气溶胶-云-降水-辐射相互作用-中文v02

北极地区气溶胶-云-辐射相互作用赵传峰北京师范大学2017年11月14日@国防科技大学Aerosol,cloudsandtheirinteractionplaycrucialrolestobothenergybalanceandhydrologicalcycle,andthusclimatechangeEnergyBalanceHydrologicalCycleMotivation[Wildetal.2012,ClimateDynamics]NASAArcticGlobalAverageMotivationTheArcticiswarmingatadoublerateofglobalmeaninrecentcentury,cuasingsignificantimpactstosociety.ForArcticfastwarming,doaerosolsfrommid-latitudesplayacontributingrole?[Smithetal.2015,NatureClimateChange]30%reductionoficecoverageintheArctic1.云微观特征多个云微观特征产品的比对分析[Zhaoetal.2012,JGR]各个云产品之间有着非常显著的差异云反演不确定性的量化/云产品评估[Zhaoetal.2014,JGR]集合扰动方法MICROBASE发现：云水含量误差主要源于观测数据误差；云水有效半径误差主要源于所用假设；云冰特征误差主要源于所用经验公式参数。ThinStratusCloudRetrievalAlgorithmΔε:ε1-ε2re:effectiveradiusτ:geometricopticaldepthN:particleconcentrationLWP:liquidwaterpathMeasuredspectralradiationinatmosphericwindowandozonebandII(ע)SubtractionofprecipitationeffectsfromI(ע)temperature(T)andO3profileε:IandcloudbaseTt:LBLRTM(O3,Tprofile)andIPhasedeterminationModel(DISORT)calculatedLook-uptable(εandt)re:1.0to25;step0.1(μm)τ:0to8;step0.02Inter-comparisonMin{[ε1,Δε,t]measure–[ε1,Δε,t]calculation}Cloudproperties(re,τ)(re,τ,N,LWP)ZhaoandGarrett,AMS,2006GarrettandZhao,AMT,2013CO2Strat.O3Atmos.windowCloudMicrowindowsRetrievalbands云的微观特征：基于AERI的薄云特征反演方法用臭氧波段云传输系数代替太阳短波波段云传输系数，反演方法不再依赖于太阳，可以昼夜连续测量云特性。[GarrettandZhao2013,AMT]臭氧波段太阳短波波数臭氧波段传输系数与飞机观测比对分析Myretrievalsarecomparabbletosolar-basedretrievalsbyDongandMace2003(DongandMace2003)与基于太阳辐射反演方法比对分析2.北极云微观特征对气溶胶的高敏感性Theincreasingamountofaerosolscouldresultinmorecloudcondensationnuclei,moreclouddroplets,smallerclouddropleteffectiveradius,andhighercloudabldeo(Twomeyeffect);alsolongerlifetime;...气溶胶-云相互作用结构图IPCC2007气溶胶对云微观结构的影响-北极云微观特征对气溶胶的强敏感性[Garrett,Zhaoetal.2004,GRL]spspedNdNEdrdIElnlnlnln3/1Nre0.13-0.19气溶胶对云微观结构的影响-气溶胶影响N:(CAM5)FIE:0.07-0.14AerosolLightScattering(Obs)0.11-0.19CCN:(CAM5)FIE:0.10-0.25[Zhaoetal.2012][Zhao,etal.2012，GRL]3.气溶胶-云相互作用的间接辐射效应[Evenmore(0.5-0.6inwinter)foundbyicestation(WalshandChapman1998]0.060.040.020.001/821/841/861/881/901/921/941/961/981/001/021/040.040.030.020.010.001/981/991/001/011/021/031/040.40.30.20.10.01.00.80.60.40.20.0AlertBarrowNO3-,ugNm-3SO4=,ugSm-3北极Haze[Quinnetal.2007]红外云辐射对云水含量和云滴有效半径的敏感性[Garrettetal.2002]气溶胶第一间接辐射效应气溶胶增多-云滴数目增多、云滴有效半径减小(第一间接作用)-云长波辐射系数增加-北极气候变暖[GarrettandZhao,2006,Nature]气溶胶第一间接辐射效应LWPrange(gm-2)Δε5-100.0510-200.0620-400.08Range0.05-0.08北极冬春季节，气溶胶污染会通过改变云特征导致辐射增加3-5W/m2或地面增温2-3K（用云量50%权重平均，地面增温1-1.6K），增温效应堪比温室气体。[GarrettandZhao,2006,Nature](EqualContributionfromBothAuthors)北极层云主导多数云量Fullresolutionimage(30mx300m)600m薄云云量和长波辐射系数云-辐射反馈NominallycleanNominallypollutedLESSimulationsIndicateFasterDevelopmentofArcticStratusCloudswithSmallre[Garrettetal.2011]气溶胶间接气候效应的季节分布规律净辐射效应夏季冷却，其余季节增暖；冬春的强增暖效应促进了冰雪融化，后续反馈进一步使气候增暖。[Zhaoetal.2015,GRL]2000-2003增暖效应冷却效应温度季节分布在清洁和污染情况下的差异统计上来说，干净和污染情景下云底温度没有显著性差别4.云降水对气溶胶的冲刷作用气溶胶浓度的影响因子气溶胶浓度：-源项(HeintzenbergandLarssen,1983,RaatzandShaw,1984,Stohl2006)决定于中纬度气溶胶传输的北极的传输效率和中纬度的污染排放量。-汇项(Shaw,1995)dtdlndwmLPr/-Mixing（混合项）：夏季混合效率仅有冬季的一半(Stohl,2006)-Drydeposition（干沉降）：由于地面缺乏植被，北极干沉降非常缓慢-Wetdeposition（湿沉降）：降水存在时，湿沉降是最有效的去除机制Barrow站点观测表明日均降水量为1mm(ZhaoandGarrett,2008),可溶性气溶胶在北极夏天被雨水完全冲刷的典型时间大约为1小时SummerFall气溶胶冲刷与长距离传输的相对贡献[Garrettetal.,2010,TellusB]SummaryCloudpropertiesgenerallyhavelargeuncertainties,moreaccuratecloudretrievalalgorithmisnecessary.Anoptimalretrievalalgorithmwhichcanobtaincloudpropertiesdayandnightwasdeveloped.TheseasonaldistributionofArcitcaerosolisassociatedwiththeimpactsoflong-rangetransportefficiencyfrommid-latitudesandprecipitationscavengingefficiency.ThesensitivityofcloudstoaerosolsislargeintheArctic.Aerosolfirstindirecteffectplayastrongwarmingeffect(3-5W/m2)intheArcticinwinterandspring；Forthewholeaerosolwarmingeffect(8-10W/m2)inwinterandspring,~60%causedbyFIE,~40%byotherfeedbacks.谢谢各位聆听！敬请批评指正！