In this study,the decomposed fast and slow responses of clouds to an abruptly quadrupled CO2 concentration(approximately 1139 ppmv)in East Asia(EA)are obtained quantitatively by using a general circulation model,BCC-AGCM2.0.Our results show that in the total response,the total cloud cover(TCC),low cloud cover(LCC),and high cloud cover(HCC)all increased north of 40oN and decreased south of 40oN except in the Tibetan Plateau(TP).The mean changes of the TCC,LCC,and HCC in EA were-0.74％,0.38％,and-0.38％in the total response,respectively;1.05％,-0.03％,and 1.63％in the fast response,respectively;and-1.79％,0.41％,and-2.01％in the slow response,respectively.By comparison,we found that changes in cloud cover were dominated by the slow response in most areas in EA due to the changes in atmospheric temperature,circulation,and water vapor supply together.Overall,the changes in the cloud forcing over EA related to the fast and slow responses were opposite to each other,and the final cloud forcing was dominated by the slow response.The mean net cloud forcing(NCF)in the total response over EA was-1.80 W m-2,indicating a cooling effect which partially offset the warming effect caused by the quadrupled CO2.The total responses of NCF in the TP,south China(SC),and northeast China(NE)were-6.74 W m-2,6.11 W m-2,and-7.49 W m-2,respectively.Thus,the local effects of offsetting or amplifying warming were particularly obvious.

Xixun ZHOU;Bing XIE;Hua ZHANG;Jingyi HE;Qi CHEN

State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;University of Chinese Academy of Sciences,Beijing 100049,China;Laboratory for Climate Studies of China Meteorological Administration,National Climate Center,Beijing 100081,China

大气科学进展（英文版）

[1]Xixun ZHOU;Bing XIE;Hua ZHANG;Jingyi HE;Qi CHEN-.Decomposition of Fast and Slow Cloud Responses to Quadrupled CO2 Forcing in BCC-AGCM2.0 over East Asia)[J].大气科学进展（英文版）,2022(12):2188-2202

Quadrupled,AGCM2,quadrupled,40oN

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