Abstract:The recent status of hail suppression in Soviet Union, United States, China, and many countries in Europe are presented, based on the results published in the international weather modification conferences. The methods of hail,suppression operation and evaluation of hail prevention effects, especially the statistical method of kinetic energy of hail fall to the ground are also involved in the paper.Timing and correct placement of seeding materical and time of seeding are particularly critical to "successful suppression.

Abstract:In this paper, based on 4 squall line processes occured over North China during 6-7, 1986,the synoptic situations of occurrence of squall line are analysed, and have been compared with commonly convective activity. It is found that the occurrence of squall line is related to the cold air breakout in the middle levels.Before its occurrence,. the unstable energy are characteristic of larger, concentrative distribution and increased with time. Some significant results could be useful for analysing and forecasting the occurrence of squall line.

Abstract:In this paper, a method to select some nonlinear predictors and to build a nonlinear forecasting equation was proposed based on optimization principles. The experiments show both the nonlinear predictors and corresponding equation based on this method are better than those linear equations. Finally, the authors indicate that this method can be extended to building of nonlinear discriminatory equation when predi-ctands are discrete. This method is applicable to various forecastings of long-, medium- and short-ranges.

Abstract:From the long-term continuous automatic observation to the global solar radiation Q and PAR Q_PAR in Beijing, Yantai, Zhengzhou and Jinan during the growth period, it is discovered that the value of Q_PAR/Q is about stable. The effect of the season and cloud amount to it is nominal. The variation at the lower solar elevation is caused by the cosine response of the instrument. The current instrument manufacturing technique can not satisfy the need of the study on effect of the solar elevation on Q_PAR/Q. The analysis of the observation data gives that some formula parameters in abroad is higher,the computation formula Q_PAR = 0.42 Q which suitable to the east plain in China is obtained.

Abstract:The retrievals from the AVHRR/HRPT data sea surface temperature computation software system using the NOAA-7 and NOAA-9 AVHRR data received at Beijing Meteorological Satellite Ground Station during the periods of 17, February and 7, September 1984, and 19-20, August, 14, September and 13-15, October, 1986, respectively, were compared with simultaneous measurements from ships and buoys. The result from these comparisons shows that the averaged root mean sq'uare deviation for the above five periods is about 1.01℃.

Abstract:This text introduces a pocket electronic instrument which is designed by the method of Ultrasonic pulses and is able to digitally display the meaned results of the evaporation and the water level. The working principles of the instrument, the calculation, the measuring circuit and the experimental results have been discussed and analyzed. The status of the evaporating observation and the problems about its automation have been discussed as well.