The impact of the Indonesian Throughflow and tidal mixing on the summertime sea surface temperature in the western Indonesian Seas
The impact of the Indonesian Throughflow and tidal mixing on the summertime sea surface temperature in the western Indonesian Seas
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DOI：
10.1029/2012jc008162
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发表时间：
2012-09-06
影响因子：
3.6
通讯作者：
Wijffels, Susan
中科院分区：
文献类型：
--
作者：
Kida, Shinichiro;Wijffels, Susan
利用一个数值模式研究了印尼贯穿流和潮汐混合对印度尼西亚海表面温度(SST)季节循环的影响。这些海域的海温被认为对澳大利亚夏季风的发展起着重要作用。根据对热量收支的定量评估，发现印尼贯通气流主要在南部夏季影响印尼西部海域的海温。当西北季风风引起努沙登加拉岛北侧沿岸上升流并使海温降温时，贯通气流使来自太平洋的暖水平流并维持温暖的海温。这种平衡得到了观察结果的支持。水文剖面显示，当卫星观测显示该地区的SST略有下降时，等温线向努沙腾加拉河北部海岸向上倾斜。潮汐混合对夏季海温的降温作用最强。这是因为西北季风风在海山上方发生强烈潮汐混合的地方附近引发海岸上升流，并将潮汐混合良好的上层温跃层水带到水面。表面的埃克曼流也将这些冷水扩散到班达海周围，那里不会发生潮汐混合。潮汐混合对SST的影响也被发现主要来自海山上方的影响。潮汐混合对大陆架的影响仅限于大陆架破裂，因为冷的次表层水对于加强垂直混合以冷却SST是必要的。
A numerical model is used to investigate how the Indonesian Throughflow and tidal mixing are affecting the seasonal cycle of the sea surface temperature (SST) in the Indonesian Seas. The SST in these seas is considered to play a major role on the development of the Australian Summer Monsoon. Based on a quantitative assessment of the heat budget, the Indonesian Throughflow is found to affect the SST in the western Indonesian Seas primarily during Austral summer. The Throughflow advects the warm water from the Pacific and maintains the warm SST when the Northwestern Monsoonal wind induces coastal upwelling along the northern side of the Nusa Tenggara and cools the SST. Such balance is supported by observations. The hydrographic sections show the isotherms tilting upward toward the northern coast of the Nusa Tenggara when satellite observations show slight decrease of the SST in the region. Tidal mixing is found to cool the SST during summer the most. This is because the Northwest Monsoonal wind induces coastal upwelling near where strong tidal mixing above seamount occurs and brings the tidally well-mixed upper thermocline water to the surface. The surface Ekman flow also spreads this cool water around the Banda Sea where tidal mixing does not occur. The impact of tidal mixing on the SST is also found to come largely from that occurring above seamounts. The impact of tidal mixing on the continental shelves is limited to shelf-breaks because cold subsurface water is necessary for enhanced vertical mixing to cool the SST.