利用云与地球辐射能量系统CERES(clouds and the earth’s radiant energy system)资料,对2003-2016年东亚不同区域单层低云物理属性及地面短波辐射强迫的季节时空分布特征进行研究。结果表明:①在空间分布上,辐射强迫与单层低云量在春...利用云与地球辐射能量系统CERES(clouds and the earth’s radiant energy system)资料,对2003-2016年东亚不同区域单层低云物理属性及地面短波辐射强迫的季节时空分布特征进行研究。结果表明:①在空间分布上,辐射强迫与单层低云量在春秋两季有着较好的相似性,而与冰/液态水柱含量在春、夏、秋三个季节有着较好的一致性。②在时间变化上,北方地区夏季的单层低云对短波辐射的削弱作用是最强的;南方地区和西北地区最强的削弱作用发生在春季;东部海域则发生在冬季。在空间分布上,春、秋、冬季最强的低云削弱效应在南方地区。夏季,东亚低云对短波辐射的削弱作用各区域都较弱,大部分区域的负辐射强迫的绝对值小于200 W·m^-2。展开更多
Cloud and its radiative effects are major sources of uncertainty that lead to simulation discrepancies in climate models. In this study, shortwave cloud radiative forcing （SWCF） over major stratus regions is evaluat...Cloud and its radiative effects are major sources of uncertainty that lead to simulation discrepancies in climate models. In this study, shortwave cloud radiative forcing （SWCF） over major stratus regions is evaluated for Atmospheric Models Intercomparison Project （AMIP）-type simulations of models involved in the third and fifth phases of the Coupled Models Intercomparison Project （CMIP3 and CMIP5）. Over stratus regions, large deviations in both climatological mean and seasonal cycle of SWCF are found among the models. An ambient field sorted by dynamic （vertical motion） and thermodynamic （inversion strength or stability） regimes is constructed and used to measure the response of SWCF to large-scale controls. In marine boundary layer regions, despite both CMIP3 and CMIP5 models being able to capture well the center and range of occurrence frequency for the ambient field, most of the models fail to simulate the dependence of SWCF on boundary layer inversion and the insensitivity of SWCF to vertical motion. For eastern China, there are large differences even in the simulated ambient fields. Moreover, almost no model can reproduce intense SWCF in rising motion and high stability regimes. It is also found that models with a finer grid resolution have no evident superiority than their lower resolution versions. The uncertainties relating to SWCF in state-of-the-art models may limit their performance in IPCC experiments.展开更多
The Grid-point Atmospheric Model of IAP LASG version 1.0（GAMIL1.0） is used to investigate the impacts of different convective schemes on the radiative energy budget.The two convective schemes are Zhang and McFarlanc...The Grid-point Atmospheric Model of IAP LASG version 1.0（GAMIL1.0） is used to investigate the impacts of different convective schemes on the radiative energy budget.The two convective schemes are Zhang and McFarlance（1995）/Hack（1994）（ZM） and Tiedtke（1989）/Nordeng（1994）（TN）.Two simulations are performed：one with the ZM scheme（EX_ZM） and the other with the TN scheme（EX_TN）.The results indicate that during the convective process,more water vapor consumption and temperature increment are found in the EX_ZM,especially in the lower model layer,its environment is therefore very dry.In contrast, there is a moister atmosphere in the EX_TN,which favors low cloud formation and large-scale condensation, and hence more low cloud fraction,higher cloud water mixing ratio,and deeper cloud extinction optical depth are simulated,reflecting more solar radiative flux in the EX_TN.This explains why the TN scheme underestimates the net shortwave radiative flux at the top of the atmosphere and at surface.In addition, convection influences longwave radiation,surface sensible and latent heat fluxes through changes in cloud emissivity and precipitation.展开更多
利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室的格点大气环流模式(GAMIL)1.0版设计了两组数值模拟实验来研究两种不同的对流参数化方案对辐射能量收支的影响。这两种对流参数化方案分别是:Zhang and McFa...利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室的格点大气环流模式(GAMIL)1.0版设计了两组数值模拟实验来研究两种不同的对流参数化方案对辐射能量收支的影响。这两种对流参数化方案分别是:Zhang and McFarlance/Hack方案(简称ZM)和Tiedtke/Nordeng方案(简称TN)。对应的数值模拟实验分别取名为EX_ZM和EX_TN。通过对实验结果的分析表明:在对流过程中,EX_ZM允许深对流和浅对流同时发生,因此两种对流同时在模式低层消耗了更多的水汽,释放了更多的潜热,引起了更大的增温;EX_TN每次只允许一种对流发生,也就避免了不同类型的对流在同一层同时消耗水汽的现象。因此对流过后,EX_ZM的环境空气相对湿度较小,而EX_TN周围空气的相对湿度较大,有利于低云云量的生成和大尺度的凝结,因此EX_TN模拟的低云云量偏多,低层的云水含量偏高,模式低层的云光学厚度偏大,这就使得EX_TN中更多的太阳短波辐射通量被云反射掉,严重低估了模式对短波波段的辐射通量的模拟。此外,不同的对流参数化方案通过改变云的长波发射率和降水,进而影响了模式对长波波段的辐射通量、感热和潜热通量的模拟。展开更多
