摘要
利用南宁市气温、海平面气压、露点温度、水气压等气象要素资料与探空分析资料,ECMWF分析资料,对2006~2014年南宁市2~4月"回南天"天气过程进行了气象条件特征分析,结果表明:(1)南宁市"回南天"天气主要出现在2~3月,年平均出现3次,出现次数最多年6次,出现次数最少年1次,最长持续天数6天;(2)当2月份月平均气温出现异常偏低或异常偏高,3月份月平均气温出现异常偏高时,当月不易出现"回南天"天气,当4月份月平均气温出现异常偏低时,易出现"回南天"天气;(3)近9年2~4月南宁市出现5次明显"回南天"天气过程,各次过程发生前12小时南宁锋面逆温层顶已降到≤925h Pa,925h Pa有≥10m·s-1的偏南风,近地层大气接近或达到饱和状态;(4)5次明显"回南天"天气过程发生前后出现了明显的降压、升温和增湿现象,过程前一日20时开始温度露点差呈持续下降趋势,在过程当日08时左右到达最低值,表明空气达到或接近饱和,"回南天"天气在此阶段开始。
Based on temperature, sea level pressure, dew point temperature, water pressure data, air sounding data and ECMWF reanalysis data, the characteristics of climate and weather conditions of high- humidity weather from February and March during 2006 to 2014 were analyzed. The results show that: (1) The special high-humidity weather in Nanning mainly appears in February and March ( 3 times a year on average with the maximum being 6 , minimum being 1, and the longest duration being 6 days ) ; (2) when the average temperature of February shows abnormal lower or higher, or the average temperature of March shows abnormal higher, then the special high-humidity weather may not occur event, but when the average temperature of April shows abnormal lower , the special high-humidity weather may occur. (3) Nanning occurred 5 times serious special high-humidity weather during February to April in recent 9 years, with the frontal inversion layer roof having dropped to 925 or less hpa and the speed of S-SSW ≥ 10m ·s^-1 and surface layer atmosphere closing to or reaching saturation state before 12 hours of all the process appearing; (4) There are obvious atmospheric pressure reducing, temperature rising and humidity increasing, before or after the occurring these 5 serious special high-humidity weather, the depression of the dew point was persistent decreasing since 20:00 in the day which previous high-humidity weather event started, and it came to its' minimum value near 8:00 in the second day, this phenomenon indicates that the air closed to or reached saturated and this is the start of high-humidity weather.
出处
《气象研究与应用》
2015年第2期21-25,30,共6页
Journal of Meteorological Research and Application
关键词
2~4月
“回南天”天气
气象要素
high-humidity weather
meteorological elements
statistical characteristic