简介:用32,CMIP5(联合模型Intercomparison工程阶段5)当模特儿,这研究在为1850-2005的观察外部放射的强迫驾驶的历史的跑在云数量和他们的放射的效果(CRE)的模拟检验诚实,并且他们的未来在4.5情形竞选的RCP(代表性的集中小径)改变2006-2100。为历史的跑的确认度量标准被设计为climatological在空间模式的表示检验精确性吝啬、年度并且云和CRE的interannual变化。模型在云数量的模拟显示出大传播,明确地在低云总计。大规模环境也是的在云数量并且控制之间的观察关系由各种各样的模型不同地复制了。基于作为四个模型的最好的模型,和一般水准选择的确认度量标准,四modelsACCESS1.0,ACCESS1.3,HadGEM2-CC,和HadGEM2-ESare比multimodel整体一般水准更熟练地表现。模型投射全球平均数的SST在温室气体的增加温暖的所有,而是大小越过在1和2K之间的模拟变化,它对在云数量和分发的变化的差别大部分可归因。模仿温暖的更多的SST的模型由于减少的低云和增加的到来的短波放射在网CRE显示出更大的增加,特别地在在画热带的海洋的边界层的区域上。选择最好执行的模型在大约0.99%K1的全球平均数的云数量投射重要减小并且捕捞建议积极反馈的一个角色到全球温暖的0.46Wm2K1,的放射的温暖。
简介:Thetemperaturebiasesof28CMIP5AGCMsareevaluatedovertheTibetanPlateau(TP)fortheperiod1979–2005.TheresultsdemonstratethatthemajorityofCMIP5modelsunderestimateannualandseasonalmeansurface2-mairtemperatures(Tas)overtheTP.Inaddition,theensembleofthe28AGCMsandhalfoftheindividualmodelsunderestimateannualmeanskintemperatures(Ts)overtheTP.ThecoldbiasesarelargerinTasthaninTs,andarelargeroverthewesternTP.BydecomposingtheTsbiasusingthesurfaceenergybudgetequation,weinvestigatethecontributionstothecoldsurfacetemperaturebiasontheTPfromvariousfactors,includingthesurfacealbedo-inducedbias,surfacecloudradiativeforcing,clear-skyshortwaveradiation,clear-skydownwardlongwaveradiation,surfacesensibleheatflux,latentheatflux,andheatstorage.Theresultsshowasuiteofphysicallyinterlinkedprocessescontributingtothecoldsurfacetemperaturebias.Strongnegativesurfacealbedo-inducedbiasassociatedwithexcessivesnowcoverandthesurfaceheatfluxesarehighlyanticorrelated,andthecancellingoutofthesetwotermsleadstoarelativelyweakcontributiontothecoldbias.Smallersurfaceturbulentfluxesleadtocolderlower-tropospherictemperatureandlowerwatervaporcontent,whichinturncausenegativeclear-skydownwardlongwaveradiationandcoldbias.Theresultssuggestthatimprovementsintheparameterizationoftheareaofsnowcover,aswellastheboundarylayer,andhencesurfaceturbulentfluxes,mayhelptoreducethecoldbiasovertheTPinthemodels.