on Random Forest (RF) machine learning to retrieve subsurface temperature anomaly (STA) in the global ocean from multisource satellite observations including sea surface height anomaly (SSHA), sea surface temperature anomaly (SSTA), sea surface salinity anomaly (SSSA), and sea surface wind anomaly (SSWA) via in situ Argo data for RF training and testing. RF machine-learning approach can accurately retrieve the STA in the global ocean from satellite observations of sea surface parameters (SSHA, SSTA, SSSA, SSWA). The Argo STA data were used to validate the accuracy and reliability of the results from the RF model. The results indicated that SSHA, SSTA, SSSA, and SSWA together are useful parameters for detecting SDO thermal information and obtaining accurate STA estimations. The proposed method also outperformed support vector regression (SVR) in global STA estimation. It will be a useful technique for studying SDO thermal variability and its role in global climate system from global-scale satellite observations.

The self-consistent dynamic pole tide in global oceans

Science.gov (United States)

Dickman, S. R.

1985-01-01

The dynamic pole tide is characterized in a self-consistent manner by means of introducing a single nondifferential matrix equation compatible with the Liouville equation, modelling the ocean as global and of uniform depth. The deviations of the theory from the realistic ocean, associated with the nonglobality of the latter, are also given consideration, with an inference that in realistic oceans long-period modes of resonances would be increasingly likely to exist. The analysis of the nature of the pole tide and its effects on the Chandler wobble indicate that departures of the pole tide from the equilibrium may indeed be minimal.

C-GLORSv5: an improved multipurpose global ocean eddy-permitting physical reanalysis

OpenAIRE

A. Storto; S. Masina

2016-01-01

Global ocean reanalyses combine in situ and satellite ocean observations with a general circulation ocean model to estimate the time-evolving state of the ocean, and they represent a valuable tool for a variety of applications, ranging from climate monitoring and process studies to downstream applications, initialization of long-range forecasts and regional studies. The purpose of this paper is to document the recent upgrade of C-GLORS (version 5), the latest ocean reanalysi...

Scientists’ perspectives on global ocean research priorities

Directory of Open Access Journals (Sweden)

Murray Alan Rudd

2014-08-01

Full Text Available Diverse natural and social science research is needed to support policies to recover and sustain healthy oceans. While a wide variety of expert-led prioritization initiatives have identified research themes and priorities at national and regional scale, over the past several years there has also been a surge in the number of scanning exercises that have identified important environmental research questions and issues ‘from the bottom-up’. From those questions, winnowed from thousands of contributions by scientists and policy-makers around the world who participated in terrestrial, aquatic and domain-specific horizon scanning and big question exercises, I identified 657 research questions potentially important for informing decisions regarding ocean governance and sustainability. These were distilled to a short list of 67 distinctive research questions that, in an internet survey, were ranked by 2179 scientists from 94 countries. Five of the top 10 research priorities were shared by respondents globally. Despite significant differences between physical and ecological scientists’ priorities regarding specific research questions, they shared seven common priorities among their top 10. Social scientists’ priorities were, however, much different, highlighting their research focus on managerial solutions to ocean challenges and questions regarding the role of human behavior and values in attaining ocean sustainability. The results from this survey provide a comprehensive and timely assessment of current ocean research priorities among research-active scientists but highlight potential challenges in stimulating crossdisciplinary research. As ocean and coastal research necessarily becomes more transdisciplinary to address complex ocean challenges, it will be critical for scientists and research funders to understand how scientists from different disciplines and regions might collaborate and strengthen the overall evidence base for ocean

Using Green's Functions to initialize and adjust a global, eddying ocean biogeochemistry general circulation model

Science.gov (United States)

Brix, H.; Menemenlis, D.; Hill, C.; Dutkiewicz, S.; Jahn, O.; Wang, D.; Bowman, K.; Zhang, H.

2015-11-01

The NASA Carbon Monitoring System (CMS) Flux Project aims to attribute changes in the atmospheric accumulation of carbon dioxide to spatially resolved fluxes by utilizing the full suite of NASA data, models, and assimilation capabilities. For the oceanic part of this project, we introduce ECCO2-Darwin, a new ocean biogeochemistry general circulation model based on combining the following pre-existing components: (i) a full-depth, eddying, global-ocean configuration of the Massachusetts Institute of Technology general circulation model (MITgcm), (ii) an adjoint-method-based estimate of ocean circulation from the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) project, (iii) the MIT ecosystem model "Darwin", and (iv) a marine carbon chemistry model. Air-sea gas exchange coefficients and initial conditions of dissolved inorganic carbon, alkalinity, and oxygen are adjusted using a Green's Functions approach in order to optimize modeled air-sea CO2 fluxes. Data constraints include observations of carbon dioxide partial pressure (pCO2) for 2009-2010, global air-sea CO2 flux estimates, and the seasonal cycle of the Takahashi et al. (2009) Atlas. The model sensitivity experiments (or Green's Functions) include simulations that start from different initial conditions as well as experiments that perturb air-sea gas exchange parameters and the ratio of particulate inorganic to organic carbon. The Green's Functions approach yields a linear combination of these sensitivity experiments that minimizes model-data differences. The resulting initial conditions and gas exchange coefficients are then used to integrate the ECCO2-Darwin model forward. Despite the small number (six) of control parameters, the adjusted simulation is significantly closer to the data constraints (37% cost function reduction, i.e., reduction in the model-data difference, relative to the baseline simulation) and to independent observations (e.g., alkalinity). The adjusted air-sea gas

Dynamic biogeochemical provinces in the global ocean

Science.gov (United States)

Reygondeau, Gabriel; Longhurst, Alan; Martinez, Elodie; Beaugrand, Gregory; Antoine, David; Maury, Olivier

2013-12-01

In recent decades, it has been found useful to partition the pelagic environment using the concept of biogeochemical provinces, or BGCPs, within each of which it is assumed that environmental conditions are distinguishable and unique at global scale. The boundaries between provinces respond to features of physical oceanography and, ideally, should follow seasonal and interannual changes in ocean dynamics. But this ideal has not been fulfilled except for small regions of the oceans. Moreover, BGCPs have been used only as static entities having boundaries that were originally established to compute global primary production. In the present study, a new statistical methodology based on non-parametric procedures is implemented to capture the environmental characteristics within 56 BGCPs. Four main environmental parameters (bathymetry, chlorophyll a concentration, surface temperature, and salinity) are used to infer the spatial distribution of each BGCP over 1997-2007. The resulting dynamic partition allows us to integrate changes in the distribution of BGCPs at seasonal and interannual timescales, and so introduces the possibility of detecting spatial shifts in environmental conditions.

A Compilation of Global Bio-Optical in Situ Data for Ocean-Colour Satellite Applications

Science.gov (United States)

Valente, Andre; Sathyendranath, Shubha; Brotus, Vanda; Groom, Steve; Grant, Michael; Taberner, Malcolm; Antoine, David; Arnone, Robert; Balch, William M.; Barker, Kathryn;

Global Ocean Sedimentation Patterns: Plate Tectonic History Versus Climate Change

Science.gov (United States)

Goswami, A.; Reynolds, E.; Olson, P.; Hinnov, L. A.; Gnanadesikan, A.

2014-12-01

Global sediment data (Whittaker et al., 2013) and carbonate content data (Archer, 1996) allows examination of ocean sedimentation evolution with respect to age of the underlying ocean crust (Müller et al., 2008). From these data, we construct time series of ocean sediment thickness and carbonate deposition rate for the Atlantic, Pacific, and Indian ocean basins for the past 120 Ma. These time series are unique to each basin and reflect an integrated response to plate tectonics and climate change. The goal is to parameterize ocean sedimentation tied to crustal age for paleoclimate studies. For each basin, total sediment thickness and carbonate deposition rate from 0.1 x 0.1 degree cells are binned according to basement crustal age; area-corrected moments (mean, variance, etc.) are calculated for each bin. Segmented linear fits identify trends in present-day carbonate deposition rates and changes in ocean sedimentation from 0 to 120 Ma. In the North and South Atlantic and Indian oceans, mean sediment thickness versus crustal age is well represented by three linear segments, with the slope of each segment increasing with increasing crustal age. However, the transition age between linear segments varies among the three basins. In contrast, mean sediment thickness in the North and South Pacific oceans are numerically smaller and well represented by two linear segments with slopes that decrease with increasing crustal age. These opposing trends are more consistent with the plate tectonic history of each basin being the controlling factor in sedimentation rates, rather than climate change. Unlike total sediment thickness, carbonate deposition rates decrease smoothly with crustal age in all basins, with the primary controls being ocean chemistry and water column depth.References: Archer, D., 1996, Global Biogeochem. Cycles 10, 159-174.Müller, R.D., et al., 2008, Science, 319, 1357-1362.Whittaker, J., et al., 2013, Geochem., Geophys., Geosyst. DOI: 10.1002/ggge.20181

Global biogeography of Prochlorococcus genome diversity in the surface ocean.

Science.gov (United States)

Kent, Alyssa G; Dupont, Chris L; Yooseph, Shibu; Martiny, Adam C

2016-08-01

Prochlorococcus, the smallest known photosynthetic bacterium, is abundant in the ocean's surface layer despite large variation in environmental conditions. There are several genetically divergent lineages within Prochlorococcus and superimposed on this phylogenetic diversity is extensive gene gain and loss. The environmental role in shaping the global ocean distribution of genome diversity in Prochlorococcus is largely unknown, particularly in a framework that considers the vertical and lateral mechanisms of evolution. Here we show that Prochlorococcus field populations from a global circumnavigation harbor extensive genome diversity across the surface ocean, but this diversity is not randomly distributed. We observed a significant correspondence between phylogenetic and gene content diversity, including regional differences in both phylogenetic composition and gene content that were related to environmental factors. Several gene families were strongly associated with specific regions and environmental factors, including the identification of a set of genes related to lower nutrient and temperature regions. Metagenomic assemblies of natural Prochlorococcus genomes reinforced this association by providing linkage of genes across genomic backbones. Overall, our results show that the phylogeography in Prochlorococcus taxonomy is echoed in its genome content. Thus environmental variation shapes the functional capabilities and associated ecosystem role of the globally abundant Prochlorococcus.

The role of clouds and oceans in global greenhouse warming. Final report

Energy Technology Data Exchange (ETDEWEB)

Hoffert, M.I.

1996-10-01

This research focuses on assessing connections between anthropogenic greenhouse gas emissions and global climatic change. it has been supported since the early 1990s in part by the DOE ``Quantitative Links`` Program (QLP). A three-year effort was originally proposed to the QLP to investigate effects f global cloudiness on global climate and its implications for cloud feedback; and to continue the development and application of climate/ocean models, with emphasis on coupled effects of greenhouse warming and feedbacks by clouds and oceans. It is well-known that cloud and ocean processes are major sources of uncertainty in the ability to predict climatic change from humankind`s greenhouse gas and aerosol emissions. And it has always been the objective to develop timely and useful analytical tools for addressing real world policy issues stemming from anthropogenic climate change.

The GULLS project: a comparison of vulnerabilities across selected ocean hotspots and implications for adaptation to global change.

Science.gov (United States)

Cochrane, K.; Hobday, A. J.; Aswani, S.; Byfield, V.; Dutra, L.; Gasalla, M.; Haward, M.; Paytan, A.; Pecl, G.; Plaganyi-Lloyd, E.; Popova, K.; Salim, S. S.; Savage, C.; Sauer, W.; van Putten, I. E.; Visser, N.; Team, T G

2016-12-01

The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.

Patterns and Variability in Global Ocean Chlorophyll: Satellite Observations and Modeling

Science.gov (United States)

Gregg, Watson

2004-01-01

Recent analyses of SeaWiFS data have shown that global ocean chlorophyll has increased more than 4% since 1998. The North Pacific ocean basin has increased nearly 19%. These trend analyses follow earlier results showing decadal declines in global ocean chlorophyll and primary production. To understand the causes of these changes and trends we have applied the newly developed NASA Ocean Biogeochemical Assimilation Model (OBAM), which is driven in mechanistic fashion by surface winds, sea surface temperature, atmospheric iron deposition, sea ice, and surface irradiance. The model utilizes chlorophyll from SeaWiFS in a daily assimilation. The model has in place many of the climatic variables that can be expected to produce the changes observed in SeaWiFS data. This enables us to diagnose the model performance, the assimilation performance, and possible causes for the increase in chlorophyll. A full discussion of the changes and trends, possible causes, modeling approaches, and data assimilation will be the focus of the seminar.

Drivers of fluorescent dissolved organic matter in the global epipelagic ocean

KAUST Repository

Catalá, T. S.

2016-03-24

Fluorescent dissolved organic matter (FDOM) in open surface waters (< 200 m) of the Atlantic, Pacific, and Indian oceans was analysed by excitation-emission matrix (EEM) spectroscopy and parallel factor analysis (PARAFAC). A four-component PARAFAC model was fit to the EEMs, which included two humic- (C1 and C2) and two amino acid-like (C3 and C4) components previously identified in ocean waters. Generalized-additive models (GAMs) were used to explore the environmental factors that drive the global distribution of these PARAFAC components. The explained variance for the humic-like components was substantially larger (> 70%) than for the amino acid-like components (< 35%). The environmental variables exhibiting the largest effect on the global distribution of C1 and C2 were apparent oxygen utilisation followed by chlorophyll a. Positive non-linear relationships between both predictor variables and the two humic-like PARAFAC components suggest that their distribution are biologically controlled. Compared with the dark ocean (> 200 m), the relationships of C1 and C2 with AOU indicate a higher C1/AOU and C2/AOU ratios of the humic-like substances in the dark ocean than in the surface ocean where a net effect of photobleaching is also detected. C3 (tryptophan-like) and C4 (tyrosine-like) variability was mostly dictated by salinity (S), by means of positive non-linear relationships, suggesting a primary physical control of their distributions at the global surface ocean scale that could be related to the changing evaporation-precipitation regime. Remarkably, bacterial biomass (BB) only contributed to explain a minor part of the variability of C1 and C4.

Global ocean monitoring for the World Climate Research Programme.

Science.gov (United States)

Revelle, R; Bretherton, F

1986-07-01

Oceanic research and modelling for the World Climate Research Program will utilize several recently-developed instruments and measuring techniques as well as well-tested, long-used instruments. Ocean-scanning satellites will map the component of the ocean-surface topography related to ocean currents and mesoscale eddies and to fluctuating water volumes caused by ocean warming and cooling. Other satellite instruments will measure the direction and magnitude of wind stress on the sea surface, surface water temperatures, the distribution of chlorophyll and other photosynthetic pigments, the characteristics of internal waves, and possible precipitation over the ocean. Networks of acoustic transponders will obtain a three-dimensional picture of the distribution of temperature from the surface down to mid-depth and of long-term changes in temperature at depth. Ocean research vessels will determine the distribution and fate of geochemical tracers and will also make high-precision, deep hydrographic casts. Ships of opportunity, using expendable instruments, will measure temperature, salinity and currents in the upper water layers. Drifting and anchored buoys will also measure these properties as well as those of the air above the sea surface. Tide gauges installed on islands and exposed coastal locations will measure variations in monthly and shorter-period mean sea level. These tide gauges will provide 'ground truth' for the satellite maps of sea-surface topography, and will also determine variations in ocean currents and temperature.All these instruments will be used in several major programs, the most ambitious of which is the World Ocean Circulation Experiment (WOCE) designed to obtain global measurements of major currents throughout the world ocean, greater understanding of the transformation of water masses, and the role of advective, convective, and turbulent processes in exchange of properties between surface and deep-ocean layers.A five- to ten-year experiment

C-GLORSv5: an improved multipurpose global ocean eddy-permitting physical reanalysis

Science.gov (United States)

Storto, Andrea; Masina, Simona

2016-11-01

Global ocean reanalyses combine in situ and satellite ocean observations with a general circulation ocean model to estimate the time-evolving state of the ocean, and they represent a valuable tool for a variety of applications, ranging from climate monitoring and process studies to downstream applications, initialization of long-range forecasts and regional studies. The purpose of this paper is to document the recent upgrade of C-GLORS (version 5), the latest ocean reanalysis produced at the Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC) that covers the meteorological satellite era (1980-present) and it is being updated in delayed time mode. The reanalysis is run at eddy-permitting resolution (1/4° horizontal resolution and 50 vertical levels) and consists of a three-dimensional variational data assimilation system, a surface nudging and a bias correction scheme. With respect to the previous version (v4), C-GLORSv5 contains a number of improvements. In particular, background- and observation-error covariances have been retuned, allowing a flow-dependent inflation in the globally averaged background-error variance. An additional constraint on the Arctic sea-ice thickness was introduced, leading to a realistic ice volume evolution. Finally, the bias correction scheme and the initialization strategy were retuned. Results document that the new reanalysis outperforms the previous version in many aspects, especially in representing the variability of global heat content and associated steric sea level in the last decade, the top 80 m ocean temperature biases and root mean square errors, and the Atlantic Ocean meridional overturning circulation; slight worsening in the high-latitude salinity and deep ocean temperature emerge though, providing the motivation for further tuning of the reanalysis system. The dataset is available in NetCDF format at doi:10.1594/PANGAEA.857995.

The bioeroding sponge Cliona orientalis will not tolerate future projected ocean warming.

Science.gov (United States)

Ramsby, Blake D; Hoogenboom, Mia O; Smith, Hillary A; Whalan, Steve; Webster, Nicole S

2018-05-29

Coral reefs face many stressors associated with global climate change, including increasing sea surface temperature and ocean acidification. Excavating sponges, such as Cliona spp., are expected to break down reef substrata more quickly as seawater becomes more acidic. However, increased bioerosion requires that Cliona spp. maintain physiological performance and health under continuing ocean warming. In this study, we exposed C. orientalis to temperature increments increasing from 23 to 32 °C. At 32 °C, or 3 °C above the maximum monthly mean (MMM) temperature, sponges bleached and the photosynthetic capacity of Symbiodinium was compromised, consistent with sympatric corals. Cliona orientalis demonstrated little capacity to recover from thermal stress, remaining bleached with reduced Symbiodinium density and energy reserves after one month at reduced temperature. In comparison, C. orientalis was not observed to bleach during the 2017 coral bleaching event on the Great Barrier Reef, when temperatures did not reach the 32 °C threshold. While C. orientalis can withstand current temperature extremes (<3 °C above MMM) under laboratory and natural conditions, this species would not survive ocean temperatures projected for 2100 without acclimatisation or adaptation (≥3 °C above MMM). Hence, as ocean temperatures increase above local thermal thresholds, C. orientalis will have a negligible impact on reef erosion.

Emergence of a global science-business initiative for ocean stewardship.

Science.gov (United States)

Österblom, Henrik; Jouffray, Jean-Baptiste; Folke, Carl; Rockström, Johan

2017-08-22

The ocean represents a fundamental source of micronutrients and protein for a growing world population. Seafood is a highly traded and sought after commodity on international markets, and is critically dependent on healthy marine ecosystems. A global trend of wild stocks being overfished and in decline, as well as multiple sustainability challenges associated with a rapid growth of aquaculture, represent key concerns in relation to the United Nations Sustainable Development Goals. Existing efforts aimed to improve the sustainability of seafood production have generated important progress, primarily at the local and national levels, but have yet to effectively address the global challenges associated with the ocean. This study highlights the importance of transnational corporations in enabling transformative change, and thereby contributes to advancing the limited understanding of large-scale private actors within the sustainability science literature. We describe how we engaged with large seafood producers to coproduce a global science-business initiative for ocean stewardship. We suggest that this initiative is improving the prospects for transformative change by providing novel links between science and business, between wild-capture fisheries and aquaculture, and across geographical space. We argue that scientists can play an important role in facilitating change by connecting knowledge to action among global actors, while recognizing risks associated with such engagement. The methods developed through this case study contribute to identifying key competences in sustainability science and hold promises for other sectors as well.

Emergence of a global science–business initiative for ocean stewardship

Science.gov (United States)

Jouffray, Jean-Baptiste; Folke, Carl; Rockström, Johan

2017-01-01

The ocean represents a fundamental source of micronutrients and protein for a growing world population. Seafood is a highly traded and sought after commodity on international markets, and is critically dependent on healthy marine ecosystems. A global trend of wild stocks being overfished and in decline, as well as multiple sustainability challenges associated with a rapid growth of aquaculture, represent key concerns in relation to the United Nations Sustainable Development Goals. Existing efforts aimed to improve the sustainability of seafood production have generated important progress, primarily at the local and national levels, but have yet to effectively address the global challenges associated with the ocean. This study highlights the importance of transnational corporations in enabling transformative change, and thereby contributes to advancing the limited understanding of large-scale private actors within the sustainability science literature. We describe how we engaged with large seafood producers to coproduce a global science–business initiative for ocean stewardship. We suggest that this initiative is improving the prospects for transformative change by providing novel links between science and business, between wild-capture fisheries and aquaculture, and across geographical space. We argue that scientists can play an important role in facilitating change by connecting knowledge to action among global actors, while recognizing risks associated with such engagement. The methods developed through this case study contribute to identifying key competences in sustainability science and hold promises for other sectors as well. PMID:28784792

Climatological distribution of aragonite saturation state in the global oceans

Science.gov (United States)

Jiang, Li-Qing; Feely, Richard A.; Carter, Brendan R.; Greeley, Dana J.; Gledhill, Dwight K.; Arzayus, Krisa M.

2015-10-01

Aragonite saturation state (Ωarag) in surface and subsurface waters of the global oceans was calculated from up-to-date (through the year of 2012) ocean station dissolved inorganic carbon (DIC) and total alkalinity (TA) data. Surface Ωarag in the open ocean was always supersaturated (Ω > 1), ranging between 1.1 and 4.2. It was above 2.0 (2.0-4.2) between 40°N and 40°S but decreased toward higher latitude to below 1.5 in polar areas. The influences of water temperature on the TA/DIC ratio, combined with the temperature effects on inorganic carbon equilibrium and apparent solubility product (K'sp), explain the latitudinal differences in surface Ωarag. Vertically, Ωarag was highest in the surface mixed layer. Higher hydrostatic pressure, lower water temperature, and more CO2 buildup from biological activity in the absence of air-sea gas exchange helped maintain lower Ωarag in the deep ocean. Below the thermocline, aerobic decomposition of organic matter along the pathway of global thermohaline circulation played an important role in controlling Ωarag distributions. Seasonally, surface Ωarag above 30° latitudes was about 0.06 to 0.55 higher during warmer months than during colder months in the open-ocean waters of both hemispheres. Decadal changes of Ωarag in the Atlantic and Pacific Oceans showed that Ωarag in waters shallower than 100 m depth decreased by 0.10 ± 0.09 (-0.40 ± 0.37% yr-1) on average from the decade spanning 1989-1998 to the decade spanning 1998-2010.

The CAFE model: A net production model for global ocean phytoplankton

Science.gov (United States)

Silsbe, Greg M.; Behrenfeld, Michael J.; Halsey, Kimberly H.; Milligan, Allen J.; Westberry, Toby K.

2016-12-01

The Carbon, Absorption, and Fluorescence Euphotic-resolving (CAFE) net primary production model is an adaptable framework for advancing global ocean productivity assessments by exploiting state-of-the-art satellite ocean color analyses and addressing key physiological and ecological attributes of phytoplankton. Here we present the first implementation of the CAFE model that incorporates inherent optical properties derived from ocean color measurements into a mechanistic and accurate model of phytoplankton growth rates (μ) and net phytoplankton production (NPP). The CAFE model calculates NPP as the product of energy absorption (QPAR), and the efficiency (ϕμ) by which absorbed energy is converted into carbon biomass (CPhyto), while μ is calculated as NPP normalized to CPhyto. The CAFE model performance is evaluated alongside 21 other NPP models against a spatially robust and globally representative set of direct NPP measurements. This analysis demonstrates that the CAFE model explains the greatest amount of variance and has the lowest model bias relative to other NPP models analyzed with this data set. Global oceanic NPP from the CAFE model (52 Pg C m-2 yr-1) and mean division rates (0.34 day-1) are derived from climatological satellite data (2002-2014). This manuscript discusses and validates individual CAFE model parameters (e.g., QPAR and ϕμ), provides detailed sensitivity analyses, and compares the CAFE model results and parameterization to other widely cited models.

The critical role of ocean container transport in global supply chain performance

NARCIS (Netherlands)

Fransoo, J.C.; Lee, C.Y.

2013-01-01

With supply chains distributed across global markets, ocean container transport now is a critical element of any such supply chain. We identify key characteristics of ocean container transport from a supply chain perspective. We find that unlike continental (road) transport, service offerings tend

Perfluoroalkylated substances in the global tropical and subtropical surface oceans.

Science.gov (United States)

González-Gaya, Belén; Dachs, Jordi; Roscales, Jose L; Caballero, Gemma; Jiménez, Begoña

2014-11-18

In this study, perfluoroalkylated substances (PFASs) were analyzed in 92 surface seawater samples taken during the Malaspina 2010 expedition which covered all the tropical and subtropical Atlantic, Pacific and Indian oceans. Nine ionic PFASs including C6-C10 perfluoroalkyl carboxylic acids (PFCAs), C4 and C6-C8 perfluoroalkyl sulfonic acids (PFSAs) and two neutral precursors perfluoroalkyl sulfonamides (PFASAs), were identified and quantified. The Atlantic Ocean presented the broader range in concentrations of total PFASs (131-10900 pg/L, median 645 pg/L, n = 45) compared to the other oceanic basins, probably due to a better spatial coverage. Total concentrations in the Pacific ranged from 344 to 2500 pg/L (median = 527 pg/L, n = 27) and in the Indian Ocean from 176 to 1976 pg/L (median = 329, n = 18). Perfluorooctanesulfonic acid (PFOS) was the most abundant compound, accounting for 33% of the total PFASs globally, followed by perfluorodecanoic acid (PFDA, 22%) and perfluorohexanoic acid (PFHxA, 12%), being the rest of the individual congeners under 10% of total PFASs, even for perfluorooctane carboxylic acid (PFOA, 6%). PFASAs accounted for less than 1% of the total PFASs concentration. This study reports the ubiquitous occurrence of PFCAs, PFSAs, and PFASAs in the global ocean, being the first attempt, to our knowledge, to show a comprehensive assessment in surface water samples collected in a single oceanic expedition covering tropical and subtropical oceans. The potential factors affecting their distribution patterns were assessed including the distance to coastal regions, oceanic subtropical gyres, currents and biogeochemical processes. Field evidence of biogeochemical controls on the occurrence of PFASs was tentatively assessed considering environmental variables (solar radiation, temperature, chlorophyll a concentrations among others), and these showed significant correlations with some PFASs, but explaining small to moderate percentages of variability

Assimilation of Earth rotation parameters into a global ocean model (FESOM)

Science.gov (United States)

Androsov, A.; Schröter, J.; Brunnabend, S.; Saynisch, J.

2012-04-01

Earth Rotation Parameters (ERP) are used to improve estimates of the ocean circulation and mass budget. GRACE data can be used for verification or for further improvements. The Finite Element Sea-ice Ocean Model (FESOM) is used to simulate weekly ocean circulation and mass variations. The FESOM model is a hydrostatic ocean circulation model with a fully non-linear free surface. It solves the hydrostatic primitive equations with volume (Boussinesq approximation) and mass (Greatbatch correction) conservation. Fresh water exchange with the atmosphere and land is modelled as mass flux. This flux is the weakest part of the mass budget as it is the difference of large and uncertain quantities: evaporation, precipitation and river runoff. All uncertainties included in these parameters are directly reflected in the model results. ERP help in closing the budget in a realistic manner. Our strategy is designed for testing parametric estimation on a weekly basis. First, Oceanographic Earth rotation parameters (OERP) are calculated by subtracting atmospheric and hydrologic estimates from observed ERP. They are compared to OERP derived from a global ocean circulation model. The difference can be inverted to diagnose a correction of the oceanic mass budget. Additionally mass variations measured by GRACE are used for verification. In a second step, the global mass correction parameter, derived by the inversion, is used to improve the fresh water budget of FESOM.

Deep oceans may acidify faster than anticipated due to global warming

Science.gov (United States)

Chen, Chen-Tung Arthur; Lui, Hon-Kit; Hsieh, Chia-Han; Yanagi, Tetsuo; Kosugi, Naohiro; Ishii, Masao; Gong, Gwo-Ching

2017-12-01

Oceans worldwide are undergoing acidification due to the penetration of anthropogenic CO2 from the atmosphere1-4. The rate of acidification generally diminishes with increasing depth. Yet, slowing down of the thermohaline circulation due to global warming could reduce the pH in the deep oceans, as more organic material would decompose with a longer residence time. To elucidate this process, a time-series study at a climatically sensitive region with sufficient duration and resolution is needed. Here we show that deep waters in the Sea of Japan are undergoing reduced ventilation, reducing the pH of seawater. As a result, the acidification rate near the bottom of the Sea of Japan is 27% higher than the rate at the surface, which is the same as that predicted assuming an air-sea CO2 equilibrium. This reduced ventilation may be due to global warming and, as an oceanic microcosm with its own deep- and bottom-water formations, the Sea of Japan provides an insight into how future warming might alter the deep-ocean acidification.

Insights into global diatom distribution and diversity in the world’s ocean

KAUST Repository

Malviya, Shruti; Scalco, Eleonora; Audic, Sté phane; Vincent, Flora; Veluchamy, Alaguraj; Poulain, Julie; Wincker, Patrick; Iudicone, Daniele; de Vargas, Colomban; Bittner, Lucie; Zingone, Adriana; Bowler, Chris

2016-01-01

Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 sizefractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.

Insights into global diatom distribution and diversity in the world’s ocean

KAUST Repository

Malviya, Shruti

2016-03-01

Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 sizefractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.

Respiration of new and old carbon in the surface ocean: Implications for estimates of global oceanic gross primary productivity

Science.gov (United States)

Carvalho, Matheus C.; Schulz, Kai G.; Eyre, Bradley D.

2017-06-01

New respiration (Rnew, of freshly fixated carbon) and old respiration (Rold, of storage carbon) were estimated for different regions of the global surface ocean using published data on simultaneous measurements of the following: (1) primary productivity using 14C (14PP); (2) gross primary productivity (GPP) based on 18O or O2; and (3) net community productivity (NCP) using O2. The ratio Rnew/GPP in 24 h incubations was typically between 0.1 and 0.3 regardless of depth and geographical area, demonstrating that values were almost constant regardless of large variations in temperature (0 to 27°C), irradiance (surface to 100 m deep), nutrients (nutrient-rich and nutrient-poor waters), and community composition (diatoms, flagellates, etc,). As such, between 10 and 30% of primary production in the surface ocean is respired in less than 24 h, and most respiration (between 55 and 75%) was of older carbon. Rnew was most likely associated with autotrophs, with minor contribution from heterotrophic bacteria. Patterns were less clear for Rold. Short 14C incubations are less affected by respiratory losses. Global oceanic GPP is estimated to be between 70 and 145 Gt C yr-1.Plain Language SummaryHere we present a comprehensive coverage of ocean new and old respiration. Our results show that nearly 20% of oceanic gross primary production is consumed in the first 24 h. However, most (about 60%) respiration is of older carbon fixed at least 24 h before its consumption. Rates of new respiration relative to gross primary production were remarkably constant for the entire ocean, which allowed a preliminary estimation of global primary productivity as between 70 and 145 gt C yr-1.

A Global Ocean Tide Model From TOPEX/POSEIDON Altimetry: GOT99.2

Science.gov (United States)

Ray, Richard D.

1999-01-01

Goddard Ocean Tide model GOT99.2 is a new solution for the amplitudes and phases of the global oceanic tides, based on over six years of sea-surface height measurements by the TOPEX/POSEIDON satellite altimeter. Comparison with deep-ocean tide-gauge measurements show that this new tidal solution is an improvement over previous global models, with accuracies for the main semidiurnal lunar constituent M2 now below 1.5 cm (deep water only). The new solution benefits from use of prior hydrodynamic models, several in shallow and inland seas as well as the global finite-element model FES94.1. This report describes some of the data processing details involved in handling the altimetry, and it provides a comprehensive set of global cotidal charts of the resulting solutions. Various derived tidal charts are also provided, including tidal loading deformation charts, tidal gravimetric charts, and tidal current velocity (or transport) charts. Finally, low-degree spherical harmonic coefficients are computed by numerical quadrature and are tabulated for the major short-period tides; these are useful for a variety of geodetic and geophysical purposes, especially in combination with similar estimates from satellite laser ranging.

Estimating Climatological Bias Errors for the Global Precipitation Climatology Project (GPCP)

Science.gov (United States)

Adler, Robert; Gu, Guojun; Huffman, George

2012-01-01

A procedure is described to estimate bias errors for mean precipitation by using multiple estimates from different algorithms, satellite sources, and merged products. The Global Precipitation Climatology Project (GPCP) monthly product is used as a base precipitation estimate, with other input products included when they are within +/- 50% of the GPCP estimates on a zonal-mean basis (ocean and land separately). The standard deviation s of the included products is then taken to be the estimated systematic, or bias, error. The results allow one to examine monthly climatologies and the annual climatology, producing maps of estimated bias errors, zonal-mean errors, and estimated errors over large areas such as ocean and land for both the tropics and the globe. For ocean areas, where there is the largest question as to absolute magnitude of precipitation, the analysis shows spatial variations in the estimated bias errors, indicating areas where one should have more or less confidence in the mean precipitation estimates. In the tropics, relative bias error estimates (s/m, where m is the mean precipitation) over the eastern Pacific Ocean are as large as 20%, as compared with 10%-15% in the western Pacific part of the ITCZ. An examination of latitudinal differences over ocean clearly shows an increase in estimated bias error at higher latitudes, reaching up to 50%. Over land, the error estimates also locate regions of potential problems in the tropics and larger cold-season errors at high latitudes that are due to snow. An empirical technique to area average the gridded errors (s) is described that allows one to make error estimates for arbitrary areas and for the tropics and the globe (land and ocean separately, and combined). Over the tropics this calculation leads to a relative error estimate for tropical land and ocean combined of 7%, which is considered to be an upper bound because of the lack of sign-of-the-error canceling when integrating over different areas with a

Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from PROFESSOR MESYATSYEV, VOZROZHDENIYE and AKADEMIK KNIPOVICH in the North Pacific Ocean, South Atlantic Ocean and South Pacific Ocean from 1973-02-12 to 1990-04-09 (NODC Accession 9600100)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Hydrochemical data in this accession was collected as part of Global Ocean Data Archeaology and Rescue (GODAR) project between February 12, 1973 and April 9,...

