大洋环流的诊断计算

Diagnostic Calculation of the Oceanic Circulation

采用二维的全球高分辨率(1/4°×1/4°)的自由表面诊断模型结合动力计算估算全球大洋环流,模拟结果与其他模拟结果非常相似。流函数的分布表明,全球大洋中的主要流系均得到体现,包括大洋环流的西向强化的现象(黑潮、湾流等)。黑潮主轴的流量约54Sv(1Sv=106m3/s),非常接近实测值;各层水平流场分布情况显示,各大洋的一些基本流系都能得到很好的再现。如黑潮和南极绕极流可深达底层。湾流不能到达深层,大约在1000～2000m之间海流即已转向。

A 2-dimensional global free surface diagnostic model, combined with the dynamic calculation, is used to investigate the world ocean circulation, which has a horizontal resolution of 1/4°×1/4°, The simulated results agree well with the results of other models and observations, The distribution of Stream Function suggests that the main circulation systems in the world ocean have been represented, involving that oceanic currents strengthened to the west. The net mass transport of the Kuroshio axes is estimated about 54 Sv, where is close to the observing result; The distribution of the horizontal circulation in each layer shows that the main circulation systems in the world ocean can be well simulated. For example, the Kuroshio and the Antarctic Circumpolar Current can go down to the bottom layer, but the Gulf Stream cannot, and its direction reverses at the depths from 1 000 to 2 000 m.