期刊名称:Tellus A: Dynamic Meteorology and Oceanography
电子版ISSN:1600-0870
出版年度:2008
卷号:60
期号:5
页码:946-961
DOI:10.1111/j.1600-0870.2008.00345.x
摘要:We compared the climate response of doubled CO 2 equilibrium experiments (2 × CO 2 ) by atmosphere–slab ocean coupled general circulation models (ASGCMs) and that of 1% per year CO 2 increase experiments (1%CO 2 by atmosphere–ocean coupled general circulation models (AOGCMs) using eight state-of-the-art climate models. Climate feedback processes in 2 × CO 2 are different from those in 1%CO 2 , and the equilibrium climate sensitivity ( T 2× ) in 2 × CO 2 is different from the effective climate sensitivity ( T 2×,eff ) in 1%CO 2 . The difference between T 2× and T 2×,eff is from −1.3 to 1.6 K, a large part of which can be explained by the difference in the ice-albedo and cloud feedback. The largest contribution is cloud SW feedback, and the difference in cloud SW feedback for 2 × CO 2 and 1%CO 2 could be determined by the distribution of the SAT anomaly which causes differences in the atmospheric thermal structure. An important factor which determines the difference in ice-albedo feedback is the initial sea ice distribution at the Southern Ocean, which is generally overestimated in 2 × CO 2 as compared to 1%CO 2 and observation. Through the comparison of climate feedback processes in 2 × CO 2 and 1%CO 2 , the possible behaviour of the time evolution of T 2×,eff is discussed.