"中国登陆台风外场科学试验"风廓线仪探测资料在四维同化中的初步应用研究

RESEARCHES ON ATMOSPHERIC PROFILE OBSERVATIONS OF "CLATEX" IN FOUR-DIMENSIONAL DATA ASSIMILATION

该文将"中国登陆台风外场科学试验"(CLATEX)中得到的风廓线仪探测资料加入到模式中进行牛顿张弛逼近(nudging)四维同化分析,并讨论在同化过程中不同nudging时间间隔以及不同逼近因子对风场及降水数值模拟结果的影响。结果表明:将风廓线仪探测资料通过nudging技术同化到模式中,一定程度上改善了对降水的数值模拟结果;单纯应用nudging技术及单点的风廓线仪探测资料,通过缩短nudging时间间隔以最终改进同化效果有一定局限性;合理的选择逼近因子值(4.0×10-4s-1)得到的同化结果与实况更为接近。

With strong tropical cyclone 'Vongfong' as the target typhoon, and adopting the wind-profiler data gained from 'CLATEX' into nudging four-dimensional data assimilation process of meso-scale model MM5V3, the influence of the different nudging-assimilation interval and nudging factor on the simulation were detected. Results demonstrate that the assimilated initial field was changed, the simulation of rainfall with assimilated initial field is better than that with directly objective analyzed field to some extend. Furthermore, the simulation is not changed too much by shortening the nudging time-interval in terms of the nudging method and the data from a single observation station. With nudging factor 4.0×10-4s-1, the simulation is closer to the observations.