Coastal upwelling events, salinity stratification and barrier layer observed along the southwestern coast of Sumatra
Coastal upwelling events, salinity stratification and barrier layer observed along the southwestern coast of Sumatra
复制标题
苏门答腊西南海岸观测到的沿海上升流事件、盐度分层和屏障层
DOI：
10.1029/2020jc016287
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
and K. Ando
中科院分区：
文献类型：
--
作者：
Horii;T.;I. Ueki;and K. Ando
苏门答腊岛西南海岸沿岸上升流是发生在印度洋暖池东南缘海面温度高、降水丰富地区的季节性上升流。基于对在苏门答腊岛附近漂流和停留的两个 Argo 浮标的观测，我们研究了 2013 年至 2017 年观察到的几次沿海上升流事件期间的海洋温度和盐度变化。 Argo浮标每10天观测一次苏门答腊岛西南海岸100公里范围内的温度和盐度的垂直结构。观测数据显示，在异常的局地东南风和赤道东风的带动下，出现了季节内规模的地下温度变冷事件，温跃层和高盐度水体显着向上位移。在沿海上升流事件期间，还观察到与局部降水相关的盐度分层和厚屏障层。与显着的地下异常相比，表面混合层温度冷却相对较小。研究发现，在沿海上升流事件中，当存在盐度分层和厚屏障层时，地下冷水上升流信号不一定到达混合层。讨论了这些观测结果对于理解当地大气海洋相互作用以及印度洋偶极子发生的影响。
Coastal upwelling along the southwestern coast of Sumatra is a seasonal upwelling that occurs in areas of high sea surface temperature and abundant precipitation at the southeastern edge of the Indian Ocean warm pool. Based on observations from two Argo floats that drifted and stayed around Sumatra, we investigated ocean temperature and salinity variations during several coastal upwelling events observed in 2013–2017. The Argo floats observed the vertical structure of temperature and salinity every 10 days within 100 km from the southwestern coast of Sumatra. The observation data show intraseasonal‐scale subsurface temperature cooling events with significant upward displacements of the thermocline and high‐salinity water, led by anomalous local southesterly winds and equatorial easterly winds. During the coastal upwelling events, salinity stratification and a thick barrier layer related to local precipitation were also observed. Surface mixed layer temperature cooling were relatively small in contrast to the significant subsurface anomalies. It was found that during the coastal upwelling events, subsurface cold‐water upwelling signals did not necessarily reach the mixed layer when salinity stratification and a thick barrier layer were present. The implications of these observational results for understanding the local atmosphere ocean interaction, and hence the occurrence of the Indian Ocean Dipole, are discussed.