Analysis Of Precipitation Detected By Spaceborne Radar In The Yangtze River Delta And Simulation Study On Raindrop Size Distribution Of Dual Frequency Retrieval

Satellite-borne rain radars have a unique detection perspective to monitor the Earth.The first and second generations of on-board rain radars have been launched and orbited for more than two decades and have accumulated a wealth of information that enables them to carry out precipitation and rainfall measurements.detection-related studies.This paper uses the TRMM?Tropical Rainfall Measuring?Mission?satellite-borne radar PR?Precipitation Radar?data were analyzed.Seasonal-scale climate characteristics of the Yangtze River Delta region;selection of GPM?Global Precipitation??Measurement?and TRMM during the coexistence of the two satellites,using the radar on board the GPM,respectively.DPR?Dual-frequency Precipitation Radar?and PR Level 2 products on TRMM are analyzed on a case-by-case basis,where there are several scan mode products in DPR,the ones used in this paper are DPRNS?Normal Scans?,Ku NS,Ka MS?Ka-band?Matched Scans?and Ka HS?Ka-band High Sensitivity Scans?;product differences and precipitation were compared between the two radars and between different algorithms.structural features.In addition,the microphysical properties of dual-frequency radar under different combinations of frequency bands as well as the retrieval of precipitation particles under an improved dual-frequency retrieval algorithm are simulated.The conclusions are as follows:?1?The proportion of effective precipitation imagery in the Yangtze River Delta is less than 10%of the total imagery,of which stratocumulus precipitation imagery accounts for a very large proportion of nearly 80%;the Yangtze River Delta shows obvious seasonal changes in precipitation,with a marked increase in summer precipitation,but the average of stratocumulus and convective precipitation is about 80%.The low storm top height may be due to changes in the algorithm for classifying precipitation types in the PR V7 and V8 data versions.The total number of convective precipitation like elements in PRV8 is low,and its average storm top height is more affected by this.?2?The ability of DPRNS and Ku NS to detect precipitation is nearly identical,with Ku NS detecting more high storm tops than PRV8 Top-height precipitation,Ka MS has a weak ability to detect precipitation,and Ka HS can detect more lower-level precipitation.The dual-frequency retrieval algorithm detects a greater range of raindrop spectral parameters than the single-frequency retrieval algorithm,and the precipitation rates obtained by the single-frequency retrieval algorithm are low.?3?Partial centimeter wave band combination in the case of common precipitation particles with DFR?Dual-Frequency Ratio?has been negative,the DFR and median volume diameter D₀ relationship is very sensitive to the shape factor of the gamma distribution,and as the increase of D₀,the first shape factor small DFR increases quickly,when D₀ increases to a certain extent,the shape factor large instead of DFR increases more rapidly.Temperature has a greater effect on DFR at lower D₀.DFR is not directly usable on common centimeter band radars,adding correction factors can improve the usability of the DFR algorithm.