In this study,the decomposed fast and slow responses of clouds to an abruptly quadrupled CO_(2)concentration(approximately 1139 ppmv)in East Asia(EA)are obtained quantitatively by using a general circulation model,BCC...In this study,the decomposed fast and slow responses of clouds to an abruptly quadrupled CO_(2)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 40°N and decreased south of 40°N 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 CO_(2).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.展开更多
基金supported by the National Key R&D Program of China(2017YFA0603502)the National Natural Science Foundation of China(Grant No.41905081)S&T Development Fund of CAMS(2021KJ004&2022KJ019).
文摘In this study,the decomposed fast and slow responses of clouds to an abruptly quadrupled CO_(2)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 40°N and decreased south of 40°N 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 CO_(2).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.
