Abstract:The presentation of back trajectory information from synoptic analyses and forecasts can provide additional forecast guidance. A package has been developed to compute backward and forward trajectories in three dimensions,with three velocity components. from the Australia Bureau of Meteorology operational limited area 36-hour forecasts. Three forms of output are available,backward trajectories,forward trajectories, and a contoured field of 36(hour air parcel displacement to a chosen vertical coordinate surface. The package has also been applied to diagnostic studles.

Abstract:The heat balance character of artificial vegetation on sand dunes in Shapotou region were calculated and analysed. The results show that: (1) about 70 percent of net radiation is dispersing as latent flux,about 15 percent is dispersing as sensible heat flux,and about 15 percent is stored in the soil in the artificial vegetation region on sand dunes. (2) about 60 percent of net radiation is dispersing as latent heat flux,about 15 percent is dispersing as sensible heat flux,about 25 persent is stored in the soil in the bare sand dunes. (3) the water vapour content is higher than that of another dry area in Shapotou region.

Abstract:Weather conditions of citrus growing processes and quality forming are studied. The results show that temperature is a key factor for citrus quality and quantity. And proper meteorological indexes to fruit growth and the best quality are obtained.

Abstract:Data at 925hpa standard prssure level is included in TTAA synoptic code since october,1991. According to the summer experiment in 1992 at the Beijing-Tianjin-Hebei Disastrous Weather Experiment Base Centre,it was indicated that the data at 925hpa standard pressure level is very useful for severe convective weather forecasting.

Abstract:The one-layer mesoscale model designed by David is used to study the daily variation factors of thermal contrast between land and sea,the mescscale air stream resulted from the heating or cooling of the underlying surface daily variation process over Tianjin and Bobal bay areas in winter and summer,and therefore to inquire into the cause in resulting the suddenly severe weathe r(high wind, torrential rain )etc.) over Bobal bay.

Abstract:Approximate formulas for calculating saturated water vapor pressure over ice are reviewed.A new and more accurate and simple approximate formula is given. Its calculation results are compared with other formulas.

Abstract:Based on data from 1974 to 1992,the date of rainy seasons beginning is determined with synoptic and statistical method.And some forecast indexes for the rainy season beginning are found with general circulation features and meteorological elements at Xichang Satellite Launch Center.

Abstract:The temporal and spatial change of plant climate productivity recent 40 years and the changes of anomaly field in 1950s, 1960s, 1970s and 1980s are analyesed with the data at 350 stations well distributed in China. And the effects of “Warm-Dry", “Warm-Wet",“Cold-Wet"and“Cold-Dry"climate on plant climate productivity are discussed.

Abstract:Synoptic and diagnostic analysis have been performed for a heavy rainstorm in June, 6-7, 1986 in Kunming, Yunnan Province, of which is Kunming'S maximum daily precipitation since 1951. The results show that local heavy rainstorm may occur at single point in early summer in Yunnan Province,with its rainfall equals that in midsummer and autumn. The main characters of heavy rainstorm are as following. Dry cold trough at 500hpa moved eastward while double vortexes attracting and rotating moved westward. Weak cold air at surface induced stationary front with strong vertical wind shear,and therefore there existed a direct circulation and a counter circulation. These are different from the regional heavy rain and heavy rainstorm in low latitude plateau area.

Abstract:The terms and speacial indices,which can be refered for the hydroelectric meteorological service,of a series of meteorological services to small hydroelectric station are obtained.

Abstract:Based on meteorological observations and forest fires from 1980 to 1991, the relationship between forest fire and meteorological elements is analysed. Indices and a model for weather forecast of forest fire are given. The weather forecast of forest fire grade has been made.