Study On The Characteristics Of Rainstorm And The Spring Typical Regional Rainstorm In Dalian

The rainstorm is one of the main disasters weather in Dalian, but in the past few decades related research is less, and the researches focused on the analysis of the typical examples rainstorm, lack of systematic and deep research. The comprehensive and system research is not only have improve prediction accuracy and reduce disasters loss's real meaning, while have reveal Peninsula rainstorm significance's scientific meaning.Based on statistics analysis of historical rainstorm data of Dalian, and use the reference of related achievements, summarizes the typical types of rainstorm in Dalian, comparison analysis the rainstorm difference of the Liaodong peninsula south region and northeast, find out the special of peninsula's rainstorm, study two spring typical regional rainstorms. Using the 7 stations of Dalian 24 hours precipitation amount during 1962 to 2007, high and surface observe data, automatic meteorological observation Doppler radar satellite and NCEP 2.5°×2.5°grid 4-times daily data.The paper mainly includes four parts. The first part is base on statistical daily rainfall in 46 years Dalian area, and analysis rainstorm's characteristics from time space and climate, the study found:days of rainstorm have obvious inter-annual change; rainstorm season changes obviously, from a regional distribution has from west to east, south to north increase characteristics.The second part is establish type. Through the survey of heavy weather situation large scope, using of statistical analysis, combined with classified and compared, similar to large scope of Dalian heavy weather situation, classified into five types:(1) the typhoon rainstorm, (2) the long distance interaction of typhoon rainstorm, (3) cyclone rainstorm, (4) Vortex rainstorm, (5) near the subtropical high rainstorm.The third part analysis the difference of the Liaodong peninsula south region and northeast, find that occur early and over later, the center of northeast is Liaodong peninsula,1970-1987 and 1987-2005' inter-annual change is opposite to Jilin and Heilongjiang, the main influencing system is subtropical high and cyclone, the influence of vortex is less than northeast others area.The fourth part focuses on analyzing the spring rainstorm in Dalian area. Selecting typical cyclone rainstorm 2 cases, the case A(March 4,2007)and the case B(April 19,2009).The result show that:(1)Jianghuai cyclone is the main effect system in spring rainstorm, and the path of cyclone has important influence on the rainstorm drop zone.(2) During the spring rainstorm there is good large scale circulation.(3) The rainy area and the intensity of rainstorm are closely related to the coupling of low level and upper level Jet.(4) Low-level warming, humidification, and the invasion of cold air is the main factor leading to the spring rainstorm.(5) The establishment and prolonged maintenance of vapor conveyor belt for rainstorm provided sufficient water vapor conditions.(6)High-level divergence and low-level convergence of the vertical configuration, and deep a strong upward sport, in order to rainstorms in the conditions provided a strong impetus to.(7) A strong increase in the formation of a deep cyclone movement vertical circulation, the development of cyclone on the ground to strengthen the role of promoting.Concludingly,the paper revealed the rainstorm spatial and temporal distribution characteristics in Dalian area, and established mainly rainstorm weather model, analysis the character of peninsula rainstorm,also deeply analyzes the characteristics of the spring rainstorm, all this basic work has certain practical value not only for more scientific and comprehensive understanding of Dalian rainstorm but also for further scientific research and practical forecast.