American Meteorological Society;Boston, MA: American Meteorological Society
摘要:
摘要： Reducing climate drift in coupled atmosphere–ocean general circulation models (AOGCMs) usually requires 1000–2000 years of spinup, which has not been practical for every modeling group to do. For the purpose of evaluating the impact of climate drift, the authors have performed a multimillennium-long control run of the Goddard Institute for Space Studies model (GISS-EH) AOGCM and produced different twentieth-century historical simulations and subsequent twenty-first-century projections by branching off the control run at various stages of equilibration. The control run for this model is considered at quasi equilibration after a 1200-yr spinup from a cold start. The simulations that branched off different points after 1200 years are robust, in the sense that their ensemble means all produce the same future projection of warming, both in the global mean and in spatial detail. These robust projections differ from the one that was originally submitted to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4), which branched off a not-yet-equilibrated control run. The authors test various common postprocessing schemes in removing climate drift caused by a not-yet-equilibrated ocean initial state and find them to be ineffective, judging by the fact that they differ from each other and from the robust results that branched off an equilibrated control. The authors' results suggest that robust twenty-first-century projections of the forced response can be achieved by running climate simulations from an equilibrated ocean state, because memory of the different initial ocean state is lost in about 40 years if the forced run is started from a quasi-equilibrated state. 出版者： Boston, MA: American Meteorological Society 出版日期： 2013-10-01 出處： Journal of the atmospheric sciences, 2013-10, Vol.70 (10), p.3321-3327 資源來源： EBSCOhost OmniFile Full Text Select 版權： 2014 INIST-CNRS 版權： Copyright American Meteorological Society Oct 2013 版權： Copyright American Meteorological Society 2013 識別號： ISSN: 0022-4928 識別號： EISSN: 1520-0469 識別號： DOI: 10.1175/JAS-D-13-0149.1 識別號： CODEN: JAHSAK
