The Climatology and Interannual Variability of East Asian Summer Monsoon in CMIP5 Coupled Models: Does Air-Sea Coupling Improve the Simulations?
The Climatology and Interannual Variability of East Asian Summer Monsoon in CMIP5 Coupled Models: Does Air-Sea Coupling Improve the Simulations?
复制标题
CMIP5 耦合模型中东亚夏季风的气候学和年际变化：海气耦合是否改善了模拟？
DOI：
10.1175/jcli-d-14-00396.1
复制
发表时间：
2014-12-01
影响因子：
4.9
通讯作者：
Zhou, Tianjun
中科院分区：
文献类型：
--
作者：
Song, Fengfei;Zhou, Tianjun
对耦合模型比对项目 (CMIP5) 第 5 阶段的 34 个耦合大气环流模型 (CGCM) 模拟的东亚夏季风 (EASM) 的气候学和年际变化进行了评估。为了估计海气耦合的作用，将 17 个 CGCM 与其相应的大气环流模型 (AGCM) 进行了比较。 CGCM 中的气候低层季风环流和梅雨/昌马/白乌降雨带均比 AGCM 有所改善。这种改善是以 CGCM 中局部冷海表面温度 (SST) 偏差为代价的，因为它们减少了表面蒸发并增强了环流。年际 EASM 模式通过技能公式进行评估，并选择最高/最低的 8 个模型来研究技能起源。观测到的印度洋（IO）变暖、热带东印度洋（TEIO）降雨异常和开尔文波响应在高技能模型中得到了很好的捕捉，而这些特征在低技能模型中不存在。此外，高技能和低技能模型之间IO变暖的差异根源于之前的ENSO模拟。因此，与 AGCM 类似，IO-西太平洋反气旋 (WPAC) 遥相关对于 CGCM 很重要。然而，与 AGCM 相比，CGCM 中的 TEIO 海温异常偏暖，因为 WPAC 南翼的东风异常减少了气候季风西风并减少了地表蒸发。 TEIO越暖，降水异常越强，遥相关性越强。因此，CGCM 比 AGCM 更能模拟 EASM 年际格局。
The climatology and interannual variability of the East Asian summer monsoon (EASM) simulated by 34 coupled general circulation models (CGCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are evaluated. To estimate the role of air-sea coupling, 17 CGCMs are compared to their corresponding atmospheric general circulation models (AGCMs). The climatological low-level monsoon circulation and mei-yu/changma/baiu rainfall band are improved in CGCMs from AGCMs. The improvement is at the cost of the local cold sea surface temperature (SST) biases in CGCMs, since they decrease the surface evaporation and enhance the circulation. The interannual EASM pattern is evaluated by a skill formula and the highest/lowest eight models are selected to investigate the skill origins. The observed Indian Ocean (IO) warming, tropical eastern Indian Ocean (TEIO) rainfall anomalies, and Kelvin wave response are captured well in high-skill models, while these features are not present in low-skill models. Further, the differences in the IO warming between high-skill and low-skill models are rooted in the preceding ENSO simulation. Hence, the IO-western Pacific anticyclone (WPAC) teleconnection is important for CGCMs, similar to AGCMs. However, compared to AGCMs, the TEIO SST anomaly is warmer in CGCMs, since the easterly wind anomalies in the southern flank of the WPAC reduce the climatological monsoon westerlies and decrease the surface evaporation. The warmer TEIO induces the stronger precipitation anomaly and intensifies the teleconnection. Hence, the interannual EASM pattern is better simulated in CGCMs than that in AGCMs.