平流层球面大气地转适应过程和惯性重力波的激发  

Geostrophic Adaptation Process and Excitement of Inertial-GravityWaves in the Stratospheric Spherical Atmosphere

作　　者：黄荣辉[1] 陈金中[1] 

机构地区：[1]中国科学院大气物理研究所,北京100080

出　　处：《大气科学》2002年第3期289-306,共18页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展规划项目G1998040900第一部分资助

摘　　要：观测表明，在1979年2月平流层爆发性增温期间由于准定常行星波的上传，平流层存在着强烈非地转运动，从而导致很强的散度场和很强的大振幅重力波活动。作者用Hough函数构造一个线性正压全球谱模式，以1979年2月22日平流层爆发性增温期间10hPa上的实际地转偏差作为初始扰动来模拟平流层在爆发性增温时非地转扰动的地转适应过程，并从散度场的变化来讨论平流层爆发性增温时重力波的激发和传播。模拟结果表明：由于在平流层爆发增温时，伴随着大范围的非地转运动的产生，气压场将很快与流场相互调整（此过程以气压场向流场调整为主），经过2～4h气压场与流场达到地转关系，并且在适应过程中散度场产生剧烈变化，这说明在适应过程中所激发的惯性重力波的活动是很剧烈的。Abstract The observations showed that due to the upward propagation of' quasi-stationary planetu-ry waves, strong gcostrophic motion existed in the stratosphere, which caused strong divergence field and strong, large-amplitude gravity-wave actions during the stralospherif sudden warming in February, 1979. In order to simulate this process, the Hough function is used to structure a linear, harotropic spherical-spectral model. Taking the actual geostrophic deviations at 10 hPa in February 22, 1979 as the initial disturbances, the gcos trophic adaptation process of geoslrophic disturbances during I he stratospheric sudden warming is simulated by using this model. Moreover, the excitement and propagation of gravity waves during the stratospheric sudden warming are also discussed from the variations of divergence field. The simulated result shows that when (he sudden warming occurs in the stratosphere, the pressure field adjusts quickly with the velocity field each other (in the adaptation process, mainly the pressure field is adjusted to the velocity field), and through 2-*' 3 h. a geoslrophic relation between the pressure field and the velocity field is established. Moreover, (he divergence field occurs serious varia lions during the adaptation process, and this may explain that the meitial-gravity wave actions excited in the adaptation process arc serious.

关 键 词：平流场 地转适应 惯性重力波 Hough函数 平流层 线性正压全球谱模式 非地球运动 气压场 

分 类 号：P433[天文地球—大气科学及气象学]