A Destabilizing Thermohaline Circulation–Atmosphere–Sea Ice
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Fronts in the World Ocean's Large Marine Ecosystems. ICES CM 2007
- 1 - This paper can be freely cited without prior reference to the authors International Council ICES CM 2007/D:21 for the Exploration Theme Session D: Comparative Marine Ecosystem of the Sea (ICES) Structure and Function: Descriptors and Characteristics Fronts in the World Ocean’s Large Marine Ecosystems Igor M. Belkin and Peter C. Cornillon Abstract. Oceanic fronts shape marine ecosystems; therefore front mapping and characterization is one of the most important aspects of physical oceanography. Here we report on the first effort to map and describe all major fronts in the World Ocean’s Large Marine Ecosystems (LMEs). Apart from a geographical review, these fronts are classified according to their origin and physical mechanisms that maintain them. This first-ever zero-order pattern of the LME fronts is based on a unique global frontal data base assembled at the University of Rhode Island. Thermal fronts were automatically derived from 12 years (1985-1996) of twice-daily satellite 9-km resolution global AVHRR SST fields with the Cayula-Cornillon front detection algorithm. These frontal maps serve as guidance in using hydrographic data to explore subsurface thermohaline fronts, whose surface thermal signatures have been mapped from space. Our most recent study of chlorophyll fronts in the Northwest Atlantic from high-resolution 1-km data (Belkin and O’Reilly, 2007) revealed a close spatial association between chlorophyll fronts and SST fronts, suggesting causative links between these two types of fronts. Keywords: Fronts; Large Marine Ecosystems; World Ocean; sea surface temperature. Igor M. Belkin: Graduate School of Oceanography, University of Rhode Island, 215 South Ferry Road, Narragansett, Rhode Island 02882, USA [tel.: +1 401 874 6533, fax: +1 874 6728, email: [email protected]]. -
Tropical Climate
UGAMP: A network of excellence in climate modelling and research Issue 27 October 2003 UGAMP Coordinator: Prof. Julia Slingo [email protected] Newsletter Editor: Dr. Glenn Carver [email protected] Newsletter website: acmsu.nerc.ac.uk/newsletter.html Contents NCAS News . 2 NCAS Websites . 3 NCAS Centres and Facilities . 3 UGAMP Coordinator . 4 CGAM Director . 4 ACMSU Director . 4 HPC Facilities . 5 New areas of UGAMP science 7 Chemistry-climate interactions . 19 Climate variability and predictability . 32 Atmospheric Composition . 48 Tropospheric chemistry and aerosols . 58 Climate Dynamics . 64 Model development . 72 Group News . 78 (for full contents see listing on the inside back cover) NERC Centres for Atmospheric Science, NCAS Alan Thorpe ([email protected]): Director NCAS Since the last UGAMP Newsletter there have been a significant number of NCAS developments relevant to the UK atmospheric science community. These include the following, which are particularly pertinent to the UGAMP community: • NERC have agreed to fund a new directed (new name for thematic) programme called “Surface Ocean – Lower Atmosphere Study” or SOLAS for short. • NERC have agreed to fund a “pump-priming” activity for a proposed new directed programme called Flood Risk from Extreme Events, FREE. The full proposal for FREE will be considered by NERC early in 2004. •NCAS is supporting a project to develop a new chemistry module for the HadGEM model. This is called UK-CHEM and Olaf Morgenstern at ACMSU is collaborating closely with the Hadley Centre on the project. •NCAS is supporting a project to develop the science for a new aerosol module for HadGEM. -
Results from the Implementation of the Elastic Viscous Plastic Sea Ice Rheology in Hadcm3 W
