Multi-source Occultation Data Quality Control And Its Application With Radiosonde Network

GNSS multi-source occultation observation,as a new high-altitude detection method,has the advantages of high vertical resolution,little weather influence,and wide data distribution,etc.,and is widely used,but it also has system deviation and inversion error,there have been few studies on its quality control and occultation from different sources in previous studies.Sounding observations play an important role in meteorological observations,but they are rarely observed in high-altitude regions and ocean areas in western China,and the spatial distribution is uneven,which seriously affects the analysis of weather processes and the improvement of the quality of numerical forecasts in China.Therefore,in order to make full use of the contribution of GNSS occultation data and sounding observations to weather process analysis and numerical weather forecasting,the region is innovatively divided into different climatic zones according to climatic characteristics,using double-weighted standard deviation and setting the of the correlation coefficient threshold in the quality control scheme,the refractive index of the COSMIC,Metop-A,Metop-B multi-source occultation data and the temperature,pressure,and humidity variables of the second-order inversion products were quality controlled,and compared with the traditional standard deviation method.And on this basis,the multi-source occultation data after quality control and conventional observation data such as sounding are used in the application of network assimilation forecast.Through case analysis and batch test,the data after assimilation networking is analyzed for the analysis field and forecast field.The main conclusions are as follows:(1)Divide different climate zones according to climatic characteristics,the multi-source occultation data is better quality controlled by using the double weight standard deviation and setting the correlation coefficient threshold method,this method is significantly better than the traditional standard deviation quality control method.The correlation between occultation and reference field was improved after quality control,and the quality control effect is better,which can provide more accurate observation data for weather analysis and numerical forecast assimilation.And this quality control method can also provide a reference for the quality control of other observation data,effectively improve the data quality.(2)The analysis of a typhoon case shows that the data after assimilation networking is better than the test of assimilation sounding or only the occultation observation data for the improvement of the typhoon's path forecast and intensity forecast,but compared with there is still a certain gap between the actual observation path and intensity.(3)Batch test results show that assimilated multi-source occultation and soundings and other conventional observations have a positive contribution to the geopotential height field,temperature field,wind field,and relative humidity field for analysis and forecast fields,and the improvement effect of the geopotential height field and temperature field is compared to other variables are better.And the improvement effect is better than the experiment of assimilating no observation data and only sounding observation,and the assimilation prediction effect is the best after networking.