Retrieval Method of Path-integrated LWC for Airborne Upward-Looking Microwave Radiometer Using Cloud Model
|School||Nanjing University of Information Engineering|
|Course||Atmospheric Physics and Atmospheric Environment|
|Keywords||Airborne microwave radiometer Cloud liquid water content of the vertical path Inversion method One-dimensional layered cloud model Radiative transfer model|
Developed a cloud numerical model generated cloud samples, the new method of path integral to-air microwave radiometer measuring cloud liquid water content inversion coefficient through the the statistical regression strike airborne history sounding statistics relative humidity diagnosis produces original cloud samples 0. The analysis shows that on July 8, 2001 Jilin observing a case, due to the one-dimensional layered cloud model takes into account the dynamic process of the development of stratiform clouds and microphysical processes, the fitting cloud samples is more in line with the day of the actual observations inversion error caused due to the uncertainty of the background atmospheric water vapor and temperature profiles, and vertical distribution of cloud liquid water content is reduced to some extent, the inversion accuracy has improved at all altitudes. increased by between 0.15% to 7.28%. Seen by the one-dimensional layered cloud model sensitivity experiments, samples of the mode basic cover a weather process all possible cloud liquid water profiles, and cloud conditions for the detection of the actual flight is only one part. In addition, the combination of the July 8, 2001, by factor analysis method, the error estimates of the major factors affecting the detection accuracy, the results show that the cause of the error and instrument drift, as well as the uncertainty of the background field compared by cloud error caused by the base height and cloud within the uncertainty of the vertical distribution of liquid water can not be ignored, and in many cases much larger than the error of the instrument and the background field. Therefore, a large number of samples to improve the inversion accuracy, other independent measurement information according to the cloud stratification of clouds base height, Genting high cloud thick or cloud, the cloud model generated by the Filter formed sample 2, and Re-fitting the the inversion coefficient into inversion method 2. Analysis shows that on July 8, 2001, a case has been further improved on the basis of Method 1, Method 2 inversion accuracy increased by between 0.8% to 5.9%. Visible, adding a separate cloud observation information to bind the sample 1, inversion accuracy can be further improved. Method 2 on July 8, 2001, July 9 and April 22, 2002, three case analysis results show that the methods used can fit the sample compared to the more in line with the actual situation of the day, and the method 0 inversion has improved the accuracy of all heights, the range between 1.9% to 37.2%, compared to the improvement of this precision instrument drift error has practical application value. In addition, the spatial and temporal distribution of the the vertical path integral method 2 inversion cloud liquid water content better positive correlation with the radar PPI echo intensity.