Climate Impacts of the Southern Annular Mode Simulated by the CMIP3 Models
Climate Impacts of the Southern Annular Mode Simulated by the CMIP3 Models
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DOI：
10.1175/2009jcli2788.1
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发表时间：
2009-07
影响因子：
4.9
通讯作者：
A. Karpechko;N. Gillett;G. Marshall;J. Screen
中科院分区：
文献类型：
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作者：
A. Karpechko;N. Gillett;G. Marshall;J. Screen
南方环形模态（SAM）对南半球的气候有着公认的影响。在南极观测到的地表气温（SAT）响应最强，但SAM的影响范围更远，对温度和降水的统计学显著影响在北至20°S的地方被检测到。在这里，作者量化的能力耦合模式相互比较项目，第3阶段（CMIP 3）耦合气候模式模拟观测到的SAT，总降水量，海表面温度（SST），海冰浓度响应SAM。这些模型能够相当好地模拟SAT中响应的空间模式;然而，所有模型都低估了南极洲表面和自由对流层响应的幅度。这种低估的温度响应的影响，预测未来的温度变化与预期的变化在SAM。模式具有合理的技能，在模拟模式的降水和SST响应，但是，存在一些相当大的区域偏差。模拟的降水和SST响应比SAT响应受观测的约束更小，特别是在量级上，因为在参考数据集中的响应之间检测到显著的差异。最大的问题是在模拟海冰对SAM的响应时发现的，有些模型甚至模拟了与观测结果负相关的响应。
The southern annular mode (SAM) has a well-established impact on climate in the Southern Hemisphere. The strongest response in surface air temperature (SAT) is observed in the Antarctic, but the SAM's area of influence extends much farther, with statistically significant effects on temperature and precipitation being detected as far north as 20°S. Here the authors quantify the ability of the Coupled Model Intercomparison Project, phase 3 (CMIP3) coupled climate models to simulate the observed SAT, total precipitation, sea surface temperature (SST), and sea ice concentration responses to the SAM. The models are able to simulate the spatial pattern of response in SAT reasonably well; however, all models underestimate the magnitude of the response over Antarctica, both at the surface and in the free troposphere. This underestimation of the temperature response has implications for prediction of the future temperature changes associated with expected changes in the SAM. The models possess reasonable skill in simulating patterns of precipitation and SST response; however, some considerable regional deviations exist. The simulated precipitation and SST responses are less constrained by the observations than the SAT response, particularly in magnitude, as significant discrepancies are detected between the responses in the reference datasets. The largest problems are identified in simulating the sea ice response to the SAM, with some models even simulating a response that is negatively correlated with that observed.