摘要
基于静止卫星红外云图的MCS普查标准不统一不利于各种MCS普查结果的对比分析,该文在总结MCS普查研究进展的基础上,依据Orlanski尺度分类标准对MβCS普查的最小尺度标准作了修订,即修订为TBB≤-32℃的连续冷云区直径≥20km。根据马禹等的MβCS普查标准和该文修订的MβCS普查标准,利用GOES-9卫星红外云图普查了2003年6月19日—7月22日淮河大水期间的MCS,结果发现共有10个MαCS和24个MβCS,并对24个MβCS作了普查标准修订前后的统计结果对比,发现新的普查标准比根据马禹等的MβCS普查标准获得的结果多7个MβCS,并且这7个MβCS中有6个都引起强降水,因此这种对比分析结果表明:新MβCS普查标准对揭示淮河大水和MCS的关系更具合理性。此外,还分析了3个因MβCS而引起局地强降水的典型个例,这些MβCS的直径尺度只有几十至一百多公里,不符合马禹等的MβCS普查标准。对这3个MβCS分析结果表明:该文新MβCS普查标准有助于对产生剧烈天气的MCS的普查研究和预报。
MCSs （mesoscale convective systems） are significant weather systems causing heavy rain and other severe weather events during the warm season, which are very difficult to forecast in operation. Geostationary satellite infrared imagery with higher spatial and temporal resolution can provide much available information for MCS surveillance and forecasting. Since Maddox defined the MCCs （mesoscale convective complexes） based on enhanced satellite IR imagery, there are many detailed studies on the MCSs, but these studies revealed that Maddox＇s MCC definition is too strict. Then the MCS definition based on satellite i recent years, some studies classified MCS to MαCS （meso-α convective system） magery is always m and MβCS （meso-β odified. In convective system）. But because the definition of MCS based on satellite imagery is not uniform, it is very hard to compare various results of MCS census. First, the progress of MCS census research is reviewed, and the smallest horizontal scale of MβCS （meso-β convective system） is modified as that the diameter of cold cloud continuous area of TBB value≤ - 32 ℃ is more than 20 kin. Secondly, based on the new definition of MβCS, the mesoscale convective systems are investigated over the Huaihe River Basin utilizing GOES-9 satellite IR imagery during June 21-July 22 2003, the results reveal that there are 10 MαCSs and 24 MβCSs. Comparing the definition of MβCS with that in the study of Ma et al, there are 7 MβCSs which can not satisfy the MβCS definition of Ma et al, and 6 of them lead to heavy rain over Huaihe River Basin. It shows that the new MβCS definition can better reveal the relationship between heavy rain and MCSs over the Huaihe River Basion. Finally, the other three typical MβCSs which produced heavy rainfall over Beijing are analyzed, Shalan Town of Heilongjiang Province, and Shanghai. The diameter of these three MβCSs is about 20--150 kin, so they satisfy the new MβCS definition,but do not satisfy the MβCS definition of Ma et al.
出处
《应用气象学报》
CSCD
北大核心
2008年第1期82-90,共9页
Journal of Applied Meteorological Science
基金
国家自然科学基金项目(40305004)
高等学校博士学科点专项科研基金(20040001008)
国家973项目(2004CB418300)共同资助
关键词
卫星云图
MCS
普查标准
修订
satellite IR imagery
MCS
definition
modification
