一个大洋环流模式中赤道西太平洋暖池海面温度对西风爆发的响应  

Simulated Responses of SST to Westerly Wind Bursts in the Western Equatorial Pacific Warm Pool

作　　者：刘海龙[1] 李薇[1] 张学洪[1] 俞永强[1] 

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029

出　　处：《大气科学》2002年第2期171-184,共14页Chinese Journal of Atmospheric Sciences

基　　金：国家"九五"重中之重项目"我国短期气候预测系统的研究"(96-908-02-03);优秀国家重点实验室研究项目4982-300

摘　　要：用逐日的欧洲中期数值预报中心再分析（ＥＲＡ）风应力，和由Ｈａｎｅｙ公式结合ＥＲＡ海表资料与预报海温计算出的热通量强迫一个全球大洋环流模式。并用逐日的模拟结果与ＴＯＧＡ－ＣＯＡＲＥ（Ｔｒｏｐｉｃａｌ Ｏｃｅａｎ－Ｇｌｏｂａｌ Ａｔｍｏｓｐｈｅｒｅ－Ｃｏｕｐｌｅｄ Ｏｃｅａｎ—ＡｔｍｏｓｐｈｅｒｅＲｅｓｐｏｎｓｅ Ｅｘｐｅｒｉｍｅｎｔ）浮标观测资料对比，分析模拟结果中暖池海区上层海洋热量平衡对西风爆发（ＷＷＢ）的响应。在第一次ＷＷＢ过程中，模拟与观测的主要差异在ＷＷＢ期间，而造成差异的原因主要是模式中由下沉运动引起的增温和由强的纬向温度梯度引起的暖平流。初步认为下沉增温可能是差分格式本身和模式分辨率不足造成的。从热量平衡的结果看，第二次ＷＷＢ事件的模拟比第一次更成功，两次差异可能与两次ＷＷＢ事件的季节背景不同有关。An ocean general circulation model is forced by daily ECMWF reanalysis(ERA) wind stresses and the heat fluxes calculated by Haney formula in the tropical Pacific. To examine the intraseansonal variabilities of simulated sea surface temperature(SST) in the warm pool, the heat bal- ance of the upper ocean mixed layer has been calculated based on Stevenson and Niiler's isopycnal method using the daily model output. The results are compared with the mooring buoys data during Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment(TOGA COARE) in the TOGA COARE domain. There are some differences between the simulated and the ob- served variabilities of SST on intraseasonal timescale around(0°, 156°E), especially during the first westerly wind bursts(WWB) from October 17, 1992 to November 12, 1992. The simulated heat balance indicates that the bias during the first WWB is mainly caused by downwelling and zonal warm advection. The difference scheme and the insuffcient resolution are two causes that lead to this phe- nomenon. It is worth to point out that the simulated heat balance during the second WWB from De- cember 8, 1992 to December 17, 1992 is much closer to the observation than that during the first WWB, which, we guess, is connected with the different seasonal background of the two WWBs.

关 键 词：西风爆发 大洋环流模式 西太平洋 暖池 热量平衡 海面温度 风应力 海表热通量 

分 类 号：P732.6[天文地球—海洋科学]