Abstract:Large-and meso-scale flow fields of SW vortex heavy rainfall are comprehensively analysed and their physics schemes are given.Their meso-scale characteristics are revealed using hourly rain intensity, rader echoes and satellite data That does us a great help to further understand the formation development and internal constructure of SW vortex.

Abstract:In the paper, the low temperature and steadily rainy synoptic process is defined based on temperature and precipitation data. It is discovered that the tropical circulation and spectrum features in the process of steadily rainning varies significantly from that of steadily shining. The distribution of total cloud cover on the section of 156°E is obviously differents from that of 180° in the tropical Pacific. In addition ,the El Nino year has got a relationship much closer with the steadily rainning weather in the middle and lower reaches of the Changjiang River .

Abstract:An analysis of the instantaneous wind speed measurements made once every minute by LSF1-1 type anemometer has shown that such kind of instrument can be used to measure the wind speed fluctuation in a longer period while its accuracy is quite low EL and Dyne anemometers are not suitable for measuring wind speed fluctuation in a small-scale wind field because of their low precision and sensitivity.

Abstract:Since the prediction model is influenced by the multicolinearity of the selected factors and the unstability of the correlated coefficient, principal component analysis is used in this paper. Along with the compound factors of pricipal components of primary selected factors and the periodic components of prediction factors as well as the principal components itself, a stepwite regression model for predicting winter wheat yield in the major winter wheat areas of North Chian is established. Both its fitness and feasibility are better than those of the ordinary stepvvise regression models.