黄、东海陆架海域温度垂直结构类型划分与温跃层分析

基于黄、东海陆架海域1997—1999年4个季节调查的CTD资料,采用拟阶梯函数逼近法对温度垂直剖面拟合逼近,然后按拟合均方差和跃层强度对黄、东海陆架区的温度垂直结构进行类型划分,共划分为6个类型:三层结构型(T型)、主跃层上位型(U型)、主跃层下位型(L型)、多阶梯状结构型(M型)、异常结构型(A型)和垂直均匀型(H型)。分析结果表明:温度垂直结构类型在黄海区域为:春季呈L型;夏季呈U型;秋季呈T型;冬季呈H型。东海北部春季基本呈T型;夏季西部呈T型,东部呈U型;秋、冬季演变为H型;东海南部春、夏季主要呈L型;秋、冬季除近岸出现逆温类型外,大部分区域呈H型。利用风和潮的混合卷挟模式阐述了各种温度垂直结构的形成机制,最后给出了黄、东海陆架海域的主温跃层特征值的区域分布和季节变化。

Classification of Vertical Temperature Structure and Thermocline Analysis in the Yellow Sea and East China Sea Shelf Sea Areas

Based on the CTD data observed in the Yellow Sea and East China Sea shelf sea areas in different seasons during 1997 to 1999,the quasi-step function approximation method was used to fit the vertical temperature profiles,and the vertical temperature structures in the sea areas were then classified according to the fitted RMS errors and thermocline strengths.The vertical temperature structures can be classified into 6 types: three-layer type(type T),main thermocline upperlying type(type U),main thermocline lowerlying type(type L),multi-step type(type M),abnormal type(type A) and vertically homogeneous type(type H).It is shown from the analysis results that the vertical temperature structure types in the Yellow Sea are type L in spring,type U in summer,type T in autumn and type H in winter;those in the northern East China Sea are type T in spring,type T in the west part and type U in the east part in summer,type H in autumn and winter;those in the southern East China Sea are type L in spring and summer,type H in most of the sea area expect for type A1 in the inshore area in autumn and winter.In this paper,the mixed wind and tide entrainment model is used to expound the formation mechanisms of different vertical temperature structures,and the regional distributions and seasonal variations of the main thermocline characteristic values in the Yellow Sea and East China Sea shelf sea areas are also given.