GRAPES模式对西南季风爆发的数值模拟及初值影响试验  

NUMERICAL SIMULATION OF SOUTH CHINA SEA MONSOON ONSET BASED ON GRAPES MODEL AND EXPERIMENT ON INITIAL MODEL FIELDS

作　　者：周慧 朱国强 陈江民 彭敦 戴泽军 

机构地区：[1]湖南省气象台,湖南长沙410007 [2]湖南省气象服务中心,湖南长沙410007 [3]株洲市气象局,湖南株洲412003

出　　处：《热带气象学报》2010年第1期98-104,共7页Journal of Tropical Meteorology

基　　金：国家863计划专项(2006AA01A123);湖南省高分辨率数值预报释用技术研究;GRAPES湖南暴雨预报系统研究及其在湖南省的检验评估及湖南省科技计划重大专项(2008FJ1006)共同资助

摘　　要：使用GRAPES模式对南海季风爆发进行模拟研究。针对模拟预报中初始场信息偏弱的情况,引入NOAA17卫星AMSU-B资料改进初值。直接利用GRAPES三维变分同化系统,设计了两个同化试验方案:试验1(T1)同时同化探空资料和AMSU-B资料、试验2(T2)仅仅同化常规探空资料,然后应用GRAPES有限区域模式进行模拟预报。通过对比试验发现,该模式对初始场的改变十分敏感,可以比较成功地模拟出南海夏季风的爆发时间和爆发候的高、低层风场配置以及季风与季风雨带的向北推进。然而该方案对于雨量和副热带高压位置的模拟,与观测相比尚存在一定的偏差,主要表现为副热带高压位置模拟偏西、偏北;南海地区的降水量模拟偏大、降水范围偏大。Generally speaking, the onset of South China Sea summer monsoon （SCSSM） is regarded as the beginning of the East and Southeast Asian summer monsoons and the major rainy seasons in these regions. Therefore, the correct simulation of SCSSM has significant implication. In this paper, in order to verify the impact of different initial model fields on model simulations, two tests are designed： Test 1 （T1） assimilates both sounding and AMSU-B data and Test 2（T2） assimilates only the sounding data. using the three-dimensional variation data assimilation system of GRAPES. Comparative experiments show that the model is very sensitive to the initial fields. The model with the T2 assimilation scheme simulates the onset of SCSSM reasonably well, including the onset time, dramatic changes before and after onset, especially the upper and lower level flow patterns. For the amount of precipitation and location of the subtropical high, there are still some biases between the simulations and the observations. For example, the simulated location of the subtropical high was shifted more to the north and west, the simulated amount of precipitation for the South China Sea was too large and the simulated domain of precipitation was too broad.

关 键 词：天气预报 数值模拟 GRAPES模式 南海夏季风 爆发 三维变分同化 

分 类 号：P435[天文地球—大气科学及气象学]