东海黑潮区温度的月际变化特征

MONTH TEMPERATURE DISTRIBUTION OF KUROSHIO IN EAST CHINA SEA

使用美国海洋大气局2010年发布的海洋温度数据库、地球物理数据中心2006年发布的海底地形数据库,研发三维体积、切面可视和分析技术,探讨东海黑潮区温度逐月空间变化。得出,从东海黑潮的入口到出口,表层平均温度的差值在4—5月份最大,8—9月份最小,反映黑潮与东海热交换的月季变化;表层温度的年较差和月差值在128°E附近最大,指示了黑潮与东海陆架水热量交换最多的部位。以深度220m为转换层,从东海黑潮的入口到出口,在转换层以上同深度温度呈下降趋势,以下呈上升的趋势;反映黑潮进入东海后中层水的扩张。从温位差判断,在表层,东海黑潮区的热交换在3—4月份最大,在9月份最小;热交换主要出现在靠东海大陆架一侧,热交换最大的区域在台湾东北海域、127°E附近的海域和吐噶喇海峡东北侧。从平均温位差推断,在东海黑潮区,热交换主要出现在30—150m层,在7—9月份最大,11—1月份最小。

The temperature distribution for the Kuroshio in the East China Sea （ECS-Kuroshio） is analyzed using the data from World Ocean Atlas 2009. It is found, the monthly temperature difference at surface layer （0—50m） gets the largest in the April-May and the least in the August--September, from the entrance of ECS-Kuroshio, section 24.5°N near east of Taiwan island, to the exit of ECS-Kuroshio, section 130°E near the Tokara Strait. It implies that the heat ex- change in ECS-Kuroshio gets to the biggest in April--May at surface layer. Along ECS-Kuroshio current, the values of yearly-temperature-difference and monthly-temperature-difference become largest around section 128°E, it implies that the region around 128°E is area with largest heat exchange between East China Sea and Kuroshio. From the entrance to the exit of ECS-Kuroshio, there is temperature transformational layer （TTL） at the depth around 220m. Up the TTL, the tem- perature is decreasing with ECS-Kuroshio current for the same depth, but the temperature is increasing below the TTL. This characteristic is most remarkably in February. The process should be when Kuroshio enters ECS, the upper water outspread toward area of ECS continental shelf, and the water layer below the TTL expand toward the bottom of Okinawa Trough. Analysis of the temperature-potential-difference shows that heat exchange becomes the largest around March-April and the lowest at September at surface layer of ECS-Kuroshio; the areas with the larger heat exchange values are at the sea areas of northeast out Taiwan Island, around 127°E and Northeast of Tokara Strait. The heat exchange gets to the largest at July--September and reduces to the lowest at November--January in the layer of 30--150m in ECS-Kuroshio depending temperature-potential-difference.