中国台湾周边深水区温度跃层特征分析

Analysis of thermocline features in the deep water near Taiwan Island

本文基于1992—2002年(不包含1999年)十年间的中国台湾周边海域深水区3 700多个高分辨率CTD剖面观测数据和垂向梯度法,分析了中国台湾西南、东南和东北三个海域深水区的温跃层特征。结果表明:中国台湾西南海域的温跃层深度浅于中国台湾东南和东北海域的温跃层深度,但中国台湾西南海域的温跃层厚度介于中国台湾东南和东北海域的温跃层厚度之间。中国台湾东南和西南海域的温跃层深度和厚度存在明显的季节变化规律:温跃层深度冬季最大,夏季最小;而温跃层厚度的变化规律正好相反,即夏季最大,冬季最小。对于中国台湾东北海域,其温跃层深度和厚度则在6—10月间存在显著的震荡特征。此外,三个区域的温跃层深度均在1998年前后出现一个极小值,推测与当年的厄尔尼诺事件有关。

Based on the temperature measurements from nearly 3600 CTD stations during 1992 to 2002(excluding 1999) and the vertical gradient method,the thermocline features in the southwestern,southeastern and northeastern regions of Taiwan Island were investigated.Results indicated that the thermocline depth in the southwestern region is shallower than those in the southeastern and northeastern regions,whereas the thermocline thickness was in the middle of those in the southeastern and northeastern regions.Both thermocline depth and thickness in the southwestern and southeastern regions had seasonal variations:the thermocline depth reached the maximum in winter and minimum in summer,while the thermocline thickness reached the maximum in summer and minimum in winter.However,in the northeastern region,both thermocline depth and thickness exhibited oscillations during June to October.Moreover,the thermocline depths in the three regions reached the minimum in 1998,which may be attributed to the El Nino event.