Response of the tropical Pacific Ocean to El Niño versus global warming

Energy Technology Data Exchange (ETDEWEB)

Liu, Fukai; Luo, Yiyong; Lu, Jian; Wan, Xiuquan

2016-04-15

Climate models project an El Niño-like SST response in the tropical Pacific Ocean to global warming (GW). By employing the Community Earth System Model (CESM) and applying an overriding technique to its ocean component, Parallel Ocean Program version 2 (POP2), this study investigates the similarity and difference of formation mechanism for the changes in the tropical Pacific Ocean under El Niño and GW. Results show that, despite sharing some similarities between the two scenarios, there are many significant distinctions between GW and El Niño: 1) the phase locking of the seasonal cycle reduction is more notable under GW compared with El Niño, implying more extreme El Niño events in the future; 2) in contrast to the penetration of the equatorial subsurface temperature anomaly that appears to propagate in the form of an oceanic equatorial upwelling Kelvin wave during El Niño, the GW-induced subsurface temperature anomaly manifest in the form of off-equatorial upwelling Rossby waves; 3) while significant across-equator northward heat transport (NHT) is induced by the wind stress anomalies associated with El Niño, little NHT is found at the equator due to a symmetric change in the shallow meridional overturning circulation that appears to be weakened in both North and South Pacific under GW; and 4) the maintaining mechanisms for the eastern equatorial Pacific warming are also substantially different.

Projected Changes on the Global Surface Wave Drift Climate towards the END of the Twenty-First Century

Science.gov (United States)

Carrasco, Ana; Semedo, Alvaro; Behrens, Arno; Weisse, Ralf; Breivik, Øyvind; Saetra, Øyvind; Håkon Christensen, Kai

2016-04-01

The global wave-induced current (the Stokes Drift - SD) is an important feature of the ocean surface, with mean values close to 10 cm/s along the extra-tropical storm tracks in both hemispheres. Besides the horizontal displacement of large volumes of water the SD also plays an important role in the ocean mix-layer turbulence structure, particularly in stormy or high wind speed areas. The role of the wave-induced currents in the ocean mix-layer and in the sea surface temperature (SST) is currently a hot topic of air-sea interaction research, from forecast to climate ranges. The SD is mostly driven by wind sea waves and highly sensitive to changes in the overlaying wind speed and direction. The impact of climate change in the global wave-induced current climate will be presented. The wave model WAM has been forced by the global climate model (GCM) ECHAM5 wind speed (at 10 m height) and ice, for present-day and potential future climate conditions towards the end of the end of the twenty-first century, represented by the Intergovernmental Panel for Climate Change (IPCC) CMIP3 (Coupled Model Inter-comparison Project phase 3) A1B greenhouse gas emission scenario (usually referred to as a ''medium-high emissions'' scenario). Several wave parameters were stored as output in the WAM model simulations, including the wave spectra. The 6 hourly and 0.5°×0.5°, temporal and space resolution, wave spectra were used to compute the SD global climate of two 32-yr periods, representative of the end of the twentieth (1959-1990) and twenty-first (1969-2100) centuries. Comparisons of the present climate run with the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-40 reanalysis are used to assess the capability of the WAM-ECHAM5 runs to produce realistic SD results. This study is part of the WRCP-JCOMM COWCLIP (Coordinated Ocean Wave Climate Project) effort.

An Optimization Method for Virtual Globe Ocean Surface Dynamic Visualization

Directory of Open Access Journals (Sweden)

HUANG Wumeng

2016-12-01

Full Text Available The existing visualization method in the virtual globe mainly uses the projection grid to organize the ocean grid. This special grid organization has the defects in reflecting the difference characteristics of different ocean areas. The method of global ocean visualization based on global discrete grid can make up the defect of the projection grid method by matching with the discrete space of the virtual globe, so it is more suitable for the virtual ocean surface simulation application.But the available global discrete grids method has many problems which limiting its application such as the low efficiency of rendering and loading, the need of repairing grid crevices. To this point, we propose an optimization for the global discrete grids method. At first, a GPU-oriented multi-scale grid model of ocean surface which develops on the foundation of global discrete grids was designed to organize and manage the ocean surface grids. Then, in order to achieve the wind-drive wave dynamic rendering, this paper proposes a dynamic wave rendering method based on the multi-scale ocean surface grid model to support real-time wind field updating. At the same time, considering the effect of repairing grid crevices on the system efficiency, this paper presents an efficient method for repairing ocean surface grid crevices based on the characteristics of ocean grid and GPU technology. At last, the feasibility and validity of the method are verified by the comparison experiment. The experimental results show that the proposed method is efficient, stable and fast, and can compensate for the lack of function of the existing methods, so the application range is more extensive.

GFDL CM2.1 Global Coupled Ocean-Atmosphere Model Water ...

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. GFDL CM2.1 Global Coupled Ocean-Atmosphere Model Water Hosing Experiment with 1 Sv equivalent of Freshening Control Expt: 100 yrs After Hosing: 300 yrs.

Risks of ocean acidification in the California Current food web and fisheries: ecosystem model projections.

Science.gov (United States)

Marshall, Kristin N; Kaplan, Isaac C; Hodgson, Emma E; Hermann, Albert; Busch, D Shallin; McElhany, Paul; Essington, Timothy E; Harvey, Chris J; Fulton, Elizabeth A

2017-04-01

The benefits and ecosystem services that humans derive from the oceans are threatened by numerous global change stressors, one of which is ocean acidification. Here, we describe the effects of ocean acidification on an upwelling system that already experiences inherently low pH conditions, the California Current. We used an end-to-end ecosystem model (Atlantis), forced by downscaled global climate models and informed by a meta-analysis of the pH sensitivities of local taxa, to investigate the direct and indirect effects of future pH on biomass and fisheries revenues. Our model projects a 0.2-unit drop in pH during the summer upwelling season from 2013 to 2063, which results in wide-ranging magnitudes of effects across guilds and functional groups. The most dramatic direct effects of future pH may be expected on epibenthic invertebrates (crabs, shrimps, benthic grazers, benthic detritivores, bivalves), and strong indirect effects expected on some demersal fish, sharks, and epibenthic invertebrates (Dungeness crab) because they consume species known to be sensitive to changing pH. The model's pelagic community, including marine mammals and seabirds, was much less influenced by future pH. Some functional groups were less affected to changing pH in the model than might be expected from experimental studies in the empirical literature due to high population productivity (e.g., copepods, pteropods). Model results suggest strong effects of reduced pH on nearshore state-managed invertebrate fisheries, but modest effects on the groundfish fishery because individual groundfish species exhibited diverse responses to changing pH. Our results provide a set of projections that generally support and build upon previous findings and set the stage for hypotheses to guide future modeling and experimental analysis on the effects of OA on marine ecosystems and fisheries. © 2017 John Wiley & Sons Ltd.

Dynamical reconstruction of the global ocean state during the Last Glacial Maximum

Science.gov (United States)

Kurahashi-Nakamura, Takasumi; Paul, André; Losch, Martin

2017-04-01

The global ocean state for the modern age and for the Last Glacial Maximum (LGM) was dynamically reconstructed with a sophisticated data assimilation technique. A substantial amount of data including global seawater temperature, salinity (only for the modern estimate), and the isotopic composition of oxygen and carbon (only in the Atlantic for the LGM) were integrated into an ocean general circulation model with the help of the adjoint method, thereby the model was optimized to reconstruct plausible continuous fields of tracers, overturning circulation and water mass distribution. The adjoint-based LGM state estimation of this study represents the state of the art in terms of the length of forward model runs, the number of observations assimilated, and the model domain. Compared to the modern state, the reconstructed continuous sea-surface temperature field for the LGM shows a global-mean cooling of 2.2 K, and the reconstructed LGM ocean has a more vigorous Atlantic meridional overturning circulation, shallower North Atlantic Deep Water (NADW) equivalent, stronger stratification, and more saline deep water.

Biomass changes and trophic amplification of plankton in a warmer ocean

KAUST Repository

Chust, Guillem; Allen, Julian Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason T.; Tsiaras, Kostas P.; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle C.; Daewel, Ute; Wakelin, Sarah L.; Machú , Eric; Pushpadas, Dhanya; Butenschö n, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris J M; Garç on, Vé ronique C.; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A.; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

2014-01-01

Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

Biomass changes and trophic amplification of plankton in a warmer ocean

KAUST Repository

Chust, Guillem

2014-05-07

Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

Biomass changes and trophic amplification of plankton in a warmer ocean.

Science.gov (United States)

Chust, Guillem; Allen, J Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason; Tsiaras, Kostas; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle; Daewel, Ute; Wakelin, Sarah L; Machu, Eric; Pushpadas, Dhanya; Butenschon, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris; Garçon, Veronique; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

2014-07-01

Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

Historical and future trends in ocean climate and biogeochemistry

International Nuclear Information System (INIS)

Doney, Scott C.; Bopp, Laurent; Long, Matthew C.

2014-01-01

Changing atmospheric composition due to human activities, primarily carbon dioxide (CO 2 ) emissions from fossil fuel burning, is already impacting ocean circulation, biogeochemistry, and ecology, and model projections indicate that observed trends will continue or even accelerate over this century. Elevated atmospheric CO 2 alters Earth's radiative balance, leading to global-scale warming and climate change. The ocean stores the majority of resulting anomalous heat, which in turn drives other physical, chemical, and biological impacts. Sea surface warming and increased ocean vertical stratification are projected to reduce global-integrated primary production and export flux as well as to lower subsurface dissolved oxygen concentrations. Upper trophic levels will be affected both directly by warming and indirectly from changes in productivity and expanding low oxygen zones. The ocean also absorbs roughly one-quarter of present-day anthropogenic CO 2 emissions. The resulting changes in seawater chemistry, termed ocean acidification, include declining pH and saturation state for calcium carbon minerals that may have widespread impacts on many marine organisms. Climate warming will likely slow ocean CO 2 uptake but is not expected to significantly reduce upper ocean acidification. Improving the accuracy of future model projections requires better observational constraints on current rates of ocean change and a better understanding of the mechanisms controlling key physical and biogeochemical processes. (authors)

Database of diazotrophs in global ocean: abundance, biomass and nitrogen fixation rates

Directory of Open Access Journals (Sweden)

Y.-W. Luo

2012-08-01

Full Text Available Marine N₂ fixing microorganisms, termed diazotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen (N₂ to bioavailable nitrogen provides an important new source of nitrogen for pelagic marine ecosystems and influences primary productivity and organic matter export to the deep ocean. As one of a series of efforts to collect biomass and rates specific to different phytoplankton functional groups, we have constructed a database on diazotrophic organisms in the global pelagic upper ocean by compiling about 12 000 direct field measurements of cyanobacterial diazotroph abundances (based on microscopic cell counts or qPCR assays targeting the nifH genes and N₂ fixation rates. Biomass conversion factors are estimated based on cell sizes to convert abundance data to diazotrophic biomass. The database is limited spatially, lacking large regions of the ocean especially in the Indian Ocean. The data are approximately log-normal distributed, and large variances exist in most sub-databases with non-zero values differing 5 to 8 orders of magnitude. Reporting the geometric mean and the range of one geometric standard error below and above the geometric mean, the pelagic N₂ fixation rate in the global ocean is estimated to be 62 (52–73 Tg N yr⁻¹ and the pelagic diazotrophic biomass in the global ocean is estimated to be 2.1 (1.4–3.1 Tg C from cell counts and to 89 (43–150 Tg C from nifH-based abundances. Reporting the arithmetic mean and one standard error instead, these three global estimates are 140 ± 9.2 Tg N yr⁻¹, 18 ± 1.8 Tg C and 590 ± 70 Tg C, respectively. Uncertainties related to biomass conversion factors can change the estimate of geometric mean pelagic diazotrophic biomass in the global ocean by about ±70%. It was recently established that the most commonly applied method used to measure N₂

Provenance Usage in the OceanLink Project

Science.gov (United States)

Narock, T.; Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Fils, D.; Finin, T.; Hitzler, P.; Janowicz, K.; Jones, M.; Krisnadhi, A.; Lehnert, K. A.; Mickle, A.; Raymond, L. M.; Schildhauer, M.; Shepherd, A.; Wiebe, P. H.

2014-12-01

A wide spectrum of maturing methods and tools, collectively characterized as the Semantic Web, is helping to vastly improve thedissemination of scientific research. The OceanLink project, an NSF EarthCube Building Block, is utilizing semantic technologies tointegrate geoscience data repositories, library holdings, conference abstracts, and funded research awards. Provenance is a vital componentin meeting both the scientific and engineering requirements of OceanLink. Provenance plays a key role in justification and understanding when presenting users with results aggregated from multiple sources. In the engineering sense, provenance enables the identification of new data and the ability to determine which data sources to query. Additionally, OceanLink will leverage human and machine computation for crowdsourcing, text mining, and co-reference resolution. The results of these computations, and their associated provenance, will be folded back into the constituent systems to continually enhance precision and utility. We will touch on the various roles provenance is playing in OceanLink as well as present our use of the PROV Ontology and associated Ontology Design Patterns.

Ocean acidification postcards

Science.gov (United States)

Schreppel, Heather A.; Cimitile, Matthew J.

2011-01-01

The U.S. Geological Survey (USGS) is conducting research on ocean acidification in polar, temperate, subtropical, and tropical regions including the Arctic, West Florida Shelf, and the Caribbean. Project activities include field assessment, experimental laboratory studies, and evaluation of existing data. The USGS is participating in international and interagency working groups to develop research strategies to increase understanding of the global implications of ocean acidification. Research strategies include new approaches for seawater chemistry observation and modeling, assessment of physiological effects on organisms, changes in marine ecosystem structure, new technologies, and information resources. These postcards highlight ongoing USGS research efforts in ocean acidification and carbon cycling in marine and coastal ecosystems in three different regions: polar, temperate, and tropical. To learn more about ocean acidification visit: http://coastal.er.usgs.gov/ocean-acidification/.

Spiraling pathways of global deep waters to the surface of the Southern Ocean.

Science.gov (United States)

Tamsitt, Veronica; Drake, Henri F; Morrison, Adele K; Talley, Lynne D; Dufour, Carolina O; Gray, Alison R; Griffies, Stephen M; Mazloff, Matthew R; Sarmiento, Jorge L; Wang, Jinbo; Weijer, Wilbert

2017-08-02

Upwelling of global deep waters to the sea surface in the Southern Ocean closes the global overturning circulation and is fundamentally important for oceanic uptake of carbon and heat, nutrient resupply for sustaining oceanic biological production, and the melt rate of ice shelves. However, the exact pathways and role of topography in Southern Ocean upwelling remain largely unknown. Here we show detailed upwelling pathways in three dimensions, using hydrographic observations and particle tracking in high-resolution models. The analysis reveals that the northern-sourced deep waters enter the Antarctic Circumpolar Current via southward flow along the boundaries of the three ocean basins, before spiraling southeastward and upward through the Antarctic Circumpolar Current. Upwelling is greatly enhanced at five major topographic features, associated with vigorous mesoscale eddy activity. Deep water reaches the upper ocean predominantly south of the Antarctic Circumpolar Current, with a spatially nonuniform distribution. The timescale for half of the deep water to upwell from 30° S to the mixed layer is ~60-90 years.Deep waters of the Atlantic, Pacific and Indian Oceans upwell in the Southern Oceanbut the exact pathways are not fully characterized. Here the authors present a three dimensional view showing a spiralling southward path, with enhanced upwelling by eddy-transport at topographic hotspots.

Declining Global Per Capita Agricultural Production and Warming Oceans Threaten Food Security

Science.gov (United States)

Funk, Chris C.; Brown, Molly E.

2009-01-01

Despite accelerating globalization, most people still eat food that was grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be controlled by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices, and policies. In this paper we discuss several emerging threats to global and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian Ocean and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia, and Central and Southern America will experience substantial declines in per capita cereal production. Global per capita cereal production will potentially decline by 14 percent between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific Oceans, may also reduce 21 st century food availability by disrupting Indian Ocean moisture transports and tilting the 21 st century climate toward a more El Nino-like state. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian Ocean warming appears to have already reduced main growing season rainfall along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, we present an analysis of

Ocean container transport : an underestimated and critical link in global supply chain performance

NARCIS (Netherlands)

Fransoo, J.C.; Lee, C.Y.

2010-01-01

With supply chains distributed across global markets, ocean container transport now is a critical element of any such supply chain. We identify key characteristics of ocean container transport from a supply chain perspective. We find that unlike continental (road) transport, service offerings tend

The Ocean State Power Project

International Nuclear Information System (INIS)

Makowski, J.

1987-01-01

Ocean State Power is an independent partnership in the form of utility companies and private developers who have joined forces to build a gas-fired, combined cycle generating plant in Burrillville, Rhode Island. The initial capacity of the plant is expected to be approximately 250 MW, with a provision to double the size. Unit I will be on-line 2989/2990 with unit II shortly thereafter. The OSP equity group includes TransCanada PipeLines, Easter Utilities Associates, New England Electric System, Newport Electric and J. Makowski Associates. The author describes the project's major features and turns to a brief status report on the contracts and licenses. Ocean State Power came about because of; the rapid growth in demand for capacity in new England; the availability of a long-term supply of natural gas from Canada which has recently revised export policies and the inherent efficiency and reliability of combined cycle power generation

Global Carbon Budget 2017

NARCIS (Netherlands)

Le Quere, Corinne; Andrew, Robbie M.; Friedlingstein, Pierre; Sitch, Stephen; Pongratz, Julia; Manning, Andrew C.; Korsbakken, Jan Ivar; Peters, Glen P.; Canadell, Josep G.; Jackson, Robert B.; Boden, Thomas A.; Tans, Pieter P.; Andrews, Oliver D.; Arora, Vivek K.; Bakker, Dorothee C. E.; Barbero, Leticia; Becker, Meike; Betts, Richard A.; Bopp, Laurent; Chevallier, Frederic; Chini, Louise P.; Ciais, Philippe; Cosca, Catherine E.; Cross, Jessica; Currie, Kim; Gasser, Thomas; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Houghton, Richard A.; Hunt, Christopher W.; Hurtt, George; Ilyina, Tatiana; Jain, Atul K.; Kato, Etsushi; Kautz, Markus; Keeling, Ralph F.; Goldewijk, Kees Klein; Koertzinger, Arne; Landschuetzer, Peter; Lefevre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lima, Ivan; Lombardozzi, Danica; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M. S.; Munro, David R.; Nabel, Julia E. M. S.; Nakaoka, Shin-ichiro; Nojiri, Yukihiro; Padin, X. Antonio; Peregon, Anna; Pfeil, Benjamin; Pierrot, Denis; Poulter, Benjamin; Rehder, Gregor; Reimer, Janet; Roedenbeck, Christian; Schwinger, Jorg; Seferian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Tian, Hanqin; Tilbrook, Bronte; Tubiello, Francesco N.; van der Laan-Luijkx, Ingrid T.; van der Werf, Guido R.; van Heuven, Steven; Viovy, Nicolas; Vuichard, Nicolas; Walker, Anthony P.; Watson, Andrew J.; Wiltshire, Andrew J.; Zaehle, Soenke; Zhu, Dan

2018-01-01

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere - the "global carbon budget" - is important to better understand the global carbon cycle, support the development of climate policies, and project

Global Carbon Budget 2016

NARCIS (Netherlands)

Le Quéré, Corinne; Andrew, Robbie M.; Canadell, Josep G.; Sitch, Stephen; Ivar Korsbakken, Jan; Peters, Glen P.; Manning, Andrew C.; Boden, Thomas A.; Tans, Pieter P.; Houghton, Richard A.; Keeling, Ralph F.; Alin, Simone; Andrews, Oliver D.; Anthoni, Peter; Barbero, Leticia; Bopp, Laurent; Chevallier, Frédéric; Chini, Louise P.; Ciais, Philippe; Currie, Kim; Delire, Christine; Doney, Scott C.; Friedlingstein, Pierre; Gkritzalis, Thanos; Harris, Ian A; Hauck, Judith; Haverd, Vanessa; Hoppema, Mario; Klein Goldewijk, Kees; Jain, Atul K.; Kato, Etsushi; Körtzinger, Arne; Landschützer, Peter; Lefèvre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lombardozzi, Danica; Melton, Joe R.; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M S; Munro, David R.; Nabel, Julia E M S; Nakaoka, Shin Ichiro; O'Brien, Kevin; Olsen, Are; Omar, Abdirahman M.; Ono, Tsuneo; Pierrot, Denis; Poulter, Benjamin; Rödenbeck, Christian; Salisbury, Joe; Schuster, Ute; Schwinger, Jörg; Séférian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Sutton, Adrienne J.; Takahashi, Taro; Tian, Hanqin; Tilbrook, Bronte; Van Der Laan-Luijkx, Ingrid T.; Van Der Werf, Guido R.; Viovy, Nicolas; Walker, Anthony P.; Wiltshire, Andrew J.; Zaehle, Sönke

2016-01-01

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere-the "global carbon budget"-is important to better understand the global carbon cycle, support the development of climate policies, and project future

Analysis of the global ocean sampling (GOS) project for trends in iron uptake by surface ocean microbes.

Science.gov (United States)

Toulza, Eve; Tagliabue, Alessandro; Blain, Stéphane; Piganeau, Gwenael

2012-01-01

Microbial metagenomes are DNA samples of the most abundant, and therefore most successful organisms at the sampling time and location for a given cell size range. The study of microbial communities via their DNA content has revolutionized our understanding of microbial ecology and evolution. Iron availability is a critical resource that limits microbial communities' growth in many oceanic areas. Here, we built a database of 2319 sequences, corresponding to 140 gene families of iron metabolism with a large phylogenetic spread, to explore the microbial strategies of iron acquisition in the ocean's bacterial community. We estimate iron metabolism strategies from metagenome gene content and investigate whether their prevalence varies with dissolved iron concentrations obtained from a biogeochemical model. We show significant quantitative and qualitative variations in iron metabolism pathways, with a higher proportion of iron metabolism genes in low iron environments. We found a striking difference between coastal and open ocean sites regarding Fe(2+) versus Fe(3+) uptake gene prevalence. We also show that non-specific siderophore uptake increases in low iron open ocean environments, suggesting bacteria may acquire iron from natural siderophore-like organic complexes. Despite the lack of knowledge of iron uptake mechanisms in most marine microorganisms, our approach provides insights into how the iron metabolic pathways of microbial communities may vary with seawater iron concentrations.

Global assessment of oceanic lead pollution using sperm whales (Physeter macrocephalus) as an indicator species.

Science.gov (United States)

Savery, Laura C; Wise, Sandra S; Falank, Carolyne; Wise, James; Gianios, Christy; Douglas Thompson, W; Perkins, Christopher; Zheng, Tongzhang; Zhu, Cairong; Wise, John Pierce

2014-02-15

Lead (Pb) is an oceanic pollutant of global concern. Anthropogenic activities are increasing oceanic levels, but to an unknown extent. The sperm whale (Physeter macrocephalus) has a global distribution and high trophic level. The aim of this study was to establish a global baseline of oceanic Pb concentrations using free-ranging sperm whales as an indicator species. Skin biopsies (n=337) were collected during the voyage of the Odyssey (2000-2005) from 17 regions considering gender and age. Pb was detectable in 315 samples with a global mean of 1.6 ug/gww ranging from 0.1 to 129.6 ug/gww. Papua New Guinea, Bahamas and Australia had the highest regional mean with 6.1, 3.4, and 3.1 ug/gww, respectively. Pb concentrations were not significantly different between sex and age in males. This is the first global toxicological dataset for Pb in a marine mammal and confirms Pb is widely distributed with hotspots in some regions. Copyright © 2014. Published by Elsevier Ltd.

Impact of biomass burning on nutrient deposition to the global ocean

Science.gov (United States)

Kanakidou, Maria; Myriokefalitakis, Stelios; Daskalakis, Nikos; Mihalopoulos, Nikolaos; Nenes, Athanasios

2017-04-01

Atmospheric deposition of trace constituents, both of natural and anthropogenic origin, can act as a nutrient source into the open ocean and affect marine ecosystem functioning and subsequently the exchange of CO2 between the atmosphere and the global ocean. Dust is known as a major source of nutrients (Fe and P) into the atmosphere, but only a fraction of these nutrients is released in soluble form that can be assimilated by the ecosystems. Dust is also known to enhance N deposition by interacting with anthropogenic pollutants and neutralisation of part of the acidity of the atmosphere by crustal alkaline species. These nutrients have also primary anthropogenic sources including combustion emissions. The global atmospheric N [1], Fe [2] and P [3] cycles have been parameterized in the global 3-D chemical transport model TM4-ECPL, accounting for inorganic and organic forms of these nutrients, for all natural and anthropogenic sources of these nutrients including biomass burning, as well as for the link between the soluble forms of Fe and P atmospheric deposition and atmospheric acidity. The impact of atmospheric acidity on nutrient solubility has been parameterised based on experimental findings and the model results have been evaluated by extensive comparison with available observations. In the present study we isolate the significant impact of biomass burning emissions on these nutrients deposition by comparing global simulations that consider or neglect biomass burning emissions. The investigated impact integrates changes in the emissions of the nutrients as well as in atmospheric oxidants and acidity and thus in atmospheric processing and secondary sources of these nutrients. The results are presented and thoroughly discussed. References [1] Kanakidou M, S. Myriokefalitakis, N. Daskalakis, G. Fanourgakis, A. Nenes, A. Baker, K. Tsigaridis, N. Mihalopoulos, Past, Present and Future Atmospheric Nitrogen Deposition, Journal of the Atmospheric Sciences (JAS-D-15

Cloud amount/frequency, SALINITY and other data from ORION, FUJI II and other platforms in the Southern Oceans, Indian Ocean and other waters from 1950-01-04 to 1989-03-16 (NODC Accession 9200239)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Serial data in this accession was collected in Southern Oceans (> 60 degrees South) as part of Global Ocean Data Archeaology and Rescue (GODAR) project...

The Global S$_1$ Ocean Tide

Science.gov (United States)

Ray, Richard D.; Egbert, G. D.

2003-01-01

The small S$_1$ ocean tide is caused primarily by diurnal atmospheric pressure loading. Its excitation is therefore unlike any other diurnal tide. The global character of $S-1$ is here determined by numerical modeling and by analysis of Topex/Poseidon satellite altimeter data. The two approaches yield reasonably consistent results, and large ( $ greater than $l\\cm) amplitudes in several regions are further confirmed by comparison with coastal tide gauges. Notwithstanding their excitation differences, S$-1$ and other diurnal tides are found to share several common features, such as relatively large amplitudes in the Arabian Sea, the Sea of Okhotsk, and the Gulf of Alaska. The most noticeable difference is the lack of an S$-1$ Antarctic Kelvin wave. These similarities and differences can be explained in terms of the coherences between near-diurnal oceanic normal modes and the underlying tidal forcings. While gravitational diurnal tidal forces excite primarily a 28-hour Antarctic-Pacific mode, the S$_1$ air tide excites several other near-diurnal modes, none of which has large amplitudes near Antarctica.

Light penetration structures the deep acoustic scattering layers in the global ocean.

KAUST Repository

Aksnes, Dag L.; Rø stad, Anders; Kaartvedt, Stein; Martinez, Udane; Duarte, Carlos M.; Irigoien, Xabier

2017-01-01

The deep scattering layer (DSL) is a ubiquitous acoustic signature found across all oceans and arguably the dominant feature structuring the pelagic open ocean ecosystem. It is formed by mesopelagic fishes and pelagic invertebrates. The DSL animals are an important food source for marine megafauna and contribute to the biological carbon pump through the active flux of organic carbon transported in their daily vertical migrations. They occupy depths from 200 to 1000 m at daytime and migrate to a varying degree into surface waters at nighttime. Their daytime depth, which determines the migration amplitude, varies across the global ocean in concert with water mass properties, in particular the oxygen regime, but the causal underpinning of these correlations has been unclear. We present evidence that the broad variability in the oceanic DSL daytime depth observed during the Malaspina 2010 Circumnavigation Expedition is governed by variation in light penetration. We find that the DSL depth distribution conforms to a common optical depth layer across the global ocean and that a correlation between dissolved oxygen and light penetration provides a parsimonious explanation for the association of shallow DSL distributions with hypoxic waters. In enhancing understanding of this phenomenon, our results should improve the ability to predict and model the dynamics of one of the largest animal biomass components on earth, with key roles in the oceanic biological carbon pump and food web.

Light penetration structures the deep acoustic scattering layers in the global ocean.

KAUST Repository

Aksnes, Dag L.

2017-05-01

The deep scattering layer (DSL) is a ubiquitous acoustic signature found across all oceans and arguably the dominant feature structuring the pelagic open ocean ecosystem. It is formed by mesopelagic fishes and pelagic invertebrates. The DSL animals are an important food source for marine megafauna and contribute to the biological carbon pump through the active flux of organic carbon transported in their daily vertical migrations. They occupy depths from 200 to 1000 m at daytime and migrate to a varying degree into surface waters at nighttime. Their daytime depth, which determines the migration amplitude, varies across the global ocean in concert with water mass properties, in particular the oxygen regime, but the causal underpinning of these correlations has been unclear. We present evidence that the broad variability in the oceanic DSL daytime depth observed during the Malaspina 2010 Circumnavigation Expedition is governed by variation in light penetration. We find that the DSL depth distribution conforms to a common optical depth layer across the global ocean and that a correlation between dissolved oxygen and light penetration provides a parsimonious explanation for the association of shallow DSL distributions with hypoxic waters. In enhancing understanding of this phenomenon, our results should improve the ability to predict and model the dynamics of one of the largest animal biomass components on earth, with key roles in the oceanic biological carbon pump and food web.

Flexible global ocean-atmosphere-land system model. A modeling tool for the climate change research community

International Nuclear Information System (INIS)

Zhou, Tianjun; Yu, Yongqiang; Liu, Yimin; Wang, Bin

2014-01-01

First book available on systematic evaluations of the performance of the global climate model FGOALS. Covers the whole field, ranging from the development to the applications of this climate system model. Provide an outlook for the future development of the FGOALS model system. Offers brief introduction about how to run FGOALS. Coupled climate system models are of central importance for climate studies. A new model known as FGOALS (the Flexible Global Ocean-Atmosphere-Land System model), has been developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (LASG/IAP, CAS), a first-tier national geophysical laboratory. It serves as a powerful tool, both for deepening our understanding of fundamental mechanisms of the climate system and for making decadal prediction and scenario projections of future climate change. ''Flexible Global Ocean-Atmosphere-Land System Model: A Modeling Tool for the Climate Change Research Community'' is the first book to offer systematic evaluations of this model's performance. It is comprehensive in scope, covering both developmental and application-oriented aspects of this climate system model. It also provides an outlook of future development of FGOALS and offers an overview of how to employ the model. It represents a valuable reference work for researchers and professionals working within the related areas of climate variability and change.

The Ocean Food and Energy Farm Project

Science.gov (United States)

Wilcox, Howard A.

1976-01-01

This three-phase, 15-year project is designed to explore and develop the ability to raise the grant California kelp and other marine organisms for food, fuels, fertilizers and plastics in the temperate and tropical oceans. The needed technology is established, but the economic feasibility is yet to be determined. (BT)

On Verifying Currents and Other Features in the Hawaiian Islands Region Using Fully Coupled Ocean/Atmosphere Mesoscale Prediction System Compared to Global Ocean Model and Ocean Observations

Science.gov (United States)

Jessen, P. G.; Chen, S.

2014-12-01

This poster introduces and evaluates features concerning the Hawaii, USA region using the U.S. Navy's fully Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS-OS™) coupled to the Navy Coastal Ocean Model (NCOM). It also outlines some challenges in verifying ocean currents in the open ocean. The system is evaluated using in situ ocean data and initial forcing fields from the operational global Hybrid Coordinate Ocean Model (HYCOM). Verification shows difficulties in modelling downstream currents off the Hawaiian islands (Hawaii's wake). Comparing HYCOM to NCOM current fields show some displacement of small features such as eddies. Generally, there is fair agreement from HYCOM to NCOM in salinity and temperature fields. There is good agreement in SSH fields.

Signature of ocean warming in global fisheries catch.

Science.gov (United States)

Cheung, William W L; Watson, Reg; Pauly, Daniel

2013-05-16

Marine fishes and invertebrates respond to ocean warming through distribution shifts, generally to higher latitudes and deeper waters. Consequently, fisheries should be affected by 'tropicalization' of catch (increasing dominance of warm-water species). However, a signature of such climate-change effects on global fisheries catch has so far not been detected. Here we report such an index, the mean temperature of the catch (MTC), that is calculated from the average inferred temperature preference of exploited species weighted by their annual catch. Our results show that, after accounting for the effects of fishing and large-scale oceanographic variability, global MTC increased at a rate of 0.19 degrees Celsius per decade between 1970 and 2006, and non-tropical MTC increased at a rate of 0.23 degrees Celsius per decade. In tropical areas, MTC increased initially because of the reduction in the proportion of subtropical species catches, but subsequently stabilized as scope for further tropicalization of communities became limited. Changes in MTC in 52 large marine ecosystems, covering the majority of the world's coastal and shelf areas, are significantly and positively related to regional changes in sea surface temperature. This study shows that ocean warming has already affected global fisheries in the past four decades, highlighting the immediate need to develop adaptation plans to minimize the effect of such warming on the economy and food security of coastal communities, particularly in tropical regions.

Global Carbon Budget 2016

NARCIS (Netherlands)

Quéré, Le Corinne; Andrew, Robbie M.; Canadell, Josep G.; Sitch, Stephen; Korsbakken, Jan Ivar; Peters, Glen P.; Manning, Andrew C.; Boden, Thomas A.; Tans, Pieter P.; Houghton, Richard A.; Keeling, Ralph F.; Alin, Simone; Andrews, Oliver D.; Anthoni, Peter; Barbero, Leticia; Bopp, Laurent; Chevallier, Frédéric; Chini, Louise P.; Ciais, Philippe; Currie, Kim; Delire, Christine; Doney, Scott C.; Friedlingstein, Pierre; Gkritzalis, Thanos; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Hoppema, Mario; Klein Goldewijk, Kees; Jain, Atul K.; Kato, Etsushi; Körtzinger, Arne; Landschützer, Peter; Lefèvre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lombardozzi, Danica; Melton, Joe R.; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M.S.; Munro, David R.; Nabel, Julia E.M.S.; Nakaoka, S.; O'Brien, Kevin; Olsen, Are; Omar, Abdirahman M.; Ono, Tsuneo; Pierrot, Denis; Poulter, Benjamin; Rödenbeck, Christian; Salisbury, Joe; Schuster, Ute; Schwinger, Jörg; Séférian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Sutton, Adrienne J.; Takahashi, Taro; Tian, Hanqin; Tilbrook, Bronte; Laan-Luijkx, van der Ingrid T.; Werf, van der Guido R.; Viovy, Nicolas; Walker, Anthony P.; Wiltshire, Andrew J.; Zaehle, Sönke

2016-01-01

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project

Effect of ocean gateways on the global ocean circulation in the late Oligocene and early Miocene

NARCIS (Netherlands)

von der Heydt, A.S.|info:eu-repo/dai/nl/245567526; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467

2006-01-01

We investigate the effect of changes in the tectonic boundary conditions on global ocean circulation patterns. Using a fully coupled climate model in an idealized setup, we compare situations corresponding to the late Oligocene, the early Miocene, and present day. The model results show the

Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial.

