A Numerical Study of Direct Radiative Forcing Due to Black Carbon and Its Effects on the Summer Precipitation in China
A Numerical Study of Direct Radiative Forcing Due to Black Carbon and Its Effects on the Summer Precipitation in China
复制标题
黑碳直接辐射强迫及其对我国夏季降水影响的数值研究
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
W. Zhili
中科院分区：
文献类型：
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作者：
W. Zhili
利用CAM 3模式研究了大气顶部和地面黑碳直接辐射强迫的全球平均分布和季节变化，以及云对黑碳直接辐射强迫的影响（社区大气模式第三版）。然后，结果表明，全球平均年降水量存在明显的季节变化结果表明，在多云天气条件下，大气BC在TOA和地面产生正的辐射强迫和负的辐射强迫，大气BC在TOA和地面产生的直接辐射强迫的全球平均值分别为+0.33W·m-2和-0.56W·m-2;在晴朗天气条件下，大气BC在TOA和地面产生的直接辐射强迫的全球平均值分别为+0.33W·m-2和-0.56W·m-2;在多云天气条件下，大气BC在TOA和地面产生的直接辐射强迫的全球平均值分别为+0.33W·m-2和-0.56W·m-2。m-2和-0.71 W·m-2，云的存在使TOA正强迫增强，地面负强迫减弱，夏季30°N ~ 45°N之间华北降水明显增加，由于BC的影响，除海南和广西的部分城市外，长江以南地区的降水量明显减少，模拟结果没有模拟出近50年来中国夏季频繁出现的北旱南涝型降水。
The global mean distribution and seasonal changes of direct radiative forcing due to black carbon(BC)at the top of atmosphere(TOA)and surface and the effect of cloud on BC direct radiative forcing have been investigated by using the CAM3(Community Atmosphere Model Version 3)developed by NCAR.Then,the influence of BC on summer precipitation in China is discussed.The results show that there exist obviously seasonal changes in the global mean distribution and intensity of direct radiative forcing due to BC at the TOA and the surface.In cloudy sky,BC induces a positive radiative forcing at the TOA and negative radiative forcing at the surface.The global mean values of the direct radiative forcing at the TOA and surface due to BC are +0.33 W·m-2 and-0.56 W·m-2,respectively.In clear sky,the corresponding values are +0.2 W·m-2 and-0.71 W·m-2,respectively.The positive forcing at the TOA is enhanced and the negative forcing at the surface is weakened because of the existing of cloud.The precipitation increases obviously in the north of China in summer between 30°N and 45°N,whereas it decreases obviously in the south of the Yangtze River except for some cities of Hainan and Guangxi Provinces because of the effect of BC.The simulations have not produced the north drought/south flooding precipitation pattern that has frequently occurred in the summer of China during the last 50 years.