2008年1月一次强雨雪过程的诊断分析  

Diagnostic Analysis on a Heavy Snowfall/rain Process in January 2008

作　　者：朱坤[1] 刘华强[1] 刘宇丹 蒋坡[3] 

机构地区：[1]91867部队气象台 [2]65521部队气象测绘室 [3]71687部队气象台

出　　处：《气象与环境科学》2009年第3期15-21,共7页Meteorological and Environmental Sciences

基　　金：国家自然科学基金项目(40375027)资助

摘　　要：采用NCEP 1°×1°客观再分析资料和常规观测资料,对2008年1月25-29日发生在长江中下游地区的强雨雪过程进行诊断分析,结果表明,低空急流与强雨雪有着密切关系,强雨雪的发生需具备一定的温度条件以及水汽场与动力场的耦合机制。对强雨雪过程的湿Q矢量诊断分析表明,700 hPa湿Q矢量辐合区以及850 hPa锋生函数正值区与强雨雪区对应较好,对雨雪天气的发生有着很好的指示意义。湿位涡特征分析表明,此次强雨雪过程发生在层结稳定的大气中且垂直涡度发展较强。Based on the NCEP reanalysis and regular observational data, a heavy snowfall/rain process occurred in the middle and lower reaches of the Yangtze River region from 25 to 29 January 2008 is diagnosed. The results indicate that the low-level jet has close relation with heavy snowfall/rain, the occurring of heavy snowfall/rain must have appropriate temperature, the mechanism of coupling between dynamic field and moisture field. The diagnostic analysis of wet Q-vector shows that the convergence field of the ageostrophic wet Q-vector at 700 hPa and the positive field of frontogenesis function at 850 hPa have good relationship with the heave snowfall/rain field, which indicates a very good denoting signification to snowfall/rain weather. The diagnosis of moist potential vorticity shows that this process occurred in a steady atmosphere and the vertical vorticity was in a great development.

关 键 词：强雨雪 非地转湿Q矢量 湿位涡 长江中下游 

分 类 号：P458.3[天文地球—大气科学及气象学]