Results from the implementation of the Elastic Viscous Plastic sea ice rheology in HadCM3 W. M. Connolley, A. B. Keen, A. J. Mclaren To cite this version: W. M. Connolley, A. B. Keen, A. J. Mclaren. Results from the implementation of the Elastic Viscous Plastic sea ice rheology in HadCM3. Ocean Science, European Geosciences Union, 2006, 2 (2), pp.201- 211. hal-00298295 HAL Id: hal-00298295 https://hal.archives-ouvertes.fr/hal-00298295 Submitted on 23 Oct 2006 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Ocean Sci., 2, 201–211, 2006 www.ocean-sci.net/2/201/2006/ Ocean Science © Author(s) 2006. This work is licensed under a Creative Commons License. Results from the implementation of the Elastic Viscous Plastic sea ice rheology in HadCM3 W. M. Connolley1, A. B. Keen2, and A. J. McLaren2 1British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK 2Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK Received: 13 June 2006 – Published in Ocean Sci. Discuss.: 10 July 2006 Revised: 21 September 2006 – Accepted: 16 October 2006 – Published: 23 October 2006 Abstract. We present results of an implementation of the a full dynamical model incorporating wind stresses and in- Elastic Viscous Plastic (EVP) sea ice dynamics scheme into ternal ice stresses leads to errors in the detailed representa- the Hadley Centre coupled ocean-atmosphere climate model tion of sea ice and limits our confidence in its future predic- HadCM3. -
3. CICE-Mixed Layer Model 4. Mixed Layer/ Sea Ice Results 5. Surface
The ocean mixed layer, buoyancy fluxes, and sea ice over the Antarctic continental shelf Alek Petty1, Daniel Feltham2 & Paul Holland3 1. Centre for Polar Observation and Modelling, Department of Earth Sciences, UCL, London, WC1E6BT 2. Centre for Polar Observation and Modelling, Department of Meteorology, Reading University, Reading, RG6 6BB 2. British Antarctic Survey, High Cross, Cambridge, CB3 0ET A sea ice-mixed layer model has been used to investigate regional variations in the surface-driven formation of Antarctic shelf sea waters. The model captures well the expected sea ice thickness distribution, and produces deep mixed layers in the Weddell and Ross shelf seas each winter (1985-2011). By deconstructing the surface power input to the mixed layer, we have shown that the salt/fresh water flux from sea ice growth/melt dominates the evolution of the mixed layer in all shelf sea regions, with a smaller contribution from the mixed layer-surface heat flux. An analysis of the sea ice mass balance has demonstrated the contrasting mean ice growth, melt and export in each region. The Weddell and Ross shelf seas expereince the highest annual ice growth, with a large fraction of this ice exported northwards each year, whereas the Bellingshausen shelf sea experiences the highest annual ice melt, despite the low annual ice growth. Cur- rent work (not shown) is focussed on atmospheric forcing trends and the resultant trends in the sea ice and mixed layer evolution using both ERA-I hindcast forcing and hadGEM2 future climate projections. 1. Introduction The continental shelf seas surround- ing Antarctica are a crucial compo- nent of the Earth’s climate system, with the Weddell and Ross (WR) shelf seas cooling and ventilating the deep ocean and feeding the global thermohaline circulation, whereas the warm waters in the Amundsen and Bellingshausen (AB) shelf seas (see Figure 1) are implicit in the recent ocean-driven melting of the Antarctic ice sheet. -
Glacial Ocean Circulation and Stratification Explained by Reduced
Glacial ocean circulation and stratification explained by reduced atmospheric temperature Malte F. Jansena,1 aDepartment of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637 Edited by Mark H. Thiemens, University of California, San Diego, La Jolla, CA, and approved November 7, 2016 (received for review June 27, 2016) Earth’s climate has undergone dramatic shifts between glacial and We test the connection between atmospheric temperature interglacial time periods, with high-latitude temperature changes and ocean circulation and stratification changes, using idealized on the order of 5–10 ◦C. These climatic shifts have been asso- numerical simulations, which allow us to isolate the proposed ciated with major rearrangements in the deep ocean circulation mechanism. We use a coupled ocean–sea-ice model, with atmo- and stratification, which have likely played an important role in spheric temperature, winds, and evaporation–precipitation pre- the observed atmospheric carbon dioxide swings by affecting the scribed as boundary conditions (Materials and Methods). The partitioning of carbon between the atmosphere and the