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Title: Secular Trends and Climate Drift in Coupled Ocean-Atmosphere General Circulation Models

Secular Trends and Climate Drift in Coupled Ocean-Atmosphere General Circulation Models Coupled ocean-atmosphere general circulation models (coupled GCMs) with interactive sea ice are the primary tool for investigating possible future global warming and numerous other issues in climate science. A long-standing problem with such models is that when different components of the physical climate system are linked together, the simulated climate can drift away from observations unless constrained by ad hoc adjustments to interface fluxes. However, eleven modern coupled GCMs--including three that do not employ flux adjustments--behave much better in this respect than the older generation of models. Surface temperature trends in control run simulations (with external climate forcing such as solar brightness and atmospheric carbon dioxide held constant) are small compared with observed trends, which include 20th century climate change due to both anthropogenic and natural factors. Sea ice changes in the models are dominated by interannual variations. Deep ocean temperature and salinity trends are small enough for model control runs to extend over 1000 simulated years or more, but trends in some regions, most notably the Arctic, are inconsistent among the models and may be problematic.
Authors: ; ; ;
Publication Date:
OSTI Identifier:883745
Report Number(s):UCRL-JRNL-208282
Journal ID: ISSN 0148-0227; JGREA2; TRN: US200615%%207
DOE Contract Number:W-7405-ENG-48
Resource Type:Journal Article
Data Type:
Resource Relation:Journal Name: Journal of Geophysical Research; Journal Volume: 111
Research Org:Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Org:USDOE
Country of Publication:United States
Language:English
Subject: 54 ENVIRONMENTAL SCIENCES; 58 GEOSCIENCES; BRIGHTNESS; CARBON DIOXIDE; CLIMATES; GENERAL CIRCULATION MODELS; GREENHOUSE EFFECT; SALINITY; SEAS