Stratus cloud and convective cloud automatic recognition method based on Doppler radar data

Abstract

The invention discloses a stratus cloud and convective cloud automatic recognition method based on Doppler radar data. The method includes that actually-measured Doppler radar data of a measured point are interpolated in a three-dimensional rectangular coordinate system, layering is performed according to vertical direction height and vertical grid interval, echo strength and horizontal wind field of each height layer are inverted, and corresponding horizontal divergence is calculated; simultaneously three related characteristic parameters are extracted and calculated; divergence characteristic parameters are calculated and extracted through horizontal gradient inversion wind information with maximum echo strength Zmax, vertical liquid water content VIL and maximum echo strength, membership functions are established, membership degree of each characteristic parameter is calculated, finally Pc and Ps are obtained through summation of membership degrees of the different characteristic parameters corresponding to upper layer could and convective cloud of each horizontal grid point, and when the Pc> the Ps, the measured point is determined to be the convective cloud, otherwise the tested point is stratus cloud.

Description

technical field [0001] The invention relates to a method for processing and identifying meteorological information, specifically a method for processing data measured by a weather radar to determine whether a measured point belongs to a stratus cloud or a convective cloud. Background technique [0002] It is of great help in precipitation estimation in the field of meteorology, monitoring and early warning of disastrous weather, artificial weather modification and the vertical distribution of non-adiabatic process in precipitation area in thermodynamics. Precipitation is directly related to cloud type. [0003] The precipitation system can be divided into convective cloud precipitation and stratiform cloud precipitation from the formation mechanism, duration, and internal structure differences. Convective cloud systems are often accompanied by strong vertical velocity, local convergence and heavy precipitation, while stratiform cloud systems are often accompanied by weak up...

AI Technical Summary

Problems solved by technology

In 2000, on the basis of the traditional SHY95 method, Michael and Stevenz added the echo vertical profile feature to the method according to the characteristics of the bright band and considering the echo gradient changes in the horizontal and vertical directions, and used data other than radar data. For information on the height of the 0° isotherm, see Biggerstaff, Michael I., Steven A.Listemaa, 2000: An Improved Scheme for Convective / Stratiform Echo Classification Using Radar Reflectivity.J.Appl.Meteor., 39, 2129-2150., This information may not be available in practical applications, and there are certain limitations in its use

However, when this method uses statistical methods to determine the breakpoints of membership functions in the fuzzification process, it needs to use the results of manual identification as the true values ​​of stratus and convective cloud observations.

Therefore, this algorithm cannot be automated, and the workload is large, and there is a large subjective component, which is not easy to use in business

In addition, these algorithms only use one observation of Doppler radar - the echo intensity, lacking other observation information

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