摘要
利用常规观测资料、NCEP1°×1°格点资料,对2008年9月5日宁波地区出现的暴雨天气过程进行综合分析。分析表明:冷空气、西南暖湿气流及东南气流的交汇,为宁波地区暴雨的发生提供了有利的天气背景条件。暴雨一般出现在θse最陡峭密集区内,该区内气旋性涡度发展最强。垂直螺旋度中心向低层移动,将会导致地面降水强度明显增强。湿位涡正异常中心能较好的反映高空冷空气的活动。中低层湿位涡的湿斜压项(mpv2)负中心强度变化对降水强度有一定指示作用。大气湿斜压不稳定的增强对暴雨的贡献不容忽视。
By using the conventional observation data and NCEP 1°×1° reanalysis data, an extraordinary storm occurred in Ningbo on September 5, 2008 is analyzed. The analysis shows that the join of cold air, warm and humid air from southwest and the southeast provided a favorable condition for the occurrence of heavy rain in Ningbo. Heavy rain typically appears in the steepest and densest areas of θse where cyclonic vorticity development is most powerful. Helicity center moving vertically to the lower level will result in an obvious enhancement of rainfall intensity. Moist Potential Vorticity positive Center can better reflect the upper cold air activities. The changes of the negative intensity of Mpv2 on the low -level have some indication to the precipitation intensity. It can not be ignored that the enhancement of the atmosphere baroclinicity could contribute to heavy rain.
出处
《暴雨灾害》
2010年第2期166-170,180,共6页
Torrential Rain and Disasters
