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CN-121978692-A - Method for inverting aerial raindrop spectrum by utilizing characteristic parameters of dual-polarization radar

CN121978692ACN 121978692 ACN121978692 ACN 121978692ACN-121978692-A

Abstract

The invention relates to the technical field of raindrop spectrum inversion, in particular to a method for inverting an aerial raindrop spectrum by utilizing characteristic parameters of a dual-polarization radar, which comprises the steps of data collection, quality control, calculation and fusion; modeling and statistics, specifically comprising statistics of radar and rainfall type relation and statistics of parting and raindrop spectrum type fitting relation, and business application process comprising four-dimensional raindrop spectrum products and rainfall estimation products. The research of the invention can bring about three remarkable improvements, namely enriching radar secondary product systems in terms of monitoring capability and realizing visual visualization of spatial precipitation particle distribution characteristics, and can be used for judging strong precipitation landing areas in advance through aerial particle distribution characteristics in terms of early warning and forecasting, so that the early warning and ageing of disastrous weather can be effectively prolonged, and refined precipitation micro-physical structure information can be provided in terms of artificial weather influence, so that reliable technical support is provided for operation condition identification and effect evaluation.

Inventors

  • LIN XIAOMENG
  • ZHANG PENGLIANG
  • YANG XIAOJUN
  • ZHANG LU
  • WEI YINGHUA
  • CHEN HONG

Assignees

  • 天津市气象台

Dates

Publication Date
20260505
Application Date
20251113

Claims (7)

  1. 1. A method for inverting an aerial raindrop spectrum by utilizing characteristic parameters of a dual-polarization radar, which is characterized by comprising the following steps: Step one, data collection, quality control, calculation and fusion; modeling and statistics, namely, statistics of radar and rainfall type relation and statistics of parting and raindrop spectrum type fitting relation; And step three, a business application process comprises a four-dimensional raindrop spectrum product and a precipitation estimation product.
  2. 2. A method for inverting an air raindrop spectrum using a characteristic parameter of a dual-polarization radar according to claim 1, In the first step, the data collection, quality control, calculation and fusion include the following steps: Step 1, live data preparation, namely collecting national station rain intensity statistics, wherein the resolution is hour; Step 2, the raindrop spectrum data are read, three basic parameters are calculated, the raindrop spectrum base data corresponding to the precipitation process are collected, 3 rounds of quality control are carried out on the data, three basic parameters of the raindrop spectrum are calculated by utilizing an intercept method, wherein the three basic parameters are respectively intercept parameter N reflecting the concentration of small drops, shape parameter u controlling the steepness of the spectrum shape, slope parameter Λ determining the attenuation rate of large drops and related to the precipitation intensity, and the resolution is 1 minute; Step 3, reading radar base data of Tianjin Baodi radar stations, performing quality control, namely finding out the positions of national station stations from a radar map, extracting a layer-by-layer radar reflectivity factor REF and a differential reflectivity factor Zdr of corresponding positions and peripheral 3*3 =9 pixel points, and performing time resolution for 6 minutes, wherein if Zdr data are bad in quality, the quality control is required, namely, firstly, overall offset, zdr of precipitation examples are larger than 0, and hair rain is concentrated near 0, so that Zdr is integrally added with 1, secondly, scale is carried out, values smaller than-2 and larger than 5 are removed, thirdly, smoothing is performed, and Zdr is smoothed in different modes according to different values of REF; And 4, corresponding the raindrop spectrum and radar data, namely unifying three parameters of the raindrop spectrum corresponding to the previous output precipitation time period and the national station site position and radar parameters as well as corresponding time-space points into a large table, wherein the table comprises the site, longitude and latitude, time, three parameters of the raindrop spectrum, the radar REF and the ZDR, and the time resolution is unified to be 6 minutes.
  3. 3. A method for inverting an air raindrop spectrum using the characteristic parameters of a dual-polarization radar according to claim 2, In the second step, in the statistics of the relationship between the radar and the precipitation type, the precipitation type is aimed at judging the precipitation type according to the radar product first and selecting a proper model for calculating three basic parameters of the raindrop spectrum according to the precipitation type when the service is applied, the precipitation type is related to the spectrum shape of the raindrop spectrum, and the particle size and the concentration are considered simultaneously during the type separation, so that the precipitation is classified into 9 types according to different thresholds of REF and ZDR.
  4. 4. A method of inverting the raindrop spectrum in the air using the characteristic parameters of a dual polarization radar according to claim 3, wherein in precipitation typing, the REF nodes are 40, 50, and the zdr nodes are 1 and 2.
  5. 5. A method for inverting an air raindrop spectrum using the characteristic parameters of a dual-polarization radar according to claim 3, In the statistics of the fitting relation between the parting and the raindrop spectrum type, according to the 9 types of parting, a large table is utilized to obtain fitting relation between raindrop spectrum parameters and radar parameters in different parting respectively, wherein the relation between lambda and u and the fitting effect of lambda-10 log (REF/N0) are good, the value of lambda is related to Zdr, accurate lambda can be obtained, and the other two parameters are accurate, wherein lambda is not parting, and the other two parameters are nine types.
  6. 6. The method for inverting an aerial raindrop spectrum by utilizing characteristic parameters of dual-polarization radars according to claim 5 is characterized in that in the third step, in a four-dimensional raindrop spectrum product, input sources are real-time and past 2h radar parameters, radar 0-2km corresponds to live 1km, radar 1-3km corresponds to live 2km, radar 3-5km corresponds to live 3km, radar parameters corresponding to height positions are firstly found, each grid point with large spatial resolution corresponds to 3 groups of REF and Zdr of 3 heights, precipitation is respectively typed by utilizing REF and ZDR for each height of each point, three parameters of the raindrop spectrum are obtained by means of different typing, and various raindrop spectrum parameters including median particle size, concentration of particle size and mass weighted diameter are calculated for the three parameters, so that each space point corresponds to three height of the basic parameters of the raindrop spectrum and secondary products, three units of 1km, 2km and 3 units of volume are found out, the volume is filled with particles, the volume is full of the volume, the volume is different in the volume is different, and the volume can be changed when the volume is different.
  7. 7. The method for inverting an aerial raindrop spectrum by utilizing characteristic parameters of a dual-polarization radar according to claim 5, wherein in the third step, in a precipitation estimation product, an input source is a real-time radar parameter, a radar parameter corresponding to a 1km height position is found, each grid point with large spatial resolution corresponds to 1 group of REF and Zdr, three parameters of the raindrop spectrum and 1h precipitation estimation products are made, different grades of color filling are carried out, the raindrop intensity is calculated according to the raindrop spectrum of each grid point with the 1km height, the color filling is stability, convection non-short intensity and short intensity, short-intensity precipitation quantity is determined, and whether convection echo is strong or not is carried out.

