Abstract:There were ten typhoon torrential rain events in North China during the midsummer from 1949 to 1996.Their maxima of total course rainfall (abbreviated to MTCR) each event were more than 400mm.By using the view point of the interaction between typhoon and westerly trough,weather patterns of these events have been classified.By practical experience,the typhoon trough,Hetao westerly trough,the high pressure of Japanese seaBohai sea,SEwind jet at 850hPa over Shanghai area and the weakcold air intrusion into typhoon are to be considered as the weather pattern criteria.It is shown that only five of the ten events belong to the interaction weather patterns′ but the others aren′t.These five events took place in the first tendays of Aug.in 1950,1963,1975,1984 and 1996.Besides,the interannual variations in typhoon′s MTCR have been computed by the lagcovariance power spectral analysis.It is shown that there are two periods.One is 11 yrs,the other is 31 yrs.And the 5 interaction weather pattern events mentioned above are the main components of the 11 yr period.According to the crossspectral analysis,there is a high coherence with high confidence at intervals of 11 years between the typhoon′s MTCR and the sun spots.Phase angle difference shows that the year of typhoon′s exceptional MTCR in general lags around 5 yrs behind the Myear of the sun spots.

Abstract:The satellite monitoring fire spot threeply position system in Yunnan province is a computer position system that can position fire spot similar to GIS.Practices show that the system can implement the most of satellite monitoring forest fire works and satisfy the needs of mountain area fire prevention of Yunnan.

Abstract:By using real-time data and physical parameters given by HLAFS,the weather/climate features of torrential rainfalls during the flood season in 1996 are analysed and the causes of four torrential rain events during the period of meiyu and the heavy storm rainfall of typhoon 9608 are diagnosed.The results will benefit both operational forecast and research work.

Abstract:The reason of the extreme rainfall event occurred in 3-5 August 1996 over Hebei province has been studied using conventional meteorological data and satellite imagery.The results show that the event presented itself in a strong meridional circulation in eastern Asia and stronger lowlevel southern jet which was caused by stronger pressure gradient between typhoon low and subtropical high.The jet transmitted high thermal and moisture air from the tropics to North China,and interacted with weaker cold air near surface.And generated and developed were two mesoscale cloud clusters causing the extreme rainfall directly.

Abstract:Using the routine synoptic maps,autographic precipitation data and satellite cloud picture,the evolution of a mesoscale system was analysed,which caused a rarely heavy torrential rain in Shangxi and Hebei from 3 to 5 August in 1996 under the influence of 9608 typhoon.Some features of typhoon torrential rain in North China were revealed.

Abstract:Using the data of 3dimension wind vane,the diffusionparameter of radiation fog in Anning City is studied.Results show that the average velocity is a key factor that affects the horizontal turbulence and contributes much to the mean square deviation of winddirection.It is also revealed that the horizontal turbulence is much stronger than the vertical turbulence while the radiation-fog appears.

Abstract:The total rice yields prediction all the world are discussed by means of spectrum analysis and stepwise regression period analysis,the result shows that the stepwise regression period analysis has better simulation precision and forecasting precision.

Abstract:Application of catastrophe theory to visibility forecast is discussed.The results show that the low visibility can be estimated by computing the change distribution of middle upper air temperature and air pressure.Furthermore ,to some extent the mathematical symbols alternation of the middle upper air temperature changes and the air pressure changes indicate the formation or the elimination of low visibility.

Abstract:The data of T63L16 and NWP of Japan are used to select the canonical factor fields.Based on the correlations analysis,the average and maximum fields are then made by the use of the canonical factor fields.The regression analysis is used to forecast precipitation during flood season in the Yellow River delta.Results show that the regression equations have value in the operational forecast.

Abstract:The typhoon year-book data (1949-1994)are used to analyse the tropical cyclone.First,the tropical cyclones entered in north of 30°N and west of 125°E are defined as the influencing the northern China tropical cyclones.Then according to the track differences of rtopical cyclones,they are further classified into six kinds(Northwards before landfall,turn before landfall,northwards after landfall,filling after landfall,turn after landfall and westwards).In the last,the climate features of each kind of tropical cyclones are analysed in detail.

Abstract:The nearly 40 years data of nocturnal torrential rain was studied for 34 weather stations located in the Eerduosi Basin and its surrounding area with characteristics of arid and semi-arid zone,and desert region.The daytime and nighttime distribution of torrential rain in the basin and surroundings was analysed.The extremes of torrential rain during daytime or nighttime was given.The orographic influence on the nocturnal torrential rain was discussed.

Abstract:Based on the daily precipitation data of 29 meteorological stations in Sanxia reservoir region from 1961 to 1994,a climatic analysis of the dates on which the first heavy rain occurred in the region after the dry seasons is carried out. The region is divided into the east and the west parts, and the dates of the first heavy rain in the two parts are compared. The statistical results obtained provide a valuable reference for the current construction in Sanxia region.

Abstract:By analysis of the forest fire occured in Hubei province from Jan.1987 to April 1990,a set of objective forecasting indexes of atmospheric circulation about fire weather are established.In addition,surface weather factor are used to calculate the index reflecting moisture content of fuels,and the level of forest fire danger can be forecasted.From Nov.1995 to Jan.1996,the experiment results showed that the forecasting method is a useful tool for forecasting forest fire weather.