Impacts of the Atlantic warm pool on North American precipitation and global sea surface temperature in a coupled general circulation model
Impacts of the Atlantic warm pool on North American precipitation and global sea surface temperature in a coupled general circulation model
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耦合大气环流模型中大西洋暖池对北美降水和全球海面温度的影响
DOI：
10.1007/s00382-020-05527-5
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发表时间：
2020-11
期刊：
影响因子：
4.6
通讯作者：
Xin Wang
中科院分区：
文献类型：
--
作者：
Chunzai Wang;Sheng Chen;Zhenya Song;Xin Wang
利用观测资料和NCAR共同体地球系统模式，研究了北美降水对大西洋暖池（AWP）的响应。我们发现，在不同的季节，响应由不同的物理机制控制。在温暖的季节，一个大的AWP减少了北大西洋副热带高压，与吉尔的物理学一致。对北美的相应影响是低层大气偏北风异常，导致美国中部降水抑制。而在冷季，AWP对北美降水的影响是通过AWP引起的热带太平洋冷海温异常的遥相关来实现的。一个大的AWP增强了当地的Hadley环流，在北半球夏季穿越赤道到热带东南太平洋。这一南北半球间的过程加强了大气下沉，使南太平洋副热带高压增强，导致地面东风信风增强，热带东南太平洋海温异常偏冷。风-蒸发-SST和Bjerknes的反馈作用进一步导致热带中太平洋SST出现类La Niña型，这与20世纪90年代以后AWP领先6-9个月时ENSO与AWP显著负相关相一致。AWP在热带中太平洋引起的类似拉尼娜的海温异常进一步促使太平洋北美遥相关的负相位，导致美国南部降水减少;反之亦然。除了AWP引起的中太平洋型ENSO事件外，本文还讨论了AWP对北太平洋和印度洋海温的影响。
The responses of North American precipitation to the Atlantic warm pool (AWP) are investigated by using observational data and the NCAR Community Earth System Model. We show that the responses are controlled by different physical mechanisms in different seasons. In the warm season, a large AWP reduces the North Atlantic subtropical high, consistent with Gill’s physics. The corresponding influence over North America is northerly wind anomalies in the lower atmosphere, which leads to a precipitation suppression in the central United States. However, in the cold season the AWP’s impact on North American precipitation is operated via the teleconnection of cold SST anomalies in the tropical Pacific which are induced by the AWP. A large AWP enhances the local Hadley circulation that moves across the equator to the tropical southeastern Pacific in the boreal summer. This inter-hemispheric process strengthens the atmospheric sinking and then increases the South Pacific subtropical high, resulting in the enhancement of the surface easterly trade wind and thus cold SST anomalies in tropical southeastern Pacific. The wind-evaporation-SST and Bjerknes feedbacks further lead tropical central Pacific SST to a La Niña-like pattern, which is consistent with that the significant and negative correlation between ENSO and the AWP is observed after the 1990s when the AWP leads by 6–9 months. The AWP-induced La Niña-like SST anomalies in the tropical central Pacific further prompts a negative phase of the Pacific North American teleconnection, resulting in decreased precipitation over the southern United States; and vice versa. In addition to the AWP-induced central Pacific-type of ENSO events, the paper also shows the influences of the AWP on SSTs in the North Pacific and Indian Oceans.
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影响因子：
4.9
作者：
R. Sutton;D. Hodson
通讯作者：
R. Sutton;D. Hodson
影响因子：
8
作者：
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通讯作者：
J. Hawkins;Thomas F. Lee;J. Turk;C. Sampson;J. Kent;K. Richardson
影响因子：
4.9
作者：
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通讯作者：
Chunzai Wang;Sang‐Ki Lee;D. Enfield
影响因子：
8.9
作者：
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通讯作者：
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影响因子：
56.9
作者：
Hoerling, M;Kumar, A
通讯作者：
Kumar, A