ocean. model uses an idealized continental configuration resembling the The mechanisms by which the deep ocean circulation changed, Atlantic and Southern Oceans, where the most elemental circu- however, are still unclear and represent a major challenge to our lation changes have been inferred (3, 5, 6, 12). understanding of glacial climates. This study shows that vari- ous inferred changes in the deep ocean circulation and stratifica- Results tion between glacial and interglacial climates can be interpreted We first focus on the model’s ability to reproduce key features as a direct consequence of atmospheric temperature differences. -
Ice Production in Ross Ice Shelf Polynyas During 2017–2018 from Sentinel–1 SAR Images
remote sensing Article Ice Production in Ross Ice Shelf Polynyas during 2017–2018 from Sentinel–1 SAR Images Liyun Dai 1,2, Hongjie Xie 2,3,* , Stephen F. Ackley 2,3 and Alberto M. Mestas-Nuñez 2,3 1 Key Laboratory of Remote Sensing of Gansu Province, Heihe Remote Sensing Experimental Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; [email protected] 2 Laboratory for Remote Sensing and Geoinformatics, Department of Geological Sciences, University of Texas at San Antonio, San Antonio, TX 78249, USA; [email protected] (S.F.A.); [email protected] (A.M.M.-N.) 3 Center for Advanced Measurements in Extreme Environments, University of Texas at San Antonio, San Antonio, TX 78249, USA * Correspondence: [email protected]; Tel.: +1-210-4585445 Received: 21 April 2020; Accepted: 5 May 2020; Published: 7 May 2020 Abstract: High sea ice production (SIP) generates high-salinity water, thus, influencing the global thermohaline circulation. Estimation from passive microwave data and heat flux models have indicated that the Ross Ice Shelf polynya (RISP) may be the highest SIP region in the Southern Oceans. However, the coarse spatial resolution of passive microwave data limited the accuracy of these estimates. The Sentinel-1 Synthetic Aperture Radar dataset with high spatial and temporal resolution provides an unprecedented opportunity to more accurately distinguish both polynya area/extent and occurrence. In this study, the SIPs of RISP and McMurdo Sound polynya (MSP) from 1 March–30 November 2017 and 2018 are calculated based on Sentinel-1 SAR data (for area/extent) and AMSR2 data (for ice thickness). -
Antarctic Sea Ice Control on Ocean Circulation in Present and Glacial Climates
Antarctic sea ice control on ocean circulation in present and glacial climates Raffaele Ferraria,1, Malte F. Jansenb, Jess F. Adkinsc, Andrea Burkec, Andrew L. Stewartc, and Andrew F. Thompsonc aDepartment of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139; bAtmospheric and Oceanic Sciences Program, Geophysical Fluid Dynamics Laboratory, Princeton, NJ 08544; and cDivision of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 Edited* by Edward A. Boyle, Massachusetts Institute of Technology, Cambridge, MA, and approved April 16, 2014 (received for review December 31, 2013) In the modern climate, the ocean below 2 km is mainly filled by waters possibly associated with an equatorward shift of the Southern sinking into the abyss around Antarctica and in the North Atlantic. Hemisphere westerlies (11–13), (ii) an increase in abyssal stratifi- Paleoproxies indicate that waters of North Atlantic origin were instead cation acting as a lid to deep carbon (14), (iii)anexpansionofseaice absent below 2 km at the Last Glacial Maximum, resulting in an that reduced the CO2 outgassing over the Southern Ocean (15), and expansion of the volume occupied by Antarctic origin waters. In this (iv) a reduction in the mixing between waters of Antarctic and Arctic study we show that this rearrangement of deep water masses is origin, which is a major leak of abyssal carbon in the modern climate dynamically linked to the expansion of summer sea ice around (16). Current understanding is that some combination of all of these Antarctica. A simple theory further suggests that these deep waters feedbacks, together with a reorganization of the biological and only came to the surface under sea ice, which insulated them from carbonate pumps, is required to explain the observed glacial drop in atmospheric forcing, and were weakly mixed with overlying waters, atmospheric CO2 (17). -