Description

Method for inverting aerial raindrop spectrum by utilizing characteristic parameters of dual-polarization radar Technical Field The invention relates to the technical field of raindrop spectrum inversion, in particular to a method for inverting an aerial raindrop spectrum by utilizing characteristic parameters of a dual-polarization radar. Background The airborne precipitation particle spectrum generally refers to the size distribution of precipitation particles such as raindrops, snowflakes, ice particles and the like in the atmosphere. Changes in the airborne precipitation particle spectrum are the most direct description of complex precipitation particle interactions in the cloud. Meanwhile, precipitation particles are used as the most direct observation object of the weather radar, and due to the limitation of the radar detection principle, the sensitivity of different detection amounts to raindrops with different sizes is different. The difference in the distribution of precipitation particle spectra will also directly affect the accuracy of radar precipitation estimation. However, the existing technology cannot accurately obtain inversion parameters of ground and air micro-physical parameters, namely, the formation, development and change mechanism of atmospheric cloud precipitation cannot be known, and thus, the atmospheric process and meteorological disasters cannot be accurately predicted and explained. In the prior art, an article for inverting a raindrop spectrum by using a dual-polarization radar is disclosed, but parameters of the dual-polarization radar are inverted by using parameters of a raindrop spectrometer, and observation parameters of the dual-polarization radar are calibrated. There are few dual-polarization radar parameter inversion raindrop spectra, because the error is large in the inversion process, and service application is difficult to realize. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a method for inverting the air raindrop spectrum by utilizing the characteristic parameters of a dual-polarization radar, which utilizes the capacity of the dual-polarization radar for global observation and the capacity of the characteristic parameters for reflecting the size and concentration of raindrops and inverts the air raindrop spectrum in real time. In order to achieve the above object, the technical scheme provided is as follows: A method for inverting an aerial raindrop spectrum by utilizing characteristic parameters of a dual-polarization radar, which is characterized by comprising the following steps: step one, data collection, quality control, calculation and fusion, which specifically comprises the following steps: Step 1, live data preparation, namely collecting national station rain intensity statistics, wherein the resolution is hour; step 2, the raindrop spectrum data are read, three basic parameters are calculated, the raindrop spectrum base data corresponding to the precipitation process are collected, 3 rounds of quality control are carried out on the data, three basic parameters 0,1 of the raindrop spectrum are calculated by utilizing an intercept method, wherein the three basic parameters are respectively N (intercept parameter), reflecting the concentration of small drops, u (shape parameter), controlling the steepness of the spectrum shape, Λ (slope parameter), determining the large drop attenuation rate and being related to the precipitation intensity, and the resolution is 1 minute; Step 3, reading radar base data of Tianjin Baodi radar stations (Z9025) and performing quality control, namely finding positions (corresponding to longitudes and latitudes) of 13 national station stations from a radar image, extracting corresponding positions and positions of 3*3 =9 pixel points on the periphery, namely, layer-by-layer REF (radar reflectivity factor) and Zdr (differential reflectivity factor) with time resolution of 6 minutes, wherein if Zdr data are bad in quality, the quality control is required, namely, firstly, overall offset, zdr of precipitation examples are larger than 0, and hair rain is concentrated near 0, so that Zdr overall is added with 1, secondly, scale is carried out, values smaller than-2 and larger than 5 are removed, thirdly, smoothing is carried out, and Zdr is smoothed in different modes according to different values of REF; Step 4, the raindrop spectrum and radar data are corresponding, the raindrop spectrum three parameters and radar parameters corresponding to the previous output precipitation time period and the national station site position are corresponding to time-space points, a large table is unified, the contents of the table comprise the site, longitude and latitude, time, the raindrop spectrum three parameters, the radar REF and the ZDR, and the time resolution is unified to 6 minutes; step two, modeling and statistics, which specifically comprises the following steps: Step 1, statistics of relat