Science.gov (United States)

Turney, Chris S M; Jones, Richard T; Phipps, Steven J; Thomas, Zoë; Hogg, Alan; Kershaw, A Peter; Fogwill, Christopher J; Palmer, Jonathan; Bronk Ramsey, Christopher; Adolphi, Florian; Muscheler, Raimund; Hughen, Konrad A; Staff, Richard A; Grosvenor, Mark; Golledge, Nicholas R; Rasmussen, Sune Olander; Hutchinson, David K; Haberle, Simon; Lorrey, Andrew; Boswijk, Gretel; Cooper, Alan

2017-09-12

Contrasting Greenland and Antarctic temperatures during the last glacial period (115,000 to 11,650 years ago) are thought to have been driven by imbalances in the rates of formation of North Atlantic and Antarctic Deep Water (the 'bipolar seesaw'). Here we exploit a bidecadally resolved 14 C data set obtained from New Zealand kauri (Agathis australis) to undertake high-precision alignment of key climate data sets spanning iceberg-rafted debris event Heinrich 3 and Greenland Interstadial (GI) 5.1 in the North Atlantic (~30,400 to 28,400 years ago). We observe no divergence between the kauri and Atlantic marine sediment 14 C data sets, implying limited changes in deep water formation. However, a Southern Ocean (Atlantic-sector) iceberg rafted debris event appears to have occurred synchronously with GI-5.1 warming and decreased precipitation over the western equatorial Pacific and Atlantic. An ensemble of transient meltwater simulations shows that Antarctic-sourced salinity anomalies can generate climate changes that are propagated globally via an atmospheric Rossby wave train.A challenge for testing mechanisms of past climate change is the precise correlation of palaeoclimate records. Here, through climate modelling and the alignment of terrestrial, ice and marine 14 C and 10 Be records, the authors show that Southern Ocean freshwater hosing can trigger global change.

Ocean Depths: The Mesopelagic and Implications for Global Warming.

Science.gov (United States)

Costello, Mark J; Breyer, Sean

2017-01-09

The mesopelagic or 'twilight zone' of the oceans occurs too deep for photosynthesis, but is a major part of the world's carbon cycle. Depth boundaries for the mesopelagic have now been shown on a global scale using the distribution of pelagic animals detected by compiling echo-soundings from ships around the world, and been used to predict the effect of global warming on regional fish production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Global Project Management: Graduate Course

National Research Council Canada - National Science Library

Beranek, Thomas R

2006-01-01

..., A. James Clark School of Engineering - Project Management Program. The course slides and suggested readings provide a general exploration of the nuances of doing projects globally as compared to domestically...

Global assessment of ocean carbon export by combining satellite observations and food-web models

Science.gov (United States)

Siegel, D. A.; Buesseler, K. O.; Doney, S. C.; Sailley, S. F.; Behrenfeld, M. J.; Boyd, P. W.

2014-03-01

The export of organic carbon from the surface ocean by sinking particles is an important, yet highly uncertain, component of the global carbon cycle. Here we introduce a mechanistic assessment of the global ocean carbon export using satellite observations, including determinations of net primary production and the slope of the particle size spectrum, to drive a food-web model that estimates the production of sinking zooplankton feces and algal aggregates comprising the sinking particle flux at the base of the euphotic zone. The synthesis of observations and models reveals fundamentally different and ecologically consistent regional-scale patterns in export and export efficiency not found in previous global carbon export assessments. The model reproduces regional-scale particle export field observations and predicts a climatological mean global carbon export from the euphotic zone of 6 Pg C yr-1. Global export estimates show small variation (typically model parameter values. The model is also robust to the choices of the satellite data products used and enables interannual changes to be quantified. The present synthesis of observations and models provides a path for quantifying the ocean's biological pump.

Ocean Margins Programs, Phase I research summaries

Energy Technology Data Exchange (ETDEWEB)

Verity, P. [ed.

1994-08-01

During FY 1992, the DOE restructured its regional coastal-ocean programs into a new Ocean Margins Program (OMP), to: Quantify the ecological and biogeochemical processes and mechanisms that affect the cycling, flux, and storage of carbon and other biogenic elements at the land/ocean interface; Define ocean-margin sources and sinks in global biogeochemical cycles, and; Determine whether continental shelves are quantitatively significant in removing carbon dioxide from the atmosphere and isolating it via burial in sediments or export to the interior ocean. Currently, the DOE Ocean Margins Program supports more than 70 principal and co-principal investigators, spanning more than 30 academic institutions. Research funded by the OMP amounted to about $6.9M in FY 1994. This document is a collection of abstracts summarizing the component projects of Phase I of the OMP. This phase included both research and technology development, and comprised projects of both two and three years duration. The attached abstracts describe the goals, methods, measurement scales, strengths and limitations, and status of each project, and level of support. Keywords are provided to index the various projects. The names, addresses, affiliations, and major areas of expertise of the investigators are provided in appendices.

MERSEA, the European Gate to Ocean Data

Science.gov (United States)

Blanc, F. P.; Manzella, G.; Maudire, G.; Bahurel, P.; Bell, M.; Haines, K.

2004-12-01

Mersea ('Marine Environment and Security for the European Area'), a European project to manage the oceans, aims to develop by 2008 the GMES ocean component ('Global Monitoring for Environment and Security'), a system for operational monitoring and forecasting on global and regional scales of the ocean physics, bio-geochemistry and ecosystems. Mersea project started on April 1st, 2004. This ocean monitoring system is envisioned as an operational network that systematically acquires data and disseminates information to serve the needs of intermediate users and policy makers, in support of safe and efficient off-shore activities, environmental management, security, and sustainable use of marine resources. Three real-time data streams have been identified: remote sensed from satellites, in situ from ocean observing networks, and surface forcing fields from numerical weather prediction agencies. Mersea will ensure the availability of near real time and delayed mode products over the period 2004-2008, global and regional products optimised for supporting operational oceanography. Historical data sets for the last 15 years will also be prepared. Mersea is also the European center serving Godae goals ('Global Ocean Data Assimilation Experiment', 2003-2005). The timely delivery of high quality and reliable information to many user categories is essential for the success of such integrated project. There is consequently a large effort to coordinate all delivery actions giving special attention on the users' needs. This effort will cover many issues like product presentation, products and web services catalogue and how to deal for an interdisciplinary and integrated use. A first major difficulty is to reach at many levels product coherency and standardisation, which is needed to facilitate the visibility, understanding and exchange of the ocean observing data. A first task will therefore be to write a common unified framework guide, a kind of member chart, which will require

The ocean sampling day consortium

DEFF Research Database (Denmark)

Kopf, Anna; Bicak, Mesude; Kottmann, Renzo

2015-01-01

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate...... the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our...

Antarctic and Southern Ocean influences on Late Pliocene global cooling

NARCIS (Netherlands)

McKay, R.; Naish, T.; Carter, L.; Riesselman, C.; Dunbar, R.; Sjunneskog, C.; Winter, D.; Sangiorgi, F.; Warren, C.; Pagani, M.; Schouten, S.; Willmott, V.; Levy, R.; DeConto , R.M.; Powell, R.D.

2012-01-01

The influence of Antarctica and the Southern Ocean on Late Pliocene global climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL

Distribution of known macrozooplankton abundance and biomass in the global ocean

Science.gov (United States)

Moriarty, R.; Buitenhuis, E. T.; Le Quéré, C.; Gosselin, M.-P.

2013-07-01

Macrozooplankton are an important link between higher and lower trophic levels in the oceans. They serve as the primary food for fish, reptiles, birds and mammals in some regions, and play a role in the export of carbon from the surface to the intermediate and deep ocean. Little, however, is known of their global distribution and biomass. Here we compiled a dataset of macrozooplankton abundance and biomass observations for the global ocean from a collection of four datasets. We harmonise the data to common units, calculate additional carbon biomass where possible, and bin the dataset in a global 1 × 1 degree grid. This dataset is part of a wider effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. Over 387 700 abundance data and 1330 carbon biomass data have been collected from pre-existing datasets. A further 34 938 abundance data were converted to carbon biomass data using species-specific length frequencies or using species-specific abundance to carbon biomass data. Depth-integrated values are used to calculate known epipelagic macrozooplankton biomass concentrations and global biomass. Global macrozooplankton biomass, to a depth of 350 m, has a mean of 8.4 μg C L-1, median of 0.2 μg C L-1 and a standard deviation of 63.5 μg C L-1. The global annual average estimate of macrozooplankton biomass in the top 350 m, based on the median value, is 0.02 Pg C. There are, however, limitations on the dataset; abundance observations have good coverage except in the South Pacific mid-latitudes, but biomass observation coverage is only good at high latitudes. Biomass is restricted to data that is originally given in carbon or to data that can be converted from abundance to carbon. Carbon conversions from abundance are restricted by the lack of information on the size of the organism and/or the absence of taxonomic information. Distribution patterns of global

The ocean quasi-homogeneous layer model and global cycle of carbon dioxide in system of atmosphere-ocean

Science.gov (United States)

Glushkov, Alexander; Glushkov, Alexander; Loboda, Nataliya; Khokhlov, Valery; Serbov, Nikoly; Svinarenko, Andrey

The purpose of this paper is carrying out the detailed model of the CO2 global turnover in system of "atmosphere-ocean" with using the ocean quasi-homogeneous layer model. Practically all carried out models are functioning in the average annual regime and accounting for the carbon distribution in bio-sphere in most general form (Glushkov et al, 2003). We construct a modified model for cycle of the carbon dioxide, which allows to reproduce a season dynamics of carbon turnover in ocean with account of zone ocean structure (up quasi-homogeneous layer, thermocline and deepest layer). It is taken into account dependence of the CO2 transfer through the bounder between atmosphere and ocean upon temperature of water and air, wind velocity, buffer mechanism of the CO2 dissolution. The same program is realized for atmosphere part of whole system. It is obtained a tempo-ral and space distribution for concentration of non-organic carbon in ocean, partial press of dissolute CO2 and value of exchange on the border between atmosphere and ocean. It is estimated a role of the wind intermixing of the up ocean layer. The increasing of this effect leads to increasing the plankton mass and further particles, which are transferred by wind, contribute to more quick immersion of microscopic shells and organic material. It is fulfilled investigation of sen-sibility of the master differential equations system solutions from the model parameters. The master differential equa-tions system, describing a dynamics of the CO2 cycle, is numerically integrated by the four order Runge-Cutt method under given initial values of valuables till output of solution on periodic regime. At first it is indicated on possible real-zation of the chaos scenario in system. On our data, the difference of the average annual values for the non-organic car-bon concentration in the up quasi-homogeneous layer between equator and extreme southern zone is 0.15 mol/m3, be-tween the equator and extreme northern zone is 0

MONDO Project: real time ocean monitoring through Lagrangian drifters during offshore drilling operations

Energy Technology Data Exchange (ETDEWEB)

Mafra, Tatiana [Eni Oil do Brasil, Rio de Janeiro, RJ (Brazil); Fragoso, Mauricio da Rocha; Santos, Francisco Alves dos; Cruz, Leonardo M. Marques A.; Pellegrini, Julio A.C.; Cerrone, Bruna Nogueira [Prooceano, Rio de Janeiro, RJ (Brazil); Assireu, Arcilan Trevenzoli [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

2008-07-01

Monitoring the ocean conditions during offshore operations is essential for both operational and environmental aspects. Environmentally, not only to know better the environment where the activity is taking place, but also to be able to provide fast and accurate response in case of accidents. MONDO Project (Monitoring by Ocean Drifters) is a pioneer initiative from ENI Oil do Brasil and PROOCEANO that aimed to monitor currents as a part of a metoceanographic data monitoring project of drilling operations in Brazilian Waters, in Santos Basin throughout September to November 2007, 40 satellite tracked ocean drifters were deployed will be transmitting data up to November 2008. The results of this project can be used to study a wide range of subjects about ocean dynamics. Following the principles of social and environmental responsibility, MONDO Project aims to benefit the local ecosystem in increasing the scientific knowledge of the area to calibrate hydrodynamic models that will lead to more accurate modeling results and, as a consequence, to a better management of contingency plans. Based on these principles, the project will also provide unrestricted access to oceanographic data even after the end of operations. (author)

Preliminary assessment of the performance of a global coupled atmosphere-ocean model

International Nuclear Information System (INIS)

Cubasch, U.

1990-01-01

A low-resolution version of the ECMWF global atmosphere model has been coupled to a global ocean model developed at the Max Planck Institute in Hamburg. The atmosphere model is driven by the sea surface temperature and the ice thickness calculated by the ocean model, which, in return, is driven by the wind stress, the heat flux and the freshwater flux diagnosed by the atmosphere model. Even though each model reaches stationarity when integrated on its own, the coupling of both creates problems, since the fields calculated by each model are not consistent with the ones the other model has to have in order to stay stationary, because some of the fluxes are not balanced. In the coupled experiment the combined ocean-atmosphere system drifts toward a colder state. To counteract this problem, a flux correction has been applied which balances the mean biases of each model. This method almost eliminates the climate drift of the coupled model. Problems still arise over ice covered regions

Towards accounting for dissolved iron speciation in global ocean models

Directory of Open Access Journals (Sweden)

A. Tagliabue

2011-10-01

Full Text Available The trace metal iron (Fe is now routinely included in state-of-the-art ocean general circulation and biogeochemistry models (OGCBMs because of its key role as a limiting nutrient in regions of the world ocean important for carbon cycling and air-sea CO₂ exchange. However, the complexities of the seawater Fe cycle, which impact its speciation and bioavailability, are simplified in such OGCBMs due to gaps in understanding and to avoid high computational costs. In a similar fashion to inorganic carbon speciation, we outline a means by which the complex speciation of Fe can be included in global OGCBMs in a reasonably cost-effective manner. We construct an Fe speciation model based on hypothesised relationships between rate constants and environmental variables (temperature, light, oxygen, pH, salinity and assumptions regarding the binding strengths of Fe complexing organic ligands and test hypotheses regarding their distributions. As a result, we find that the global distribution of different Fe species is tightly controlled by spatio-temporal environmental variability and the distribution of Fe binding ligands. Impacts on bioavailable Fe are highly sensitive to assumptions regarding which Fe species are bioavailable and how those species vary in space and time. When forced by representations of future ocean circulation and climate we find large changes to the speciation of Fe governed by pH mediated changes to redox kinetics. We speculate that these changes may exert selective pressure on phytoplankton Fe uptake strategies in the future ocean. In future work, more information on the sources and sinks of ocean Fe ligands, their bioavailability, the cycling of colloidal Fe species and kinetics of Fe-surface coordination reactions would be invaluable. We hope our modeling approach can provide a means by which new observations of Fe speciation can be tested against hypotheses of the processes present in governing the ocean Fe cycle in an

Global Ocean Circulation in Thermohaline Coordinates and Small-scale and Mesoscale mixing: An Inverse Estimate.

Science.gov (United States)

Groeskamp, S.; Zika, J. D.; McDougall, T. J.; Sloyan, B.

2016-02-01

I will present results of a new inverse technique that infers small-scale turbulent diffusivities and mesoscale eddy diffusivities from an ocean climatology of Salinity (S) and Temperature (T) in combination with surface freshwater and heat fluxes.First, the ocean circulation is represented in (S,T) coordinates, by the diathermohaline streamfunction. Framing the ocean circulation in (S,T) coordinates, isolates the component of the circulation that is directly related to water-mass transformation.Because water-mass transformation is directly related to fluxes of salt and heat, this framework allows for the formulation of an inverse method in which the diathermohaline streamfunction is balanced with known air-sea forcing and unknown mixing. When applying this inverse method to observations, we obtain observationally based estimates for both the streamfunction and the mixing. The results reveal new information about the component of the global ocean circulation due to water-mass transformation and its relation to surface freshwater and heat fluxes and small-scale and mesoscale mixing. The results provide global constraints on spatially varying patterns of diffusivities, in order to obtain a realistic overturning circulation. We find that mesoscale isopycnal mixing is much smaller than expected. These results are important for our understanding of the relation between global ocean circulation and mixing and may lead to improved parameterisations in numerical ocean models.

NODC Standard Product: Global ocean temperature and salinity profiles (2 disc set) (NODC Accession 0098058)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This set of CD-ROMs contains global ocean temperature and salinity profiles derived from NODC archive data files. It includes oceanographic station (bottle) data,...

Flexible global ocean-atmosphere-land system model. A modeling tool for the climate change research community

Energy Technology Data Exchange (ETDEWEB)

Zhou, Tianjun; Yu, Yongqiang; Liu, Yimin; Wang, Bin (eds.) [Chinese Academy of Sciences, Beijing, (China). Inst. of Atmospheric Physics

2014-04-01

First book available on systematic evaluations of the performance of the global climate model FGOALS. Covers the whole field, ranging from the development to the applications of this climate system model. Provide an outlook for the future development of the FGOALS model system. Offers brief introduction about how to run FGOALS. Coupled climate system models are of central importance for climate studies. A new model known as FGOALS (the Flexible Global Ocean-Atmosphere-Land System model), has been developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (LASG/IAP, CAS), a first-tier national geophysical laboratory. It serves as a powerful tool, both for deepening our understanding of fundamental mechanisms of the climate system and for making decadal prediction and scenario projections of future climate change. ''Flexible Global Ocean-Atmosphere-Land System Model: A Modeling Tool for the Climate Change Research Community'' is the first book to offer systematic evaluations of this model's performance. It is comprehensive in scope, covering both developmental and application-oriented aspects of this climate system model. It also provides an outlook of future development of FGOALS and offers an overview of how to employ the model. It represents a valuable reference work for researchers and professionals working within the related areas of climate variability and change.

The Global Lives Project: Making New Media Matter in a Global World

DEFF Research Database (Denmark)

Hasse Jørgensen, Stina

2010-01-01

Computing has infiltrated the everyday life of people all over the world. It is no longer merely a tool for communication and interaction, but also something-to-think-with, a medium that can give us new dimensions in the way we experience and engage with the world.Critical computing evokes...... in the user new ways of thinking and interacting with a globalized world. The Global Lives Project is a compelling example of this usage of computing technology. The GLP archive, which contains visual documentation of the lives of different people from around the world on a digital platform on the Internet......, enables users to actively engage with global cultures. As a critical computing project, the Global Lives Project hopes to bring a critical awareness of how culture is categorized and transformed by engaging users in a collaborative new media project....

Progress Report on the GROWTH (GNSS Reflectometry for Ocean Waves, Tides, and Height) Research Project

Science.gov (United States)

Kitazawa, Y.; Ichikawa, K.; Akiyama, H.; Ebinuma, T.; Isoguchi, O.; Kimura, N.; Konda, M.; Kouguchi, N.; Tamura, H.; Tomita, H.; Yoshikawa, Y.; Waseda, T.

2016-12-01

Global Navigation Satellite Systems (GNSS), such as GPS is a system of satellites that provide autonomous geo-spatial positioning with global coverage. It allows small electronic receivers to determine their location to high precision using radio signals transmitted from satellites, GNSS reflectometry (GNSS-R) involves making measurements from the reflections from the Earth of navigation signals from GNSS satellites. Reflected signals from sea surface are considered that those are useful to observe sea state and sea surface height. We have started a research program for GNSS-R applications on oceanographic observations under the contract with MEXT (Ministry of Education Culture, Sports, Science and Technology, JAPAN) and launched a Japanese research consortium, GROWTH (GNSS Reflectometry for Ocean Waves, Tides, and Height). It is aiming to evaluate the capabilities of GNSS-R observations for oceanographic phenomena with different time scales, such as ocean waves (1/10 to tens of seconds), tides (one or half days), and sea surface dynamic height (a few days to years). In situ observations of ocean wave spectrum, wind speed vertical profile, and sea surface height will be quantitatively compared with equivalent estimates from simultaneous GNSS-R measurements. The GROWTH project will utilize different types of observation platforms; marine observation towers (about 20 m height), multi-copters (about 100 to 150 m height), and much higher-altitude CYGNSS data. Cross-platform data, together with in situ oceanographic observations, will be compared after adequate temporal averaging that accounts differences of the footprint sizes and temporal and spatial scales of oceanographic phenomena. This paper will provide overview of the GROWTH project, preliminary test results, obtained by the multi-sensor platform at observation towers, suggest actual footprint sizes and identification of swell. Preparation status of a ground station which will be supplied to receive CYGNSS data

Twenty Years of Progress on Global Ocean Tides: The Impact of Satellite Altimetry

Science.gov (United States)

Egbert, Gary; Ray, Richard

2012-01-01

At the dawn of the era of high-precision altimetry, before the launch of TOPEX/Poseidon, ocean tides were properly viewed as a source of noise--tidal variations in ocean height would represent a very substantial fraction of what the altimeter measures, and would have to be accurately predicted and subtracted if altimetry were to achieve its potential for ocean and climate studies. But to the extent that the altimetry could be severely contaminated by tides, it also represented an unprecedented global-scale tidal data set. These new data, together with research stimulated by the need for accurate tidal corrections, led to a renaissance in tidal studies in the oceanographic community. In this paper we review contributions of altimetry to tidal science over the past 20 years, emphasizing recent progress. Mapping of tides has now been extended from the early focus on major constituents in the open ocean to include minor constituents, (e.g., long-period tides; non-linear tides in shelf waters, and in the open ocean), and into shallow and coastal waters. Global and spatially local estimates of tidal energy balance have been refined, and the role of internal tide conversion in dissipating barotropic tidal energy is now well established through modeling, altimetry, and in situ observations. However, energy budgets for internal tides, and the role of tidal dissipation in vertical ocean mixing remain controversial topics. Altimetry may contribute to resolving some of these important questions through improved mapping of low-mode internal tides. This area has advanced significantly in recent years, with several global maps now available, and progress on constraining temporally incoherent components. For the future, new applications of altimetry (e.g., in the coastal ocean, where barotropic tidal models remain inadequate), and new mission concepts (studies of the submesoscale with SWOT, which will require correction for internal tides) may bring us full circle, again pushing

Global Land Survey Impervious Mapping Project Web Site

Science.gov (United States)

DeColstoun, Eric Brown; Phillips, Jacqueline

2014-01-01

The Global Land Survey Impervious Mapping Project (GLS-IMP) aims to produce the first global maps of impervious cover at the 30m spatial resolution of Landsat. The project uses Global Land Survey (GLS) Landsat data as its base but incorporates training data generated from very high resolution commercial satellite data and using a Hierarchical segmentation program called Hseg. The web site contains general project information, a high level description of the science, examples of input and output data, as well as links to other relevant projects.

Ocean Data Interoperability Platform (ODIP): developing a common framework for marine data management on a global scale

Science.gov (United States)

Glaves, Helen; Schaap, Dick

2016-04-01

The increasingly ocean basin level approach to marine research has led to a corresponding rise in the demand for large quantities of high quality interoperable data. This requirement for easily discoverable and readily available marine data is currently being addressed by initiatives such as SeaDataNet in Europe, Rolling Deck to Repository (R2R) in the USA and the Australian Ocean Data Network (AODN) with each having implemented an e-infrastructure to facilitate the discovery and re-use of standardised multidisciplinary marine datasets available from a network of distributed repositories, data centres etc. within their own region. However, these regional data systems have been developed in response to the specific requirements of their users and in line with the priorities of the funding agency. They have also been created independently of the marine data infrastructures in other regions often using different standards, data formats, technologies etc. that make integration of marine data from these regional systems for the purposes of basin level research difficult. Marine research at the ocean basin level requires a common global framework for marine data management which is based on existing regional marine data systems but provides an integrated solution for delivering interoperable marine data to the user. The Ocean Data Interoperability Platform (ODIP/ODIP II) project brings together those responsible for the management of the selected marine data systems and other relevant technical experts with the objective of developing interoperability across the regional e-infrastructures. The commonalities and incompatibilities between the individual data infrastructures are identified and then used as the foundation for the specification of prototype interoperability solutions which demonstrate the feasibility of sharing marine data across the regional systems and also with relevant larger global data services such as GEO, COPERNICUS, IODE, POGO etc. The potential

Synthesis and Assimilation Systems - Essential Adjuncts to the Global Ocean Observing System

Science.gov (United States)

Rienecker, Michele M.; Balmaseda, Magdalena; Awaji, Toshiyuki; Barnier, Bernard; Behringer, David; Bell, Mike; Bourassa, Mark; Brasseur, Pierre; Breivik, Lars-Anders; Carton, James;

Sinking of Dense North Atlantic Waters in a Global Ocean Model : Location and Controls

NARCIS (Netherlands)

Katsman, C.A.; Drijfhout, SS; Dijkstra, H. A.; Spall, M. A.

2018-01-01

We investigate the characteristics of the sinking of dense waters in the North Atlantic Ocean that constitute the downwelling limb of the Atlantic Meridional Overturning Circulation (AMOC) as simulated by two global ocean models: an eddy-permitting model at 1/4° resolution and its coarser 1°

Thermosteric contribution of warming oceans to the global sea level variations

OpenAIRE

Bâki Iz H.

2016-01-01

Thermosteric contribution of warming oceans to the global sea level variations during the last century was evaluated at globally distributed 27 tide gauge stations with records over 80 years. The assessment was made using a recently proposed lagged model inclusive of a sea level trend, long and decadal periodicities, and lagged sea surface temperature measurements. The new model solutions revealed that almost all the long period periodic sea level changes experienced a...

Projected range contractions of European protected oceanic montane plant communities: focus on climate change impacts is essential for their future conservation.

Science.gov (United States)

Hodd, Rory L; Bourke, David; Skeffington, Micheline Sheehy

2014-01-01

Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly

Projected range contractions of European protected oceanic montane plant communities: focus on climate change impacts is essential for their future conservation.

Directory of Open Access Journals (Sweden)

Rory L Hodd

Full Text Available Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1 oceanic montane bryophytes and vascular plants; 2 species belonging to different montane plant communities; 3 species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need

Validation Test Report for the 1/8 deg Global Navy Coastal Ocean Model Nowcast/Forecast System

National Research Council Canada - National Science Library

Barron, Charlie N; Kara, A. B; Rhodes, Robert C; Rowley, Clark; Smedstad, Lucy F

2007-01-01

.... Global NCOM supports predictions of ocean currents, temperatures, salinity, sea surface height, and sound speed both directly and by providing initial and boundary conditions for higher-resolution nested ocean models...

Manifestation, Drivers, and Emergence of Open Ocean Deoxygenation

Science.gov (United States)

Levin, Lisa A.

2018-01-01

Oxygen loss in the ocean, termed deoxygenation, is a major consequence of climate change and is exacerbated by other aspects of global change. An average global loss of 2% or more has been recorded in the open ocean over the past 50-100 years, but with greater oxygen declines in intermediate waters (100-600 m) of the North Pacific, the East Pacific, tropical waters, and the Southern Ocean. Although ocean warming contributions to oxygen declines through a reduction in oxygen solubility and stratification effects on ventilation are reasonably well understood, it has been a major challenge to identify drivers and modifying factors that explain different regional patterns, especially in the tropical oceans. Changes in respiration, circulation (including upwelling), nutrient inputs, and possibly methane release contribute to oxygen loss, often indirectly through stimulation of biological production and biological consumption. Microbes mediate many feedbacks in oxygen minimum zones that can either exacerbate or ameliorate deoxygenation via interacting nitrogen, sulfur, and carbon cycles. The paleo-record reflects drivers of and feedbacks to deoxygenation that have played out through the Phanerozoic on centennial, millennial, and hundred-million-year timescales. Natural oxygen variability has made it difficult to detect the emergence of a climate-forced signal of oxygen loss, but new modeling efforts now project emergence to occur in many areas in 15-25 years. Continued global deoxygenation is projected for the next 100 or more years under most emissions scenarios, but with regional heterogeneity. Notably, even small changes in oxygenation can have significant biological effects. New efforts to systematically observe oxygen changes throughout the open ocean are needed to help address gaps in understanding of ocean deoxygenation patterns and drivers.

Manifestation, Drivers, and Emergence of Open Ocean Deoxygenation.

Science.gov (United States)

Levin, Lisa A

2018-01-03

Oxygen loss in the ocean, termed deoxygenation, is a major consequence of climate change and is exacerbated by other aspects of global change. An average global loss of 2% or more has been recorded in the open ocean over the past 50-100 years, but with greater oxygen declines in intermediate waters (100-600 m) of the North Pacific, the East Pacific, tropical waters, and the Southern Ocean. Although ocean warming contributions to oxygen declines through a reduction in oxygen solubility and stratification effects on ventilation are reasonably well understood, it has been a major challenge to identify drivers and modifying factors that explain different regional patterns, especially in the tropical oceans. Changes in respiration, circulation (including upwelling), nutrient inputs, and possibly methane release contribute to oxygen loss, often indirectly through stimulation of biological production and biological consumption. Microbes mediate many feedbacks in oxygen minimum zones that can either exacerbate or ameliorate deoxygenation via interacting nitrogen, sulfur, and carbon cycles. The paleo-record reflects drivers of and feedbacks to deoxygenation that have played out through the Phanerozoic on centennial, millennial, and hundred-million-year timescales. Natural oxygen variability has made it difficult to detect the emergence of a climate-forced signal of oxygen loss, but new modeling efforts now project emergence to occur in many areas in 15-25 years. Continued global deoxygenation is projected for the next 100 or more years under most emissions scenarios, but with regional heterogeneity. Notably, even small changes in oxygenation can have significant biological effects. New efforts to systematically observe oxygen changes throughout the open ocean are needed to help address gaps in understanding of ocean deoxygenation patterns and drivers.

The Sea Around Us Project: documenting and communicating global fisheries impacts on marine ecosystems.

Science.gov (United States)

Pauly, Daniel

2007-06-01

The Sea Around Us Project, initiated by the Pew Charitable Trusts in Philadelphia, PA, and located at the Fisheries Centre, University of British Columbia, Vancouver, Canada, started in mid 1999. Its goal was (and still is) to investigate the impact of fisheries on marine ecosystems and to propose policies to mitigate these impacts. Although conceived as a global activity, the project first emphasized the data-rich North Atlantic as a test bed for developing its approaches, which rely on mapping of catch data and indicators of ecosystem health derived from the analysis of long catch time series data. Initial achievements included mapping the decline, throughout the North Atlantic basin, of high-trophic level fishes from 1900 to the present and the presentation of compelling evidence of change in the functioning of the North Atlantic ecosystems, summarized in a 2003 book. The Central and South Atlantic were the next basins to be tackled, with emphasis on the distant-water fleet off West Africa, culminating in a major conference in Dakar, Senegal, in 2002. The project then emphasized the North Pacific, Antarctica, and marine mammals and the multiplicity of tropical Indo-Pacific fisheries before it turned completely global, with all our major analyses and reports (e.g., on the interactions between marine mammals and fisheries, on fuel consumption by fleets, on the catches of small-scale fisheries, on subsidies to fisheries) being based on global studies. Broadly, the work of the project is aimed at a reappraisal of fisheries, from the benign activity that many interested people still perceive them to be, to a realization that they have become the driver for massive loss of biodiversity in the ocean. Moreover, the emphasis on global estimates (rather than local estimates of dubious generality) has allowed the project to contribute to various global initiatives (e.g., developing the Marine Trophic Index for the Convention on Biological Diversity, quantifying marine

Role of mesoscale eddies in the global ocean uptake of anthropogenic CO2

International Nuclear Information System (INIS)

Zouhair, Lachkar

2007-02-01

Mesoscale eddies play a fundamental role in ocean dynamics particularly in the Southern Ocean. Global-scale tracer simulations are typically made at coarse resolution without explicitly modeling eddies. Here we ask what role do eddies play in ocean uptake, storage, and meridional transport of anthropogenic CO 2 , CFC-11 and bomb Δ 14 C. We made global anthropogenic transient tracer simulations in coarse-resolution, ORCA2, and eddy-permitting, ORCA05 and ORCA025, versions of the ocean modelling system NEMO. We focus on the Southern Ocean where tracer air-sea fluxes are largest. Eddies have little effect on bomb Δ 14 C uptake and storage. Yet for CFC-11 and anthropogenic CO 2 , increased eddy activity reduces southern extra-tropical uptake by 28% and 25% respectively, thereby providing better agreement with observations. It is shown that the discrepancies in the equilibration times between the three tracers determine their respective sensitivities to the model horizontal resolution. Applying Gent and McWilliams (1990) (GM) parameterization of eddies in the non-eddying version of the model does improve results, but not enough. An in-depth investigation of the mechanisms by which eddies affect the uptake of the transient tracers shows that including mesoscale eddies leads to an overall reduction in the Antarctic Intermediate Water (AAIW) ventilation, and modifies substantially the spatial distribution of their source regions. This investigation reveals also that the GM parameterization still overestimates the ventilation and the subduction of AAIW in the Indian Ocean where the simulated mixed layer is particularly deep during the winter. This work suggests that most current coarse-resolution models may overestimate the ventilation of AAIW in the Indian sector of the Southern Ocean. This study shows also that the use of the GM parameterization may be of limited utility where mixed layer is relatively deep and confirms the general need for a more adequate

The OceanLink Project

Science.gov (United States)

Narock, T.; Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Finin, T.; Hitzler, P.; Krisnadhi, A.; Raymond, L. M.; Shepherd, A.; Wiebe, P. H.

2014-12-01

A wide spectrum of maturing methods and tools, collectively characterized as the Semantic Web, is helping to vastly improve the dissemination of scientific research. Creating semantic integration requires input from both domain and cyberinfrastructure scientists. OceanLink, an NSF EarthCube Building Block, is demonstrating semantic technologies through the integration of geoscience data repositories, library holdings, conference abstracts, and funded research awards. Meeting project objectives involves applying semantic technologies to support data representation, discovery, sharing and integration. Our semantic cyberinfrastructure components include ontology design patterns, Linked Data collections, semantic provenance, and associated services to enhance data and knowledge discovery, interoperation, and integration. We discuss how these components are integrated, the continued automated and semi-automated creation of semantic metadata, and techniques we have developed to integrate ontologies, link resources, and preserve provenance and attribution.

