ENSO发展期琼东上升流的动力过程响应差异

Response of Qiongdong upwelling dynamics to the ENSO event

上升流是海洋中最重要的海洋现象之一,通过ROMS数值模型模拟并研究了2000—2013年间琼东上升流对ENSO信号(2002和2009年作为典型ElNio年;2008和2010年作为典型LaNia年)的响应。结果表明,琼东上升流对ENSO气候事件有明显的响应。在ElNio信号较强时琼东上升流减弱,近岸海域水温升高;而在LaNia信号较强时琼东上升流加强,沿岸海域水温降低。对海面风场以及琼东海域沿岸流的分析表明,ENSO信号通过局地海面风场以及沿岸流对琼东上升流产生影响,并且风和沿岸流对琼东上升流的影响是协同的,在ElNio期间均不利于上升流的发展,而在LaNia期间二者的变化均有助于上升流的强化。

Upwelling is considered as one of the most important phenomena of the ocean currents. Based on a simple ROMS model, the responses of Qiongdong upwelling to different ENSO events from 2000 to 2013 (El Ni o events in 2002 and 2009, and La Ni a events in 2008 and 2010, respectively) are illustrated. It turns out that El Ni o favors warm water temperature anomalies along the coast attributing to the weakened upwelling. On the contrary, cold water temperature anomalies develop with the strengthened upwelling during La Ni a. It is demonstrated that the influence of different ENSO events was associated with sea surface winds and alongshore currents, both of which are not in favor of the development of upwelling during El Ni o except for La Ni a periods.