Assessing aerosol indirect effect on clouds and regional climate of East/South Asia and West Africa using NCEP GFS
Assessing aerosol indirect effect on clouds and regional climate of East/South Asia and West Africa using NCEP GFS
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DOI：
10.1007/s00382-018-4476-9
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发表时间：
2019-05-01
期刊：
影响因子：
4.6
通讯作者：
Zhao, Bin
中科院分区：
文献类型：
--
作者：
Huang, Huilin;Gu, Yu;Zhao, Bin
气溶胶可以作为云凝结核和冰核，导致云滴/粒子数量/大小的变化，从而改变辐射收支。本研究借由将最新的冰云参数化加入大气环流模式，探讨气溶胶与冰云之间的相互作用。模拟结果表明，有效的冰云晶体尺寸的减少对应于气溶胶的增加，被称为气溶胶第一间接效应，这还没有得到全面的研究。颗粒较小的冰云反射更多的短波辐射，吸收更多的红外辐射，导致大气顶部（TOA）辐射变化0.5-1.0W/m（2）。TOA辐射场还受到气溶胶引起的环流变化引起的云量变化的影响。气溶胶对降水的影响主要取决于深对流系统的存在：气溶胶与冰云的相互作用在亚洲季风区产生偶极降水异常;而在西非，增强的对流受到高层反气旋效应的限制，降水增加很少。我们还进行了一个实验，评估气溶胶和液体云之间的相互作用，并比较了气候这是由于冰云的影响。液态云产生的辐射和温度变化通常比冰云产生的辐射和温度变化大1-2倍。与冰云相比，辐射变化与液滴大小的关系更密切，而不是与液云量的关系。
Aerosols can act as cloud condensation nuclei and ice nuclei, resulting in changes in cloud droplet/particle number/size, and hence altering the radiation budget. This study investigates the interactions between aerosols and ice clouds by incorporating the latest ice clouds parameterization in an atmospheric general circulation model. The simulation shows a decrease in effective ice cloud crystal size corresponding to aerosol increase, referred to as the aerosol first indirect effect, which has not been comprehensively studied. Ice clouds with smaller particles reflect more shortwave radiation and absorb more infrared radiation, resulting in radiation change by 0.5-1.0W/m(2) at the top of the atmosphere (TOA). The TOA radiation field is also influenced by cloud cover change due to aerosol-induced circulation change. Such aerosol effects on precipitation highly depend on the existence of a deep convection system: interactions between aerosols and ice clouds create dipole precipitation anomalies in the Asian monsoon regions; while in West Africa, enhanced convections are constrained by anticyclone effects at high levels and little precipitation increase is found. We also conduct an experiment to assess interactions between aerosols and liquid clouds and compare the climatic effects with that due to ice clouds. Radiation and temperature changes generated by liquid clouds are normally 1-2 times larger than those generated by ice clouds. The radiation change has a closer relationship to liquid cloud droplet size than liquid cloud cover, in contrast with what we find for ice clouds.