| DOI: | 10.1007/s00382-013-1752-6
|
| Scopus记录号: | 2-s2.0-84886724835
|
| 论文题名: | Asian monsoon simulations by Community Climate Models CAM4 and CCSM4 |
| 作者: | Islam S.U.; Tang Y.; Jackson P.L.
|
| 刊名: | Climate Dynamics
|
| ISSN: | 9307575
|
| 出版年: | 2013
|
| 卷: | 41, 期:2017-09-10 | | 起始页码: | 2617
|
| 结束页码: | 2642
|
| 语种: | 英语
|
| 英文摘要: | This study examines the ability of Community Atmosphere Model (CAM) and Community Climate System Model (CCSM) to simulate the Asian summer monsoon, focusing particularly on inter-model comparison and the role of air-sea interaction. Two different versions of CAM, namely CAM4 and CAM5, are used for uncoupled simulations whereas coupled simulations are performed with CCSM4 model. Ensemble uncoupled simulations are performed for a 30 year time period whereas the coupled model is integrated for 100 years. Emphasis is placed on the simulation of monsoon precipitation by analyzing the interannual variability of the atmosphere-only simulations and sea surface temperature bias in the coupled simulation. It is found that both CAM4 and CAM5 adequately simulated monsoon precipitation, and considerably reduced systematic errors that occurred in predecessors of CAM4, although both tend to overestimate monsoon precipitation when compared with observations. The onset and cessation of the precipitation annual cycle, along with the mean climatology, are reasonably well captured in their simulations. In terms of monsoon interannual variability and its teleconnection with SST over the Pacific and Indian Ocean, both CAM4 and CAM5 showed modest skill. CAM5, with revised model physics, has significantly improved the simulation of the monsoon mean climatology and showed better skill than CAM4. Using idealized experiments with CAM5, it is seen that the adoption of new boundary layer schemes in CAM5 contributes the most to reduce the monsoon overestimation bias in its simulation. In the CCSM4 coupled simulations, several aspects of the monsoon simulation are improved by the inclusion of air-sea interaction, including the cross-variability of simulated precipitation and SST. A significant improvement is seen in the spatial distribution of monsoon mean climatology where a too-heavy monsoon precipitation, which occurred in CAM4, is rectified. A detailed investigation of this significant precipitation reduction showed that the large systematic cold SST errors in the Northern Indian Ocean reduces monsoon precipitation and delays onset by weakening local evaporation. Sensitivity experiments with CAM4 further confirmed these results by simulating a weak monsoon in the presence of cold biases in the Northern Indian Ocean. It is found that although the air-sea coupling rectifies the major weaknesses of the monsoon simulation, the SST bias in coupled simulations induces significant differences in monsoon precipitation. The overall simulation characteristics demonstrate that although the new model versions CAM4, CAM5 and CCSM4, are significantly improved, they still have major weaknesses in simulating Asian monsoon precipitation. © 2013 Springer-Verlag Berlin Heidelberg. |
| 资助项目: | Canadian Foundation for Climate and Atmospheric Sciences
|
| Citation statistics: |
|
| 资源类型: | 期刊论文
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/54736
|
| Appears in Collections: | 过去全球变化的重建
|
|
There are no files associated with this item.
|
|
作者单位: | Environmental Science and Engineering, University of Northern British Columbia, 3333 University way, Prince George, BC, V2N 4Z9, Canada
|
| Recommended Citation: | |
Islam S.U.,Tang Y.,Jackson P.L.. Asian monsoon simulations by Community Climate Models CAM4 and CCSM4[J]. Climate Dynamics,2013-01-01,41(2017-09-10)
|
|
|