基于Argo的热带东印度洋上层水团季节分布

为研究热带东印度洋上层海洋孟加拉湾水(BBW)及阿拉伯海水(ASW)的季节分布,利用2003-2012年的地转海洋学实时观测阵(Argo)资料,依据温盐标准分析其分布特征。结果显示,BBW在11月至次年3月主要分布在阿拉伯海东南部海域,6-10月出现在苏门答腊岛外海及赤道海域,并持续至次年2月。ASW在5,6月及10月至次年1月沿赤道向东延伸最远,可至90°E以东海域,在多数月份(6月至次年4月)还出现在湾内。分析表明,BBW有3个出湾通道:11月至次年3月,东印度沿岸流及东北季风漂流是BBW从湾内进入阿拉伯海东南部海域的2个主要流路,6-10月,BBW通过湾口东侧的连续南向流输送至苏门答腊岛外海;ASW入侵湾内有2个路径:11月至次年4月,由赤道至湾口的连续北向流经湾口东侧进入湾内,6-9月ASW由西南季风漂流输运至湾内。

Seasonal variations of upper-layer watermassesin eastern tropical Indian Ocean explored by Argo floats

To study the seasonal variation of the Bay of Bengal water(BBW) and Arabian Sea water(ASW) in the upper Eastern Tropical Indian Ocean(ETIO), nearly 10 years(2003-2012) Array for Real-time Geostrophic Oceanography (Argo) float data and the standard of watermass analysis were used to analyse their distribution characteristics. The result shows that BBW mainly distributes in the southeast of Arabian Sea from November to the proceeding March, while it appears at the equator and off Sumatra during June and October, which persists until the proceeding February. ASW extends eastward along the equator, as far as 90°E in the May-June and October-the proceeding January. Besides, ASW also appears in the bay most of the time (June-the proceeding April). Further analysis shows that BBW has three pathways out of the bay. During November and the proceeding March, East India Coastal Current and the northeast monsoon current are two main pathways for transporting BBW from the interior bay to the southeast of Arabian Sea. During June and October, BBW is carried southward into the equator and off the Sumatra via the eastern bay mouth by the continuously southward current. There are two pathways for ASW to invade into the bay. During november and the proceeding april, ASW is carried into the bay through the eastern bay mouth by the northward flow located between the bay and the equator. It is transported into the bay by the summer monsoon current during June and September.