Incentivizing More Effective Marine Protected Areas with the Global Ocean Refuge System (GLORES

Directory of Open Access Journals (Sweden)

Sarah O. Hameed

2017-06-01

Full Text Available Healthy oceans are essential to human survival and prosperity, yet oceans are severely impacted worldwide by anthropogenic threats including overfishing, climate change, industrialization, pollution, and habitat destruction. Marine protected areas (MPAs have been implemented around the world and are effective conservation tools that can mitigate some of these threats and build resilience when designed and managed well. However, despite a rich scientific literature on MPA effectiveness, science is not the main driver behind the design and implementation of many MPAs, leading to variable MPA effectiveness and bias in global MPA representativity. As a result, the marine conservation community focuses on promoting the creation of more MPAs as well as more effective ones, however no structure to improve or accelerate effective MPA implementation currently exists. To safeguard marine ecosystems on a global scale and better monitor progress toward ecosystem protection, robust science-based criteria are needed for evaluating MPAs and synthesizing the extensive and interdisciplinary science on MPA effectiveness. This paper presents a strategic initiative led by Marine Conservation Institute called the Global Ocean Refuge System (GLORES. GLORES aims to set standards to improve the quality of MPAs and catalyze strong protection for at least 30% of the ocean by 2030. Such substantial increase in marine protection is needed to maintain the resilience of marine ecosystems and restore their benefits to people. GLORES provides a comprehensive strategy that employs the rich body of MPA science to scale up existing marine conservation efforts.

Big Jump of Record Warm Global Mean Surface Temperature in 2014-2016 Related to Unusually Large Oceanic Heat Releases

Science.gov (United States)

Yin, Jianjun; Overpeck, Jonathan; Peyser, Cheryl; Stouffer, Ronald

2018-01-01

A 0.24°C jump of record warm global mean surface temperature (GMST) over the past three consecutive record-breaking years (2014-2016) was highly unusual and largely a consequence of an El Niño that released unusually large amounts of ocean heat from the subsurface layer of the northwestern tropical Pacific. This heat had built up since the 1990s mainly due to greenhouse-gas (GHG) forcing and possible remote oceanic effects. Model simulations and projections suggest that the fundamental cause, and robust predictor of large record-breaking events of GMST in the 21st century, is GHG forcing rather than internal climate variability alone. Such events will increase in frequency, magnitude, and duration, as well as impact, in the future unless GHG forcing is reduced.

Warming up, turning sour, losing breath: ocean biogeochemistry under global change.

Science.gov (United States)

Gruber, Nicolas

2011-05-28

In the coming decades and centuries, the ocean's biogeochemical cycles and ecosystems will become increasingly stressed by at least three independent factors. Rising temperatures, ocean acidification and ocean deoxygenation will cause substantial changes in the physical, chemical and biological environment, which will then affect the ocean's biogeochemical cycles and ecosystems in ways that we are only beginning to fathom. Ocean warming will not only affect organisms and biogeochemical cycles directly, but will also increase upper ocean stratification. The changes in the ocean's carbonate chemistry induced by the uptake of anthropogenic carbon dioxide (CO(2)) (i.e. ocean acidification) will probably affect many organisms and processes, although in ways that are currently not well understood. Ocean deoxygenation, i.e. the loss of dissolved oxygen (O(2)) from the ocean, is bound to occur in a warming and more stratified ocean, causing stress to macro-organisms that critically depend on sufficient levels of oxygen. These three stressors-warming, acidification and deoxygenation-will tend to operate globally, although with distinct regional differences. The impacts of ocean acidification tend to be strongest in the high latitudes, whereas the low-oxygen regions of the low latitudes are most vulnerable to ocean deoxygenation. Specific regions, such as the eastern boundary upwelling systems, will be strongly affected by all three stressors, making them potential hotspots for change. Of additional concern are synergistic effects, such as ocean acidification-induced changes in the type and magnitude of the organic matter exported to the ocean's interior, which then might cause substantial changes in the oxygen concentration there. Ocean warming, acidification and deoxygenation are essentially irreversible on centennial time scales, i.e. once these changes have occurred, it will take centuries for the ocean to recover. With the emission of CO(2) being the primary driver

Biotic and human vulnerability to projected changes in ocean biogeochemistry over the 21st century.

Science.gov (United States)

Mora, Camilo; Wei, Chih-Lin; Rollo, Audrey; Amaro, Teresa; Baco, Amy R; Billett, David; Bopp, Laurent; Chen, Qi; Collier, Mark; Danovaro, Roberto; Gooday, Andrew J; Grupe, Benjamin M; Halloran, Paul R; Ingels, Jeroen; Jones, Daniel O B; Levin, Lisa A; Nakano, Hideyuki; Norling, Karl; Ramirez-Llodra, Eva; Rex, Michael; Ruhl, Henry A; Smith, Craig R; Sweetman, Andrew K; Thurber, Andrew R; Tjiputra, Jerry F; Usseglio, Paolo; Watling, Les; Wu, Tongwen; Yasuhara, Moriaki

2013-10-01

Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions.

Biotic and human vulnerability to projected changes in ocean biogeochemistry over the 21st century.

Directory of Open Access Journals (Sweden)

Camilo Mora

2013-10-01

Full Text Available Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions.

Project CLIMPEAT - Influence of global warming and drought on the carbon sequestration and biodiversity of Sphagnum peatlands

Science.gov (United States)

Lamentowicz, M.; Buttler, A.; Mitchell, E. A. D.; Chojnicki, B.; Słowińska, S.; Słowiński, M.

2012-04-01

Northern peatlands represent a globally significant pool of carbon and are subject to the highest rates of climate warming, and most of these peatlands are in continental settings. However, it is unclear if how fast peatlands respond to past and present changes in temperature and surface moisture in continental vs. oceanic climate settings. The CLIMPEAT project brings together scientists from Poland and Switzerland. Our goal is to assess the past and present vulnerability to climate change of Sphagnum peatland plant and microbial communities, peat organic matter transformations and carbon sequestration using a combination of field and mesocosm experiments simulating warming and water table changes and palaeoecological studies. Warming will be achieved using ITEX-type "Open-Top Chambers". The field studies are conducted in Poland, at the limit between oceanic and continental climates, and are part of a network of projects also including field experiments in the French Jura (sub-oceanic) and in Siberia (continental). We will calibrate the response of key biological (plants, testate amoebae) and geochemical (isotopic composition of organic compounds, organic matter changes) proxies to warming and water table changes and use these proxies to reconstruct climate changes during the last 1000 years.

Global ocean tide models on the eve of Topex/Poseidon

Science.gov (United States)

Ray, Richard D.

1993-01-01

Some existing global ocean tide models that can provide tide corrections to Topex/Poseidon altimeter data are described. Emphasis is given to the Schwiderski and Cartwright-Ray models, as these are the most comprehensive, highest resolution models, but other models that will soon appear are mentioned. Differences between models for M2 often exceed 10 cm over vast stretches of the ocean. Comparisons to 80 selected pelagic and island gauge measurements indicate the Schwiderski model is more accurate for the major solar tides, Cartwright-Ray for the major lunar tides. The adequacy of available tide models for studying basin-scale motions is probably marginal at best.

Global patterns of organic carbon export and sequestration in the ocean (Arne Richter Award for Outstanding Young Scientists)

Science.gov (United States)

Henson, S.; Sanders, R.; Madsen, E.; Le Moigne, F.; Quartly, G.

2012-04-01

A major term in the global carbon cycle is the ocean's biological carbon pump which is dominated by sinking of small organic particles from the surface ocean to its interior. Here we examine global patterns in particle export efficiency (PEeff), the proportion of primary production that is exported from the surface ocean, and transfer efficiency (Teff), the fraction of exported organic matter that reaches the deep ocean. This is achieved through extrapolating from in situ estimates of particulate organic carbon export to the global scale using satellite-derived data. Global scale estimates derived from satellite data show, in keeping with earlier studies, that PEeff is high at high latitudes and low at low latitudes, but that Teff is low at high latitudes and high at low latitudes. However, in contrast to the relationship observed for deep biomineral fluxes in previous studies, we find that Teff is strongly negatively correlated with opal export flux from the upper ocean, but uncorrelated with calcium carbonate export flux. We hypothesise that the underlying factor governing the spatial patterns observed in Teff is ecosystem function, specifically the degree of recycling occurring in the upper ocean, rather than the availability of calcium carbonate for ballasting. Finally, our estimate of global integrated carbon export is only 50% of previous estimates. The lack of consensus amongst different methodologies on the strength of the biological carbon pump emphasises that our knowledge of a major planetary carbon flux remains incomplete.

Declining global per capita agricultural production and warming oceans threaten food security

Science.gov (United States)

Funk, Christopher C.; Brown, Molly E.

2009-01-01

Despite accelerating globalization, most people still eat food that is grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be determined by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices and policies. This paper discusses several emerging threats to global and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian Ocean and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia and Central and Southern America will experience substantial declines in per capita cereal production. Global per capita cereal production will potentially decline by 14% between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific Oceans, may also reduce 21st century food availability in some countries by disrupting moisture transports and bringing down dry air over crop growing areas. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian Ocean warming appears to have already reduced rainfall during the main growing season along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, this study presents an analysis of emerging

Poseidon's paintbox : historical archives of ocean colour in global-change perspective

Science.gov (United States)

Wernand, M. R.

2011-11-01

In the thesis introduction issues are discussed on the historical background of marine optics and on marine optical devices that were used over the past centuries to observe and measure; as in all sciences, in marine optics we can see a steady development: that of ‘measuring’, beginning many centuries ago, to 'knowing' and since less than a century to the understanding of the phenomenon. Hereafter, six themes are treated successively. The first theme, ‘Ocean optics from 1600 (Hudson) to 1930 (Raman), shift in interpretation of natural water colouring’, addresses the question of why it took so long a time to explain the phenomenon ‘the colouring of the sea’, especially the blue colour, despite the age-long interest of sailors, for practical purposes of navigation and detection of fish - of which more later. The second theme ‘On the history of the Secchi disc’, describes the search to establish methods for the determination of (sea) water clarity concerning purposes of navigation (near coast colour changes) just mentioned to detect shoals, and for a more basic purpose, tracing lost objects. The search to determine the clarity of lakes and seas culminated in the invention of the Secchi disc, used since the late 19th century. The third theme, ‘Spectral analysis of the Forel-Ule ocean colour comparator scale’, addresses the accuracy of a colour scale proposed, used in limnology and oceanography. Scale observations are put into perspective with contemporary measurements on the colour of the sea. The fourth theme, ‘Ocean colour changes in the North Pacific since 1930’, handles the question whether long-term ocean colour changes using historic Forel-Ule observations, in this part of the ocean made very frequently over time, can be determined in relation to global change. In principal global warming may cause a gradual change in ocean colour due to the effect of biological, chemical and physical aspects of the ocean-surface. The fifth theme, �

Role of the ocean mixed layer processes in the response of the North Pacific winter SST and MLD to global warming in CGCMs

Energy Technology Data Exchange (ETDEWEB)

Yim, Bo Young; Noh, Yign [Yonsei University, Department of Atmospheric Sciences, Global Environmental Laboratory, Seoul (Korea, Republic of); Yeh, Sang-Wook [Hanyang University, Department of Environmental Marine Science, Ansan (Korea, Republic of)

2012-03-15

It is investigated how the changes of winter sea surface temperature (SST) and mixed layer depth (MLD) under climate change projections are predicted differently in the North Pacific depending on the coupled general circulation models (CGCMs), and how they are related to the dynamical property of the simulated ocean mixed layer. For this purpose the dataset from eleven CGCMs reported to IPCC's AR4 are used, while detailed analysis is given to the MRI and MIROC models. Analysis of the CGCM data reveals that the increase of SST and the decrease of MLD in response to global warming tend to be smaller for the CGCM in which the ratio of ocean heat transport (OHT) to surface heat flux (SHF), R (=OHT/SHF), is larger in the heat budget of the mixed layer. The negative correlation is found between the changes of OHT and SHF under global warming, which may weaken the response to global warming in the CGCM with larger R. It is also found that the models with low horizontal resolution tend to give broader western boundary currents, larger R, and the smaller changes of SST and MLD under global warming. (orig.)

Marine geochemistry ocean circulation, carbon cycle and climate change

CERN Document Server

Roy-Barman, Matthieu

2016-01-01

Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides a simple introduction to the concepts (environmental chemistry, isotopes), the methods (field approach, remote sensing, modeling) and the applications (ocean circulation, carbon cycle, climate change) of marine geochemistry with a particular emphasis on isotopic tracers. Marine geochemistry is not an isolated discipline: numerous openings on physical oceanography, marine biology, climatology, geology, pollutions and ecology are proposed and provide a global vision of the ocean. It includes new topics based on ongoing research programs such as GEOTRACES, Global Carbon Project, Tara Ocean. It provides a complete outline for a course in marine geochemistry. To favor a...

Sensitivity of global ocean biogeochemical dynamics to ecosystem structure in a future climate

Science.gov (United States)

Manizza, Manfredi; Buitenhuis, Erik T.; Le Quéré, Corinne

2010-07-01

Terrestrial and oceanic ecosystem components of the Earth System models (ESMs) are key to predict the future behavior of the global carbon cycle. Ocean ecosystem models represent low complexity compared to terrestrial ecosystem models. In this study we use two ocean biogeochemical models based on the explicit representation of multiple planktonic functional types. We impose to the models the same future physical perturbation and compare the response of ecosystem dynamics, export production (EP) and ocean carbon uptake (OCU) to the same physical changes. Models comparison shows that: (1) EP changes directly translate into changes of OCU on decadal time scale, (2) the representation of ecosystem structure plays a pivotal role at linking OCU and EP, (3) OCU is highly sensitive to representation of ecosystem in the Equatorial Pacific and Southern Oceans.

Report on an international joint research project for global environment technology in fiscal 1998; 1998 nendo chikyu kankyo gijutsu kokusai kyodo kenkyu jigyo hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

In order to serve for measures against global problems taken by Japan, joint research was carried out with overseas research organizations. The research project selected ten themes considering urgency, internationality and economic proliferation effect in areas to serve for solution of global environment problems. These themes include removal or emission control of greenhouse effect gases, measures against atmospheric environment problems such as acid rains and ozone layer destruction, prevention of ocean contamination, development and effective utilization of energies and resources. When the feedback of these themes to the NEDO projects is considered, the research achievements in relation with development of the acid rain monitoring system in particular support indirectly development of carbon dioxide fixation technologies. The research achievements in developing an environmentally friendly biomass energy manufacturing process and environmental effect evaluation thereon contribute as an effective process to carbon dioxide reduction using biomass as raw materials. The achievements in research of nonlinear interfacial properties and mixed phase turbulence of low-purity carbon dioxide bubbles contribute to a project related to storage of carbon dioxide in oceans. (NEDO)

Projections of oceanic N2O emissions in the 21st century using the IPSL Earth system model

Science.gov (United States)

Martinez-Rey, J.; Bopp, L.; Gehlen, M.; Tagliabue, A.; Gruber, N.

2015-07-01

The ocean is a substantial source of nitrous oxide (N2O) to the atmosphere, but little is known about how this flux might change in the future. Here, we investigate the potential evolution of marine N2O emissions in the 21st century in response to anthropogenic climate change using the global ocean biogeochemical model NEMO-PISCES. Assuming nitrification as the dominant N2O formation pathway, we implemented two different parameterizations of N2O production which differ primarily under low-oxygen (O2) conditions. When forced with output from a climate model simulation run under the business-as-usual high-CO2 concentration scenario (RCP8.5), our simulations suggest a decrease of 4 to 12 % in N2O emissions from 2005 to 2100, i.e., a reduction from 4.03/3.71 to 3.54/3.56 TgN yr-1 depending on the parameterization. The emissions decrease strongly in the western basins of the Pacific and Atlantic oceans, while they tend to increase above the oxygen minimum zones (OMZs), i.e., in the eastern tropical Pacific and in the northern Indian Ocean. The reduction in N2O emissions is caused on the one hand by weakened nitrification as a consequence of reduced primary and export production, and on the other hand by stronger vertical stratification, which reduces the transport of N2O from the ocean interior to the ocean surface. The higher emissions over the OMZ are linked to an expansion of these zones under global warming, which leads to increased N2O production, associated primarily with denitrification. While there are many uncertainties in the relative contribution and changes in the N2O production pathways, the increasing storage seems unequivocal and determines largely the decrease in N2O emissions in the future. From the perspective of a global climate system, the averaged feedback strength associated with the projected decrease in oceanic N2O emissions amounts to around -0.009 W m-2 K-1, which is comparable to the potential increase from terrestrial N2O sources. However

Assessing global carbon burial during Oceanic Anoxic Event 2, Cenomanian-Turonian boundary event

Science.gov (United States)

Owens, J. D.; Lyons, T. W.; Lowery, C. M.

2017-12-01

Reconstructing the areal extent and total amount of organic carbon burial during ancient events remains elusive even for the best documented oceanic anoxic event (OAE) in Earth history, the Cenomanian-Turonian boundary event ( 93.9 Ma), or OAE 2. Reports from 150 OAE 2 localities provide a wide global distribution. However, despite the large number of sections, the majority are found within the proto-Atlantic and Tethyan oceans and interior seaways. Considering these gaps in spatial coverage, the pervasive increase in organic carbon (OC) burial during OAE2 that drove carbon isotope values more positive (average of 4‰) can provide additional insight. These isotope data allow us to estimate the total global burial of OC, even for unstudied portions of the global ocean. Thus, we can solve for any `missing' OC sinks by comparing our estimates from a forward carbon-isotope box model with the known, mapped distribution of OC for OAE 2 sediments. Using the known OC distribution and reasonably extrapolating to the surrounding regions of analogous depositional conditions accounts for only 13% of the total seafloor, mostly in marginal marine settings. This small geographic area accounts for more OC burial than the entire modern ocean, but significantly less than the amount necessary to produce the observed isotope record. Using modern and OAE 2 average OC rates we extrapolate further to appropriate depositional settings in the unknown portions of seafloor, mostly deep abyssal plains. This addition significantly increases the predicted amount buried but still does not account for total burial. Additional sources, including hydrocarbon migration, lacustrine, and coal also cannot account for the missing OC. This difference points to unknown portions of the open ocean with high TOC contents or exceptionally high TOC in productive marginal marine regions, which are underestimated in our extrapolations. This difference might be explained by highly productive margins within the

Projected Impact of Climate Change on the Energy Budget of the Arctic Ocean by a Global Climate Model

Science.gov (United States)

Miller, James R.; Russell, Gary L.; Hansen, James E. (Technical Monitor)

2001-01-01

The annual energy budget of the Arctic Ocean is characterized by a net heat loss at the air-sea interface that is balanced by oceanic heat transport into the Arctic. The energy loss at the air-sea interface is due to the combined effects of radiative, sensible, and latent heat fluxes. The inflow of heat by the ocean can be divided into two components: the transport of water masses of different temperatures between the Arctic and the Atlantic and Pacific Oceans and the export of sea ice, primarily through Fram Strait. Two 150-year simulations (1950-2099) of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. One is a control simulation for the present climate with constant 1950 atmospheric composition, and the other is a transient experiment with observed GHGs from 1950 to 1990 and 0.5% annual compounded increases of CO2 after 1990. For the present climate the model agrees well with observations of radiative fluxes at the top of the atmosphere, atmospheric advective energy transport into the Arctic, and surface air temperature. It also simulates the seasonal cycle and summer increase of cloud cover and the seasonal cycle of sea-ice cover. In addition, the changes in high-latitude surface air temperature and sea-ice cover in the GHG experiment are consistent with observed changes during the last 40 and 20 years, respectively. Relative to the control, the last 50-year period of the GHG experiment indicates that even though the net annual incident solar radiation at the surface decreases by 4.6 W(per square meters) (because of greater cloud cover and increased cloud optical depth), the absorbed solar radiation increases by 2.8 W(per square meters) (because of less sea ice). Increased cloud cover and warmer air also cause increased downward thermal radiation at the surface so that the net radiation into the ocean increases by 5.0 Wm-2. The annual increase in radiation into the ocean, however, is

Assessing carbon dioxide removal through global and regional ocean alkalinization under high and low emission pathways

Science.gov (United States)

Lenton, Andrew; Matear, Richard J.; Keller, David P.; Scott, Vivian; Vaughan, Naomi E.

2018-04-01

Atmospheric carbon dioxide (CO2) levels continue to rise, increasing the risk of severe impacts on the Earth system, and on the ecosystem services that it provides. Artificial ocean alkalinization (AOA) is capable of reducing atmospheric CO2 concentrations and surface warming and addressing ocean acidification. Here, we simulate global and regional responses to alkalinity (ALK) addition (0.25 PmolALK yr-1) over the period 2020-2100 using the CSIRO-Mk3L-COAL Earth System Model, under high (Representative Concentration Pathway 8.5; RCP8.5) and low (RCP2.6) emissions. While regionally there are large changes in alkalinity associated with locations of AOA, globally we see only a very weak dependence on where and when AOA is applied. On a global scale, while we see that under RCP2.6 the carbon uptake associated with AOA is only ˜ 60 % of the total, under RCP8.5 the relative changes in temperature are larger, as are the changes in pH (140 %) and aragonite saturation state (170 %). The simulations reveal AOA is more effective under lower emissions, therefore the higher the emissions the more AOA is required to achieve the same reduction in global warming and ocean acidification. Finally, our simulated AOA for 2020-2100 in the RCP2.6 scenario is capable of offsetting warming and ameliorating ocean acidification increases at the global scale, but with highly variable regional responses.

In situ imaging reveals the biomass of giant protists in the global ocean.

Science.gov (United States)

Biard, Tristan; Stemmann, Lars; Picheral, Marc; Mayot, Nicolas; Vandromme, Pieter; Hauss, Helena; Gorsky, Gabriel; Guidi, Lionel; Kiko, Rainer; Not, Fabrice

2016-04-28

Planktonic organisms play crucial roles in oceanic food webs and global biogeochemical cycles. Most of our knowledge about the ecological impact of large zooplankton stems from research on abundant and robust crustaceans, and in particular copepods. A number of the other organisms that comprise planktonic communities are fragile, and therefore hard to sample and quantify, meaning that their abundances and effects on oceanic ecosystems are poorly understood. Here, using data from a worldwide in situ imaging survey of plankton larger than 600 μm, we show that a substantial part of the biomass of this size fraction consists of giant protists belonging to the Rhizaria, a super-group of mostly fragile unicellular marine organisms that includes the taxa Phaeodaria and Radiolaria (for example, orders Collodaria and Acantharia). Globally, we estimate that rhizarians in the top 200 m of world oceans represent a standing stock of 0.089 Pg carbon, equivalent to 5.2% of the total oceanic biota carbon reservoir. In the vast oligotrophic intertropical open oceans, rhizarian biomass is estimated to be equivalent to that of all other mesozooplankton (plankton in the size range 0.2-20 mm). The photosymbiotic association of many rhizarians with microalgae may be an important factor in explaining their distribution. The previously overlooked importance of these giant protists across the widest ecosystem on the planet changes our understanding of marine planktonic ecosystems.

Technical Report Series on Global Modeling and Data Assimilation. Volume 31; Global Surface Ocean Carbon Estimates in a Model Forced by MERRA

Science.gov (United States)

Gregg, Watson W.; Casey, Nancy W.; Rousseaux, Cecile S.

2013-01-01

MERRA products were used to force an established ocean biogeochemical model to estimate surface carbon inventories and fluxes in the global oceans. The results were compared to public archives of in situ carbon data and estimates. The model exhibited skill for ocean dissolved inorganic carbon (DIC), partial pressure of ocean CO2 (pCO2) and air-sea fluxes (FCO2). The MERRA-forced model produced global mean differences of 0.02% (approximately 0.3 microns) for DIC, -0.3% (about -1.2 (micro) atm; model lower) for pCO2, and -2.3% (-0.003 mol C/sq m/y) for FCO2 compared to in situ estimates. Basin-scale distributions were significantly correlated with observations for all three variables (r=0.97, 0.76, and 0.73, P<0.05, respectively for DIC, pCO2, and FCO2). All major oceanographic basins were represented as sources to the atmosphere or sinks in agreement with in situ estimates. However, there were substantial basin-scale and local departures.

Finding the missing plastic -resolving the global mass (im)balance for plastic pollution in the ocean

Science.gov (United States)

Wilcox, C.; van Sebille, E.

2016-02-01

Several global studies have attempted to estimate the standing stock of plastic debris in the oceans at the global scale. However, recent work estimating the amount lost from land on an annual basis suggests that the standing stock should be several orders of magnitude larger than the global estimates. We investigate the role of coastal deposition within the first few weeks after plastic enters the ocean and very near its sources, one of the hypothesized sinks for the missing plastic in this mass balance. We utilize a continental scale dataset of plastics collected along Australia's coast and in the offshore regions together with models of plastic release and transport based on Lagrangian tracking to investigate the role of local deposition in the coastal environment. Our models predict that the vast majority of positively buoyant plastic is deposited within a very short distance from its release point, with only a small fraction escaping into the open ocean. These predictions match our coastal and offshore observations, providing clear evidence that this mechanism of immediate coastal deposition is, at least in part, driving the apparent mismatch between coastal emissions and the standing stock in the ocean.

Developing a global ocean observing system that prioritises ecosystem variables from a political and societal point of view

Science.gov (United States)

Miloslavich, P.; Bax, N. J.; Simmons, S. E.; Appeltans, W.; Garcia, M.

2016-02-01

The Biology and Ecosystems Panel of GOOS aims to develop and coordinate efforts to implement a sustained and targeted global ocean observation system. This system will be driven by societal needs (including the Sustainable Development Goals), and identify Essential Ocean Variables (EOVs) to inform priority scientific and societal questions that will facilitate critical policy development and management decision-making on ocean and coastal resource sustainability and health. Mature EOVs need to have global relevance and the capacity for global measurement. Our goal is to implement at least one (set of) mature EOVs by 2019, and identify a further three (sets of) pilot EOVs with a clear pathway to maturity. Our initial work includes (1) identifying drivers and pressures of societal and scientific needs, and (2) identifying internationally agreed goals that need sustained global observations of ocean biological & ecosystem variables for a healthy ocean. We reviewed 24 major conventions/international organizations (including the CBD and 16 UN related) to identify the societal needs these organizations address through their goals, and to produce a set of overlapping objectives. Main drivers identified in these conventions were: knowledge (science/data access), development (sustainable economic growth), conservation (biodiversity & ecosystems), sustainable use (biodiversity & resources), environmental quality (health), capacity building (technology transfer), food security, threat prevention and impact mitigation (to different pressures) and improved management (integrated ecosystem approach). The main pressures identified were climate change, ocean acidification, extreme weather events, overfishing/ overexploitation, pollution/ eutrophication, mining, solid wastes. Our next step will be to develop consensus with the observing community about the EOVs that will meet these needs and support the expansion of these identified EOVs into successful global observing systems.

M2, S2, K1 models of the global ocean tide

Science.gov (United States)

Parke, M. E.; Hendershott, M. C.

1979-01-01

Ocean tidal signals appear in many geophysical measurements. Geophysicists need realistic tidal models to aid in interpretation of their data. Because of the closeness to resonance of dissipationless ocean tides, it is difficult for numerical models to correctly represent the actual open ocean tide. As an approximate solution to this problem, test functions derived by solving Laplace's Tidal Equations with ocean loading and self gravitation are used as a basis for least squares dynamic interpolation of coastal and island tidal data for the constituents M2, S2, and Kl. The resulting representations of the global tide are stable over at least a ?5% variation in the mean depth of the model basin, and they conserve mass. Maps of the geocentric tide, the induced free space potential, the induced vertical component of the solid earth tide, and the induced vertical component of the gravitational field for each contituent are presented.

Schwarz-Christoffel Conformal Mapping based Grid Generation for Global Oceanic Circulation Models

Science.gov (United States)

Xu, Shiming

2015-04-01

We propose new grid generation algorithms for global ocean general circulation models (OGCMs). Contrary to conventional, analytical forms based dipolar or tripolar grids, the new algorithm are based on Schwarz-Christoffel (SC) conformal mapping with prescribed boundary information. While dealing with the conventional grid design problem of pole relocation, it also addresses more advanced issues of computational efficiency and the new requirements on OGCM grids arisen from the recent trend of high-resolution and multi-scale modeling. The proposed grid generation algorithm could potentially achieve the alignment of grid lines to coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the generated grids are still orthogonal curvilinear, they can be readily 10 utilized in existing Bryan-Cox-Semtner type ocean models. The proposed methodology can also be applied to the grid generation task for regional ocean modeling when complex land-ocean distribution is present.

Combined simulation of carbon and water isotopes in a global ocean model

Science.gov (United States)

Paul, André; Krandick, Annegret; Gebbie, Jake; Marchal, Olivier; Dutkiewicz, Stephanie; Losch, Martin; Kurahashi-Nakamura, Takasumi; Tharammal, Thejna

2013-04-01

Carbon and water isotopes are included as passive tracers in the MIT general circulation model (MITgcm). The implementation of the carbon isotopes is based on the existing MITgcm carbon cycle component and involves the fractionation processes during photosynthesis and air-sea gas exchange. Special care is given to the use of a real freshwater flux boundary condition in conjunction with the nonlinear free surface of the ocean model. The isotopic content of precipitation and water vapor is obtained from an atmospheric GCM (the NCAR CAM3) and mapped onto the MITgcm grid system, but the kinetic fractionation during evaporation is treated explicitly in the ocean model. In a number of simulations, we test the sensitivity of the carbon isotope distributions to the formulation of fractionation during photosynthesis and compare the results to modern observations of δ13C and Δ14C from GEOSECS, WOCE and CLIVAR. Similarly, we compare the resulting distribution of oxygen isotopes to modern δ18O data from the NASA GISS Global Seawater Oxygen-18 Database. The overall agreement is good, but there are discrepancies in the carbon isotope composition of the surface water and the oxygen isotope composition of the intermediate and deep waters. The combined simulation of carbon and water isotopes in a global ocean model will provide a framework for studying present and past states of ocean circulation such as postulated from deep-sea sediment records.

Community Observatories: Fostering Ideas that STEM From Ocean Sense: Local Observations. Global Connections.

Science.gov (United States)

Pelz, M. S.; Ewing, N.; Hoeberechts, M.; Riddell, D. J.; McLean, M. A.; Brown, J. C. K.

2015-12-01

Ocean Networks Canada (ONC) uses education and communication to inspire, engage and educate via innovative "meet them where they are, and take them where they need to go" programs. ONC data are accessible via the internet allowing for the promotion of programs wherever the learners are located. We use technologies such as web portals, mobile apps and citizen science to share ocean science data with many different audiences. Here we focus specifically on one of ONC's most innovative programs: community observatories and the accompanying Ocean Sense program. The approach is based on equipping communities with the same technology enabled on ONC's large cabled observatories. ONC operates the world-leading NEPTUNE and VENUS cabled ocean observatories and they collect data on physical, chemical, biological, and geological aspects of the ocean over long time periods, supporting research on complex Earth processes in ways not previously possible. Community observatories allow for similar monitoring on a smaller scale, and support STEM efforts via a teacher-led program: Ocean Sense. This program, based on local observations and global connections improves data-rich teaching and learning via visualization tools, interactive plotting interfaces and lesson plans for teachers that focus on student inquiry and exploration. For example, students use all aspects of STEM by accessing, selecting, and interpreting data in multiple dimensions, from their local community observatories to the larger VENUS and NEPTUNE networks. The students make local observations and global connections in all STEM areas. The first year of the program with teachers and students who use this innovative technology is described. Future community observatories and their technological applications in education, communication and STEM efforts are also described.

Key Issues in Global Technological Innovation Projects

Directory of Open Access Journals (Sweden)

Roberto Sbragia

2012-04-01

Full Text Available This article aimed to identify those issues that were present in global technological innovation projects carried out by Brazilian multinational companies and which performance criterions these undertakings met. We investigated 36 global technological innovation projects from Brazilian multinational enterprises through a web-survey. Findings show that these companies went beyond the traditional iron triangle to evaluate their technological efforts and considered additional performance dimensions such as customer satisfaction, business results, and preparation for the future. Results also show high degree of presence for issues emerging from the industry, moderate degree of presence for issues emerging from both the project and R&D activities, and low degree of presence for issues emerging from the headquarters, the subsidiaries, and the external environment. Further research is needed to find out if and how these issues influenced the performance of the global technological innovation projects studied.DOI:10.5585/gep.v3i1.72

Worldwide marine radioactivity studies (WOMARS): Radionuclide levels in oceans and seas. Final report of a coordinated research project

International Nuclear Information System (INIS)

2005-01-01

This publication summarizes the results of the Coordinated Research Project (CRP) on Worldwide Marine Radioactivity Studies (WOMARS) carried out by the IAEA's Marine Environment Laboratory in Monaco. It provides the most comprehensive information on levels of anthropogenic radionuclides in the world ocean. Three anthropogenic radionuclides - 90 Sr, 137 Cs and 239,240 Pu - were chosen as the most representative of anthropogenic radioactivity in the marine environment, comprising beta-, gamma- and alpha-emitters which have the highest potential contribution to radiation doses to humans via seafood consumption. Although the ocean contains the majority of the anthropogenic radionuclides released into the environment, the radiological impact of this contamination is low. Radiation doses from naturally-occurring radionuclides in the marine environment (e.g. 210 Po) are on the average two orders of magnitude higher. The results confirm that the dominant source of anthropogenic radionuclides in the marine environment is global fallout. The total 137 Cs input from global fallout was estimated to be 311 PBq for the Pacific Ocean, 201 PBq for the Atlantic Ocean, 84 PBq for the Indian Ocean and 7.4 PBq for the Arctic Ocean. For comparison, about 40 PBq of 137 Cs was released to the marine environment from Sellafield and Cap de la Hague reprocessing plants. The Chernobyl accident contributed about 16 PBq of 137 Cs to the sea, mainly the Baltic and Black Seas, where the present average concentrations of 137 Cs in surface water were estimated to be about 60 and 25 Bq/m 3 , respectively, while the worldwide average concentration due to global fallout is about 2 Bq/m 3 . For the purposes of this study, the world ocean was divided into latitudinal belts for which average radionuclide concentrations were estimated. Further, where available, time trends in radionuclide concentrations in surface water were studied and mean residence times of radionuclides in these areas as well as in

Eurasia: The Rivalry of Global Integration Projects

Directory of Open Access Journals (Sweden)

Olesia Kobenko

2016-05-01

Full Text Available The article reveals the Eurasian integration projects as major drivers of world globalization. Eurasian regionalism seems to be gaining attention in the scientific literature. Under the current political circumstance many regions are accelerating integration and many countries are opting for regional associations as a mechanism to help them overcome the global recession. Moreover, the global political leaders , some developed countries - the U.S., China, and the European Union (EU are interested to set up regional economic blocs such as Eurasian Economic Union (The EEU, the China's project 'One Belt One Road', the U.S's projects - The Trans-Pacific Partnership (TPP and The Transatlantic Trade and Investment Partnership (TTIP. The goal of this paper is to introduce a number of integration initiatives and to analyze the current strategies of Eurasian regionalism.

