Characteristic analysis of dual-polarization weather radar echoes of clear air and precipitation in the Mount Everest region

Abstract. X-band dual-polarization weather radar parameters characterized by clear-air turbulence and precipitation over Mount Everest are introduced. As the X-band radar wavelength is short, data quality control is exercised over the obtained differential phase (Φdp), reflectivity (Zh), differential reflectivity (Zdr), and other polarization physical quantities. Based on the X-band dual-polarization weather radar, FY4 satellite, and EC reanalysis data, the 3D structural characteristics of clear-air turbulence, weak precipitation, and meso-microscale strong convective precipitation on the northern slope of Mount Everest from June 2019 to July 2019 are analyzed. Our results reveal that clear-air turbulence on Mount Everest is mainly wet turbulence, and Zh and Zdr are significantly greater than those in the plain area. The ground clutter in some locations exhibits low Zdr and high ρhv characteristics, opposite to those in the plain area. Weak precipitation on Mount Everest has a typical three-layer structure similar to that in the plain area, and when Zh  >  25  dBZ, Zh and Zdr display a positive linear correlation. Alternatively, Mount Everest’s atmospheric environment is conducive to triggering strong convective weather, consisting of common isolated convection cells at the microscale. The echo top height and maximum precipitation intensity of strong convection weather on Mount Everest are greater than those in the plain area. However, the whole layer convective thickness is much smaller than that in the plain area. Our preliminary results reveal the raindrop size distribution, quantitative precipitation estimation, and microphysical parameterization scheme of cloud precipitation in the Mount Everest region.

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