Diurnal Variation of MCSs over Asia and the Western Pacific Region |
| |
Authors: | SHU Yu PAN Yinong and WANG Jinxin |
| |
Institution: | 1. Nanjing Meteorology Bureau, Nanjing 210019;Key Laboratory of Mesoscale Severe Weather/Ministry of Education, and School of Atmospheric Sciences, Nanjing University, Nanjing 210093 2. Key Laboratory of Mesoscale Severe Weather/Ministry of Education, and School of Atmospheric Sciences, Nanjing University, Nanjing 210093 |
| |
Abstract: | Mesoscale convective systems (MCSs) are severe disaster-producing weather systems. Radar data and infrared satellite image are useful tools in MCS surveillance. The previous method of MCS census is to look through the printed infrared imagery manually. This method is not only subjective and inaccurate, but also inefficient. Different from previous studies, a new automatic MCS identification (AMI) method, which overcomes the above disadvantages, is used in the present study. The AMI method takes three steps: searching potential MCS profiles, tracking the MCS, and assessing the MCS, so as to capture MCSs from infrared satellite images. Finally, 47468 MCSs are identified over Asia and the western Pacific region during the warm seasons (May–October) from 1995 to 2008. From this database, the geographical distribution and diurnal variation of MCSs are analyzed. The results show that different types of MCSs have similar geographical distributions. Latitude is the main control factor for MCS distribution. MCSs are most frequent over the central Tibetan Plateau; meanwhile, this area also has the highest hail frequency according to previous studies. Further, it is found that the diurnal variation of MCSs has little to do with MCSs’ size or shape; MCSs in different areas have their own particular diurnal variation patterns. Based on the diurnal variation characteristics, MCSs are classified into four categories: the whole-day occurring MCSs in low latitude, the whole-day occurring MCSs in high latitude, the nocturnal MCSs, and the postmeridian MCSs. MCSs over most places of mainland China are postmeridian; but MCSs over the Sichuan basin and its vicinity are nocturnal. This conclusion is coincidental with the hail climatology of China. |
| |
Keywords: | mesoscale convective system automatic MCS identification method diurnal variation |
本文献已被 CNKI 万方数据 SpringerLink 等数据库收录! |
| 点击此处可从《Acta Meteorologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Meteorologica Sinica》下载免费的PDF全文 |
|