Abstract:In this paper, the description of an AMT model is given and the analysis on the feasibility of replacing the large-scale forecast winds with large-scale forecast geostrophic winds in operating AMT model in Changchun is made. Then,the scheme for the replacement is determined, which is tested in Changchun. Finally,the results of the experiment are given.

Abstract:In this paper, the characters of mesoscale structurs near the trough line are analysed based on the wind data of Doppler weather radar.It is shown that there are mesoscale divergence and convergence regions exis-ting near the trough line,thus causing the uneven distribution of precipi-tation. A cold advection occurs is in the boundary layer near to the ground while a warm advection forming at the level between 2.5km and 5.0km. The vertical wind shear appears at the 2.0-2.5km high level and the weak updraft at 2.7km high level. The precipitation area moves northeastward, due to the influence of the mesoscale circulation.

Abstract:The changes of temperature in China in the last 39 years have been studied. It is noticed that the temperature is increased by about 0.23℃ in China in the last 39 years. It is found that the most obvious warming occurs in winter time which is 0.78℃ increment and the secondary warming is a 0.34℃ increment, occuring in spring. But a cooling trend is presented in summer, which shows a -0.27℃ drop. Here the effects of the urbanization in China are also analysed. The annual temperature rising in the bigger cities is much more obviously found than that in the smaller cities in the last 39 years.

Abstract:In this paper, based on several tables and computing formulas of the Linke turbidity factor suggested in the literatures, it is found that the absorptions of solar radiation by some gases, such as O3, CO2, N,etc. in atmosphere, haven't carefully been considered in the most old methods, thus producing the greater systematic errors compared with the real values. Here, the computing formulas and tables obtained from the most recent research progress could made their contributions to the applications.