Mukherjee A, Chatterjee Abhisek, Francis P A
Indian National Centre for Ocean Information Services (INCOIS), Hyderabad, India.
Sci Rep. 2019 Jul 12;9(1):10152. doi: 10.1038/s41598-019-46542-9.
Eddies along western boundary of the Bay of Bengal (WBoB) play an important role in regulating regional climate and marine productivity of the north Indian Ocean. In this paper, role of Andaman and Nicobar islands (ANIs) in the formation of eddies along the WBoB is studied using an ocean general circulation model. Our analysis shows that, in the absence of ANIs, there is a significant reduction in the total number of mesoscale eddies in this region. The impact is particularly evident for the cyclonic eddies as a reduction of ~50% can be noticed in the absence of the islands. In contrast, influence of ANIs on anticyclonic eddies is not homogeneous in the WBoB; while absence of ANIs significantly increases anticyclonic eddies in the central part of the WBoB, a decrease can be noticed in the southern part. We further show that the reduction in number of cyclonic eddies along the WBoB is primarily driven by reduced baroclinic and barotropic instabilities. This process is more conspicuous during winter (October-January) season compared to summer (June-September) and spring (February-May) seasons.
孟加拉湾西部边界（WBoB）的涡旋在调节北印度洋的区域气候和海洋生产力方面发挥着重要作用。在本文中，利用海洋环流模型研究了安达曼和尼科巴群岛（ANIs）在WBoB沿线涡旋形成中的作用。我们的分析表明，在没有ANIs的情况下，该区域中尺度涡旋的总数显著减少。这种影响在气旋性涡旋中尤为明显，在没有岛屿的情况下，可以注意到气旋性涡旋减少了约50%。相比之下，ANIs对WBoB反气旋性涡旋的影响并不均匀；虽然没有ANIs会显著增加WBoB中部的反气旋性涡旋，但在南部可以注意到反气旋性涡旋有所减少。我们进一步表明，WBoB沿线气旋性涡旋数量的减少主要是由斜压和正压不稳定的降低驱动的。与夏季（6月至9月）和春季（2月至5月）相比，这个过程在冬季（10月至1月）更为明显。
