基金supported by the key project of Science and Technology Development Foundation of Regional Meteorological Center of Wuhan (No. QY-Z-200902)subsidized project of Key Laboratory of Meteorological Disaster of Jiangsu Province (KLME050202) subsidized project of "Qing-lan" for the Young and Middle-aged Academic Pathfinders in Colleges and Universities of Jiangsu province
基金This study was supported by the National Natural Science Foundation of China under Grant No. 49794030 and the Ministry of Science Technology of China (G1998040908).