Mixed Layer Temperature Response to the Southern Annular Mode: Mechanisms and Model Representation
Mixed Layer Temperature Response to the Southern Annular Mode: Mechanisms and Model Representation
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DOI：
10.1175/2009jcli2976.1
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发表时间：
2010-02
影响因子：
4.9
通讯作者：
J. Screen;N. Gillett;A. Karpechko;D. Stevens
中科院分区：
文献类型：
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作者：
J. Screen;N. Gillett;A. Karpechko;D. Stevens
前人的研究表明，在耦合模式对比计划(CMIP3)气候模式的第三阶段中，模拟的海表面温度(SST)对南环模(SAM)的响应与观测响应相比较差。探讨了这些模型误差背后的原因。在四个CMIP3模式中，利用观测-再分析检验了海洋混合层的热量收支。海温对SAM的响应主要受感热通量和潜热通量以及Ekman热输送异常的驱动。辐射热通量的作用较小，但不容忽视。模拟的SST响应中的误差可以追溯到大气对SAM的响应的缺陷。这些模式夸大了地面风对SAM的响应，导致了大量不切实际的埃克曼输送异常。在大气环流的正相期间，这导致了40°-65°S纬度的过度模拟冷却。与模拟的风应力响应有关的问题，部分与…
Abstract Previous studies have shown that simulated sea surface temperature (SST) responses to the southern annular mode (SAM) in phase 3 of the Coupled Model Intercomparison Project (CMIP3) climate models compare poorly to the observed response. The reasons behind these model inaccuracies are explored. The ocean mixed layer heat budget is examined in four of the CMIP3 models and by using observations–reanalyses. The SST response to the SAM is predominantly driven by sensible and latent heat flux and Ekman heat transport anomalies. The radiative heat fluxes play a lesser but nonnegligible role. Errors in the simulated SST responses are traced back to deficiencies in the atmospheric response to the SAM. The models exaggerate the surface wind response to the SAM leading to large unrealistic Ekman transport anomalies. During the positive phase of the SAM, this results in excessive simulated cooling in the 40°–65°S latitudes. Problems with the simulated wind stress responses, which relate partly to errors in ...