Studies On Physical Mechanism Of Snowstorm In Inner Mongolia And Its Forecasting Technique

China is famous for his stockbreeding all over the world. Chinese grassland is one of important compositions of Eurasian grasslands. They include Inner Mongolian grassland, which is the pride of place of all over China. Inner Mongolian Grassland ranges 4000 km from Daxingan mountain to Juyan lake and its acreage is 22％of Chinese grassland. Recently, Inner Mongolia stockbreeding have acted on the most importanted status in the economical society. The blizzard is one of severe meteorological disasters over Inner Mongolia, especially in pasturing area. For not much chance of severe snowstorm companying with strong wind and clod air break, most relative researches mainly focus on one or two aspects, and then, there are hardly ever systematic and quantitative analyses done. Therefore, it is necessary to improve our prediction skill for blizzard weather with throughout analyses.For the first time, in order to research it further, by using conventional observations data, disaster data and NCAR/NCEP reanalysis (2.5×2.5), 21 strong or relatively strong blizzard processes occurring in Inner Mongonia (mainly pasture) in recent 40 years have been studied in this paper specially. Meanwhile, we make dynamical diagnose for one powerful snowstorm process in Xilinguoie-meng and further research on Mongolia cold vortex which is the primary influential system for blizzard over Inner Mongolia, by using NECP reanalysis (1x1). Chief conclusions are as follows: (1)according to different coupling of general circulation characteristics and downstream system, three classes (weak trough developing pattern, western trough moving toward east pattern and transverse trough changing to trough pattern) of general circulation are gotten; (2)severe cold air activity is an important cause of severe snowstorm; (3)force of intensive upper level jet stream and its accompanying divergence region offers the dynamical force for the developing of Mongolian cyclone and forming of strong wind; (4)the combination of long-distance water vapor transportation and lower level cold vortex convergence play an key role in strong snowfall; (5)divergence force in upper troposphere, temperature difference between middle and lower levels and middle level vorticity advection are of high importance for the breakout develop of Mongolian cyclone; (6)meeting of lower level quasi-southern warm and wet steam and quasi-western cold and dry steam over the control area of Mongolian cyclone features the occurrence of blizzard weather; (7) the structure that middle level strong ascending motion and low level strong wind area in troposphere is helpful to identify snowfall area. On the basis of conclusions above, we summarize the effective predicting methods and fixed quantity indices for the forecast of blizzard weather in Inner Mongolia, providing significant scientific basis and feasible scheme for highlighting snowstorm prediction and establishing emergency project.