一个海洋环流模式模拟的北印度洋经向环流及其热输送

对比两个同化资料GODAS（Global Ocean Data Assimilation System）和SODA（Simple Ocean Data Assimilation），考察中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室发展的气候系统海洋模式LICOM（LASG/IAP Climate system Ocean Model）模拟的北印度洋经向环流及热输送的气候态。LICOM能抓住北印度洋大尺度环流的季节变化特征，模拟的年平均越赤道热输送为-0.24 PW （1 PW=1015W），较之以往的数值模式结果更接近观测和同化资料。与同化资料的差异主要体现在季节变化强度，北半球夏季在赤道以南偏弱0.5 PW，这与模式夏季的纬向风应力偏弱，热输送中的大项Ekman热输送模拟偏弱，从而模拟的经圈翻转环流较浅有关。

Evaluation on Seasonal Circulation and Heat Transport Simulated by LICOM in the Northern Indian Ocean

Comparing two assimilation data,GODAS(Global Ocean Data Assimilation System) and SODA(Simple Ocean Data Assimilation),the annual cycles of overturning circulation and meridional heat transport in the northern Indian Ocean simulated by LICOM(LASG/IAP Climate System Ocean Model) are evaluated.LICOM reproduces reasonably seasonal variability of large-scale circulation,and resolves the Southern Gyre and the Great Whirl around Somali in the southwest monsoon.Wind-driven meridional overturning circulation simulated by LICOM consists of a STC(southern overturning cell) and a CEC(cross-equatorial overturning cell).STC is stronger than CEC in the boreal summer while weaker in the boreal winter.The total circulation transport is about 16 Sv,whose maximum center lies at 100-200 m in the southwest monsoon and at 200-1000 m in the northeast monsoon.Annual mean cross-equatorial heat transport from LICOM is-0.24 PW,which is closer to the observation and assimilation data than numerical modeling results before.Vertical overturning circulation is the main contribution to the seasonal cycle of meridional heat transport.Meridional heat transport south of the Equator in the boreal summer in LICOM is 0.5 PW less than the assimilation data.This is related to weaker zonal wind stress of LICOM here,resulting in weaker Ekman heat transport and shallower meridional overturning circulation.