摘要
回流暴雪是山东省秋冬季重要的灾害性天气之一,为加强对这类灾害性天气的分析研究,提升预报能力和水平,利用常规气象观测资料,对2000年以来山东省11月份发生的回流暴雪天气过程进行了环流形势、中尺度特征及热力、动力诊断分析。结果表明,这期间的回流暴雪均存在雨雪相态转换,925 hPa以下的温度对降水相态有明确的指示意义;此类天气的概念模型是500 hPa和700 hPa在河套地区或东部是低槽,低层850 hPa从西南伸向山东的切变线,地面为西北-东南向的高压控制,直接影响系统包括:低槽、切变线和低空急流;大气湿度层深厚,到达对流层中层或更高;探空分析所有过程均存在逆温,这也是回流降雪的重要特征;在低层水汽通量散度场有强辐合,θse的低值区一直伸到中原腹地,在大气中高层出现对流性不稳定;散度场从下向上辐合辐散交替叠置,垂直速度场表现为从低空到对流层顶均是上升运动的特征。
Blizzard process is one of the important disastrous weather in autumn and winter in Province, to strengthen the analysis of the disastrous weather forecast, improve the ability and level, based on the conventional observational data, the circulation situation and mesoscale and Shandong the author dynamic and thermodynamic characteristics of heavy snowstorm of return-flow events in Shandong Province on November since 2000 were analyzed. The results showed that： these heavy snowstorm of return-flow events had phase transformation （rain and snow）, temperatures below 925 hPa was a very useful index for precipitation phase. The conceptual model of these events were the trough of 500 hPa and 700 hPa in the Hetao Area or east, the shear line of 850 hPa from the southwest to the Shandong, the high pressure from northwest to southeast of ground, directly affect system were trough, humidity to middle troposphere or higher, the shear line and low-level jet. The thick layers of atmospheric inversion layer was important characteristics of these events. The characteristics had strong convergence in the lower vapor flux divergence field, low zone of θse extended to the hinterland of the central plains, convective instability in the atmosphere of the top, alternately convergence and divergence of divergence from up to down, ascending motion of vertical velocity field from the surface to the tropopause.
出处
《中国农学通报》
CSCD
2014年第20期229-236,共8页
Chinese Agricultural Science Bulletin
基金
国家自然科学基金资助项目"渤海海效应暴雪的多尺度作用机制及预报技术研究"(41175044)
关键词
回流暴雪
诊断分析
相态
heavy snowstorm of return-flow
diagnostic analysis
phase
