摘要
利用NCEP/NCAR每日4次全球再分析1°×1°网格资料,计算了2004年7月17—21日华南汛期暴雨过程的水汽通量、视热源(Q1)和视水汽汇(Q2),并探讨了其垂直分布特征。结果表明:华南汛期暴雨过程中存在大量的水汽和凝结潜热。孟加拉湾、南海和西太平洋都是这次华南暴雨过程重要的水汽供应源。暴雨区南边界为水汽的主要输入区,北边界为主要输出区,而暴雨区南、东边界的水汽输送主要发生在低层,西边界在中、低层的水汽输送大致相当。在这次降水过程中,视热源和视水汽汇的较大值与降水的大值区有很好的对应关系。视热源、视水汽汇和垂直上升运动与降水量的变化总体趋势是一致的。视热源垂直方向上的峰值在400 hPa附近,而视水汽汇呈双峰型特征,峰值分别在700 hPa和450 hPa附近。垂直平流项均是视热源、视水汽汇的主要贡献者。
The water vapour flux, apparent heat source （ Q1 ） and apparent moist sink （ Q2 ） of a severe rainstorm in South China during 17th-21st July were calculated and analyzed by using the NCEP/NCAR global reanalysis grid data （4 times perday） and their vertical structures were studied. The results show that the moisture and latent heat were closely related to the heavy rain event. The Bay of Bengal, South China Sea and West Pacific were the water vapour sources in the rainstorm process. During this process, the water vapor came in mostly from the southern boundary and went out from the northern boundary of the heavy rainfall region. The inflows of water vapor of the southern and the eastern boundaries happen principally in the lower layer, and that of the western boundary in the lower and middle layers. The higher value regions of Q1 and Q2 basically corresponded with the heavy rainfall region. The variances of the Q1, Q2 and vertical velocity were well in agreement with the evolution of the precipitation. The peak value of Q1 located at 400 hPa, and that of Q2 respectively at 700 hPa and 450 hPa. The vertical advection term was the main contributor of the Q1 and Q2.
出处
《南京气象学院学报》
CSCD
北大核心
2007年第1期107-113,共7页
Journal of Nanjing Institute of Meteorology
基金
广西自然科学基金资助项目(桂科基0236041)
广西科技攻关项目(桂科攻0428008-40)
广西气象局科技攻关项目"气象诊断量软件包的开发"
关键词
华南暴雨
水汽输送
视热源
视水汽汇
South China rainstorm
water vapor transport
apparent heat source
apparent moist sink
