摘要
近年来的研究发现,瞬变扰动天气图上的扰动场天气系统对区域暴雨的落区指示能力强于传统天气图上的总场天气系统。为供预报员在业务预报中参考,本文划分1998年发生在中国东部地区的41日次区域暴雨为7类扰动场天气系统。与区域暴雨相联系的7类异常环流型分别是:华南切变线、华南涡旋、华南倒槽、长江切变线与槽、沿江涡旋、华北涡旋和东北涡旋。无论是在对流层的垂直剖面上,还是在850 hPa水平分布上,扰动天气图上位势高度低值和风扰动辐合处并配合大的水汽扰动对应有区域暴雨,而传统天气图上的低值系统和高水汽区与暴雨之间存在位置上的偏移。由此建议,用实况大气变量和中期数值模式产品绘制扰动天气图有助于预报员确定区域暴雨落区。
The advantages of the anomalous synoptic systems over the traditional total ones in locating regional heavy rain（RHR） have been revealed by recent work of the anomaly-based synoptic chart.Fortyone daily heavy rain cases in eastern China from 1998 are grouped into seven patterns based on the anomalous synoptic systems.The seven patterns of anomalous synoptic systems associated with regional heavy rain include the shear in South China,vortex in South China,reversed trough in South China,shear and trough along the Yangtze River,vortex along the Yangtze River,vortex in North China and vortex in Northeast China.The RHR can be well located by the negative regions of anomalous geopotential height,wind anomalous convergence combined with high moisture anomaly,which is evident from both the vertical cross-sections and the 850 hPa horizontal distributions.This overcomes the shortage of traditional synoptic chart in which total field systems and high moisture regions do not collocate with heavy rain areas.It is recommended that anomaly-based synoptic chart should be applied in the practice of short-term and medium-range forecasts by using the products of the current state-of-the-art operational numerical weather models.
出处
《气象》
CSCD
北大核心
2016年第6期674-685,共12页
Meteorological Monthly
基金
国家自然科学基金项目(41375703)
公益性行业(气象)科研专项(201306032)共同资助
关键词
区域暴雨
传统天气图
扰动天气图
异常环流型
regional heavy rain
traditional synoptic chart
anomaly-based synoptic chart
anomalous synoptic patterns
