Observations of ocean color in the southeastern Arabian Sea (SEAS) during the late boreal summer and fall of 2016 reveal the highest surface chlorophyll concentrations (>1.0 mg m⁻³) ever reported in the region in the past two decades of the satellite era. Anomalous chlorophyll blooms were triggered by two cold‐core eddies, along the periphery of the coastal upwelling zone. Observational evidence suggest that the eddy formation and propagation can be attributed to the local wind forcing and the remote effects originating around Sri Lanka and the southern tip of India (STI) during the extreme negative Indian Ocean Dipole (IOD) of 2016. The eddy‐induced anomalous shoaling of thermocline indicates strong upwelling of subsurface nutrients and chlorophyll and enhanced light availability for phytoplankton growth favoring the observed biological response. The study signifies the unprecedented impacts of extreme climatic events on oceanic chlorophyll and the need for better understanding of the associated biophysical interactions.

中文翻译：

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极端负印度洋偶极子期间阿拉伯海东南面空前的叶绿素绽放

在2016年夏末和秋季北部东南阿拉伯海（SEAS）观察到的海洋颜色显示出最高的表面叶绿素浓度（> 1.0 mg m ^-3），这是该卫星时代过去二十年来在该地区的报道。沿海岸上升带外围的两个冷核涡流触发了叶绿素异常开花。观测证据表明，涡旋的形成和传播可归因于2016年极端负印度洋偶极子（IOD）期间斯里兰卡和印度南端（STI）附近产生的局部风强迫和偏远影响。引起的温跃层异常暗沙指示了地下营养物质和叶绿素的强烈上升，并增加了浮游植物生长的光利用率，有利于观察到的生物反应。该研究表明极端气候事件对海洋叶绿素产生了前所未有的影响，并且需要更好地了解相关的生物物理相互作用。