On the assimilation of absolute geodetic dynamic topography in a global ocean model: impact on the deep ocean state

Science.gov (United States)

Androsov, Alexey; Nerger, Lars; Schnur, Reiner; Schröter, Jens; Albertella, Alberta; Rummel, Reiner; Savcenko, Roman; Bosch, Wolfgang; Skachko, Sergey; Danilov, Sergey

2018-05-01

General ocean circulation models are not perfect. Forced with observed atmospheric fluxes they gradually drift away from measured distributions of temperature and salinity. We suggest data assimilation of absolute dynamical ocean topography (DOT) observed from space geodetic missions as an option to reduce these differences. Sea surface information of DOT is transferred into the deep ocean by defining the analysed ocean state as a weighted average of an ensemble of fully consistent model solutions using an error-subspace ensemble Kalman filter technique. Success of the technique is demonstrated by assimilation into a global configuration of the ocean circulation model FESOM over 1 year. The dynamic ocean topography data are obtained from a combination of multi-satellite altimetry and geoid measurements. The assimilation result is assessed using independent temperature and salinity analysis derived from profiling buoys of the AGRO float data set. The largest impact of the assimilation occurs at the first few analysis steps where both the model ocean topography and the steric height (i.e. temperature and salinity) are improved. The continued data assimilation over 1 year further improves the model state gradually. Deep ocean fields quickly adjust in a sustained manner: A model forecast initialized from the model state estimated by the data assimilation after only 1 month shows that improvements induced by the data assimilation remain in the model state for a long time. Even after 11 months, the modelled ocean topography and temperature fields show smaller errors than the model forecast without any data assimilation.

BAROMETRIC PRESSURE and Other Data From Arctic Ocean from 19771114 to 19890517 (NODC Accession 9200249)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession is from the CD-Rom containing data from eastern Arctic collected as part of Global Ocean Data Archeaology and Rescue (GODAR) project...

Formulation of an ocean model for global climate simulations

Directory of Open Access Journals (Sweden)

S. M. Griffies

2005-01-01

Full Text Available This paper summarizes the formulation of the ocean component to the Geophysical Fluid Dynamics Laboratory's (GFDL climate model used for the 4th IPCC Assessment (AR4 of global climate change. In particular, it reviews the numerical schemes and physical parameterizations that make up an ocean climate model and how these schemes are pieced together for use in a state-of-the-art climate model. Features of the model described here include the following: (1 tripolar grid to resolve the Arctic Ocean without polar filtering, (2 partial bottom step representation of topography to better represent topographically influenced advective and wave processes, (3 more accurate equation of state, (4 three-dimensional flux limited tracer advection to reduce overshoots and undershoots, (5 incorporation of regional climatological variability in shortwave penetration, (6 neutral physics parameterization for representation of the pathways of tracer transport, (7 staggered time stepping for tracer conservation and numerical efficiency, (8 anisotropic horizontal viscosities for representation of equatorial currents, (9 parameterization of exchange with marginal seas, (10 incorporation of a free surface that accomodates a dynamic ice model and wave propagation, (11 transport of water across the ocean free surface to eliminate unphysical ``virtual tracer flux' methods, (12 parameterization of tidal mixing on continental shelves. We also present preliminary analyses of two particularly important sensitivities isolated during the development process, namely the details of how parameterized subgridscale eddies transport momentum and tracers.

The Indonesian Throughflow (ITF) and its impacts on the Indian Ocean during the global warming slowdown period

Science.gov (United States)

Makarim, S.; Liu, Z.; Yu, W.; Yan, X.; Sprintall, J.

2016-12-01

The global warming slowdown indicated by a slower warming rate at the surface layer accompanied by stronger heat transport into the deeper layers has been explored in the Indian Ocean. Although the mechanisms of the global warming slowdown are still under warm debate, some clues have been recognized that decadal La Nina like-pattern induced decadal cooling in the Pacific Ocean and generated an increase of the Indonesian Throughflow (ITF) transport in 2004-2010. However, how the ITF spreading to the interior of the Indian Ocean and the impact of ITF changes on the Indian Ocean, in particular its water mass transformation and current system are still unknown. To this end, we analyzed thermohaline structure and current system at different depths in the Indian Ocean both during and just before the global warming slowdown period using the ORAS4 and ARGO dataset. Here, we found the new edge of ITF at off Sumatra presumably as northward deflection of ITF Lombok Strait, and The Monsoon Onset Monitoring and Social Ecology Impact (MOMSEI) and Java Upwelling Variation Observation (JUVO) dataset confirmed this evident. An isopycnal mixing method initially proposed by Du et al. (2013) is adopted to quantify the spreading of ITF water in the Indian Ocean, and therefore the impacts of ITF changes on the variation of the Agulhas Current, Leuween Current, Bay of Bengal Water. This study also prevailed the fresher salinity in the Indian Ocean during the slowdown warming period were not only contributed by stronger transport of the ITF, but also by freshening Arabian Sea and infiltrating Antartic Intermediate Water (AAIW).

Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean.

Science.gov (United States)

Smith, Kenneth L; Ruhl, Henry A; Kahru, Mati; Huffard, Christine L; Sherman, Alana D

2013-12-03

The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (~4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections.

Ocean thermal energy: concept and resources, history and perspectives

International Nuclear Information System (INIS)

Nihous, Gerard

2015-10-01

Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

Total kinetic energy in four global eddying ocean circulation models and over 5000 current meter records

KAUST Repository

Scott, Robert B.; Arbic, Brian K.; Chassignet, Eric P.; Coward, Andrew C.; Maltrud, Mathew; Merryfield, William J.; Srinivasan, Ashwanth; Varghese, Anson

2010-01-01

We compare the total kinetic energy (TKE) in four global eddying ocean circulation simulations with a global dataset of over 5000, quality controlled, moored current meter records. At individual mooring sites, there was considerable scatter between

Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise

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J. Schewe

2011-03-01

Full Text Available We present climatic consequences of the Representative Concentration Pathways (RCPs using the coupled climate model CLIMBER-3α, which contains a statistical-dynamical atmosphere and a three-dimensional ocean model. We compare those with emulations of 19 state-of-the-art atmosphere-ocean general circulation models (AOGCM using MAGICC6. The RCPs are designed as standard scenarios for the forthcoming IPCC Fifth Assessment Report to span the full range of future greenhouse gas (GHG concentrations pathways currently discussed. The lowest of the RCP scenarios, RCP3-PD, is projected in CLIMBER-3α to imply a maximal warming by the middle of the 21st century slightly above 1.5 °C and a slow decline of temperatures thereafter, approaching today's level by 2500. We identify two mechanisms that slow down global cooling after GHG concentrations peak: The known inertia induced by mixing-related oceanic heat uptake; and a change in oceanic convection that enhances ocean heat loss in high latitudes, reducing the surface cooling rate by almost 50%. Steric sea level rise under the RCP3-PD scenario continues for 200 years after the peak in surface air temperatures, stabilizing around 2250 at 30 cm. This contrasts with around 1.3 m of steric sea level rise by 2250, and 2 m by 2500, under the highest scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m is found to exceed that of the sea surface by the second half of the 21st century under RCP3-PD. This intermediate-depth warming persists for centuries even after surface temperatures have returned to present-day values, with potential consequences for marine ecosystems, oceanic methane hydrates, and ice-shelf stability. Due to an enhanced land-ocean temperature contrast, all scenarios yield an intensification of monsoon rainfall under global warming.

Did the Chicxulub meteorite impact trigger eruptions at mid-ocean ridges globally?

Science.gov (United States)

Byrnes, J. S.; Karlstrom, L.

2017-12-01

Are there causal links between the eruption of large igneous provinces, meteorite impacts, and mass extinctions? Recent dating suggests that state shifts in Deccan Traps eruptions, including erupted volumes, feeder dike orientations, and magma chemistry, occurred shortly after the Chicxulub impact. A proposed explanation for this observation is an increase in upper mantle permeability following the Chicxulub impact that accelerated the pace of Deccan volcanism [Richards et al., 2015]. If such triggering occurred, at global distances not associated with the impact antipode, it is reasonable to hypothesize that other reservoirs of stored melt may have been perturbed as well. We present evidence that mid-ocean ridge activity increased globally following the impact. Anomalously concentrated free-air gravity and sea-floor topographic roughness suggest volumes of excess oceanic ridge magmatism in the range of 2 x 105 to 106 km3 within 1 Myrs of the Chicxulub impact. This signal is only clearly observed for half-spreading rates above 35 mm/yr, possibly because crust formed at slower spreading rates is too complex to preserve the signal. Because similar anomalies are observed separately in the Indian and Pacific Oceans, and because the timing of the signal does not clearly align with changes in spreading rates, we do not favor plume activity as an explanation. Widespread mobilization of existing mantle melt by post-impact seismic radiation, and subsequent emplacement of melt as crustal intrusions and eruptions, can explain the volume and distribution of anomalous crust without invoking impact-induced melt production. Although the mechanism for increasing permeability is not clear at either Deccan or mid-ocean ridges, these results support the hypothesis that the causes and consequences of the Deccan Traps, Chicxulub impact, and K-Pg mass extinction should not be considered in isolation. We conclude by discussing several enigmatic observations from K-Pg time that heightened

Sensitivity of ocean oxygenation to variations in tropical zonal wind stress magnitude

Science.gov (United States)

Ridder, Nina N.; England, Matthew H.

2014-09-01

Ocean oxygenation has been observed to have changed over the past few decades and is projected to change further under global climate change due to an interplay of several mechanisms. In this study we isolate the effect of modified tropical surface wind stress conditions on the evolution of ocean oxygenation in a numerical climate model. We find that ocean oxygenation varies inversely with low-latitude surface wind stress. Approximately one third of this response is driven by sea surface temperature anomalies; the remaining two thirds result from changes in ocean circulation and marine biology. Global mean O2 concentration changes reach maximum values of +4 μM and -3.6 μM in the two most extreme perturbation cases of -30% and +30% wind change, respectively. Localized changes lie between +92 μM under 30% reduced winds and -56 μM for 30% increased winds. Overall, we find that the extent of the global low-oxygen volume varies with the same sign as the wind perturbation; namely, weaker winds reduce the low-oxygen volume on the global scale and vice versa for increased trade winds. We identify two regions, one in the Pacific Ocean off Chile and the other in the Indian Ocean off Somalia, that are of particular importance for the evolution of oxygen minimum zones in the global ocean.

Projection of wave conditions in response to climate change: A community approach to global and regional wave downscaling

Science.gov (United States)

Erikson, Li H.; Hemer, M.; Lionello, Piero; Mendez, Fernando J.; Mori, Nobuhito; Semedo, Alvaro; Wang, Xiaolan; Wolf, Judith

2015-01-01

Future changes in wind-wave climate have broad implications for coastal geomorphology and management. General circulation models (GCM) are now routinely used for assessing climatological parameters, but generally do not provide parameterizations of ocean wind-waves. To fill this information gap, a growing number of studies use GCM outputs to independently downscale wave conditions to global and regional levels. To consolidate these efforts and provide a robust picture of projected changes, we present strategies from the community-derived multi-model ensemble of wave climate projections (COWCLIP) and an overview of regional contributions. Results and strategies from one contributing regional study concerning changes along the eastern North Pacific coast are presented.

Uncertainty in the global oceanic CO2 uptake induced by wind forcing: quantification and spatial analysis

Directory of Open Access Journals (Sweden)

A. Roobaert

2018-03-01

Full Text Available The calculation of the air–water CO2 exchange (FCO2 in the ocean not only depends on the gradient in CO2 partial pressure at the air–water interface but also on the parameterization of the gas exchange transfer velocity (k and the choice of wind product. Here, we present regional and global-scale quantifications of the uncertainty in FCO2 induced by several widely used k formulations and four wind speed data products (CCMP, ERA, NCEP1 and NCEP2. The analysis is performed at a 1°  ×  1° resolution using the sea surface pCO2 climatology generated by Landschützer et al. (2015a for the 1991–2011 period, while the regional assessment relies on the segmentation proposed by the Regional Carbon Cycle Assessment and Processes (RECCAP project. First, we use k formulations derived from the global 14C inventory relying on a quadratic relationship between k and wind speed (k = c ⋅ U102; Sweeney et al., 2007; Takahashi et al., 2009; Wanninkhof, 2014, where c is a calibration coefficient and U10 is the wind speed measured 10 m above the surface. Our results show that the range of global FCO2, calculated with these k relationships, diverge by 12 % when using CCMP, ERA or NCEP1. Due to differences in the regional wind patterns, regional discrepancies in FCO2 are more pronounced than global. These global and regional differences significantly increase when using NCEP2 or other k formulations which include earlier relationships (i.e., Wanninkhof, 1992; Wanninkhof et al., 2009 as well as numerous local and regional parameterizations derived experimentally. To minimize uncertainties associated with the choice of wind product, it is possible to recalculate the coefficient c globally (hereafter called c∗ for a given wind product and its spatio-temporal resolution, in order to match the last evaluation of the global k value. We thus performed these recalculations for each wind product at the resolution and time period of our study

Uncertainty in the global oceanic CO2 uptake induced by wind forcing: quantification and spatial analysis

Science.gov (United States)

Roobaert, Alizée; Laruelle, Goulven G.; Landschützer, Peter; Regnier, Pierre

2018-03-01

The calculation of the air-water CO2 exchange (FCO2) in the ocean not only depends on the gradient in CO2 partial pressure at the air-water interface but also on the parameterization of the gas exchange transfer velocity (k) and the choice of wind product. Here, we present regional and global-scale quantifications of the uncertainty in FCO2 induced by several widely used k formulations and four wind speed data products (CCMP, ERA, NCEP1 and NCEP2). The analysis is performed at a 1° × 1° resolution using the sea surface pCO2 climatology generated by Landschützer et al. (2015a) for the 1991-2011 period, while the regional assessment relies on the segmentation proposed by the Regional Carbon Cycle Assessment and Processes (RECCAP) project. First, we use k formulations derived from the global 14C inventory relying on a quadratic relationship between k and wind speed (k = c ṡ U102; Sweeney et al., 2007; Takahashi et al., 2009; Wanninkhof, 2014), where c is a calibration coefficient and U10 is the wind speed measured 10 m above the surface. Our results show that the range of global FCO2, calculated with these k relationships, diverge by 12 % when using CCMP, ERA or NCEP1. Due to differences in the regional wind patterns, regional discrepancies in FCO2 are more pronounced than global. These global and regional differences significantly increase when using NCEP2 or other k formulations which include earlier relationships (i.e., Wanninkhof, 1992; Wanninkhof et al., 2009) as well as numerous local and regional parameterizations derived experimentally. To minimize uncertainties associated with the choice of wind product, it is possible to recalculate the coefficient c globally (hereafter called c∗) for a given wind product and its spatio-temporal resolution, in order to match the last evaluation of the global k value. We thus performed these recalculations for each wind product at the resolution and time period of our study but the resulting global FCO2 estimates

Calibration of Ocean Forcing with satellite Flux Estimates (COFFEE)

Science.gov (United States)

Barron, Charlie; Jan, Dastugue; Jackie, May; Rowley, Clark; Smith, Scott; Spence, Peter; Gremes-Cordero, Silvia

2016-04-01

Predicting the evolution of ocean temperature in regional ocean models depends on estimates of surface heat fluxes and upper-ocean processes over the forecast period. Within the COFFEE project (Calibration of Ocean Forcing with satellite Flux Estimates, real-time satellite observations are used to estimate shortwave, longwave, sensible, and latent air-sea heat flux corrections to a background estimate from the prior day's regional or global model forecast. These satellite-corrected fluxes are used to prepare a corrected ocean hindcast and to estimate flux error covariances to project the heat flux corrections for a 3-5 day forecast. In this way, satellite remote sensing is applied to not only inform the initial ocean state but also to mitigate errors in surface heat flux and model representations affecting the distribution of heat in the upper ocean. While traditional assimilation of sea surface temperature (SST) observations re-centers ocean models at the start of each forecast cycle, COFFEE endeavors to appropriately partition and reduce among various surface heat flux and ocean dynamics sources. A suite of experiments in the southern California Current demonstrates a range of COFFEE capabilities, showing the impact on forecast error relative to a baseline three-dimensional variational (3DVAR) assimilation using operational global or regional atmospheric forcing. Experiment cases combine different levels of flux calibration with assimilation alternatives. The cases use the original fluxes, apply full satellite corrections during the forecast period, or extend hindcast corrections into the forecast period. Assimilation is either baseline 3DVAR or standard strong-constraint 4DVAR, with work proceeding to add a 4DVAR expanded to include a weak constraint treatment of the surface flux errors. Covariance of flux errors is estimated from the recent time series of forecast and calibrated flux terms. While the California Current examples are shown, the approach is

The Change in Oceanic O2 Inventory Associated with Recent Global Warming

Science.gov (United States)

Keeling, Ralph; Garcia, Hernan

2002-01-01

Oceans general circulation models predict that global warming may cause a decrease in the oceanic O2 inventory and an associated O2 outgassing. An independent argument is presented here in support of this prediction based on observational evidence of the ocean's biogeochemical response to natural warming. On time scales from seasonal to centennial, natural O2 flux/heat flux ratios are shown to occur in a range of 2 to 10 nmol O2 per Joule of warming, with larger ratios typically occurring at higher latitudes and over longer time scales. The ratios are several times larger than would be expected solely from the effect of heating on the O2 solubility, indicating that most of the O2 exchange is biologically mediated through links between heating and stratification. The change in oceanic O2 inventory through the 1990's is estimated to be 0.3 - 0.4 x 10(exp 14) mol O2 per year based on scaling the observed anomalous long-term ocean warming by natural O2 flux/heating ratios and allowing for uncertainty due to decadal variability. Implications are discussed for carbon budgets based on observed changes in atmospheric O2/N2 ratio and based on observed changes in ocean dissolved inorganic carbon.

Temperature and salinity profiles from expendable bathythermograph (XBT) and CTD casts from NOAA Ship MILLER FREEMAN and other Platforms from Coastal Waters of Washington/Oregon and other locations in support of the Integrated Global Ocean Services System (IGOSS) from 1977-07-12 to 1983-07-26 (NODC Accession 8300102)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XBT and CTD data were collected from NOAA Ship MILLER FREEMAN and other Platforms in support of the Integrated Global Ocean Services System (IGOSS) project. Data...

Risks to coral reefs from ocean carbonate chemistry changes in recent earth system model projections

International Nuclear Information System (INIS)

Ricke, K L; Caldeira, K; Orr, J C; Schneider, K

2013-01-01

Coral reefs are among the most biodiverse ecosystems in the world. Today they are threatened by numerous stressors, including warming ocean waters and coastal pollution. Here we focus on the implications of ocean acidification for the open ocean chemistry surrounding coral reefs, as estimated from earth system models participating in the Coupled Model Intercomparison Project, Phase 5 (CMIP5). We project risks to reefs in the context of three potential aragonite saturation (Ωa) thresholds. We find that in preindustrial times, 99.9% of reefs adjacent to open ocean in the CMIP5 ensemble were located in regions with Ωa > 3.5. Under a business-as-usual scenario (RCP 8.5), every coral reef considered will be surrounded by water with Ωa 2 emissions abatement, the Ωa threshold for reefs is critical to projecting their fate. Our results indicate that to maintain a majority of reefs surrounded by waters with Ωa > 3.5 to the end of the century, very aggressive reductions in emissions are required. The spread of Ωa projections across models in the CMIP5 ensemble is narrow, justifying a high level of confidence in these results. (letter)

ATLAS & Google — "Data Ocean" R&D Project

CERN Document Server

The ATLAS collaboration

2017-01-01

ATLAS is facing several challenges with respect to their computing requirements for LHC Run-3 (2020-2023) and HL-LHC runs (2025-2034). The challenges are not specific for ATLAS or/and LHC, but common for HENP computing community. Most importantly, storage continues to be the driving cost factor and at the current growth rate cannot absorb the increased physics output of the experiment. Novel computing models with a more dynamic use of storage and computing resources need to be considered. This project aims to start an R&D project for evaluating and adopting novel IT technologies for HENP computing. ATLAS and Google plan to launch an R&D project to integrate Google cloud resources (Storage and Compute) to the ATLAS distributed computing environment. After a series of teleconferences, a face-to-face brainstorming meeting in Denver, CO at the Supercomputing 2017 conference resulted in this proposal for a first prototype of the "Data Ocean" project. The idea is threefold: (a) to allow ATLAS to explore the...

SEDIMENT PROPERTIES and Other Data from FIXED PLATFORM and Other Platforms From North Pacific Ocean from 19881030 to 19911024 (NODC Accession 9300040)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The accession contains data collected in North Pacific Ocean from Hawaiian Ocean Time Series (HOTS) project for years 1, 2 and 3 as part of Joint Global Ocean Flux...

Global Modeling of Internal Tides Within an Eddying Ocean General Circulation Model

Science.gov (United States)

2012-05-31

paper aooo not violate: any Oisclosur~,;·of trade• secrets or suggestions of outside individuals on::oncams whiCh have· beE !n communicated 1.o...fully three- dimensional global ocean circulation model, we will provide an internal tide capability everywhere, and allow nested models to include

The Wunstorf Drilling Project: Coring a Global Stratigraphic Reference Section of the Oceanic Anoxic Event 2

Directory of Open Access Journals (Sweden)

Markus Wilmsen

2007-03-01

Full Text Available The Wunstorf drilling project aims at establishing a high resolution stable isotope record for the black shale succession (OAE 2 of the CTBI and developing this into a globally applicable high resolutionbio- and chemostratigraphic reference section. Disciplines involved include micropaleontology (calcareous nannofossils, planktonic foraminifera, macropaleontology (ammonites, inoceramids, stable isotopes and cyclostratigraphy mainly based on borehole logging, multisensor core logging, and x-ray flflfluorescence (XRF scanning data. The combination of geochemical, paleontological, and logging data will allow high resolution chemo- and biostratigraphy for the CTBI which may in the future serve as an international standard.

Enhancing Ocean Research Data Access

Science.gov (United States)

Chandler, Cynthia; Groman, Robert; Shepherd, Adam; Allison, Molly; Arko, Robert; Chen, Yu; Fox, Peter; Glover, David; Hitzler, Pascal; Leadbetter, Adam; Narock, Thomas; West, Patrick; Wiebe, Peter

2014-05-01

The Biological and Chemical Oceanography Data Management Office (BCO-DMO) works in partnership with ocean science investigators to publish data from research projects funded by the Biological and Chemical Oceanography Sections and the Office of Polar Programs Antarctic Organisms & Ecosystems Program at the U.S. National Science Foundation. Since 2006, researchers have been contributing data to the BCO-DMO data system, and it has developed into a rich repository of data from ocean, coastal and Great Lakes research programs. While the ultimate goal of the BCO-DMO is to ensure preservation of NSF funded project data and to provide open access to those data, achievement of those goals is attained through a series of related phases that benefits from active collaboration and cooperation with a large community of research scientists as well as curators of data and information at complementary data repositories. The BCO-DMO is just one of many intermediate data management centers created to facilitate long-term preservation of data and improve access to ocean research data. Through partnerships with other data management professionals and active involvement in local and global initiatives, BCO-DMO staff members are working to enhance access to ocean research data available from the online BCO-DMO data system. Continuing efforts in use of controlled vocabulary terms, development of ontology design patterns and publication of content as Linked Open Data are contributing to improved discovery and availability of BCO-DMO curated data and increased interoperability of related content available from distributed repositories. We will demonstrate how Semantic Web technologies (e.g. RDF/XML, SKOS, OWL and SPARQL) have been integrated into BCO-DMO data access and delivery systems to better serve the ocean research community and to contribute to an expanding global knowledge network.

Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles

DEFF Research Database (Denmark)

Le Quéré, Corinne; Buitenhuis, Erik T.; Moriarty, Róisín

2016-01-01

zooplankton community, despite iron limitation of phytoplankton community growth rates. This result has implications for the representation of global biogeochemical cycles in models as zooplankton faecal pellets sink rapidly and partly control the carbon export to the intermediate and deep ocean....

Long-range transport of airborne microbes over the global tropical and subtropical ocean

KAUST Repository

Mayol, Eva; Arrieta, J M; Jimé nez, Maria A.; Martí nez-Asensio, Adriá n; Garcias Bonet, Neus; Dachs, Jordi; Gonzá lez-Gaya, Belé n; Royer, Sarah-J.; Bení tez-Barrios, Veró nica M.; Fraile-Nuez, Eugenio; Duarte, Carlos M.

2017-01-01

The atmosphere plays a fundamental role in the transport of microbes across the planet but it is often neglected as a microbial habitat. Although the ocean represents two thirds of the Earth's surface, there is little information on the atmospheric microbial load over the open ocean. Here we provide a global estimate of microbial loads and air-sea exchanges over the tropical and subtropical oceans based on the data collected along the Malaspina 2010 Circumnavigation Expedition. Total loads of airborne prokaryotes and eukaryotes were estimated at 2.2 × 1021 and 2.1 × 1021 cells, respectively. Overall 33-68% of these microorganisms could be traced to a marine origin, being transported thousands of kilometres before re-entering the ocean. Moreover, our results show a substantial load of terrestrial microbes transported over the oceans, with abundances declining exponentially with distance from land and indicate that islands may act as stepping stones facilitating the transoceanic transport of terrestrial microbes.The extent to which the ocean acts as a sink and source of airborne particles to the atmosphere is unresolved. Here, the authors report high microbial loads over the tropical Atlantic, Pacific and Indian oceans and propose islands as stepping stones for the transoceanic transport of terrestrial microbes..

Long-range transport of airborne microbes over the global tropical and subtropical ocean

KAUST Repository

Mayol, Eva

2017-07-28

The atmosphere plays a fundamental role in the transport of microbes across the planet but it is often neglected as a microbial habitat. Although the ocean represents two thirds of the Earth\\'s surface, there is little information on the atmospheric microbial load over the open ocean. Here we provide a global estimate of microbial loads and air-sea exchanges over the tropical and subtropical oceans based on the data collected along the Malaspina 2010 Circumnavigation Expedition. Total loads of airborne prokaryotes and eukaryotes were estimated at 2.2 × 1021 and 2.1 × 1021 cells, respectively. Overall 33-68% of these microorganisms could be traced to a marine origin, being transported thousands of kilometres before re-entering the ocean. Moreover, our results show a substantial load of terrestrial microbes transported over the oceans, with abundances declining exponentially with distance from land and indicate that islands may act as stepping stones facilitating the transoceanic transport of terrestrial microbes.The extent to which the ocean acts as a sink and source of airborne particles to the atmosphere is unresolved. Here, the authors report high microbial loads over the tropical Atlantic, Pacific and Indian oceans and propose islands as stepping stones for the transoceanic transport of terrestrial microbes..

An integrated approach for estimating global glacio isostatic adjustment, land ice, hydrology and ocean mass trends within a complete coupled Earth system framework

Science.gov (United States)

Schumacher, M.; Bamber, J. L.; Martin, A.

2016-12-01

Future sea level rise (SLR) is one of the most serious consequences of climate change. Therefore, understanding the drivers of past sea level change is crucial for improving predictions. SLR integrates many Earth system components including oceans, land ice, terrestrial water storage, as well as solid Earth effects. Traditionally, each component have been tackled separately, which has often lead to inconsistencies between discipline-specific estimates of each part of the sea level budget. To address these issues, the European Research Council has funded a five year project aimed at producing a physically-based, data-driven solution for the complete coupled land-ocean-solid Earth system that is consistent with the full suite of observations, prior knowledge and fundamental geophysical constraints. The project is called "GlobalMass" and based at University of Bristol. Observed mass movement from the GRACE mission plus vertical land motion from a global network of permanent GPS stations will be utilized in a data-driven approach to estimate glacial isostatic adjustment (GIA) without introducing any assumptions about the Earth structure or ice loading history. A Bayesian Hierarchical Model (BHM) will be used as the framework to combine the satellite and in-situ observations alongside prior information that incorporates the physics of the coupled system such as conservation of mass and characteristic length scales of different processes in both space and time. The BHM is used to implement a simultaneous solution at a global scale. It will produce a consistent partitioning of the integrated SLR signal into its steric (thermal) and barystatic (mass) component for the satellite era. The latter component is induced by hydrological mass trends and melting of land ice. The BHM was developed and tested on Antarctica, where it has been used to separate surface, ice dynamic and GIA signals simultaneously. We illustrate the approach and concepts with examples from this test case

Dynamic ocean provinces: a multi-sensor approach to global marine ecophysiology

Science.gov (United States)

Dowell, M.; Campbell, J.; Moore, T.

The concept of oceanic provinces or domains has existed for well over a century. Such systems, whether real or only conceptual, provide a useful framework for understanding the mechanisms controlling biological, physical and chemical processes and their interactions. Criteria have been established for defining provinces based on physical forcings, availability of light and nutrients, complexity of the marine food web, and other factors. In general, such classification systems reflect the heterogeneous nature of the ocean environment, and the effort of scientists to comprehend the whole system by understanding its various homogeneous components. If provinces are defined strictly on the basis of geospatial or temporal criteria (e.g., latitude zones, bathymetry, or season), the resulting maps exhibit discontinuities that are uncharacteristic of the ocean. While this may be useful for many purposes, it is unsatisfactory in that it does not capture the dynamic nature of fluid boundaries in the ocean. Boundaries fixed in time and space do not allow us to observe interannual or longer-term variability (e.g., regime shifts) that may result from climate change. The current study illustrates the potential of using fuzzy logic as a means of classifying the ocean into objectively defined provinces using properties measurable from satellite sensors (MODIS and SeaWiFS). This approach accommodates the dynamic variability of provinces which can be updated as each image is processed. We adopt this classification as the basis for parameterizing specific algorithms for each of the classes. Once the class specific algorithms have been applied, retrievals are then recomposed into a single blended product based on the "weighted" fuzzy memberships. This will be demonstrated through animations of multi-year time- series of monthly composites of the individual classes or provinces. The provinces themselves are identified on the basis of global fields of chlorophyll, sea surface temperature

Iron control on global productivity: an efficient inverse model of the ocean's coupled phosphate and iron cycles.

Science.gov (United States)

Pasquier, B.; Holzer, M.; Frants, M.

2016-02-01

We construct a data-constrained mechanistic inverse model of the ocean's coupled phosphorus and iron cycles. The nutrient cycling is embedded in a data-assimilated steady global circulation. Biological nutrient uptake is parameterized in terms of nutrient, light, and temperature limitations on growth for two classes of phytoplankton that are not transported explicitly. A matrix formulation of the discretized nutrient tracer equations allows for efficient numerical solutions, which facilitates the objective optimization of the key biogeochemical parameters. The optimization minimizes the misfit between the modelled and observed nutrient fields of the current climate. We systematically assess the nonlinear response of the biological pump to changes in the aeolian iron supply for a variety of scenarios. Specifically, Green-function techniques are employed to quantify in detail the pathways and timescales with which those perturbations are propagated throughout the world oceans, determining the global teleconnections that mediate the response of the global ocean ecosystem. We confirm previous findings from idealized studies that increased iron fertilization decreases biological production in the subtropical gyres and we quantify the counterintuitive and asymmetric response of global productivity to increases and decreases in the aeolian iron supply.

Controls on the global distribution of contourite drifts: Insights from an eddy-resolving ocean model

Science.gov (United States)

Thran, Amanda C.; Dutkiewicz, Adriana; Spence, Paul; Müller, R. Dietmar

2018-05-01

Contourite drifts are anomalously high sediment accumulations that form due to reworking by bottom currents. Due to the lack of a comprehensive contourite database, the link between vigorous bottom water activity and drift occurrence has yet to be demonstrated on a global scale. Using an eddy-resolving ocean model and a new georeferenced database of 267 contourites, we show that the global distribution of modern contourite drifts strongly depends on the configuration of the world's most powerful bottom currents, many of which are associated with global meridional overturning circulation. Bathymetric obstacles frequently modify flow direction and intensity, imposing additional finer-scale control on drift occurrence. Mean bottom current speed over contourite-covered areas is only slightly higher (2.2 cm/s) than the rest of the global ocean (1.1 cm/s), falling below proposed thresholds deemed necessary to re-suspend and redistribute sediments (10-15 cm/s). However, currents fluctuate more frequently and intensely over areas with drifts, highlighting the role of intermittent, high-energy bottom current events in sediment erosion, transport, and subsequent drift accumulation. We identify eddies as a major driver of these bottom current fluctuations, and we find that simulated bottom eddy kinetic energy is over three times higher in contourite-covered areas in comparison to the rest of the ocean. Our work supports previous hypotheses which suggest that contourite deposition predominantly occurs due to repeated acute events as opposed to continuous reworking under average-intensity background flow conditions. This suggests that the contourite record should be interpreted in terms of a bottom current's susceptibility to experiencing periodic, high-speed current events. Our results also highlight the potential role of upper ocean dynamics in contourite sedimentation through its direct influence on deep eddy circulation.

ACCURACY ASSESSMENT OF RECENT GLOBAL OCEAN TIDE MODELS AROUND ANTARCTICA

Directory of Open Access Journals (Sweden)

J. Lei

2017-09-01

Full Text Available Due to the coverage limitation of T/P-series altimeters, the lack of bathymetric data under large ice shelves, and the inaccurate definitions of coastlines and grounding lines, the accuracy of ocean tide models around Antarctica is poorer than those in deep oceans. Using tidal measurements from tide gauges, gravimetric data and GPS records, the accuracy of seven state-of-the-art global ocean tide models (DTU10, EOT11a, GOT4.8, FES2012, FES2014, HAMTIDE12, TPXO8 is assessed, as well as the most widely-used conventional model FES2004. Four regions (Antarctic Peninsula region, Amery ice shelf region, Filchner-Ronne ice shelf region and Ross ice shelf region are separately reported. The standard deviations of eight main constituents between the selected models are large in polar regions, especially under the big ice shelves, suggesting that the uncertainty in these regions remain large. Comparisons with in situ tidal measurements show that the most accurate model is TPXO8, and all models show worst performance in Weddell sea and Filchner-Ronne ice shelf regions. The accuracy of tidal predictions around Antarctica is gradually improving.

