Response of the equatorial basin‐wide SST to non‐breaking surface wave‐induced mixing in a climate model: An amendment to tropical bias
Response of the equatorial basin‐wide SST to non‐breaking surface wave‐induced mixing in a climate model: An amendment to tropical bias
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DOI：
10.1029/2012jc007931
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发表时间：
2012-11
影响因子：
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通讯作者：
Zhenya Song;F. Qiao;Yajuan Song
中科院分区：
文献类型：
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作者：
Zhenya Song;F. Qiao;Yajuan Song
[1]没有通量订正的海气耦合环流模式（AOGCMs）普遍存在的问题之一是模拟的海表温度（SST）与观测值有明显的偏差，特别是在热带地区，如东太平洋的冷舌和赤道大西洋的SST纬向梯度倒置。大气-波浪-海洋耦合环流模式通过耦合器将非破碎面波引起的混合引入到CCSM 3中，可以改善对热带SST的模拟。在海盆尺度上，波浪引起的垂直混合可使赤道海温产生“西正东负”型，大大增强了热带偏置。通过AOGCMs和独立海洋环流模式（OGCMs）的敏感性试验，分析了这种海盆对波致混合响应的形成机制。第一，在各海盆中，由于波浪混合的直接作用，海表温度均变冷，且各海盆东部的海表温度较西部的海表温度低，这是由于混合层较浅。西太平洋海盆（或太平洋中部海盆）的海温由于东向纬向流减弱而增加。在Bjernkes反馈的作用下，西暖东冷的海温型被放大。净热通量反馈在这种SST响应中起负作用。
[1] One of the common problems of the coupled atmosphere-ocean general circulation models (AOGCMs) without flux correction is that the simulated sea surface temperature (SST) deviates noticeably from the observation especially in the tropics, such as the too cold tongue in the eastern Pacific and a reversed SST zonal gradient in the equatorial Atlantic. The coupled atmosphere-wave-ocean general circulation model, which incorporates the non-breaking surface wave-induced mixing into the CCSM3 through a coupler, can improve the simulation of the tropical SST. On the ocean-basin scale, the wave-induced vertical mixing can generate “West-Positive and East-Negative” pattern for the equatorial SST that much alleviates the tropical bias. The formation mechanism for this basin-wide response to the wave-induced mixing is analyzed through sensitive experiments of AOGCMs and stand-alone ocean general circulation models (OGCMs). First, in each basin, the SST becomes colder under the direct effect of the wave-induced mixing, and the SST in the eastern part of each basin is colder due to the shallower ocean mixed layer than that of the western part. The SST in the western basin (or central basin in the Pacific Ocean) increases due to the weakened eastward zonal current. Then, the pattern of warm SST in the west and cold SST in the east is amplified due to the Bjernkes feedback in a climate system. The net heat flux feedback plays a negative role in this kind of SST response.