南海亚中尺度过程的时空特征与垂向热量输运研究

Spatiotemporal Characteristics and Vertical Heat Transport of Submesoscale Processes in the South China Sea

基于2001—2003年1/30°水平分辨率OFES模式资料,本文探究了南海亚中尺度过程的时空特征及其导致的垂向热量输运。研究发现,在空间分布上,南海亚中尺度过程整体呈现出陆架区和岛屿周边较为活跃、内区较弱的特点,其中,台湾西南海域、吕宋海峡以及越南以东海域是亚中尺度过程的活跃区。在时间变化上,除吕宋海峡全年均较强外,南海亚中尺度过程大体呈现出冬春强、夏秋弱的季节分布特征,尤其是台湾西南海域、越南以东海域。基于其时空分布特征,进一步研究了亚中尺度过程导致的垂向热量输运,发现在其活跃的冬春季节,亚中尺度过程能产生向上的净热量输运。冬末春初,台湾西南、吕宋海峡的亚中尺度垂向热通量分别可以达到海表面净热通量的26%和40%。该结果说明南海亚中尺度过程对上层海洋热量收支和层化具有不可忽视的影响。

Based on 1/30°OFES model’soutput from 2001 to 2003,the spatial and temporal characteristics of submesoscale processesin the South China Sea has been discussed,as well as its accompanied vertical heat transport.Spatially,the submesoscale processes are active in continental shelf areas and islands’surroundings,while those in the inner areas of the basin are relatively weak.Submesoscaleprocesses are mainly active in southwest of Taiwan,Luzon strait and east of Vietnam.In terms of time variation,the submesoscale processes generally show an obvious seasonality they are stronger during winter and spring than summer and autumn,beyond the region of Luzon strait.Based on the spatial-temporal distribution,the net upward heat transport induced by the submesoscale process also has been calculated.We found that high values mainly exist in winter and spring.During the period from late winter to early spring,the submesoscale vertical heat fluxes of southwest Taiwan and Luzon strait can reach a very high level,that is,a ratio of 26%and 40%respectively,compared to the net heat fluxes of the sea surface.This result directly shows that submesoscale processes in the south China Sea have a very important influence on the heat flux budget and stratification of the upper ocean.