Accuracy Assessment of Recent Global Ocean Tide Models around Antarctica

Science.gov (United States)

Lei, J.; Li, F.; Zhang, S.; Ke, H.; Zhang, Q.; Li, W.

2017-09-01

Due to the coverage limitation of T/P-series altimeters, the lack of bathymetric data under large ice shelves, and the inaccurate definitions of coastlines and grounding lines, the accuracy of ocean tide models around Antarctica is poorer than those in deep oceans. Using tidal measurements from tide gauges, gravimetric data and GPS records, the accuracy of seven state-of-the-art global ocean tide models (DTU10, EOT11a, GOT4.8, FES2012, FES2014, HAMTIDE12, TPXO8) is assessed, as well as the most widely-used conventional model FES2004. Four regions (Antarctic Peninsula region, Amery ice shelf region, Filchner-Ronne ice shelf region and Ross ice shelf region) are separately reported. The standard deviations of eight main constituents between the selected models are large in polar regions, especially under the big ice shelves, suggesting that the uncertainty in these regions remain large. Comparisons with in situ tidal measurements show that the most accurate model is TPXO8, and all models show worst performance in Weddell sea and Filchner-Ronne ice shelf regions. The accuracy of tidal predictions around Antarctica is gradually improving.

Geophysical Global Modeling for Extreme Crop Production Using Photosynthesis Models Coupled to Ocean SST Dipoles

Science.gov (United States)

Kaneko, D.

2016-12-01

Climate change appears to have manifested itself along with abnormal meteorological disasters. Instability caused by drought and flood disasters is producing poor harvests because of poor photosynthesis and pollination. Fluctuations of extreme phenomena are increasing rapidly because amplitudes of change are much greater than average trends. A fundamental cause of these phenomena derives from increased stored energy inside ocean waters. Geophysical and biochemical modeling of crop production can elucidate complex mechanisms under seasonal climate anomalies. The models have progressed through their combination with global climate reanalysis, environmental satellite data, and harvest data on the ground. This study examined adaptation of crop production to advancing abnormal phenomena related to global climate change. Global environmental surface conditions, i.e., vegetation, surface air temperature, and sea surface temperature observed by satellites, enable global modeling of crop production and monitoring. Basic streams of the concepts of modeling rely upon continental energy flow and carbon circulation among crop vegetation, land surface atmosphere combining energy advection from ocean surface anomalies. Global environmental surface conditions, e.g., vegetation, surface air temperature, and sea surface temperature observed by satellites, enable global modeling of crop production and monitoring. The method of validating the modeling relies upon carbon partitioning in biomass and grains through carbon flow by photosynthesis using carbon dioxide unit in photosynthesis. Results of computations done for this study show global distributions of actual evaporation, stomata opening, and photosynthesis, presenting mechanisms related to advection effects from SST anomalies in the Pacific, Atlantic, and Indian oceans on global and continental croplands. For North America, climate effects appear clearly in severe atmospheric phenomena, which have caused drought and forest fires

Cloud amount/frequency, SALINITY and other data from EL AUSTRAL in the Southern Oceans from 1977-04-21 to 1977-11-12 (NCEI Accession 9200257)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Serial data in this accession was collected in Southern Oceans (> 60 degrees South) as part of Global Ocean Data Archeaology and Rescue (GODAR) project...

The coastal ocean response to the global warming acceleration and hiatus.

Science.gov (United States)

Liao, Enhui; Lu, Wenfang; Yan, Xiao-Hai; Jiang, Yuwu; Kidwell, Autumn

2015-11-16

Coastlines are fundamental to humans for habitation, commerce, and natural resources. Many coastal ecosystem disasters, caused by extreme sea surface temperature (SST), were reported when the global climate shifted from global warming to global surface warming hiatus after 1998. The task of understanding the coastal SST variations within the global context is an urgent matter. Our study on the global coastal SST from 1982 to 2013 revealed a significant cooling trend in the low and mid latitudes (31.4% of the global coastlines) after 1998, while 17.9% of the global coastlines changed from a cooling trend to a warming trend concurrently. The trend reversals in the Northern Pacific and Atlantic coincided with the phase shift of Pacific Decadal Oscillation and North Atlantic Oscillation, respectively. These coastal SST changes are larger than the changes of the global mean and open ocean, resulting in a fast increase of extremely hot/cold days, and thus extremely hot/cold events. Meanwhile, a continuous increase of SST was detected for a considerable portion of coastlines (46.7%) with a strengthened warming along the coastlines in the high northern latitudes. This suggests the warming still continued and strengthened in some regions after 1998, but with a weaker pattern in the low and mid latitudes.

The coastal ocean response to the global warming acceleration and hiatus

Science.gov (United States)

Liao, Enhui; Lu, Wenfang; Yan, Xiao-Hai; Jiang, Yuwu; Kidwell, Autumn

2015-01-01

Coastlines are fundamental to humans for habitation, commerce, and natural resources. Many coastal ecosystem disasters, caused by extreme sea surface temperature (SST), were reported when the global climate shifted from global warming to global surface warming hiatus after 1998. The task of understanding the coastal SST variations within the global context is an urgent matter. Our study on the global coastal SST from 1982 to 2013 revealed a significant cooling trend in the low and mid latitudes (31.4% of the global coastlines) after 1998, while 17.9% of the global coastlines changed from a cooling trend to a warming trend concurrently. The trend reversals in the Northern Pacific and Atlantic coincided with the phase shift of Pacific Decadal Oscillation and North Atlantic Oscillation, respectively. These coastal SST changes are larger than the changes of the global mean and open ocean, resulting in a fast increase of extremely hot/cold days, and thus extremely hot/cold events. Meanwhile, a continuous increase of SST was detected for a considerable portion of coastlines (46.7%) with a strengthened warming along the coastlines in the high northern latitudes. This suggests the warming still continued and strengthened in some regions after 1998, but with a weaker pattern in the low and mid latitudes. PMID:26568024

A Unified Model for Methylmercury Formation and Bioaccumulation in the Global Ocean

Science.gov (United States)

Zhang, Y.; Schartup, A. T.; Soerensen, A.; Dutkiewicz, S.; Sunderland, E. M.

2017-12-01

Marine fish consumption is the main exposure pathway for methylmercury (MeHg), a neurotoxin, in many countries. The Hg in the ocean is mainly from atmospheric deposition in inorganic forms. How the deposited Hg is methylated and accumulated in biota remain an open question. We develop a 3D model (MITgcm) for MeHg formation and bioaccumulation in the global ocean and evaluate the driving factors. The model is based on a previous published inorganic Hg model and is coupled with the bioaccumulation model for marine methylmercury (BAM3) with ocean biogeochemistry from DARWIN model. We develop a unified scheme that scales methylation by microbe activity and assumes demethylation a function of short wave radiation and temperature. The model result agrees well with currently available observations at the 0-100 m (mod.: 43±52 fM vs obs.: 69±67 fM, 1 fM = 10-15 mol/L), 500 m (360±280 fM vs 340±260 fM), and 1000 m depth (260±170 fM vs 290±210 fM). In the surface ocean, we find the MeHg concentrations are a function of latitude, resulting from photodemethylation. The model reproduces the high concentrations observed over the sub-thermocline of Pacific Subarctic Gyre, which is associated with active microbe activity. On the other hand, both the model and observations suggest low concentrations over oligotrophic regions such as Indian Ocean Gyre. In the tropical oceans, the model predicts the highest MeHg concentrations, consistent with observation, and it is caused by the overlapping high atmospheric deposition and active microbe activities. The model captures the high concentrations in the subsurface of the Arctic and Southern Ocean where low temperature slows down abiotic demethylation. The modeled global average MeHg concentration in phytoplankton is 2.0 ng/g (by wet weight), within the same range of observations. High concentrations are modeled over tropical and high-latitude regions due to the dominance of small sized prochlorococcus and high seawater concentrations

Narrowing the uncertainty for deep-ocean injection efficiency

Energy Technology Data Exchange (ETDEWEB)

Orr, J.C.; Aumont, O. [Laboratoire des Sciences du Climat et de l' Environnement, CEA-CNRS, Gif-sur-Yvette (France); Yool, A. [Southampton Oceanography Centre, Southampton (United Kingdom); Plattner, G.K.; Joos, F. [Bern Univ., Bern (Switzerland). Physics Inst.; Maier-Reimer, E. [Max Planck Inst. fuer Meteorologie, Hamburg (Germany); Weirig, M.F.; Schlitzer, R. [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Caldeira, K.; Wickett, M.E. [Lawrence Livermore National Laboratory, CA (United States); Matear, R.J. [Australian Commonwealth Scientific and Research Organization, Hobart (Australia); Mignone, B.K.; Sarmiento, J.L. [Princeton Univ., Princeton, NJ (United States). AOS Program

2005-07-01

Ten ocean general circulation models (OCGMs) were compared as part of an international study investigating the ocean's ability to efficiently sequester carbon dioxide (CO{sub 2}). The models were selected for their ability to simulate radiocarbon and CFC-11. All of the model simulations neglected the influence of marine biota, and the simulations used only dissolved inorganic carbon (DIC) as a tracer in order to conserve computing resources. The models were integrated using standard ocean carbon-cycle model intercomparison project (OCMIP) formulations for gas exchange boundary conditions to obtain pre-industrial conditions. All models used the same predefined atmospheric CO{sub 2} records compiled from 1765 to 2000, as well as future scenarios in which atmospheric CO{sub 2} was stabilized at 650 ppm. Injections occurred over a period of 100 years. Results of the study showed that global budgets for CFC-11 and radiocarbon were correlated with global efficiencies for a 3000 m injection simulation. The 3000 m injection efficiency was then correlated with the global mean for deep natural radiocarbon. Results showed that simultaneously accounting for constraints from both CFC-11 and natural radiocarbon narrowed the range for a 3000 m injection efficiency in the year 2500 by a factor of 4. The study showed that models must be able to simulate global inventories for CFC-11 as well as global means for radiocarbon in deep ocean scenarios in order to be credible. It was concluded that models using both constraints will more accurately simulate global injection efficiencies.

A 4.5 km resolution Arctic Ocean simulation with the global multi-resolution model FESOM 1.4

Science.gov (United States)

Wang, Qiang; Wekerle, Claudia; Danilov, Sergey; Wang, Xuezhu; Jung, Thomas

2018-04-01

In the framework of developing a global modeling system which can facilitate modeling studies on Arctic Ocean and high- to midlatitude linkage, we evaluate the Arctic Ocean simulated by the multi-resolution Finite Element Sea ice-Ocean Model (FESOM). To explore the value of using high horizontal resolution for Arctic Ocean modeling, we use two global meshes differing in the horizontal resolution only in the Arctic Ocean (24 km vs. 4.5 km). The high resolution significantly improves the model's representation of the Arctic Ocean. The most pronounced improvement is in the Arctic intermediate layer, in terms of both Atlantic Water (AW) mean state and variability. The deepening and thickening bias of the AW layer, a common issue found in coarse-resolution simulations, is significantly alleviated by using higher resolution. The topographic steering of the AW is stronger and the seasonal and interannual temperature variability along the ocean bottom topography is enhanced in the high-resolution simulation. The high resolution also improves the ocean surface circulation, mainly through a better representation of the narrow straits in the Canadian Arctic Archipelago (CAA). The representation of CAA throughflow not only influences the release of water masses through the other gateways but also the circulation pathways inside the Arctic Ocean. However, the mean state and variability of Arctic freshwater content and the variability of freshwater transport through the Arctic gateways appear not to be very sensitive to the increase in resolution employed here. By highlighting the issues that are independent of model resolution, we address that other efforts including the improvement of parameterizations are still required.

Presal36: a high resolution ocean current model for Brazilian pre-salt area: implementation and validation results

Energy Technology Data Exchange (ETDEWEB)

Schoellkopf, Jacques P. [Advanced Subsea do Brasil Ltda., Rio de Janeiro, RJ (Brazil)

2012-07-01

The PRESAL 36 JIP is a project for the development of a powerful Ocean Current Model of 1/36 of a degree resolution, nested in an existing Global Ocean global Model, Mercator PSY4 (1/12-a-degree resolution ), with tide corrections, improved bathymetry accuracy and high frequency atmospheric forcing (every 3 hours). The simulation outputs will be the 3 dimensional structure of the velocity fields (u,v,w) at 50 vertical levels over the water column, including geostrophic, Ekman and tidal currents, together with Temperature, Salinity and sea surface height at a sub-mesoscale spatial resolution. Simulations will run in hindcast, nowcast and forecast modes, with a temporal resolution of 3 hours . This Ocean current model will allow to perform detailed statistical studies on various areas using conditions analysed using hindcast mode, short term operational condition prediction for various surface and sub sea operations using realtime and Forecast modes. The paper presents a publication of significant results of the project, in term of pre-sal zoomed model implementation, and high resolution model validation. It demonstrate the capability to properly describe ocean current phenomenon at beyond mesoscale frontier. This project demonstrate the feasibility of obtaining accurate information for engineering studies and operational conditions, based on a 'zoom technique' starting from global ocean models. (author)

A Conceptual Model for Projecting Coccolithophorid Growth, Calcification and Photosynthetic Carbon Fixation Rates in Response to Global Ocean Change

Directory of Open Access Journals (Sweden)

Natasha A. Gafar

2018-01-01

Full Text Available Temperature, light and carbonate chemistry all influence the growth, calcification and photosynthetic rates of coccolithophores to a similar degree. There have been multiple attempts to project the responses of coccolithophores to changes in carbonate chemistry, but the interaction with light and temperature remains elusive. Here we devise a simple conceptual model to derive a fit equation for coccolithophorid growth, photosynthetic and calcification rates in response to simultaneous changes in carbonate chemistry, temperature and light conditions. The fit equation is able to account for up to 88% of the variability in measured metabolic rates. Equation projections indicate that temperature, light and carbonate chemistry all have different modulating effects on both optimal growth conditions and the sensitivity of responses to extreme environmental conditions. Calculations suggest that a single extreme environmental condition (CO2, temperature, light will reduce maximum rates regardless of how optimal the other environmental conditions may be. Thus, while the response of coccolithophores to ocean change depends on multiple variables, the one which is least optimal will have the most impact on overall rates. Finally, responses to ocean change are usually reported in terms of cellular rates. However, changes in cellular rates can be a poor predictor for assessing changes in production at the community level. We therefore introduce a new metric, the calcium carbonate production potential (CCPP, which combines the independent effects of changes in growth rate and cellular calcium carbonate content to assess how environmental changes will impact coccolith production. Direct comparison of CO2 impacts on cellular CaCO3 production rates and CCPP shows that while the former is still at 45% of its pre-industrial capacity at 1,000 μatm, the latter is reduced to 10%.

Projected changes in prevailing winds for transatlantic migratory birds under global warming.

Science.gov (United States)

La Sorte, Frank A; Fink, Daniel

2017-03-01

A number of terrestrial bird species that breed in North America cross the Atlantic Ocean during autumn migration when travelling to their non-breeding grounds in the Caribbean or South America. When conducting oceanic crossings, migratory birds tend to associate with mild or supportive winds, whose speed and direction may change under global warming. The implications of these changes for transoceanic migratory bird populations have not been addressed. We used occurrence information from eBird (1950-2015) to estimate the geographical location of population centres at a daily temporal resolution across the annual cycle for 10 transatlantic migratory bird species. We used this information to estimate the location and timing of autumn migration within the transatlantic flyway. We estimated how prevailing winds are projected to change within the transatlantic flyway during this time using daily wind speed anomalies (1996-2005 and 2091-2100) from 29 Atmosphere-Ocean General Circulation Models implemented under CMIP5. Autumn transatlantic migrants have the potential to encounter strong westerly crosswinds early in their transatlantic journey at intermediate and especially high migration altitudes, strong headwinds at low and intermediate migration altitudes within the Caribbean that increase in strength as the season progresses, and weak tailwinds at intermediate and high migration altitudes east of the Caribbean. The CMIP5 simulations suggest that, during this century, the likelihood of autumn transatlantic migrants encountering strong westerly crosswinds will diminish. As global warming progresses, the need for species to compensate or drift under the influence of strong westerly crosswinds during the initial phase of their autumn transatlantic journey may be diminished. Existing strategies that promote headwind avoidance and tailwind assistance will likely remain valid. Thus, climate change may reduce time and energy requirements and the chance of mortality or

Vertical eddy diffusion as a key mechanism for removing perfluorooctanoic acid (PFOA) from the global surface oceans

NARCIS (Netherlands)

Lohmann, R.; Jurado Cojo, E.|info:eu-repo/dai/nl/325788227; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467; Dachs, J.

2013-01-01

Here we estimate the importance of vertical eddy diffusion in removing perfluorooctanoic acid (PFOA) from the surface Ocean and assess its importance as a global sink. Measured water column profiles of PFOA were reproduced by assuming that vertical eddy diffusion in a 3-layer ocean model is the sole

Biogeochemical modelling of dissolved oxygen in a changing ocean

Science.gov (United States)

Andrews, Oliver; Buitenhuis, Erik; Le Quéré, Corinne; Suntharalingam, Parvadha

2017-08-01

Secular decreases in dissolved oxygen concentration have been observed within the tropical oxygen minimum zones (OMZs) and at mid- to high latitudes over the last approximately 50 years. Earth system model projections indicate that a reduction in the oxygen inventory of the global ocean, termed ocean deoxygenation, is a likely consequence of on-going anthropogenic warming. Current models are, however, unable to consistently reproduce the observed trends and variability of recent decades, particularly within the established tropical OMZs. Here, we conduct a series of targeted hindcast model simulations using a state-of-the-art global ocean biogeochemistry model in order to explore and review biases in model distributions of oceanic oxygen. We show that the largest magnitude of uncertainty is entrained into ocean oxygen response patterns due to model parametrization of pCO2-sensitive C : N ratios in carbon fixation and imposed atmospheric forcing data. Inclusion of a pCO2-sensitive C : N ratio drives historical oxygen depletion within the ocean interior due to increased organic carbon export and subsequent remineralization. Atmospheric forcing is shown to influence simulated interannual variability in ocean oxygen, particularly due to differences in imposed variability of wind stress and heat fluxes. This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

New Community Education Program on Oceans and Global Climate Change: Results from Our Pilot Year

Science.gov (United States)

Bruno, B. C.; Wiener, C.

2010-12-01

Ocean FEST (Families Exploring Science Together) engages elementary school students and their parents and teachers in hands-on science. Through this evening program, we educate participants about ocean and earth science issues that are relevant to their local communities. In the process, we hope to inspire more underrepresented students, including Native Hawaiians, Pacific Islanders and girls, to pursue careers in the ocean and earth sciences. Hawaii and the Pacific Islands will be disproportionately affected by the impacts of global climate change, including rising sea levels, coastal erosion, coral reef degradation and ocean acidification. It is therefore critically important to train ocean and earth scientists within these communities. This two-hour program explores ocean properties and timely environmental topics through six hands-on science activities. Activities are designed so students can see how globally important issues (e.g., climate change and ocean acidification) have local effects (e.g., sea level rise, coastal erosion, coral bleaching) which are particularly relevant to island communities. The Ocean FEST program ends with a career component, drawing parallel between the program activities and the activities done by "real scientists" in their jobs. The take-home message is that we are all scientists, we do science every day, and we can choose to do this as a career. Ocean FEST just completed our pilot year. During the 2009-2010 academic year, we conducted 20 events, including 16 formal events held at elementary schools and 4 informal outreach events. Evaluation data were collected at all formal events. Formative feedback from adult participants (parents, teachers, administrators and volunteers) was solicited through written questionnaires. Students were invited to respond to a survey of five questions both before and after the program to see if there were any changes in content knowledge and career attitudes. In our presentation, we will present our

Directional and Spectral Irradiance in Ocean Models: Effects on Simulated Global Phytoplankton, Nutrients, and Primary Production

Science.gov (United States)

Gregg, Watson W.; Rousseaux, Cecile S.

2016-01-01

The importance of including directional and spectral light in simulations of ocean radiative transfer was investigated using a coupled biogeochemical-circulation-radiative model of the global oceans. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary production. The importance was approached by sequentially removing directional (i.e., direct vs. diffuse) and spectral irradiance and comparing results of the above variables to a fully directionally and spectrally-resolved model. In each case the total irradiance was kept constant; it was only the pathways and spectral nature that were changed. Assuming all irradiance was diffuse had negligible effect on global ocean primary production. Global nitrate and total chlorophyll concentrations declined by about 20% each. The largest changes occurred in the tropics and sub-tropics rather than the high latitudes, where most of the irradiance is already diffuse. Disregarding spectral irradiance had effects that depended upon the choice of attenuation wavelength. The wavelength closest to the spectrally-resolved model, 500 nm, produced lower nitrate (19%) and chlorophyll (8%) and higher primary production (2%) than the spectral model. Phytoplankton relative abundances were very sensitive to the choice of non-spectral wavelength transmittance. The combined effects of neglecting both directional and spectral irradiance exacerbated the differences, despite using attenuation at 500 nm. Global nitrate decreased 33% and chlorophyll decreased 24%. Changes in phytoplankton community structure were considerable, representing a change from chlorophytes to cyanobacteria and coccolithophores. This suggested a shift in community function, from light-limitation to nutrient limitation: lower demands for nutrients from cyanobacteria and coccolithophores favored them over the more nutrient-demanding chlorophytes. Although diatoms have the highest nutrient demands in the model, their

Understanding the El Niño-like Oceanic Response in the Tropical Pacific to Global Warming

Energy Technology Data Exchange (ETDEWEB)

Luo, Yiyong; Lu, Jian; Liu, Fukai; Liu, Wei

2015-10-10

The enhanced central and eastern Pacific SST warming and the associated ocean processes under global warming are investigated using the ocean component of the Community Earth System Model (CESM), Parallel Ocean Program version 2 (POP2). The tropical SST warming pattern in the coupled CESM can be faithfully reproduced by the POP2 forced with surface fluxes computed using the aerodynamic bulk formula. By prescribing the wind stress and/or wind speed through the bulk formula, the effects of wind stress change and/or the wind-evaporation-SST (WES) feedback are isolated and their linearity is evaluated in this ocean-alone setting. Result shows that, although the weakening of the equatorial easterlies contributes positively to the El Niño-like SST warming, 80% of which can be simulated by the POP2 without considering the effects of wind change in both mechanical and thermodynamic fluxes. This result points to the importance of the air-sea thermal interaction and the relative feebleness of the ocean dynamical process in the El Niño-like equatorial Pacific SST response to global warming. On the other hand, the wind stress change is found to play a dominant role in the oceanic response in the tropical Pacific, accounting for most of the changes in the equatorial ocean current system and thermal structures, including the weakening of the surface westward currents, the enhancement of the near-surface stratification and the shoaling of the equatorial thermocline. Interestingly, greenhouse gas warming in the absence of wind stress change and WES feedback also contributes substantially to the changes at the subsurface equatorial Pacific. Further, this warming impact can be largely replicated by an idealized ocean experiment forced by a uniform surface heat flux, whereby, arguably, a purest form of oceanic dynamical thermostat is revealed.

Global charcoal mobilization from soils via dissolution and riverine transport to the oceans.

Science.gov (United States)

Jaffé, Rudolf; Ding, Yan; Niggemann, Jutta; Vähätalo, Anssi V; Stubbins, Aron; Spencer, Robert G M; Campbell, John; Dittmar, Thorsten

2013-04-19

Global biomass burning generates 40 million to 250 million tons of charcoal every year, part of which is preserved for millennia in soils and sediments. We have quantified dissolution products of charcoal in a wide range of rivers worldwide and show that globally, a major portion of the annual charcoal production is lost from soils via dissolution and subsequent transport to the ocean. The global flux of soluble charcoal accounts to 26.5 ± 1.8 million tons per year, which is ~10% of the global riverine flux of dissolved organic carbon (DOC). We suggest that the mobilization of charcoal and DOC out of soils is mechanistically coupled. This study closes a major gap in the global charcoal budget and provides critical information in the context of geoengineering.

Global assessment of benthic nepheloid layers and linkage with upper ocean dynamics

Science.gov (United States)

Gardner, Wilford D.; Richardson, Mary Jo; Mishonov, Alexey V.

2018-01-01

Global maps of the maximum bottom concentration, thickness, and integrated particle mass in benthic nepheloid layers are published here to support collaborations to understand deep ocean sediment dynamics, linkage with upper ocean dynamics, and assessing the potential for scavenging of adsorption-prone elements near the deep ocean seafloor. Mapping the intensity of benthic particle concentrations from natural oceanic processes also provides a baseline that will aid in quantifying the industrial impact of current and future deep-sea mining. Benthic nepheloid layers have been mapped using 6,392 full-depth profiles made during 64 cruises using our transmissometers mounted on CTDs in multiple national/international programs including WOCE, SAVE, JGOFS, CLIVAR-Repeat Hydrography, and GO-SHIP during the last four decades. Intense benthic nepheloid layers are found in areas where eddy kinetic energy in overlying waters, mean kinetic energy 50 m above bottom (mab), and energy dissipation in the bottom boundary layer are near the highest values in the ocean. Areas of intense benthic nepheloid layers include the Western North Atlantic, Argentine Basin in the South Atlantic, parts of the Southern Ocean and areas around South Africa. Benthic nepheloid layers are weak or absent in most of the Pacific, Indian, and Atlantic basins away from continental margins. High surface eddy kinetic energy is associated with the Kuroshio Current east of Japan. Data south of the Kuroshio show weak nepheloid layers, but no transmissometer data exist beneath the Kuroshio, a deficiency that should be remedied to increase understanding of eddy dynamics in un-sampled and under-sampled oceanic areas.

The ``Adopt A Microbe'' project: Web-based interactive education connected with scientific ocean drilling

Science.gov (United States)

Orcutt, B. N.; Bowman, D.; Turner, A.; Inderbitzen, K. E.; Fisher, A. T.; Peart, L. W.; Iodp Expedition 327 Shipboard Party

2010-12-01

We launched the "Adopt a Microbe" project as part of Integrated Ocean Drilling Program (IODP) Expedition 327 in Summer 2010. This eight-week-long education and outreach effort was run by shipboard scientists and educators from the research vessel JOIDES Resolution, using a web site (https://sites.google.com/site/adoptamicrobe) to engage students of all ages in an exploration of the deep biosphere inhabiting the upper ocean crust. Participants were initially introduced to a cast of microbes (residing within an ‘Adoption Center’ on the project website) that live in the dark ocean and asked to select and virtually ‘adopt’ a microbe. A new educational activity was offered each week to encourage learning about microbiology, using the adopted microbe as a focal point. Activities included reading information and asking questions about the adopted microbes (with subsequent responses from shipboard scientists), writing haiku about the adopted microbes, making balloon and fabric models of the adopted microbes, answering math questions related to the study of microbes in the ocean, growing cultures of microbes, and examining the gases produced by microbes. In addition, the website featured regular text, photo and video updates about the science of the expedition using a toy microbe as narrator, as well as stories written by shipboard scientists from the perspective of deep ocean microbes accompanied by watercolor illustrations prepared by a shipboard artist. Assessment methods for evaluating the effectiveness of the Adopt a Microbe project included participant feedback via email and online surveys, website traffic monitoring, and online video viewing rates. Quantitative metrics suggest that the “Adope A Microbe” project was successful in reaching target audiences and helping to encourage and maintain interest in topics related to IODP Expedition 327. The “Adopt A Microbe” project mdel can be adapted for future oceanographic expeditions to help connect the

Comparison of the Carbon System Parameters at the Global CO2 Survey Crossover Locations in the North and South Pacific Ocean, 1990-1996

Energy Technology Data Exchange (ETDEWEB)

Feely, Richard A [NOAA, Pacific Marine Environmental Laboratory (PMEL); Lamb, Marilyn F. [NOAA, Pacific Marine Environmental Laboratory (PMEL); Greeley, Dana J. [NOAA, Pacific Marine Environmental Laboratory (PMEL); Wanninkhof, Rik [NOAA, Atlantic Oceanographic and Meteorological Laboratory (AOML)

1999-10-01

As a collaborative program to measure global ocean carbon inventories and provide estimates of the anthropogenic carbon dioxide (C02) uptake by the oceans. the National Oceanic and Atmospheric Administration and the U.S. Department of Energy have sponsored the collection of ocean carbon measurements as part of the World Ocean Circulation Experiment and Ocean-Atmosphere Carbon Exchange Study cruises. The cruises discussed here occurred in the North and South Pacific from 1990 through 1996. The carbon parameters from these 30 crossover locations have been compared to ensure that a consistent global data set emerges from the survey cruises. !'he results indicate that for dissolved inorganic carbon. fugacity of C02• and pH. the a~:,rreements at most crossover locations are well within the design specifications for the global CO) survey: whereas. in the case of total alkaliniry. the agreement between crossover locations is not as close.

New global ICT-based business models

DEFF Research Database (Denmark)

The New Global Business model (NEWGIBM) book describes the background, theory references, case studies, results and learning imparted by the NEWGIBM project, which is supported by ICT, to a research group during the period from 2005-2011. The book is a result of the efforts and the collaborative ...... The NEWGIBM Cases Show? The Strategy Concept in Light of the Increased Importance of Innovative Business Models Successful Implementation of Global BM Innovation Globalisation Of ICT Based Business Models: Today And In 2020......The New Global Business model (NEWGIBM) book describes the background, theory references, case studies, results and learning imparted by the NEWGIBM project, which is supported by ICT, to a research group during the period from 2005-2011. The book is a result of the efforts and the collaborative....... The NEWGIBM book serves as a part of the final evaluation and documentation of the NEWGIBM project and is supported by results from the following projects: M-commerce, Global Innovation, Global Ebusiness & M-commerce, The Blue Ocean project, International Center for Innovation and Women in Business, NEFFICS...

Multiple stressors for oceanic primary production

KAUST Repository

Agusti, Susana

2015-12-15

Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and

Multiple stressors for oceanic primary production

KAUST Repository

Agusti, Susana; Llabré s, Moira; Lubiá n, Luis M.; Moreno-Ostos, Enrique; Estrada, Marta; Duarte, Carlos M.; Cerezo, Maria I.

2015-01-01

Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and

Upper-Ocean Heat Balance Processes and the Walker Circulation in CMIP5 Model Projections

Science.gov (United States)

Robertson, F. R.; Roberts, J. B.; Funk, C.; Lyon, B.; Ricciardulli, L.

2012-01-01

Considerable uncertainty remains as to the importance of mechanisms governing decadal and longer variability of the Walker Circulation, its connection to the tropical climate system, and prospects for tropical climate change in the face of anthropogenic forcing. Most contemporary climate models suggest that in response to elevated CO2 and a warmer but more stratified atmosphere, the required upward mass flux in tropical convection will diminish along with the Walker component of the tropical mean circulation as well. Alternatively, there is also evidence to suggest that the shoaling and increased vertical stratification of the thermocline in the eastern Pacific will enable a muted SST increase there-- preserving or even enhancing some of the dynamical forcing for the Walker cell flow. Over the past decade there have been observational indications of an acceleration in near-surface easterlies, a strengthened Pacific zonal SST gradient, and globally-teleconnected dislocations in precipitation. But is this evidence in support of an ocean dynamical thermostat process posited to accompany anthropogenic forcing, or just residual decadal fluctuations associated with variations in warm and cold ENSO events and other stochastic forcing? From a modeling perspective we try to make headway on this question by examining zonal variations in surface energy fluxes and dynamics governing tropical upper ocean heat content evolution in the WCRP CMIP5 model projections. There is some diversity among model simulations; for example, the CCSM4 indicates net ocean warming over the IndoPacific region while the CSIRO model concentrates separate warming responses over the central Pacific and Indian Ocean regions. The models, as with observations, demonstrate strong local coupling between variations in column water vapor, downward surface longwave radiation and SST; but the spatial patterns of changes in the sign of this relationship differ among models and, for models as a whole, with

Arctide2017, a high-resolution regional tidal model in the Arctic Ocean

DEFF Research Database (Denmark)

Cancet, M.; Andersen, O. B.; Lyard, F.

2018-01-01

The Arctic Ocean is a challenging region for tidal modelling. The accuracy of the global tidal models decreases by several centimeters in the Polar Regions, which has a large impact on the quality of the satellite altimeter sea surface heights and the altimetry-derived products. NOVELTIS, DTU Space...... and LEGOS have developed Arctide2017, a regional, high-resolution tidal atlas in the Arctic Ocean, in the framework of an extension of the CryoSat Plus for Ocean (CP4O) ESA STSE (Support to Science Element) project. In particular, this atlas benefits from the assimilation of the most complete satellite...... assimilation and validation. This paper presents the implementation methodology and the performance of this new regional tidal model in the Arctic Ocean, compared to the existing global and regional tidal models....

Modeling selective pressures on phytoplankton in the global ocean.

Directory of Open Access Journals (Sweden)

Jason G Bragg

Full Text Available Our view of marine microbes is transforming, as culture-independent methods facilitate rapid characterization of microbial diversity. It is difficult to assimilate this information into our understanding of marine microbe ecology and evolution, because their distributions, traits, and genomes are shaped by forces that are complex and dynamic. Here we incorporate diverse forces--physical, biogeochemical, ecological, and mutational--into a global ocean model to study selective pressures on a simple trait in a widely distributed lineage of picophytoplankton: the nitrogen use abilities of Synechococcus and Prochlorococcus cyanobacteria. Some Prochlorococcus ecotypes have lost the ability to use nitrate, whereas their close relatives, marine Synechococcus, typically retain it. We impose mutations for the loss of nitrogen use abilities in modeled picophytoplankton, and ask: in which parts of the ocean are mutants most disadvantaged by losing the ability to use nitrate, and in which parts are they least disadvantaged? Our model predicts that this selective disadvantage is smallest for picophytoplankton that live in tropical regions where Prochlorococcus are abundant in the real ocean. Conversely, the selective disadvantage of losing the ability to use nitrate is larger for modeled picophytoplankton that live at higher latitudes, where Synechococcus are abundant. In regions where we expect Prochlorococcus and Synechococcus populations to cycle seasonally in the real ocean, we find that model ecotypes with seasonal population dynamics similar to Prochlorococcus are less disadvantaged by losing the ability to use nitrate than model ecotypes with seasonal population dynamics similar to Synechococcus. The model predictions for the selective advantage associated with nitrate use are broadly consistent with the distribution of this ability among marine picocyanobacteria, and at finer scales, can provide insights into interactions between temporally varying

Modeling selective pressures on phytoplankton in the global ocean.

