不同CTD数据垂向分辨率对黑潮地转流动力计算的影响分析

The Influence of CTD Data Resolution on Calculating Geostrophic Flow of Kuroshio

基于日本海洋信息中心提供的东海黑潮PN断面垂向分辨率不同的2种CTD数据,采用动力高度法计算了2000—2011年的断面流速。通过对49个航次的流场结构、最大流速、流幅、流量等黑潮特征值的对比,分析了不同数据垂向分辨率对黑潮地转流动力计算的影响。结果表明:数据垂向分辨率不同对东海黑潮的流量几乎没有影响,对平均流幅影响很小,对流核位置略有影响,但对平均流核个数、平均最大流速影响较大。2种数据对应的流场差异主要有:与低分辨率数据对应的流场相比较,高分辨率数据对应的流场流核区流速较大、平均流核数偏多。不同流核结构在2种数据对应的流场中出现概率差别较大,低分辨率数据结果中的单核结构出现概率最高,高分辨率数据结果中的双核结构出现概率最高。

Based on the CTD data with high and low resolutions at PN section provided by Japanese Oceanographic Data Center,the current velocity during 2000 to 2011are calculated with dynamic height method.The influence of vertical resolution of data on calculating the geostrophic flow of Kuroshio is analyzed by comparing the structure,maximum velocity,flux and width of the current observed by 49 cruises.The results show that：vertical resolution of data has little influence on flux and minor influence on the location of current core,but great influences on current core number and maximum velocity.The differences in current structure derived from the two different resolution data are as follows：the current structure based on high resolution data has stronger velocity in the core area and more current cores than the one based on low resolution data;single core structure occurs more frequently in the current structure of low resolution data and double core structure has the highest occurring frequency in the current structure of high resolution data.