摘要
利用GSI(Gridpoint Statistical Interpolation)系统直接同化FY2E红外通道IR1、IR2和WV的辐射资料,并在2011年10月13-14日的华南暴雨个例模拟分析中评估了同化效果。首先对卫星资料进行了稀疏化、偏差订正、下垫面检查、标准差检查、与背景场的偏差检查等质量控制。质量控制使得观测资料更接近高斯分布。个例模拟结果表明同化FY2E辐射资料产生的分析增量主要集中在对流层中低层。其中位温、水凝物混合比分布发生了明显改变,变化幅度从大到小依次为IR2、IR1、WV。同化使得观测增量分别从1.9、1.9和1.4 K降低到1.5、1.5和1.0 K。同化WV通道资料的降水预报优于同化IR1或IR2的,在25-和100-mm量级上的ETS评分提高了约0.05。另外同时同化3个通道的资料,其预报结果并不绝对优于单独同化某一通道资料的试验。
This study examines the benefits of assimilating FY2E IR1, IR2 and WV infrared channels radiances through a local autumn heavy rainfall over Guangdong province, observed on 13 - 14 October 2011. One of the prominent features of GSI is strict quality control on satellite measurements, including data thinning, bias cor- rection, underlying surface check, standard deviation check and gross error check and so on. The strictly quali- ty control makes the distribution of FY-2E observations closer to the Gaussian function. It is shown that the as- similation of FY2E data has improved the model description of potential temperature and mixing ratio of hydro- meteors in the low troposphere, and the IR2 channel data contributes most. Assimilation of the radiances data obviously makes the analysis field closer to the observations, and the observation increment of three infrared channels decrease to 1.5, 1.5 and 1.0 K （ from 1.9, 1.9 and 1.4 K）. The quantitative precipitation forecast of E WV is better than E_IR1 and E_IR2＇s, which ETS score increase 0. 05 at 25 - 50 mm and 100 mm precip- itation. The precipitation ETS results indicate that assimilating three infrared channels data is not absolutely bet- ter than that only assimilating one infrared channel data.
出处
《热带气象学报》
CSCD
北大核心
2016年第3期334-345,共12页
Journal of Tropical Meteorology
基金
国家自然科学基金(41475102)
广东省气象局科学技术研究项目(2015B02)共同资助