Science.gov (United States)

Bragg, Jason G; Dutkiewicz, Stephanie; Jahn, Oliver; Follows, Michael J; Chisholm, Sallie W

2010-03-10

Our view of marine microbes is transforming, as culture-independent methods facilitate rapid characterization of microbial diversity. It is difficult to assimilate this information into our understanding of marine microbe ecology and evolution, because their distributions, traits, and genomes are shaped by forces that are complex and dynamic. Here we incorporate diverse forces--physical, biogeochemical, ecological, and mutational--into a global ocean model to study selective pressures on a simple trait in a widely distributed lineage of picophytoplankton: the nitrogen use abilities of Synechococcus and Prochlorococcus cyanobacteria. Some Prochlorococcus ecotypes have lost the ability to use nitrate, whereas their close relatives, marine Synechococcus, typically retain it. We impose mutations for the loss of nitrogen use abilities in modeled picophytoplankton, and ask: in which parts of the ocean are mutants most disadvantaged by losing the ability to use nitrate, and in which parts are they least disadvantaged? Our model predicts that this selective disadvantage is smallest for picophytoplankton that live in tropical regions where Prochlorococcus are abundant in the real ocean. Conversely, the selective disadvantage of losing the ability to use nitrate is larger for modeled picophytoplankton that live at higher latitudes, where Synechococcus are abundant. In regions where we expect Prochlorococcus and Synechococcus populations to cycle seasonally in the real ocean, we find that model ecotypes with seasonal population dynamics similar to Prochlorococcus are less disadvantaged by losing the ability to use nitrate than model ecotypes with seasonal population dynamics similar to Synechococcus. The model predictions for the selective advantage associated with nitrate use are broadly consistent with the distribution of this ability among marine picocyanobacteria, and at finer scales, can provide insights into interactions between temporally varying ocean processes and

Atmospheric and oceanic excitation of decadal-scale Earth orientation variations

Science.gov (United States)

Gross, Richard S.; Fukumori, Ichiro; Menemenlis, Dimitris

2005-09-01

The contribution of atmospheric wind and surface pressure and oceanic current and bottom pressure variations during 1949-2002 to exciting changes in the Earth's orientation on decadal timescales is investigated using an atmospheric angular momentum series computed from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis project and an oceanic angular momentum series computed from a near-global ocean model that was forced by surface fluxes from the NCEP/NCAR reanalysis project. Not surprisingly, since decadal-scale variations in the length of day are caused mainly by interactions between the mantle and core, the effect of the atmosphere and oceans is found to be only about 14% of that observed. More surprisingly, it is found that the effect of atmospheric and oceanic processes on decadal-scale changes in polar motion is also only about 20% (x component) and 38% (y component) of that observed. Therefore redistribution of mass within the atmosphere and oceans does not appear to be the main cause of the Markowitz wobble. It is also found that on timescales between 10 days and 4 years the atmospheric and oceanic angular momentum series used here have very little skill in explaining Earth orientation variations before the mid to late 1970s. This is attributed to errors in both the Earth orientation observations prior to 1976 when measurements from the accurate space-geodetic techniques became available and to errors in the modeled atmospheric fields prior to 1979 when the satellite era of global weather observing systems began.

Biodiversity's big wet secret: the global distribution of marine biological records reveals chronic under-exploration of the deep pelagic ocean.

Directory of Open Access Journals (Sweden)

Thomas J Webb

Full Text Available BACKGROUND: Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a global picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic ocean--the largest biome on Earth--is chronically under-represented in global databases of marine biodiversity. METHODOLOGY/PRINCIPAL FINDINGS: We use data from the Ocean Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this global picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the ocean differing in depth reveals that regardless of ocean depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. CONCLUSIONS/SIGNIFICANCE: The deep pelagic ocean is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in global databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earth's largest ecosystem.

A comparison of chemical compositions of reported altered oceanic crusts and global MORB data set: implication for isotopic heterogeneity of recycled materials

Science.gov (United States)

Shimoda, G.; Kogiso, T.

2017-12-01

Chemical composition of altered oceanic crust is one of important constraints to delineate chemical heterogeneity of the mantle. Accordingly, many researchers have been studied to determine bulk chemical composition of altered oceanic crust mainly based on chemical compositions of old oceanic crusts at Site 801 and Site 417/418, and young crust at Site 504 (e.g., Staudigel et al., 1996; Bach et al. 2003; Kuo et al., 2016). Their careful estimation provided reliable bulk chemical compositions of these Sites and revealed common geochemical feature of alteration. To assess effect of recycling of altered oceanic crust on chemical evolution of the mantle, it might be meaningful to discuss whether the reported chemical compositions of altered oceanic crusts can represent chemical composition of globally subducted oceanic crusts. Reported chemical compositions of fresh glass or less altered samples from Site 801, 417/418 and 504 were highly depleted compared to that of global MORB reported by Gale et al. (2013), suggesting that there might be sampling bias. Hence, it could be important to consider chemical difference between oceanic crusts of these three Sites and global MORB to discuss effect of recycling of oceanic crust on isotopic heterogeneity of the mantle. It has been suggested that one of controlling factors of chemical variation of oceanic crust is crustal spreading rate because different degree of partial melting affects chemical composition of magmas produced at a mid-ocean ridge. Crustal spreading rate could also affect intensity of alteration. Namely, oceanic crusts produced at slow-spreading ridges may prone to be altered due to existence of larger displacement faults compared to fast spreading ridges which have relatively smooth topography. Thus, it might be significant to evaluate isotopic evolution of oceanic crusts those were produced at different spreading rates. In this presentation, we will provide a possible chemical variation of altered oceanic

Biogeochemical protocols and diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP

Directory of Open Access Journals (Sweden)

J. C. Orr

2017-06-01

Full Text Available The Ocean Model Intercomparison Project (OMIP focuses on the physics and biogeochemistry of the ocean component of Earth system models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6. OMIP aims to provide standard protocols and diagnostics for ocean models, while offering a forum to promote their common assessment and improvement. It also offers to compare solutions of the same ocean models when forced with reanalysis data (OMIP simulations vs. when integrated within fully coupled Earth system models (CMIP6. Here we detail simulation protocols and diagnostics for OMIP's biogeochemical and inert chemical tracers. These passive-tracer simulations will be coupled to ocean circulation models, initialized with observational data or output from a model spin-up, and forced by repeating the 1948–2009 surface fluxes of heat, fresh water, and momentum. These so-called OMIP-BGC simulations include three inert chemical tracers (CFC-11, CFC-12, SF6 and biogeochemical tracers (e.g., dissolved inorganic carbon, carbon isotopes, alkalinity, nutrients, and oxygen. Modelers will use their preferred prognostic BGC model but should follow common guidelines for gas exchange and carbonate chemistry. Simulations include both natural and total carbon tracers. The required forced simulation (omip1 will be initialized with gridded observational climatologies. An optional forced simulation (omip1-spunup will be initialized instead with BGC fields from a long model spin-up, preferably for 2000 years or more, and forced by repeating the same 62-year meteorological forcing. That optional run will also include abiotic tracers of total dissolved inorganic carbon and radiocarbon, CTabio and 14CTabio, to assess deep-ocean ventilation and distinguish the role of physics vs. biology. These simulations will be forced by observed atmospheric histories of the three inert gases and CO2 as well as carbon isotope ratios of CO2. OMIP-BGC simulation

Biogeochemical Protocols and Diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP)

Science.gov (United States)

Orr, James C.; Najjar, Raymond G.; Aumont, Olivier; Bopp, Laurent; Bullister, John L.; Danabasoglu, Gokhan; Doney, Scott C.; Dunne, John P.; Dutay, Jean-Claude; Graven, Heather;

Biogeochemical protocols and diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP)

Science.gov (United States)

Orr, James C.; Najjar, Raymond G.; Aumont, Olivier; Bopp, Laurent; Bullister, John L.; Danabasoglu, Gokhan; Doney, Scott C.; Dunne, John P.; Dutay, Jean-Claude; Graven, Heather; Griffies, Stephen M.; John, Jasmin G.; Joos, Fortunat; Levin, Ingeborg; Lindsay, Keith; Matear, Richard J.; McKinley, Galen A.; Mouchet, Anne; Oschlies, Andreas; Romanou, Anastasia; Schlitzer, Reiner; Tagliabue, Alessandro; Tanhua, Toste; Yool, Andrew

2017-06-01

The Ocean Model Intercomparison Project (OMIP) focuses on the physics and biogeochemistry of the ocean component of Earth system models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6). OMIP aims to provide standard protocols and diagnostics for ocean models, while offering a forum to promote their common assessment and improvement. It also offers to compare solutions of the same ocean models when forced with reanalysis data (OMIP simulations) vs. when integrated within fully coupled Earth system models (CMIP6). Here we detail simulation protocols and diagnostics for OMIP's biogeochemical and inert chemical tracers. These passive-tracer simulations will be coupled to ocean circulation models, initialized with observational data or output from a model spin-up, and forced by repeating the 1948-2009 surface fluxes of heat, fresh water, and momentum. These so-called OMIP-BGC simulations include three inert chemical tracers (CFC-11, CFC-12, SF6) and biogeochemical tracers (e.g., dissolved inorganic carbon, carbon isotopes, alkalinity, nutrients, and oxygen). Modelers will use their preferred prognostic BGC model but should follow common guidelines for gas exchange and carbonate chemistry. Simulations include both natural and total carbon tracers. The required forced simulation (omip1) will be initialized with gridded observational climatologies. An optional forced simulation (omip1-spunup) will be initialized instead with BGC fields from a long model spin-up, preferably for 2000 years or more, and forced by repeating the same 62-year meteorological forcing. That optional run will also include abiotic tracers of total dissolved inorganic carbon and radiocarbon, CTabio and 14CTabio, to assess deep-ocean ventilation and distinguish the role of physics vs. biology. These simulations will be forced by observed atmospheric histories of the three inert gases and CO2 as well as carbon isotope ratios of CO2. OMIP-BGC simulation protocols are

Sea surface temperature and salinity from the Global Ocean Surface Underway Data (GOSUD) from 1980-01-03 to present

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains the Global Ocean Surface Underway Data (GOSUD) from 1980-01-03 to present as submitted to NOAA/NCEI. The data includes information about sea...

Global trophic ecology of yellowfin, bigeye, and albacore tunas: Understanding predation on micronekton communities at ocean-basin scales

Science.gov (United States)

Duffy, Leanne M.; Kuhnert, Petra M.; Pethybridge, Heidi R.; Young, Jock W.; Olson, Robert J.; Logan, John M.; Goñi, Nicolas; Romanov, Evgeny; Allain, Valerie; Staudinger, Michelle D.; Abecassis, Melanie; Choy, C. Anela; Hobday, Alistair J.; Simier, Monique; Galván-Magaña, Felipe; Potier, Michel; Ménard, Frederic

2017-06-01

Predator-prey interactions for three commercially valuable tuna species: yellowfin (Thunnus albacares), bigeye (T. obesus), and albacore (T. alalunga), collected over a 40-year period from the Pacific, Indian, and Atlantic Oceans, were used to quantitatively assess broad, macro-scale trophic patterns in pelagic ecosystems. Analysis of over 14,000 tuna stomachs, using a modified classification tree approach, revealed for the first time the global expanse of pelagic predatory fish diet and global patterns of micronekton diversity. Ommastrephid squids were consistently one of the top prey groups by weight across all tuna species and in most ocean bodies. Interspecific differences in prey were apparent, with epipelagic scombrid and mesopelagic paralepidid fishes globally important for yellowfin and bigeye tunas, respectively, while vertically-migrating euphausiid crustaceans were important for albacore tuna in the Atlantic and Pacific Oceans. Diet diversity showed global and regional patterns among tuna species. In the central and western Pacific Ocean, characterized by low productivity, a high diversity of micronekton prey was detected while low prey diversity was evident in highly productive coastal waters where upwelling occurs. Spatial patterns of diet diversity were most variable in yellowfin and bigeye tunas while a latitudinal diversity gradient was observed with lower diversity in temperate regions for albacore tuna. Sea-surface temperature was a reasonable predictor of the diets of yellowfin and bigeye tunas, whereas chlorophyll-a was the best environmental predictor of albacore diet. These results suggest that the ongoing expansion of warmer, less productive waters in the world's oceans may alter foraging opportunities for tunas due to regional changes in prey abundances and compositions.

Climate and oceanic fisheries: recent observations and projections and future needs

DEFF Research Database (Denmark)

Salinger, M.J.; Bell, Johan D.; Evans, Karen

2013-01-01

Several lines of evidence show that climatic variation and global warming can have a major effect on fisheries production and replenishment. To prevent overfishing and rebuild overfished stocks under changing and uncertain environmental conditions, new research partnerships between fisheries scie...... scientists and climate change experts are required. The International Workshop on Climate and Oceanic Fisheries held in Rarotonga, Cook Islands, 3–5......Several lines of evidence show that climatic variation and global warming can have a major effect on fisheries production and replenishment. To prevent overfishing and rebuild overfished stocks under changing and uncertain environmental conditions, new research partnerships between fisheries...

Global Ocean Data Quality Assessment of SARAL/AltiKa GDR products

Science.gov (United States)

Picot, Nicolas; Prandi, Pierre; desjonqueres, jean-damien

2015-04-01

The SARAL mission was successfully launched on February, 5th 2013 and cycle 1 started a few days later on March 14th. For more than 2 years, the Ka-band altimeter and dual frequency radiometer on board have been collecting high quality ocean topography measurements. Within the first months of the mission, a first patch (P1) was developed to correct some small anomalies detected in the products and to account for in-flight calibration data. At the beginning of year 2014, a second patch (P2) was produced (applied from cycle 10 pass 407 on OGDR data and from pass 566 on IGDR data) and the all GDR produced before this were reprocessed in order to deliver a consistent dataset to users. This new version of the products provides, among other changes, important improvements regarding radiometer data processing, sea-state bias and wind speed. Since the beginning of the mission, data quality assessment of OGDR, IGDR and GDR data has been routinely performed at CNES and CLS (as part of the CNES SALP project). We will present the main results of the data quality assessment over ocean based on SARAL/AltiKa GDR data reprocessed using the homogeneous P2 version. The main data quality metrics presented will include: Data availability and validity, Monitoring of the main altimeter and radiometer parameters and comparisons to other altimeter missions such as OSTM/Jason-2, Mission performance through mono-mission crossovers analysis, Investigation of inter-mission biases and large-scale regional differences from multi-mission crossovers between SARAL and Jason-2. Monitoring of the global mean SLA and comparison to Jason-2 Finally, we will present the new product version standard that is currently under development on CNES side.

Constraints of fossil fuels depletion on global warming projections

International Nuclear Information System (INIS)

Chiari, Luca; Zecca, Antonio

2011-01-01

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO 2 concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO 2 emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO 2 concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: → CO 2 and global temperature are projected under fossil fuels exhaustion scenarios. → Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. → Temperature projections are possibly lower than the IPCC ones. → Fossil fuels exhaustion will not avoid dangerous global warming.

Constraints of fossil fuels depletion on global warming projections

Energy Technology Data Exchange (ETDEWEB)

Chiari, Luca, E-mail: chiari@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy); Zecca, Antonio, E-mail: zecca@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy)

2011-09-15

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO{sub 2} concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO{sub 2} emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO{sub 2} concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: > CO{sub 2} and global temperature are projected under fossil fuels exhaustion scenarios. > Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. > Temperature projections are possibly lower than the IPCC ones. > Fossil fuels exhaustion will not avoid dangerous global warming.

The IOD-ENSO precursory teleconnection over the tropical Indo-Pacific Ocean: dynamics and long-term trends under global warming

Science.gov (United States)

Yuan, Dongliang; Hu, Xiaoyue; Xu, Peng; Zhao, Xia; Masumoto, Yukio; Han, Weiqing

2018-01-01

The dynamics of the teleconnection between the Indian Ocean Dipole (IOD) in the tropical Indian Ocean and El Niño-Southern Oscillation (ENSO) in the tropical Pacific Ocean at the time lag of one year are investigated using lag correlations between the oceanic anomalies in the southeastern tropical Indian Ocean in fall and those in the tropical Indo-Pacific Ocean in the following winter-fall seasons in the observations and in high-resolution global ocean model simulations. The lag correlations suggest that the IOD-forced interannual transport anomalies of the Indonesian Throughflow generate thermocline anomalies in the western equatorial Pacific Ocean, which propagate to the east to induce ocean-atmosphere coupled evolution leading to ENSO. In comparison, lag correlations between the surface zonal wind anomalies over the western equatorial Pacific in fall and the Indo-Pacific oceanic anomalies at time lags longer than a season are all insignificant, suggesting the short memory of the atmospheric bridge. A linear continuously stratified model is used to investigate the dynamics of the oceanic connection between the tropical Indian and Pacific Oceans. The experiments suggest that interannual equatorial Kelvin waves from the Indian Ocean propagate into the equatorial Pacific Ocean through the Makassar Strait and the eastern Indonesian seas with a penetration rate of about 10%-15% depending on the baroclinic modes. The IOD-ENSO teleconnection is found to get stronger in the past century or so. Diagnoses of the CMIP5 model simulations suggest that the increased teleconnection is associated with decreased Indonesian Throughflow transports in the recent century, which is found sensitive to the global warming forcing.

Changes in Ocean Heat, Carbon Content, and Ventilation: A Review of the First Decade of GO-SHIP Global Repeat Hydrography.

Science.gov (United States)

Talley, L D; Feely, R A; Sloyan, B M; Wanninkhof, R; Baringer, M O; Bullister, J L; Carlson, C A; Doney, S C; Fine, R A; Firing, E; Gruber, N; Hansell, D A; Ishii, M; Johnson, G C; Katsumata, K; Key, R M; Kramp, M; Langdon, C; Macdonald, A M; Mathis, J T; McDonagh, E L; Mecking, S; Millero, F J; Mordy, C W; Nakano, T; Sabine, C L; Smethie, W M; Swift, J H; Tanhua, T; Thurnherr, A M; Warner, M J; Zhang, J-Z

2016-01-01

Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19% of this excess in the abyssal ocean beneath 2,000 m, dominated by Southern Ocean warming. The ocean also has taken up about 27% of anthropogenic carbon, resulting in acidification of the upper ocean. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcing and ventilation. The most recent decade of global hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (∼20%) and deep-ocean oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the ocean's overturning circulation.

Spanish leadership in marine renewable energies. The project Ocean Lider; Liderazgo espanol en energias renovables oceanicas. El proyecto Ocean Lider

Energy Technology Data Exchange (ETDEWEB)

Amante, J.

2012-07-01

The Cenit-e Ocean Lider project is an ambitious R+D technological initiative promoted by a consortium of companies with a strong research capability which addresses the challenge of developing the necessary technologies to set up integrated large scale installations that can harness energies of marine renewable sources, such as waves, tidal currents and wind. Ocean Lider developed knowledge and technologies would provide some new power plant concepts, devices, structures, data acquisition and site characterization systems, vessels, etc. In this way, some new technologies for harnessing ocean energy generation, distribution and transmission would be developed and sized according to a large scale scheme, to make this hybrid harvest (wave, current and wind) as profitable as possible. (Author)

Carbon dioxide from surface underway survey in global oceans from 1968 to 2006 (Version 1.0) (NODC Accession 0040205)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — More than 3 million measurements of surface water partial pressure of CO2 obtained over the global oceans during 1968 to 2006 are listed in the Lamont-Doherty Earth...

Global Carbon Budget 2015

Science.gov (United States)

Le Quéré, C.; Moriarty, R.; Andrew, R. M.; Canadell, J. G.; Sitch, S.; Korsbakken, J. I.; Friedlingstein, P.; Peters, G. P.; Andres, R. J.; Boden, T. A.; Houghton, R. A.; House, J. I.; Keeling, R. F.; Tans, P.; Arneth, A.; Bakker, D. C. E.; Barbero, L.; Bopp, L.; Chang, J.; Chevallier, F.; Chini, L. P.; Ciais, P.; Fader, M.; Feely, R. A.; Gkritzalis, T.; Harris, I.; Hauck, J.; Ilyina, T.; Jain, A. K.; Kato, E.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landschützer, P.; Lauvset, S. K.; Lefèvre, N.; Lenton, A.; Lima, I. D.; Metzl, N.; Millero, F.; Munro, D. R.; Murata, A.; Nabel, J. E. M. S.; Nakaoka, S.; Nojiri, Y.; O'Brien, K.; Olsen, A.; Ono, T.; Pérez, F. F.; Pfeil, B.; Pierrot, D.; Poulter, B.; Rehder, G.; Rödenbeck, C.; Saito, S.; Schuster, U.; Schwinger, J.; Séférian, R.; Steinhoff, T.; Stocker, B. D.; Sutton, A. J.; Takahashi, T.; Tilbrook, B.; van der Laan-Luijkx, I. T.; van der Werf, G. R.; van Heuven, S.; Vandemark, D.; Viovy, N.; Wiltshire, A.; Zaehle, S.; Zeng, N.

2015-12-01

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates as well as consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover change (some including nitrogen-carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global

Turnover time of fluorescent dissolved organic matter in the dark global ocean

DEFF Research Database (Denmark)

Catalá, Teresa Serrano; Reche, Isabel; Fuentes-Lema, Antonio

2015-01-01

with a turnover time of 379±103 years is also detected. We propose the use of DOM fluorescence to study the cycling of resistant DOM that is preserved at centennial timescales and could represent a mechanism of carbon sequestration (humic-like fraction) and the decaying DOM injected into the dark global ocean......, where it decreases at centennial timescales (tyrosine-like fraction)...

Crustal accretion along the global mid-ocean ridge system based on basaltic glass and olivine-hosted melt inclusion compositions

Science.gov (United States)

Wanless, V. D.; Behn, M. D.

2015-12-01

The depth and distribution of crystallization at mid-ocean ridges controls the overall architecture of the oceanic crust, influences hydrothermal circulation, and determines geothermal gradients in the crust and uppermost mantle. Despite this, there is no overall consensus on how crystallization is distributed within the crust/upper mantle or how this varies with spreading rate. Here, we examine crustal accretion at mid-ocean ridges by combining crystallization pressures calculated from major element barometers on mid-ocean ridge basalt (MORB) glasses with vapor-saturation pressures from melt inclusions to produce a detailed map of crystallization depths and distributions along the global ridge system. We calculate pressures of crystallization from >11,500 MORB glasses from the global ridge system using two established major element barometers (1,2). Additionally, we use vapor-saturation pressures from >400 olivine-hosted melt inclusions from five ridges with variable spreading rates to constrain pressures and distributions of crystallization along the global ridge system. We show that (i) crystallization depths from MORB glasses increase and become less focused with decreasing spreading rate, (ii) maximum glass pressures are greater than the maximum melt inclusion pressure, which indicates that the melt inclusions do not record the deepest crystallization at mid-ocean ridges, and (iii) crystallization occurs in the lower crust/upper mantle at all ridges, indicating accretion is distributed throughout the crust at all spreading rates, including those with a steady-state magma lens. Finally, we suggest that the remarkably similar maximum vapor-saturation pressures (~ 3000 bars) in melt inclusion from all spreading rates reflects the CO2 content of the depleted upper mantle feeding the global mid-ocean ridge system. (1) Michael, P. & W. Cornell (1998), Journal of Geophysical Research, 103(B8), 18325-18356; (2) Herzberg, C. (2004), Journal of Petrology, 45(12), 2389.

Investigating Solution Convergence in a Global Ocean Model Using a 2048-Processor Cluster of Distributed Shared Memory Machines

Directory of Open Access Journals (Sweden)

Chris Hill

2007-01-01

Full Text Available Up to 1920 processors of a cluster of distributed shared memory machines at the NASA Ames Research Center are being used to simulate ocean circulation globally at horizontal resolutions of 1/4, 1/8, and 1/16-degree with the Massachusetts Institute of Technology General Circulation Model, a finite volume code that can scale to large numbers of processors. The study aims to understand physical processes responsible for skill improvements as resolution is increased and to gain insight into what resolution is sufficient for particular purposes. This paper focuses on the computational aspects of reaching the technical objective of efficiently performing these global eddy-resolving ocean simulations. At 1/16-degree resolution the model grid contains 1.2 billion cells. At this resolution it is possible to simulate approximately one month of ocean dynamics in about 17 hours of wallclock time with a model timestep of two minutes on a cluster of four 512-way NUMA Altix systems. The Altix systems' large main memory and I/O subsystems allow computation and disk storage of rich sets of diagnostics during each integration, supporting the scientific objective to develop a better understanding of global ocean circulation model solution convergence as model resolution is increased.

Strong relationship between DMS and the solar radiation dose over the global surface ocean.

Science.gov (United States)

Vallina, Sergio M; Simó, Rafel

2007-01-26

Marine biogenic dimethylsulfide (DMS) is the main natural source of tropospheric sulfur, which may play a key role in cloud formation and albedo over the remote ocean. Through a global data analysis, we found that DMS concentrations are highly positively correlated with the solar radiation dose in the upper mixed layer of the open ocean, irrespective of latitude, plankton biomass, or temperature. This is a necessary condition for the feasibility of a negative feedback in which light-attenuating DMS emissions are in turn driven by the light dose received by the pelagic ecosystem.

Design of the MISMIP+, ISOMIP+, and MISOMIP ice-sheet, ocean, and coupled ice sheet-ocean intercomparison projects

Science.gov (United States)

Asay-Davis, Xylar; Cornford, Stephen; Martin, Daniel; Gudmundsson, Hilmar; Holland, David; Holland, Denise

2015-04-01

The MISMIP and MISMIP3D marine ice sheet model intercomparison exercises have become popular benchmarks, and several modeling groups have used them to show how their models compare to both analytical results and other models. Similarly, the ISOMIP (Ice Shelf-Ocean Model Intercomparison Project) experiments have acted as a proving ground for ocean models with sub-ice-shelf cavities.As coupled ice sheet-ocean models become available, an updated set of benchmark experiments is needed. To this end, we propose sequel experiments, MISMIP+ and ISOMIP+, with an end goal of coupling the two in a third intercomparison exercise, MISOMIP (the Marine Ice Sheet-Ocean Model Intercomparison Project). Like MISMIP3D, the MISMIP+ experiments take place in an idealized, three-dimensional setting and compare full 3D (Stokes) and reduced, hydrostatic models. Unlike the earlier exercises, the primary focus will be the response of models to sub-shelf melting. The chosen configuration features an ice shelf that experiences substantial lateral shear and buttresses the upstream ice, and so is well suited to melting experiments. Differences between the steady states of each model are minor compared to the response to melt-rate perturbations, reflecting typical real-world applications where parameters are chosen so that the initial states of all models tend to match observations. The three ISOMIP+ experiments have been designed to to make use of the same bedrock topography as MISMIP+ and using ice-shelf geometries from MISMIP+ results produced by the BISICLES ice-sheet model. The first two experiments use static ice-shelf geometries to simulate the evolution of ocean dynamics and resulting melt rates to a quasi-steady state when far-field forcing changes in either from cold to warm or from warm to cold states. The third experiment prescribes 200 years of dynamic ice-shelf geometry (with both retreating and advancing ice) based on a BISICLES simulation along with similar flips between warm and

Ocean acidification reduces the crystallographic control in juvenile mussel shells.

Science.gov (United States)

Fitzer, Susan C; Cusack, Maggie; Phoenix, Vernon R; Kamenos, Nicholas A

2014-10-01

Global climate change threatens the oceans as anthropogenic carbon dioxide causes ocean acidification and reduced carbonate saturation. Future projections indicate under saturation of aragonite, and potentially calcite, in the oceans by 2100. Calcifying organisms are those most at risk from such ocean acidification, as carbonate is vital in the biomineralisation of their calcium carbonate protective shells. This study highlights the importance of multi-generational studies to investigate how marine organisms can potentially adapt to future projected global climate change. Mytilus edulis is an economically important marine calcifier vulnerable to decreasing carbonate saturation as their shells comprise two calcium carbonate polymorphs: aragonite and calcite. M. edulis specimens were cultured under current and projected pCO2 (380, 550, 750 and 1000μatm), following 6months of experimental culture, adults produced second generation juvenile mussels. Juvenile mussel shells were examined for structural and crystallographic orientation of aragonite and calcite. At 1000μatm pCO2, juvenile mussels spawned and grown under this high pCO2 do not produce aragonite which is more vulnerable to carbonate under-saturation than calcite. Calcite and aragonite were produced at 380, 550 and 750μatm pCO2. Electron back scatter diffraction analyses reveal less constraint in crystallographic orientation with increased pCO2. Shell formation is maintained, although the nacre crystals appear corroded and crystals are not so closely layered together. The differences in ultrastructure and crystallography in shells formed by juveniles spawned from adults in high pCO2 conditions may prove instrumental in their ability to survive ocean acidification. Copyright © 2014 Elsevier Inc. All rights reserved.

Marine data management: a positive evolution from JGOFS to OCEANS

Science.gov (United States)

Avril, B.

2003-04-01

The JGOFS project has been highly successful in providing new insights into global biogeochemical cycling of carbon and associated elements in the oceans through a multi-national effort at the regional scale (process studies in the North Atlantic, Arabian Sea, Equatorial Pacific, Southern Ocean and North Pacific), global scale (carbon survey) and from long-term measurements at key ocean sites (time-series). The database thus created is very large and complex in diversity and format, and it is currently managed at the international level, thank to the efforts of the JGOFS Data Management Task Team. To be fully usable for current and future studies, the JGOFS datasets will be organised as a single database (so-called, the International JGOFS Master Dataset), in a single format and in a single location (in the World Data Centre (WDC) system, thanks to an initiative of PANGAEA / WDC-MARE; and on CDs or DVDs) before the end of the project (Dec. 2003). This should be achieved by adapting previously developed tools, especially from the US-JGOFS DMO (for the user query interface) and from ODV/PANGAEA (for the datasets visualization and metadata handling). Whilst the OCEANS project science and implementation plans are being prepared, the international oceanographic community is now hoping to benefit from the JGOFS data management experience and to elaborate beforehand the best design and practices for its data management. The draft OCEANS data management plan (international data policy and recommendations for participating international agencies and national data managers) is presented. This plan should result in the rapid and full availability of data, and its long-term preservation and accessibility, thanks to a better, integrated and fully implemented data management system.

Effects of Model Resolution and Ocean Mixing on Forced Ice-Ocean Physical and Biogeochemical Simulations Using Global and Regional System Models

Science.gov (United States)

Jin, Meibing; Deal, Clara; Maslowski, Wieslaw; Matrai, Patricia; Roberts, Andrew; Osinski, Robert; Lee, Younjoo J.; Frants, Marina; Elliott, Scott; Jeffery, Nicole; Hunke, Elizabeth; Wang, Shanlin

2018-01-01

The current coarse-resolution global Community Earth System Model (CESM) can reproduce major and large-scale patterns but is still missing some key biogeochemical features in the Arctic Ocean, e.g., low surface nutrients in the Canada Basin. We incorporated the CESM Version 1 ocean biogeochemical code into the Regional Arctic System Model (RASM) and coupled it with a sea-ice algal module to investigate model limitations. Four ice-ocean hindcast cases are compared with various observations: two in a global 1° (40˜60 km in the Arctic) grid: G1deg and G1deg-OLD with/without new sea-ice processes incorporated; two on RASM's 1/12° (˜9 km) grid R9km and R9km-NB with/without a subgrid scale brine rejection parameterization which improves ocean vertical mixing under sea ice. Higher-resolution and new sea-ice processes contributed to lower model errors in sea-ice extent, ice thickness, and ice algae. In the Bering Sea shelf, only higher resolution contributed to lower model errors in salinity, nitrate (NO3), and chlorophyll-a (Chl-a). In the Arctic Basin, model errors in mixed layer depth (MLD) were reduced 36% by brine rejection parameterization, 20% by new sea-ice processes, and 6% by higher resolution. The NO3 concentration biases were caused by both MLD bias and coarse resolution, because of excessive horizontal mixing of high NO3 from the Chukchi Sea into the Canada Basin in coarse resolution models. R9km showed improvements over G1deg on NO3, but not on Chl-a, likely due to light limitation under snow and ice cover in the Arctic Basin.

Interhemispheric Changes in Atlantic Ocean Heat Content and Their Link to Global Monsoons

Science.gov (United States)

Lopez, H.; Lee, S. K.; Dong, S.; Goni, G. J.

2015-12-01

This study tested the hypothesis whether low frequency decadal variability of the South Atlantic meridional heat transport (SAMHT) influences decadal variability of the global monsoons. A multi-century run from a state-of-the-art coupled general circulation model is used as basis for the analysis. Our findings indicate that multi-decadal variability of the South Atlantic Ocean plays a key role in modulating atmospheric circulation via interhemispheric changes in Atlantic Ocean heat content. Weaker SAMHT produces anomalous ocean heat divergence over the South Atlantic resulting in negative ocean heat content anomaly about 15 years later. This, in turn, forces a thermally direct anomalous interhemispheric Hadley circulation in the atmosphere, transporting heat from the northern hemisphere (NH) to the southern hemisphere (SH) and moisture from the SH to the NH, thereby intensify (weaken) summer (winter) monsoon in the NH and winter (summer) monsoon in the SH. Results also show that anomalous atmospheric eddies, both transient and stationary, transport heat northward in both hemispheres producing eddy heat flux convergence (divergence) in the NH (SH) around 15-30°, reinforcing the anomalous Hadley circulation. The effect of eddies on the NH (SH) poleward of 30° is opposite with heat flux divergence (convergence), which must be balanced by sinking (rising) motion, consistent with a poleward (equatorward) displacement of the jet stream and mean storm track. The mechanism described here could easily be interpreted for the case of strong SAMHT, with the reverse influence on the interhemispheric atmospheric circulation and monsoons. Overall, SAMHT decadal variability leads its atmospheric response by about 15 years, suggesting that the South Atlantic is a potential predictor of global climate variability.