Test Plan: CICE Sea Ice Model for NGGPS
Test Plan: CICE Sea Ice Model for NGGPS Final 16 March 2016 POC: Shan Sun – NOAA ESRL/GSD/GMTB – [email protected] Introduction After reviewing several sea ice models at the Sea Ice Workshop organized by Global Modeling Test Bed (GMTB) in February 2016, the committee has selected the Los Alamos Community Ice CodE (CICE) as the sea ice model to be incorporated as a component of Next-Generation Global Prediction System (NGGPS). The GMTB is proposing to carry out testing and evaluations with this model in two phases as the next step. Testing framework Hebert et al. (2015) showed that the Arctic Cap Nowcast/Forecast System (ACNFS) demonstrated a high level of skill compared to persistence in 1-7 day forecasts over a period of one year. ACNFS uses CICE version 4.0 [Hunke and Lipscomb, 2008] as the sea ice model two-way coupled to the HYbrid Coordinate Ocean Model (HYCOM) [Bleck, 2002; Metzger et al., 2014, 2015]. Building on this study, we propose to base the test on a similar configuration. In order to make the test most relevant for NGGPS, there will be three important differences with respect to the Herbert et al. (2015) configuration. First, CICE will be upgraded to its latest version v5, [in which both the code structure and the state variables are similar to v4. The CICE5 code does include a number of new physics options such as the mushy-layer thermodynamics and two new melt pond parameterizations.] V5.1.2 is available at http://oceans11.lanl.gov/svn/CICE/tags/release-5.1.2. -
A New Dynamical Downscaling Approach with GCM Bias
PUBLICATIONS Journal of Geophysical Research: Atmospheres RESEARCH ARTICLE A new dynamical downscaling approach with GCM 10.1002/2014JD022958 bias corrections and spectral nudging Key Points: Zhongfeng Xu1 and Zong-Liang Yang2,3 • Both GCM and RCM biases should be constrained in regional climate 1RCE-TEA and Young Scientist Laboratory, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China, projection 2 3 • The NDD approach significantly RCE-TEA, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China, Department of Geological improves the downscaled climate Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA • NDD is designed for regional climate projection at various time scales Abstract To improve confidence in regional projections of future climate, a new dynamical downscaling Supporting Information: (NDD) approach with both general circulation model (GCM) bias corrections and spectral nudging is developed • Figures S1–S4 and assessed over North America. GCM biases are corrected by adjusting GCM climatological means and • Figure S1 variances based on reanalysis data before the GCM output is used to drive a regional climate model (RCM). • Figure S2 • Figure S3 Spectral nudging is also applied to constrain RCM-based biases. Three sets of RCM experiments are integrated • Figure S4 over a 31 year period. In the first set of experiments, the model configurations are identical except that the initial and lateral boundary conditions are derived from either the original GCM output, the bias-corrected GCM output, Correspondence to: orthereanalysisdata.Thesecondset of experiments is the same as the first set except spectral nudging is applied. Z.-L. Yang, [email protected] The third set of experiments includes two sensitivity runs with both GCM bias corrections and nudging where the nudging strength is progressively reduced. -
Assimila Blank
NERC NERC Strategy for Earth System Modelling: Technical Support Audit Report Version 1.1 December 2009 Contact Details Dr Zofia Stott Assimila Ltd 1 Earley Gate The University of Reading Reading, RG6 6AT Tel: +44 (0)118 966 0554 Mobile: +44 (0)7932 565822 email: [email protected] NERC STRATEGY FOR ESM – AUDIT REPORT VERSION1.1, DECEMBER 2009 Contents 1. BACKGROUND ....................................................................................................................... 4 1.1 Introduction .............................................................................................................. 