赤道西太平洋大气热结构及对流层顶变化特征的分析

Analyses of the Voriation Features of the Atmospheric Thermal Structure and Tropopause over the Equatorial Western Pacific Ocean

本文主要利用ＴＯＧＡ—ＣＯＡＲＥ强化观测期间“实验３３”号船的探空资料，经分析发现：赤道西太平洋暖池中心区，对流层大气平均温度直减率为０．６２～０．７４℃／１００ｍ，但是，在西风爆发期间，一般不低于０．６８℃／１００ｍ；对流活动的强弱对对流层顶有重要影响；对流层顶与５００ｈＰａ、２００ｈＰａ等压面温度存在显著线性相关；平流层下部有逆温层、降温层交替出现的成层现象。分析还发现，日平均的５００ｈＰａ、２００ｈＰａ温度、对流层顶、对流层顶上第一送温层的厚度和逆温强度，都具有２０～４０天振荡的特征。文章分析认为，上述有关赤道西太平洋暖池区大气热结构的基本特征，体现了热带西太平洋夏半球大气的状况；积云对流活动对大气对流层中上部温度、对流层顶以及平流层下部的２０～４０天振荡的形成有重要影响。

The features of the atmospheric thermal structure over the equatorial western Pacific ocean are discussed in this paper based on the analyses of the real time data obtained by the vessel 'Shiyan 3'during the intensive observing period of TOGA--COARE. These features are: (1) the tropospheric mean temperature lapse rate over the core of the western Pacific warm pool varies from 0.62 to 0.74℃ / 100 m, but it is not less than 0.68℃ / 100 m during the westerly outbreak, (2) convection activities have an important effect on the tropical tropopause. It is noticeable that the heating of the atmosphere between 500 hPa and 200 hPa affects the tropopause greatly, (3) there are several inversion layers and detemperature layers in the lower stratosphere, which appear alternately with the altitude, (4) a 20￣ 40day oscillation is shown in the variation of the temperature at 500 hPa and 200 hPa, the height and temperature of the tropopause, the inversion intensity and thickness of the first inversion layer in the lower stratosphere. It may be concluded that the 20￣ 40 day oscillation mentioned above is closely related with westerly outbreaks and SCCs which appear over the western Pacific warm pool.