Global abundance of planktonic heterotrophic protists in the deep ocean

Science.gov (United States)

Pernice, Massimo C; Forn, Irene; Gomes, Ana; Lara, Elena; Alonso-Sáez, Laura; Arrieta, Jesus M; del Carmen Garcia, Francisca; Hernando-Morales, Victor; MacKenzie, Roy; Mestre, Mireia; Sintes, Eva; Teira, Eva; Valencia, Joaquin; Varela, Marta M; Vaqué, Dolors; Duarte, Carlos M; Gasol, Josep M; Massana, Ramon

2015-01-01

The dark ocean is one of the largest biomes on Earth, with critical roles in organic matter remineralization and global carbon sequestration. Despite its recognized importance, little is known about some key microbial players, such as the community of heterotrophic protists (HP), which are likely the main consumers of prokaryotic biomass. To investigate this microbial component at a global scale, we determined their abundance and biomass in deepwater column samples from the Malaspina 2010 circumnavigation using a combination of epifluorescence microscopy and flow cytometry. HP were ubiquitously found at all depths investigated down to 4000 m. HP abundances decreased with depth, from an average of 72±19 cells ml−1 in mesopelagic waters down to 11±1 cells ml−1 in bathypelagic waters, whereas their total biomass decreased from 280±46 to 50±14 pg C ml−1. The parameters that better explained the variance of HP abundance were depth and prokaryote abundance, and to lesser extent oxygen concentration. The generally good correlation with prokaryotic abundance suggested active grazing of HP on prokaryotes. On a finer scale, the prokaryote:HP abundance ratio varied at a regional scale, and sites with the highest ratios exhibited a larger contribution of fungi molecular signal. Our study is a step forward towards determining the relationship between HP and their environment, unveiling their importance as players in the dark ocean's microbial food web. PMID:25290506

Interpreting the implied meridional oceanic energy transport in AMIP

International Nuclear Information System (INIS)

Randall, D.A.; Gleckler, P.J.

1993-09-01

The Atmospheric Model Intercomparison Project (AMIP) was outlined in Paper No. CLIM VAR 2.3 (entitled open-quote The validation of ocean surface heat fluxes in AMIP') of these proceedings. Preliminary results of AMIP subproject No. 5 were also summarized. In particular, zonally averaged ocean surface heat fluxes resulting from various AMIP simulations were intercompared, and to the extent possible they were validated with uncertainties in observationally-based estimates of surface heat fluxes. The intercomparison is continued in this paper by examining the Oceanic Meridional Energy Transport (OMET) implied by the net surface heat fluxes of the AMIP simulations. As with the surface heat fluxes of the AMIP simulations. As with the surface heat fluxes, the perspective here will be very cursory. The annual mean implied ocean heat transport can be estimated by integrating the zonally averaged net ocean surface heat flux, N sfc , from one pole to the other. In AGCM simulations (and perhaps reality), the global mean N sfc is typically not in exact balance when averaged over one or more years. Because of this, an important assumption must be made about changes in the distribution of energy in the oceans. Otherwise, the integration will yield a non-zero transport at the endpoint of integration (pole) which is not physically realistic. Here the authors will only look at 10-year means of the AMIP runs, and for simplicity they assume that any long term imbalance in the global averaged N sfc will be sequestered (or released) over the global ocean. Tests have demonstrated that the treatment of how the global average energy imbalance is assumed to be distributed is important, especially when the long term imbalances are in excess of 10 W m -2 . However, this has not had a substantial impact on the qualitative features of the implied heat transport of the AMIP simulations examined thus far

Characterizing post-industrial changes in the ocean carbon cycle in an Earth system model

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Katsumi; Tokos, Kathy S.; Chikamoto, Megumi O. (Geology and Geophysics, Univ. of Minnesota, MN (United States)), e-mail: katsumi@umn.edu; Ridgwell, Andy (School of Geographical Sciences, Univ. of Bristol, Bristol (United Kingdom))

2010-10-22

Understanding the oceanic uptake of carbon from the atmosphere is essential for better constraining the global budget, as well as for predicting the air-borne fraction of CO{sub 2} emissions and thus degree of climate change. Gaining this understanding is difficult, because the 'natural' carbon cycle, the part of the global carbon cycle unaltered by CO{sub 2} emissions, also responds to climate change and ocean acidification. Using a global climate model of intermediate complexity, we assess the evolution of the natural carbon cycle over the next few centuries. We find that physical mechanisms, particularly Atlantic meridional overturning circulation and gas solubility, alter the natural carbon cycle the most and lead to a significant reduction in the overall oceanic carbon uptake. Important biological mechanisms include reduced organic carbon export production due to reduced nutrient supply, increased organic carbon production due to higher temperatures and reduced CaCO{sub 3} production due to increased ocean acidification. A large ensemble of model experiments indicates that the most important source of uncertainty in ocean uptake projections in the near term future are the upper ocean vertical diffusivity and gas exchange coefficient. By year 2300, the model's climate sensitivity replaces these two and becomes the dominant factor as global warming continues

Transforming Ocean Observations of the Carbon Budget, Acidification, Hypoxia, Nutrients, and Biological Productivity: a Global Array of Biogeochemical Argo Floats

Science.gov (United States)

Talley, L. D.; Johnson, K. S.; Claustre, H.; Boss, E.; Emerson, S. R.; Westberry, T. K.; Sarmiento, J. L.; Mazloff, M. R.; Riser, S.; Russell, J. L.

2017-12-01

Our ability to detect changes in biogeochemical (BGC) processes in the ocean that may be driven by increasing atmospheric CO2, as well as by natural climate variability, is greatly hindered by undersampling in vast areas of the open ocean. Argo is a major international program that measures ocean heat content and salinity with about 4000 floats distributed throughout the ocean, profiling to 2000 m every 10 days. Extending this approach to a global BGC-Argo float array, using recent, proven sensor technology, and in close synergy with satellite systems, will drive a transformative shift in observing and predicting the effects of climate change on ocean metabolism, carbon uptake, acidification, deoxygenation, and living marine resource management. BGC-Argo will add sensors for pH, oxygen, nitrate, chlorophyll, suspended particles, and downwelling irradiance, with sufficient accuracy for climate studies. Observing System Simulation Experiments (OSSEs) using BGC models indicate that 1000 BGC floats would provide sufficient coverage, hence equipping 1/4 of the Argo array. BGC-Argo (http://biogeochemical-argo.org) will enhance current sustained observational programs such as Argo, GO-SHIP, and long-term ocean time series. BGC-Argo will benefit from deployments on GO-SHIP vessels, which provide sensor verification. Empirically derived algorithms that relate the observed BGC float parameters to the carbon system parameters will provide global information on seasonal ocean-atmosphere carbon exchange. BGC Argo measurements could be paired with other emerging technology, such as pCO2 measurements from ships of opportunity and wave gliders, to extend and validate exchange estimates. BGC-Argo prototype programs already show the potential of a global observing system that can measure seasonal to decadal variability. Various countries have developed regional BGC arrays: Southern Ocean (SOCCOM), North Atlantic Subpolar Gyre (remOcean), Mediterranean (NAOS), the Kuroshio (INBOX

Local Observations, Global Connections: An Educational Program Using Ocean Networks Canada's Community-Based Observatories

Science.gov (United States)

Pelz, M.; Hoeberechts, M.; Ewing, N.; Davidson, E.; Riddell, D. J.

2014-12-01

Schools on Canada's west coast and in the Canadian Arctic are participating in the pilot year of a novel educational program based on analyzing, understanding and sharing ocean data collected by cabled observatories. The core of the program is "local observations, global connections." First, students develop an understanding of ocean conditions at their doorstep through the analysis of community-based observatory data. Then, they connect that knowledge with the health of the global ocean by engaging with students at other schools participating in the educational program and through supplemental educational resources. Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories which supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea. This Internet connectivity permits researchers, students and members of the public to download freely available data on their computers anywhere around the globe, in near real-time. In addition to the large NEPTUNE and VENUS cabled observatories off the coast of Vancouver Island, British Columbia, ONC has been installing smaller, community-based cabled observatories. Currently two are installed: one in Cambridge Bay, Nunavut and one at Brentwood College School, on Mill Bay in Saanich Inlet, BC. Several more community-based observatories are scheduled for installation within the next year. The observatories support a variety of subsea instruments, such as a video camera, hydrophone and water quality monitor and shore-based equipment including a weather station and a video camera. Schools in communities hosting an observatory are invited to participate in the program, alongside schools located in other coastal and inland communities. Students and teachers access educational material and data through a web portal, and use video conferencing and social media tools to communicate their findings. A series of lesson plans

Shedding light on the Global Ocean microbiome with algorithms and data collection

Science.gov (United States)

Lauro, F.; Ostrowski, M.; Chénard, C.; Acerbi, E.; Paulsen, I.; Jensen, R.

2016-02-01

In the Global Oceans, the marine microbiome plays a critical role in biogeochemical cycling of nutrients, but surveying marine microbial communities requires ship time for sample collection, economically constraining the number of samples collected. An integrative understanding of the microbiome's activity and performance requires the collection of high-density data, both temporally and spatially in a cost-effective way. We have overcome this bottleneck by crowdsourcing the data collection to vessels of opportunity, including bluewater sailing yachts. Sailors know the oceans, and experience first-hand the declines in ocean productivity and the effects of pollution and climate change. Moreover, simply the ability to sample a microbial community during anomalous or inclement weather conditions is a major advance in sampling strategy. Our approach inherently incorporates the benefit of outreach and participation of people in scientific research, gaining positive media attention for sailors, scientists and concerned citizens alike. We have tested the basic methods during a 2013 Indian Ocean Concept Cruise, from Cape Town to Singapore, performing experimental work and reaching sampling locations inaccessible to traditional Oceanographic Vessels. At the same time we developed a small, yacht-adapted automated sampling device that takes a variety of biological and chemical measurements. In 2015 our first beta-cruisers sampled the Pacific Ocean in the first ever citizen-oceanography transect at high and low latitudes in both hemispheres. The collected samples were characterized with next-gen sequencing technology and analysed with a combination of novel algorithmic approaches. With big data management, machine learning algorithms and agent-based models we show that it is possible to deconvolute the complexity of the Ocean Microbiome for the scientific management of fisheries, marine protected areas and preservation of the oceans and seas for generations to come.

Climate Change and China as a Global Emerging Regulatory Sea Power in the Arctic Ocean

DEFF Research Database (Denmark)

Cassotta Pertoldi-Bianchi, Sandra; Hossain, Kamrul; Ren, Jingzheng

2015-01-01

The impact of climate change in the Arctic Ocean such as ice melting and ice retreat facilitates natural resources extraction. Arctic fossil fuel becomes the drivers of geopolitical changes in the Arctic Ocean. Climate change facilitates natural resource extractions and increases competition...... on the Law of the Sea (UNCLOS) and the Arctic Council (AC) are taken into consideration under climate change effects, to assess how global legal frameworks and institutions can deal with China’s strategy in the Arctic Ocean. China’s is moving away from its role as “humble power” to one of “informal...... imperialistic” resulting in substantial impact on the Arctic and Antartic dynamism. Due to ice-melting, an easy access to natural resources, China’s Arctic strategy in the Arctic Ocean has reinforced its military martitime strategy and has profoundly changed its maritime military doctrine shifting from regional...

SeaDataNet : Pan-European infrastructure for marine and ocean data management - Project objectives, structure and components

Science.gov (United States)

Maudire, G.; Maillard, C.; Fichaut, M.; Manzella, G.; Schaap, D. M. A.

2009-04-01

SeaDataNet : Pan-European infrastructure for marine and ocean data management Project objectives, structure and components G. Maudire (1), C. Maillard (1), G. Manzella (2), M. Fichaut (1), D.M.A. Schaap (3), E. Iona (4) and the SeaDataNet consortium. (1) IFREMER, Brest, France (Gilbert.Maudire@ifremer.fr), (2) ENEA, La Spezia, Italy, (3) Mariene Informatie Service 'MARIS', Voorburg, The Netherlands, (4) Hellenic Centre for Marine Research-HCMR, Anavyssos, Greece. Since a large part of the earth population lives near the oceans or carries on activities directly or indirectly linked to the seas (fishery and aquaculture, exploitation of sea bottom resources, international shipping, tourism), knowledge of oceans is of primary importance for security and economy. However, observation and monitoring of the oceans remains difficult and expensive even if real improvements have been achieved using research vessels and submersibles, satellites and automatic observatories like buoys, floats and seafloor observatories transmitting directly to the shore using global transmission systems. More than 600 governmental or private organizations are active in observation of seas bordering Europe, but European oceanographic data are fragmented, not always validated and not always easily accessible. That highlights the need of international collaboration to tend toward a comprehensive view of ocean mechanisms, resources and changes. SeaDataNet is an Integrated research Infrastructure Initiative (I3) in European Union Framework Program 6 (2006 - 2011) to provide the data management system adapted both to the fragmented observation systems and to the users need for an integrated access to data, meta-data, products and services. Its major objectives are to: - encourage long-term archiving at national level to secure ocean data taking into account that all the observations made in the variable oceanic environment can never be remade if they are lost; - promote best practices for data

NCEP Global Ocean Data Assimilation System (GODAS)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The GODAS dataset is a real-time ocean analysis and a reanalysis. It is used for monitoring, retrospective analysis as well as for providing oceanic initial...

The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP contribution to CMIP6: investigation of sea-level and ocean climate change in response to CO2 forcing

Directory of Open Access Journals (Sweden)

J. M. Gregory

2016-11-01

Full Text Available The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP aims to investigate the spread in simulations of sea-level and ocean climate change in response to CO2 forcing by atmosphere–ocean general circulation models (AOGCMs. It is particularly motivated by the uncertainties in projections of ocean heat uptake, global-mean sea-level rise due to thermal expansion and the geographical patterns of sea-level change due to ocean density and circulation change. FAFMIP has three tier-1 experiments, in which prescribed surface flux perturbations of momentum, heat and freshwater respectively are applied to the ocean in separate AOGCM simulations. All other conditions are as in the pre-industrial control. The prescribed fields are typical of pattern and magnitude of changes in these fluxes projected by AOGCMs for doubled CO2 concentration. Five groups have tested the experimental design with existing AOGCMs. Their results show diversity in the pattern and magnitude of changes, with some common qualitative features. Heat and water flux perturbation cause the dipole in sea-level change in the North Atlantic, while momentum and heat flux perturbation cause the gradient across the Antarctic Circumpolar Current. The Atlantic meridional overturning circulation (AMOC declines in response to the heat flux perturbation, and there is a strong positive feedback on this effect due to the consequent cooling of sea-surface temperature in the North Atlantic, which enhances the local heat input to the ocean. The momentum and water flux perturbations do not substantially affect the AMOC. Heat is taken up largely as a passive tracer in the Southern Ocean, which is the region of greatest heat input, while the weakening of the AMOC causes redistribution of heat towards lower latitudes. Future analysis of these and other phenomena with the wider range of CMIP6 FAFMIP AOGCMs will benefit from new diagnostics of temperature and salinity tendencies, which will enable

The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) Contribution to CMIP6: Investigation of Sea-Level and Ocean Climate Change in Response to CO2 Forcing

Science.gov (United States)

Gregory, Jonathan M.; Bouttes, Nathaelle; Griffies, Stephen M.; Haak, Helmuth; Hurlin, William J.; Jungclaus, Johann; Kelley, Maxwell; Lee, Warren G.; Marshall, John; Romanou, Anastasia;

High-frequency and meso-scale winter sea-ice variability in the Southern Ocean in a high-resolution global ocean model

Science.gov (United States)

Stössel, Achim; von Storch, Jin-Song; Notz, Dirk; Haak, Helmuth; Gerdes, Rüdiger

2018-03-01

This study is on high-frequency temporal variability (HFV) and meso-scale spatial variability (MSV) of winter sea-ice drift in the Southern Ocean simulated with a global high-resolution (0.1°) sea ice-ocean model. Hourly model output is used to distinguish MSV characteristics via patterns of mean kinetic energy (MKE) and turbulent kinetic energy (TKE) of ice drift, surface currents, and wind stress, and HFV characteristics via time series of raw variables and correlations. We find that (1) along the ice edge, the MSV of ice drift coincides with that of surface currents, in particular such due to ocean eddies; (2) along the coast, the MKE of ice drift is substantially larger than its TKE and coincides with the MKE of wind stress; (3) in the interior of the ice pack, the TKE of ice drift is larger than its MKE, mostly following the TKE pattern of wind stress; (4) the HFV of ice drift is dominated by weather events, and, in the absence of tidal currents, locally and to a much smaller degree by inertial oscillations; (5) along the ice edge, the curl of the ice drift is highly correlated with that of surface currents, mostly reflecting the impact of ocean eddies. Where ocean eddies occur and the ice is relatively thin, ice velocity is characterized by enhanced relative vorticity, largely matching that of surface currents. Along the ice edge, ocean eddies produce distinct ice filaments, the realism of which is largely confirmed by high-resolution satellite passive-microwave data.

Global assimilation of X Project Loon stratospheric balloon observations

Science.gov (United States)

Coy, L.; Schoeberl, M. R.; Pawson, S.; Candido, S.; Carver, R. W.

2017-12-01

Project Loon has an overall goal of providing worldwide internet coverage using a network of long-duration super-pressure balloons. Beginning in 2013, Loon has launched over 1600 balloons from multiple tropical and middle latitude locations. These GPS tracked balloon trajectories provide lower stratospheric wind information over the oceans and remote land areas where traditional radiosonde soundings are sparse, thus providing unique coverage of lower stratospheric winds. To fully investigate these Loon winds we: 1) compare the Loon winds to winds produced by a global data assimilation system (DAS: NASA GEOS) and 2) assimilate the Loon winds into the same comprehensive DAS. Results show that in middle latitudes the Loon winds and DAS winds agree well and assimilating the Loon winds have only a small impact on short-term forecasting of the Loon winds, however, in the tropics the loon winds and DAS winds often disagree substantially (8 m/s or more in magnitude) and in these cases assimilating the loon winds significantly improves the forecast of the loon winds. By highlighting cases where the Loon and DAS winds differ, these results can lead to improved understanding of stratospheric winds, especially in the tropics.

Variational Data Assimilation for the Global Ocean

Science.gov (United States)

2013-01-01

ocean includes the Geoid (a fixed gravity equipotential surface ) as well as the MDT, which is not known accurately enough relative to the centimeter...scales, including processes that control the surface mixed layer, the formation of ocean eddies, meandering ocean J.A. Cummings (E3) nography Division...variables. Examples of this in the ocean are integral quantities, such as acous^B travel time and altimeter measures of sea surface height, and direct

 Project Management as a Global Trend for Organization Work

DEFF Research Database (Denmark)

Kampf, Constance

in multination and global companies, understanding the power of visual rhetoric, genre and writing processes in the context of project management documentation can be an advantage for technical communicators.  In addition, project management tools and online documentation spaces are objects which cross...... Project Management as a Global Trend for Organization Work: Implications for Technical Communication Project Management tools and processes offer a visual approach to producing knowledge about a project in order to complete it.  As project management practices are used with increasing frequency......-cultural teams use to function.  This presentation will explore the potential of Project Management to be tightly integrated in Technical Communication curricula through a communications approach to project management.  Questions for discussion include: How tightly is project management integrated into different...

Sensitivity of sequestration efficiency to mixing processes in the global ocean

International Nuclear Information System (INIS)

Mignone, B.K.

2004-01-01

A number of large-scale sequestration strategies have been considered to help mitigate rising levels of atmospheric carbon dioxide (CO 2 ). Here, we use an ocean general circulation model (OGCM) to evaluate the efficiency of one such strategy currently receiving much attention, the direct injection of liquid CO 2 into selected regions of the abyssal ocean. We find that currents typically transport the injected plumes quite far before they are able to return to the surface and release CO 2 through air-sea gas exchange. When injected at sufficient depth (well within or below the main thermocline), most of the injected CO 2 outgasses in high latitudes (mainly in the Southern Ocean) where vertical exchange is most favored. Virtually all OGCMs that have performed similar simulations confirm these global patterns, but regional differences are significant, leading efficiency estimates to vary widely among models even when identical protocols are followed. In this paper, we make a first attempt at reconciling some of these differences by performing a sensitivity analysis in one OGCM, the Princeton Modular Ocean Model. Using techniques we have developed to maintain both the modeled density structure and the absolute magnitude of the overturning circulation while varying important mixing parameters, we estimate the sensitivity of sequestration efficiency to the magnitude of vertical exchange within the low-latitude pycnocline. Combining these model results with available tracer data permits us to narrow the range of model behavior, which in turn places important constraints on sequestration efficiency. (author)

An isopycnic ocean carbon cycle model

Directory of Open Access Journals (Sweden)

K. M. Assmann

2010-02-01

Full Text Available The carbon cycle is a major forcing component in the global climate system. Modelling studies, aiming to explain recent and past climatic changes and to project future ones, increasingly include the interaction between the physical and biogeochemical systems. Their ocean components are generally z-coordinate models that are conceptually easy to use but that employ a vertical coordinate that is alien to the real ocean structure. Here, we present first results from a newly-developed isopycnic carbon cycle model and demonstrate the viability of using an isopycnic physical component for this purpose. As expected, the model represents well the interior ocean transport of biogeochemical tracers and produces realistic tracer distributions. Difficulties in employing a purely isopycnic coordinate lie mainly in the treatment of the surface boundary layer which is often represented by a bulk mixed layer. The most significant adjustments of the ocean biogeochemistry model HAMOCC, for use with an isopycnic coordinate, were in the representation of upper ocean biological production. We present a series of sensitivity studies exploring the effect of changes in biogeochemical and physical processes on export production and nutrient distribution. Apart from giving us pointers for further model development, they highlight the importance of preformed nutrient distributions in the Southern Ocean for global nutrient distributions. The sensitivity studies show that iron limitation for biological particle production, the treatment of light penetration for biological production, and the role of diapycnal mixing result in significant changes of nutrient distributions and liniting factors of biological production.

Performance and Quality Assessment of the Forthcoming Copernicus Marine Service Global Ocean Monitoring and Forecasting Real-Time System

Science.gov (United States)

Lellouche, J. M.; Le Galloudec, O.; Greiner, E.; Garric, G.; Regnier, C.; Drillet, Y.

2016-02-01

Mercator Ocean currently delivers in real-time daily services (weekly analyses and daily forecast) with a global 1/12° high resolution system. The model component is the NEMO platform driven at the surface by the IFS ECMWF atmospheric analyses and forecasts. Observations are assimilated by means of a reduced-order Kalman filter with a 3D multivariate modal decomposition of the forecast error. It includes an adaptive-error estimate and a localization algorithm. Along track altimeter data, satellite Sea Surface Temperature and in situ temperature and salinity vertical profiles are jointly assimilated to estimate the initial conditions for numerical ocean forecasting. A 3D-Var scheme provides a correction for the slowly-evolving large-scale biases in temperature and salinity.Since May 2015, Mercator Ocean opened the Copernicus Marine Service (CMS) and is in charge of the global ocean analyses and forecast, at eddy resolving resolution. In this context, R&D activities have been conducted at Mercator Ocean these last years in order to improve the real-time 1/12° global system for the next CMS version in 2016. The ocean/sea-ice model and the assimilation scheme benefit among others from the following improvements: large-scale and objective correction of atmospheric quantities with satellite data, new Mean Dynamic Topography taking into account the last version of GOCE geoid, new adaptive tuning of some observational errors, new Quality Control on the assimilated temperature and salinity vertical profiles based on dynamic height criteria, assimilation of satellite sea-ice concentration, new freshwater runoff from ice sheets melting …This presentation doesn't focus on the impact of each update, but rather on the overall behavior of the system integrating all updates. This assessment reports on the products quality improvements, highlighting the level of performance and the reliability of the new system.

The EuroSITES network: Integrating and enhancing fixed-point open ocean observatories around Europe

Science.gov (United States)

Lampitt, Richard S.; Larkin, Kate E.; EuroSITES Consortium

2010-05-01

EuroSITES is a 3 year (2008-2011) EU collaborative project (3.5MEuro) with the objective to integrate and enhance the nine existing open ocean fixed point observatories around Europe (www.eurosites.info). These observatories are primarily composed of full depth moorings and make multidisciplinary in situ observations within the water column as the European contribution to the global array OceanSITES (www.oceansites.org). In the first 18 months, all 9 observatories have been active and integration has been significant through the maintenance and enhancement of observatory hardware. Highlights include the enhancement of observatories with sensors to measure O2, pCO2, chlorophyll, and nitrate in near real-time from the upper 1000 m. In addition, some seafloor missions are also actively supported. These include seafloor platforms currently deployed in the Mediterranean, one for tsunami detection and one to monitor fluid flow related to seismic activity and slope stability. Upcoming seafloor science missions in 2010 include monitoring benthic biological communities and associated biogeochemistry as indicators of climate change in both the Northeast Atlantic and Mediterranean. EuroSITES also promotes the development of innovative sensors and samplers in order to progress capability to measure climate-relevant properties of the ocean. These include further developing current technologies for autonomous long-term monitoring of oxygen consumption in the mesopelagic, pH and mesozooplankton abundance. Many of these science missions are directly related to complementary activities in other European projects such as EPOCA, HYPOX and ESONET. In 2010 a direct collaboration including in situ field work will take place between ESONET and EuroSITES. The demonstration mission MODOO (funded by ESONET) will be implemented in 2010 at the EuroSITES PAP observatory. Field work will include deployment of a seafloor lander system with various sensors which will send data to shore in real

Extended-range prediction trials using the global cloud/cloud-system resolving model NICAM and its new ocean-coupled version NICOCO

Science.gov (United States)

Miyakawa, Tomoki

2017-04-01

The global cloud/cloud-system resolving model NICAM and its new fully-coupled version NICOCO is run on one of the worlds top-tier supercomputers, the K computer. NICOCO couples the full-3D ocean component COCO of the general circulation model MIROC using a general-purpose coupler Jcup. We carried out multiple MJO simulations using NICAM and the new ocean-coupled version NICOCO to examine their extended-range MJO prediction skills and the impact of ocean coupling. NICAM performs excellently in terms of MJO prediction, maintaining a valid skill up to 27 days after the model is initialized (Miyakawa et al 2014). As is the case in most global models, ocean coupling frees the model from being anchored by the observed SST and allows the model climate to drift away further from reality compared to the atmospheric version of the model. Thus, it is important to evaluate the model bias, and in an initial value problem such as the seasonal extended-range prediction, it is essential to be able to distinguish the actual signal from the early transition of the model from the observed state to its own climatology. Since NICAM is a highly resource-demanding model, evaluation and tuning of the model climatology (order of years) is challenging. Here we focus on the initial 100 days to estimate the early drift of the model, and subsequently evaluate MJO prediction skills of NICOCO. Results show that in the initial 100 days, NICOCO forms a La-Nina like SST bias compared to observation, with a warmer Maritime Continent warm pool and a cooler equatorial central Pacific. The enhanced convection over the Maritime Continent associated with this bias project on to the real-time multi-variate MJO indices (RMM, Wheeler and Hendon 2004), and contaminates the MJO skill score. However, the bias does not appear to demolish the MJO signal severely. The model maintains a valid MJO prediction skill up to nearly 4 weeks when evaluated after linearly removing the early drift component estimated from

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of March 2008 for the Global Argo Data Repository, 1979-05-15 to 2008-03-31 (NODC Accession 0040187)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of September 2007 for the Global Argo Data Repository, 1996-01-05 to 2007-09-30 (NODC Accession 0033660)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of August 2006 for the Global Argo Data Repository, 1996-01-05 to 2006-08-31 (NODC Accession 0002818)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of December 2003 for the Global Argo Data Repository, 1996-01-05 to 2003-12-31 (NODC Accession 0001286)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of January 2005 for the Global Argo Data Repository, 1996-01-05 to 2005-01-31 (NODC Accession 0002005)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of August 2007 for the Global Argo Data Repository, 1996-01-05 to 2007-08-31 (NODC Accession 0032684)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of December 2004 for the Global Argo Data Repository, 1996-01-05 to 2004-12-31 (NODC Accession 0001960)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of October 2004 for the Global Argo Data Repository, 1996-01-05 to 2004-10-31 (NODC Accession 0001897)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of April 2005 for the Global Argo Data Repository, 1996-01-05 to 2005-04-30 (NODC Accession 0002163)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of January 2006 for the Global Argo Data Repository, 1996-01-05 to 2006-01-31 (NODC Accession 0002524)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of September 2004 for the Global Argo Data Repository, 1996-01-05 to 2004-09-30 (NODC Accession 0001735)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Temperature and salinity profile data from globally distributed Argo profiling floats for the month of February 2005 for the Global Argo Data Repository, 1996-01-05 to 2005-02-28 (NODC Accession 0002048)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo Project...

Impact of climate change and ocean acidification on the marine nitrogen cycle

International Nuclear Information System (INIS)

Martinez-Rey, Jorge

2015-01-01

The marine nitrogen cycle is responsible for two climate feedbacks in the Earth System. Firstly, it modulates the fixed nitrogen pool available for phytoplankton growth and hence it modulates in part the strength of the biological pump, one of the mechanisms contributing to the oceanic uptake of anthropogenic CO 2 . Secondly, the nitrogen cycle produces a powerful greenhouse gas and ozone (O 3 ) depletion agent called nitrous oxide (N 2 O). Future changes of the nitrogen cycle in response to global warming, ocean deoxygenation and ocean acidification are largely unknown. Processes such as N 2 -fixation, nitrification, denitrification and N 2 O production will experience changes under the simultaneous effect of these three stressors. Global ocean biogeochemical models allow us to study such interactions. Using NEMO-PISCES and the CMIP5 model ensemble we project changes in year 2100 under the business-as-usual high CO 2 emissions scenario in global scale N 2 -fixation rates, nitrification rates, N 2 O production and N 2 O sea-to-air fluxes adding CO 2 sensitive functions into the model parameterizations. Second order effects due to the combination of global warming in tandem with ocean acidification on the fixed nitrogen pool, primary productivity and N 2 O radiative forcing feedbacks are also evaluated in this thesis. (author) [fr

3D Visualization of Global Ocean Circulation

Science.gov (United States)

Nelson, V. G.; Sharma, R.; Zhang, E.; Schmittner, A.; Jenny, B.

2015-12-01

Advanced 3D visualization techniques are seldom used to explore the dynamic behavior of ocean circulation. Streamlines are an effective method for visualization of flow, and they can be designed to clearly show the dynamic behavior of a fluidic system. We employ vector field editing and extraction software to examine the topology of velocity vector fields generated by a 3D global circulation model coupled to a one-layer atmosphere model simulating preindustrial and last glacial maximum (LGM) conditions. This results in a streamline-based visualization along multiple density isosurfaces on which we visualize points of vertical exchange and the distribution of properties such as temperature and biogeochemical tracers. Previous work involving this model examined the change in the energetics driving overturning circulation and mixing between simulations of LGM and preindustrial conditions. This visualization elucidates the relationship between locations of vertical exchange and mixing, as well as demonstrates the effects of circulation and mixing on the distribution of tracers such as carbon isotopes.

Ocean acidification in a geoengineering context

Science.gov (United States)

Williamson, Phillip; Turley, Carol

2012-01-01

Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO2) in the atmosphere. Ocean acidity (H+ concentration) and bicarbonate ion concentrations are increasing, whereas carbonate ion concentrations are decreasing. There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100. Laboratory experiments, observations and projections indicate that such ocean acidification may have ecological and biogeochemical impacts that last for many thousands of years. The future magnitude of such effects will be very closely linked to atmospheric CO2; they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques. However, some ocean-based CDR approaches would (if deployed on a climatically significant scale) re-locate acidification from the upper ocean to the seafloor or elsewhere in the ocean interior. If solar radiation management were to be the main policy response to counteract global warming, ocean acidification would continue to be driven by increases in atmospheric CO2, although with additional temperature-related effects on CO2 and CaCO3 solubility and terrestrial carbon sequestration. PMID:22869801

A global, high-resolution data set of ice sheet topography, cavity geometry, and ocean bathymetry

Science.gov (United States)

Schaffer, Janin; Timmermann, Ralph; Arndt, Jan Erik; Savstrup Kristensen, Steen; Mayer, Christoph; Morlighem, Mathieu; Steinhage, Daniel

2016-10-01

The ocean plays an important role in modulating the mass balance of the polar ice sheets by interacting with the ice shelves in Antarctica and with the marine-terminating outlet glaciers in Greenland. Given that the flux of warm water onto the continental shelf and into the sub-ice cavities is steered by complex bathymetry, a detailed topography data set is an essential ingredient for models that address ice-ocean interaction. We followed the spirit of the global RTopo-1 data set and compiled consistent maps of global ocean bathymetry, upper and lower ice surface topographies, and global surface height on a spherical grid with now 30 arcsec grid spacing. For this new data set, called RTopo-2, we used the General Bathymetric Chart of the Oceans (GEBCO_2014) as the backbone and added the International Bathymetric Chart of the Arctic Ocean version 3 (IBCAOv3) and the International Bathymetric Chart of the Southern Ocean (IBCSO) version 1. While RTopo-1 primarily aimed at a good and consistent representation of the Antarctic ice sheet, ice shelves, and sub-ice cavities, RTopo-2 now also contains ice topographies of the Greenland ice sheet and outlet glaciers. In particular, we aimed at a good representation of the fjord and shelf bathymetry surrounding the Greenland continent. We modified data from earlier gridded products in the areas of Petermann Glacier, Hagen Bræ, and Sermilik Fjord, assuming that sub-ice and fjord bathymetries roughly follow plausible Last Glacial Maximum ice flow patterns. For the continental shelf off Northeast Greenland and the floating ice tongue of Nioghalvfjerdsfjorden Glacier at about 79° N, we incorporated a high-resolution digital bathymetry model considering original multibeam survey data for the region. Radar data for surface topographies of the floating ice tongues of Nioghalvfjerdsfjorden Glacier and Zachariæ Isstrøm have been obtained from the data centres of Technical University of Denmark (DTU), Operation Icebridge (NASA

Globalization And Knowledge Management In Projects

Directory of Open Access Journals (Sweden)

Bubel Dagmara

2015-06-01

Full Text Available Knowledge management is a field of management dealing with the use of knowledge, methods, and tools to effectively coordinate complex and unique projects. In accordance with this definition, project knowledge can be treated as a useful resource of information that allows projects to be implemented in compliance with its objectives: time, costs, and quality of results. Knowledge in the activity of an organization, including in the implementation of projects, has for many years been an area of interest to researchers, who confirmed its key importance for building permanent competitive advantages of companies and enterprises. In project management, this issue takes on a new character, as it is transferred to the field of dynamic, time restricted, temporary, and team-implemented projects. The aim of this paper is to present the results of a survey regarding the use of practices of knowledge management in projects in international organizations and to show that the concept of knowledge management in projects is a tool conducive to spreading the process of globalization.