A Study On The Tropical Cyclone Torrential Rain Over Liaodong Peninsula

Heavy rainfall in the Liaodong Peninsula is mostly induced by tropical cyclones which move northward after their landfall and pass through Huanghai Sea and Bohai Sea. The tropical cyclones moving northward gain the baroclinic energy from the cold air in middle-latitude, its structure and intensity would be changed, the mesoscale convective systems (MCS) often occur in the extratropical transition (ET) processes. The high impact weather, such as heavy rainfall and high winds, would be occurred during the tropical cyclones move toward north after landfall. Much more serious damage would happen in ET processes than it in its landfalling stage. In this connexion, the world tropical cyclone research community attaches more importance to the ET issue. This is one of scientific objectives of this thesis.The relevant data what we used are conventional data and Typhoon Year Book as well as the Tropical Cyclone Year Book published by Chinese Meteorological Press, objective analysis data of wind/temperature/humitidy from T106 with horizontal grid mesh of 1. 125° × 1. 125° and vertical resolution of 17 layers. The conventional observation of surface and upper level sounding are taken from the Micaps system. The satellite digital data are taken from MRI/JMA and FY-2C. The global grid point data with the horizontal resolution of 2.5° ×2. 5° from NCEP are used as well.The PSU/NCAR MM5V3 model and relevant bogussing techniques were employed in the numerical simulation in this thesis.Many results have been found in this study. Some of them are useful for the operational forecasting. The main part of them is summarized as follow.The climate and disaster feature analysis of TC affecting the Liaodong peninsula from 1971 to 2000 have been made.Heavy rainfall in the Liaodong Peninsula is associated with the environmental fields when the tropical cyclones move northward. The results indicate that the favorable and steady subtropical high results in that the typhoon Polly moves northward and approaches a baroclinic frontal zone, thus fails to move eastward into sea while it is reinvigorated. Superposition between the upper layer divergence and the lower layer convergence, and the non-zonal upper level jet located in north of 35° N are favorable for intensification of upward movement in vertical and northward tracking of the tropical cyclone. During the tropical cyclone passing through the Liaodong Peninsula where there exists a convergence moisture transportation by lower...