The statistical characteristics and mechanisms of mesoscale eddies in the North Indian Ocean are investigated by adopting multi-sensor satellite data from 1993 to 2019. In the Arabian Sea (AS), seasonal variation of eddy characteristics is remarkable, while the intraseasonal variability caused by planetary waves is crucial in the Bay of Bengal (BOB). Seasonal variation of the eddy kinetic energy (EKE) is distinct along the west boundary of AS, especially in the Somali Current region. In the BOB, larger EKE occurs at the northwest basin from March to May, to the east of Sri Lanka from June to September, and along the east coast of India from November to December. The wind stress work (WW) is further studied to figure out the direct influence of wind forcing on EKE. The WW exerts positive effects on EKE along the west boundary of AS and in the south of India/Sri Lanka during the two monsoon seasons. Besides, the WW also has impact on EKE along the east coast of India in November and December. Eventually, we investigate the characteristics and the driving mechanisms of long lifespan eddies. In the AS, long lifespan anti-cyclonic eddies (AEs) mainly generate in the Socotra, the West Indian Coastal Current and the East Arabian Current regions, while cyclonic eddies (CEs) are concentrated in the northwest region. In the BOB, long lifespan AEs mostly form near the west of Myanmar, while CEs are accumulated at the north and northwest basin. The instabilities caused by Rossby waves, coastal Kelvin waves, seasonal currents, together with wind stress forcing exert enormous efforts on the generation and evolution of these eddies.

Chunjian Sun;Xidong Wang;Anmin Zhang;Lianxin Zhang;Caixia Shao;Guosong Wang

School of Marine Science and Technology,Tianjin University,Tianjin 300072,China;National Marine Data and Information Service,Tianjin 300171,China;College of Oceanography,Hohai University,Nanjing 210098,China

海洋学报（英文版）

[1]Chunjian Sun;Xidong Wang;Anmin Zhang;Lianxin Zhang;Caixia Shao;Guosong Wang-.Statistical characteristics and mechanisms of mesoscale eddies in the North Indian Ocean)[J].海洋学报（英文版）,2022(05):27-40

Somali,Socotra

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