Abstract:Considering the randomness of homogeneous out-growth function ,the new criterion for screening factors is used in the period analysis and an improved scheme of stepwise regression is brought out.From the case computations, such as the sea surface temperature in the equatorial Eastern Pacific area,the precipitation over the regions along Changjiang River and in southern China during the rainy scaso,n,the sunspot and the tree ring index,it is found that the scheme is not only suitable for long-term prediction but also capable of detecting the potential periods in a time series.

Abstract:In this paper, using the model of wind profile of Monin-Obukhov in the near surface layer, the zero-plane displacement d; the roughness parameter z₀; friction velocity u and aerodynamic resistance factors γ_av and γ_am are calculated. The characteristics of d, z₀, u_*, γ_av and γ_am, and their variations with wind velocity and stability are analyzed and discussed.

Abstract:In this paper, the radar echoes in the case of heavy rain over the north of Fujian on 21, May, 1988 are analysed. The characteristics of the echoes and the embient condition are introduced. The meso-scale weather system and the influence of topography on the radar echoes are discussed.

Abstract:The economic effeciency of meteorological forecasts service for the forestry in Yichun City of China is calculated. There are two parts in this paper. Firstly, the method for such a calculation is discussed. Secondly, the result of calculation is given. It shows that the ratio of the profits gained from meteorological forecasts service for forestry in Yichun City and its cost is 54.2 to 1 .

Abstract:The relationship between El-Nino and the temperature in China is analysed in the paper. The results indicate that the temperature is lower in the spring and summer but higher in the autumn, winter and the following spring than normal during the El-Nino period. The change is caused by seasonal change of the sea surface temperature that is lower in the summer half year and is higher in the winter half year during the period in Kuro-shio current region. Temperature distribution is reverse during La-Nino period.