地形对低平流层突然增温的可能影响

本文用Nimbus7 SAM卫星观测的温度资料,分析了突然增温事例中地面地形不同的四个子午圈剖面内的温度分布及变化过程。结果表明,高山地区、平原和海面上空的行星波加热和低平流层突然增温有很大的差别。地形的影响是明显的。 

THE POSSIBLE INFLUENCE OF THE TOPOGRAPHY ON THE STRATOSPHERIC SUDDEN WARMING

The temperature data from satellite Nimbus 7 SAMS are used to analyse the latitude-altitude distribution of temperature and its temporal variation during the period of stratospheric sudden warming in winter. The distribution profiles for four meridians with different topographic features are shown in this paper. The analysis inlicates significant effects of the to pographic feature.The heating of the atmosphere caused by the planetary wave and the sudden warming in the lower stratosphere over mountain, plain and ocean, are obviously different.It is generally believed that the stratospheric planetary waves are forced in the troposphere by topography and by adiabatic heating associated with land and sea thermal contract, and propagate vertically from the troposphere. The considerable sudden warmings of the lower stratosphere over high latitudes on 80°Eand 100°Emeridians shown in this study are chiefly responding to the stronger solar heating on the land aera. The topographic effect on the stratospheric sudden warming in the west of China is of importance for understanding the coupling between the troposphere and stratosphere. The sudden warming could change the local atmospheric circulation. It is often accompanied by abnormal absorption of radio waves propagating through the ionospheric Dlayer. Therefore, the influence of the topography on the behaviors of the stratosphere and ionosphere is also an important topic for study of aeronomy.The large increase of temperature in the stratopause over high latitudes on 20 °Elongitude, which covers the Europe plain, is found in this case too. No sudden warming, however, appears in the lower stratosphere. As regard to 180°Elongitude crossing mainly over the sea area, even the enhancement of temperature in the higher stratosphere is not apparent. These different features prove again the topographic effect on stratospheric behavior.