Quality Control And Evaluation Of Round-trip Flat Drift Sounding Data

The sounding data in western China and the marine area are sparse and unevenly distributed,which greatly limits the further improvement of the quality of analysis of numerical prediction data assimilation in China.In order to effectively alleviate this problem,new roundtrip flat drift intelligent sounding system is developing.The round-trip flat drift intelligent sounding system refers to achieve long-term observations of three stages of about 6 hours in the ascending section(about 1 hour)– the flat drift section(about 4 hours)– the descending section(about 1 hour)by one-time air probe.In this way,the two sounding data of the current business interval of 12 hours per day can be encrypted into four sounding data with an interval of about 6 hours per day,and at the same time,two consecutive observations of stratospheric data for more than four hours can be obtained,which significantly improve the effectiveness of sounding observation.Therefore,the data quality of the round-trip flat drift intelligent sounding system is especially important.This paper uses FNL analysis data and current operational meteorological sounding data as reference standards to carry out quality control and evaluation research on round-trip flat drift sounding data.The main conclusions of this paper are as follows:(1)Data evaluation results: the data quality of the temperature,humidity and air pressure of the round-trip flat drift sounding data in both the rising stage and the falling stage reached the business index at 8:00 and 20:00,where the air pressure quality is the best,then the temperature,The last is humidity.The data quality of the ascending segment is slightly better than that of the falling segment;at 20 o'clock,it is slightly better than at 08.The data quality of the flat drift phase at 08 is very poor,and the error correction needs to be performed.The data quality at 20 o'clock is better,slightly weaker than the rising segment and the falling segment.(2)The effect of data quality control: The temperature of the flat drift section is corrected by the radiation error at 08,and the deviation is basically reduced by 4~10 °C.After using the mode for quality control,the quality of the data is improved,mainly reflected in the reduction of the “burr” of the deviation,the overall trend is more smooth.Except for the temperature in the flat drift phase at 08,the remaining observation data only uses the mode for quality control,and the data quality is mentioned.(3)The new data quality assessment method can objectively,accurately and multi-anglely evaluate the quality of new sounding data,and can determine data quality characteristics in more detail and accurately.The threshold values of the suspicious value and the error value selected by the new quality control method have the characteristics of error and self-adaptation.After the quality control according to the evaluation result,the quality of the sounding data is improved,and the data retains the original characteristic features,rather than simply correcting large deviations.