Abstract:Studies on the climatic simulation are reviewed. Three stages are identified according to the objectives of the studies,simulation of normal regime of the climate,sensitivity experiments,and simulation of climatic variability. Simulation studies of climatic variability during the last decade were synthesized. Simulation results on the following subjects are discussed;Indian summer monsoon rainfall, drought in Sahel,climatic variability, world atmospheric circulation oscillations, ENSO cyele and drought/flood patterns in China.

Abstract:A review of achievements on temperature variation during the last 100 years in China is made. It is found that the general tendency of warming in China is similar to that in the Northern Hemisphere,but with some significant differences in the evolutive process and warming magnitudes. These differences include (1 ) the peak temperature in China occurred in the 40's rather than after the 80's; (2 )since the 50's the cooling was observed in southwest China while the warming mainly occurred in Northeast China, North China and (3) the two sudden changes in temperature variations in China during the last 100 years were observed, with the first one occurred in 1919 and the second one in 1952. The effect of urbanization on the measurements of air temperature and their correction methods are also discussed. The amplitude of the temperature variation in China during the last 100 years does not exceed the range of natural climate fluctuations. Therefore,it is uncertain that the above temperature variation is caused by human activity.

Abstract:Obvious progress has been made in the NWP of the National Meteorological Center in resent 15 years.The numerical prediction models were developed from a Northern hemisphere model to global spectrum model with a data assimilation system and a limited area model for precipitation forecasting. The prediction models for heavy rain and typhoon track are under development.At present,the valid time of the operational NWP has extended up to 7 days. The skill of present model T63's 96 hours prediction is better than that of the 48 hours prediction five years ago.The applied technology of NWP has been developing continuously.

Abstract:The basic differences of predictabilities between the tropical cyclone motion (TCM) and the evolution of large-scale wave flow patterns are discussed, brief discription of the two kinds of methods on studies of the predictability of TCM,and review of recent progress concerning the predictability of TCM are made.

Abstract:The synoptic and climatic features of huang-huai cyclones from 1979 to 1988 are analysed. It is concluded that huang-huai cyclone is the suitable synoptic system for aircraft precipitation stimulation. A case analysis about the maroscopic and microphysical property was made. The supercooled water content is 0. 16g. m_-3.

Abstract:Air parcel backward trajectories of long-range transport at six coastal cities, Dalian, Qingdao,Shanghai, Fuzhou,Xiamen and Guangzhou,are discussed.The transport layer is assumed to be 1500 m high, the trajectories during January, April, July and October 1985,are computed. The trajectory analysis shows that: (1 )The backward trajectories of air parcel are related to weather situations and seasons,and however the backward trajectories between the coastal cities in the North and in the South are different.(2)The transport-distances (the backward trajectory of 72 h) of the coastal cities in the North are farther than that in the South.

Abstract:The causative factors of black storm in Hexi Corridor are analysed.A method of short range forecasting is developed. The forecast test of 9 black storms appeared after the 1970s.This forecasting method is noted for its simpleness,accuracy,availabihty and convenience of application.