Comparative analysis on characteristics of wind profile radar data in two winter multiphase precipitation processes
HAN Yuting
CHEN Zhaoyu
DOU Lijun
ZHANG Xi
HE Peiyi
LIN Bing
Abstract：Using the ERA5 hourly data(0.25° × 0.25°)from European Centre for Medium-Range Weather Forecasts(ECMWF)and the data of No.1 wind profile radar at Beijing Daxing International Airport,two multiphase precipitation processes at Daxing Airport from 6 to 7 November 2021 and from 11 to 12 February 2023 are compared,and the characteristics of wind profile radar in the two winter processes are explored.The results are listed below.(1)The establishment of easterly winds near the ground wind field of wind profile radar,the emergence of jet streams and the disturbance in the middle and lower layers all play a positive role in the winter snowfall nowcasting.The enhancement of cold air in the lower layer has certain indicative significance for phase transition,and the strength of warm and humid uplift in the middle and upper layers corresponds well to the change of precipitation intensity.(2)Both precipitation intensity and precipitation phase transition can be reflected in the vertical velocity detected by wind profile radar.There are large positive velocities below 2.5 km during the rainfall period of the two processes,and the vertical velocity decreases sharply with the precipitation phase transition to sleet.(3)The echo structures of the atmospheric refractive index structure constant(Cn2)and signal-to-noise ratio(SNR)are similar,and both of them can reflect the change of precipitation intensity.The logarithmic values of Cn2 in both processes begin to increase one hour before the start of precipitation,and the higher the Cn2 value,the more intense the precipitation;with the phase transition to sleet,the logarithmic values of Cn2 gradually decline and the height of the high-value area decreases.The area of high SNR in the two processes is mainly concentrated below 2.0 km,and the tighter the SNR structure and the greater the echo intensity,the more intense the precipitation.(4)The radar detection altitude is directly affected by the humidity in the upper atmosphere,which can provide a basis for judging precipitation intensity.
Keywords：Beijing Daxing International Airportwind profile radarphase transitionvertical velocityatmospheric refractive index structure constant(Cn2)signal-to-noise ratio(SNR)
Publication Date：2025-04-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：10( 89-98 )