FY-3A MWHS资料同化对湿度场预报影响评价的试验研究

Evaluating the effect of FY-3A MWHS data assimilation on atmospheric humidity field forecasting

风云三号A星(FY-3A)是中国第一颗携带微波湿度垂直探测仪(MicroWave Humidity Sounder,MWHS)的气象卫星,可以为全球及区域数值天气预报提供湿度信息。本文结合中尺度数值预报模式(Weather Research and Forecasting Model,WRF),利用改进后的中尺度数值预报同化系统(Weather Research and Forecasting Model Data Assimilation System,WRFDA),研究FY-3A/MWHS资料同化方法,并与美国国家海洋和大气管理局微波湿度计资料(National Oceanic and Atmospheric Administration/Advanced Microwave Sounding Unit-B,NOAA/AMSU-B)进行同化对比,分析FY-3A/MWHS资料同化对湿度场分析和预报的影响。结果表明:MWHS资料同化可以有效改进湿度分析场,且对分析场的改进明显优于NOAA/AMSUB资料同化,MWHS资料同化对湿度场预报的调整总体优于NOAA/AMSU-B资料同化,MWHS资料同化试验18 h内的湿度场预报精度明显优于NOAA/AMSU-B同化试验。由试验结果可知,中国FY-3A气象卫星MWHS资料在区域尺度数值预报中具有较好的应用前景。

Feng-Yun 3A is the first satellite with microwave humidity sensor （MWHS）,which can provide data for numerical weather forecasting on global and regional scales.This paper focused on assessing the effects of FY-3A MWHS data assimilation on relative humidity analysis and forecasting by using a 3D-Var data assimilation system coupling WRF model.The results show that the MWHS data assimilation improves relative humidity analysis,and obtains better relative humidity analysis compared to the NOAA AMSU-B data assimilation.In general,the method using the MWHS data assimilation improves the relative humidity forecasting accuracy compared with the method using the AMSU-B data assimilation.For 18 hour forecasting results,the humidity forecasting accuracies at 400 hPa,600 hPa and 800 hPa levels using the MWHS data assimilation method are higher than those using the AMSU-B data assimilation method.These results indicate that the FY-3A MWHS has a wide application prospect in numerical weather forecasting.