文摘利用云与地球辐射能量系统CERES(clouds and the earth’s radiant energy system)资料,对2003-2016年东亚不同区域单层低云物理属性及地面短波辐射强迫的季节时空分布特征进行研究。结果表明:①在空间分布上,辐射强迫与单层低云量在春秋两季有着较好的相似性,而与冰/液态水柱含量在春、夏、秋三个季节有着较好的一致性。②在时间变化上,北方地区夏季的单层低云对短波辐射的削弱作用是最强的;南方地区和西北地区最强的削弱作用发生在春季;东部海域则发生在冬季。在空间分布上,春、秋、冬季最强的低云削弱效应在南方地区。夏季,东亚低云对短波辐射的削弱作用各区域都较弱,大部分区域的负辐射强迫的绝对值小于200 W·m^-2。
基金supported by the Major National Basic Research Program of China(973 Program)on Global Change(Grant No.2010CB951902)the National Natural Science Foundation of China(Grant No.41221064)the Basic Scientific Research and Operation Foundation of CAMS(Grant No.2010Z003)
文摘Cloud and its radiative effects are major sources of uncertainty that lead to simulation discrepancies in climate models. In this study, shortwave cloud radiative forcing （SWCF） over major stratus regions is evaluated for Atmospheric Models Intercomparison Project （AMIP）-type simulations of models involved in the third and fifth phases of the Coupled Models Intercomparison Project （CMIP3 and CMIP5）. Over stratus regions, large deviations in both climatological mean and seasonal cycle of SWCF are found among the models. An ambient field sorted by dynamic （vertical motion） and thermodynamic （inversion strength or stability） regimes is constructed and used to measure the response of SWCF to large-scale controls. In marine boundary layer regions, despite both CMIP3 and CMIP5 models being able to capture well the center and range of occurrence frequency for the ambient field, most of the models fail to simulate the dependence of SWCF on boundary layer inversion and the insensitivity of SWCF to vertical motion. For eastern China, there are large differences even in the simulated ambient fields. Moreover, almost no model can reproduce intense SWCF in rising motion and high stability regimes. It is also found that models with a finer grid resolution have no evident superiority than their lower resolution versions. The uncertainties relating to SWCF in state-of-the-art models may limit their performance in IPCC experiments.
基金Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences under Grant No.KZCX2-YW-Q11-04the China Meteorological Administration R & D Special Fund for Public Welfare(meteorology)(Grant Nos.GYHY200806007, GYHY200806006,and GYHY200906020)+1 种基金Informalization Construction Project of Chinese Academy of Sciences during the 11th Five-Year Plan Period(No.INFO-115-B01)LASG State Key Laboratory Special Fund and LASG Free Exploration Fund
文摘The Grid-point Atmospheric Model of IAP LASG version 1.0（GAMIL1.0） is used to investigate the impacts of different convective schemes on the radiative energy budget.The two convective schemes are Zhang and McFarlance（1995）/Hack（1994）（ZM） and Tiedtke（1989）/Nordeng（1994）（TN）.Two simulations are performed：one with the ZM scheme（EX_ZM） and the other with the TN scheme（EX_TN）.The results indicate that during the convective process,more water vapor consumption and temperature increment are found in the EX_ZM,especially in the lower model layer,its environment is therefore very dry.In contrast, there is a moister atmosphere in the EX_TN,which favors low cloud formation and large-scale condensation, and hence more low cloud fraction,higher cloud water mixing ratio,and deeper cloud extinction optical depth are simulated,reflecting more solar radiative flux in the EX_TN.This explains why the TN scheme underestimates the net shortwave radiative flux at the top of the atmosphere and at surface.In addition, convection influences longwave radiation,surface sensible and latent heat fluxes through changes in cloud emissivity and precipitation.
文摘利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室的格点大气环流模式(GAMIL)1.0版设计了两组数值模拟实验来研究两种不同的对流参数化方案对辐射能量收支的影响。这两种对流参数化方案分别是:Zhang and McFarlance/Hack方案(简称ZM)和Tiedtke/Nordeng方案(简称TN)。对应的数值模拟实验分别取名为EX_ZM和EX_TN。通过对实验结果的分析表明:在对流过程中,EX_ZM允许深对流和浅对流同时发生,因此两种对流同时在模式低层消耗了更多的水汽,释放了更多的潜热,引起了更大的增温;EX_TN每次只允许一种对流发生,也就避免了不同类型的对流在同一层同时消耗水汽的现象。因此对流过后,EX_ZM的环境空气相对湿度较小,而EX_TN周围空气的相对湿度较大,有利于低云云量的生成和大尺度的凝结,因此EX_TN模拟的低云云量偏多,低层的云水含量偏高,模式低层的云光学厚度偏大,这就使得EX_TN中更多的太阳短波辐射通量被云反射掉,严重低估了模式对短波波段的辐射通量的模拟。此外,不同的对流参数化方案通过改变云的长波发射率和降水,进而影响了模式对长波波段的辐射通量、感热和潜热通量的模拟。
