摘要
采用η坐标中尺度有限区域模式,对“98.7”鄂东沿江突发性特大暴雨进行了数字化天气雷达探测降水资料调整湿度廓线的一维变分同化的敏感性试验。结果表明:(1)最速下降算法的控制精度EPS取值越小,则变分同化后模式预报的降水量更接近于实况,但迭代次数会增加。(2)降水资料进行同化时,在一定程度上忽略降水量值相对较小的点的同化,对结果不会产生重大影响,但降雨核(强降水中心)的同化至关重要,其参与同化与否可以影响整个预报效果。
With limited area meso-scale numerical model under η - coordinate, sensitivity experiments of retrieving model humidity profiles by one-dimensional variational assimilation of digital weather radar-derived precipitation are studied for the abrupt heavy rainfall along the Yangtze River in the east part of Hubei province. Results show as follows. (1) The smaller the control precision EPS of optimal decline algorithm is, the closer the model forecast precipitation after assimilation is to the real rainfall amount but the iteration times will increase. (2) In the precipitation assimulation it will not effect the results substantially to ignore to some extent the assimulation of small-valued rainfall, but that of rainfall core or heavy rainfall center is very important, with assimulating it or not leading to the changes of overall forecasting effects.
出处
《气象科学》
CSCD
北大核心
2005年第5期450-458,共9页
Journal of the Meteorological Sciences
基金
湖北省自然科学基金项目(编号:2003ABA009)
"十五"国家重点科技攻关项目(编号:2001BA607B)
科技部重点转面上项目"我国南方致洪暴雨预测预警系统"共同资助
关键词
降水
变分同化
敏感性研究
暴雨
Precipitation Variational assimilation Sensitivity research Heavy rain