4 1.2 Context .................................................................................................................... 4 1.3 Scope of the ESM audit ............................................................................................ 4 1.4 Methodology ............................................................................................................ 5 2. Scene setting ........................................................................................................................... 7 2.1 NERC Strategy......................................................................................................... 7 2.2 Definition of Earth system modelling ........................................................................ 8 2.3 Broad categories of activities supported by NERC ................................................. 10 2.4 Structure of the report ........................................................................................... -
Review of the Global Models Used Within Phase 1 of the Chemistry–Climate Model Initiative (CCMI)
Geosci. Model Dev., 10, 639–671, 2017 www.geosci-model-dev.net/10/639/2017/ doi:10.5194/gmd-10-639-2017 © Author(s) 2017. CC Attribution 3.0 License. Review of the global models used within phase 1 of the Chemistry–Climate Model Initiative (CCMI) Olaf Morgenstern1, Michaela I. Hegglin2, Eugene Rozanov18,5, Fiona M. O’Connor14, N. Luke Abraham17,20, Hideharu Akiyoshi8, Alexander T. Archibald17,20, Slimane Bekki21, Neal Butchart14, Martyn P. Chipperfield16, Makoto Deushi15, Sandip S. Dhomse16, Rolando R. Garcia7, Steven C. Hardiman14, Larry W. Horowitz13, Patrick Jöckel10, Beatrice Josse9, Douglas Kinnison7, Meiyun Lin13,23, Eva Mancini3, Michael E. Manyin12,22, Marion Marchand21, Virginie Marécal9, Martine Michou9, Luke D. Oman12, Giovanni Pitari3, David A. Plummer4, Laura E. Revell5,6, David Saint-Martin9, Robyn Schofield11, Andrea Stenke5, Kane Stone11,a, Kengo Sudo19, Taichu Y. Tanaka15, Simone Tilmes7, Yousuke Yamashita8,b, Kohei Yoshida15, and Guang Zeng1 1National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand 2Department of Meteorology, University of Reading, Reading, UK 3Department of Physical and Chemical Sciences, Universitá dell’Aquila, L’Aquila, Italy 4Environment and Climate Change Canada, Montréal, Canada 5Institute for Atmospheric and Climate Science, ETH Zürich (ETHZ), Zürich, Switzerland 6Bodeker Scientific, Christchurch, New Zealand 7National Center for Atmospheric Research (NCAR), Boulder, Colorado, USA 8National Institute of Environmental Studies (NIES), Tsukuba, Japan 9CNRM UMR 3589, Météo-France/CNRS, -
DESALINATION: Balancing the Socioeconomic Benefits and Environmental Costs
DESALINATION: Balancing the Socioeconomic Benefits and Environmental Costs www.research.natixis.com https://gsh.cib.natixis.com executive summary Chapter 1 Making sense of desalination: technological, financial and economic aspects of desalination assets Chapter 2 Sustainability assessment of desalination assets: recognizing the socioeconomic benefits and mitigating environmental costs of desalination Chapter 3 Desalination sustainability performance scorecard acknowledgements appendix biblioghraphy TABLE OF CONTENTS OF TABLE 1. Making sense of desalination: technological, financial and economic aspects of desalination assets 1. DESALINATION TECHNOLOGIES 2. FINANCIAL AND ECONOMIC ASPECTS OF DESALINATION ASSETS 1.1. AN OVERVIEW OF DESALINATION TECHNOLOGIES 2.1.THE DEVELOPMENT AND FINANCING OF DESALINATION ASSETS Thermal desalination: Multistage Flash Distillation and Multieffect Distillation Building and operating desalination assets: complex and evolving value chain Membrane desalination: Reverse Osmosis Project development models: fine-tuning Hybridization of thermal and the appropriate risk-sharing model membrane desalination Bringing capital to desalination assets: A set of parameters to assess the performance an increasingly strategic issue and efficiency of desalination assets Case study of desalination in Israel: innovative 1.2. A BRIEF HISTORY AND financing schemes achieving some of the GEOGRAPHICAL DISTRIBUTION OF lowest desalinated water costs worldwide DESALINATION TECHNOLOGIES Case study of desalination in Singapore: The market