Improvement and Application of Time–Height Profile Reconstruction Method Using X-band Dual-Polarization Radar Parameters

In recent years, the reconstruction of the time–height profile of radar reflectivity and other parameters using volume coverage pattern data to improve its vertical resolution and make it suitable for cloud microphysical research has been one of the popular topics in radar meteorology. Based on the volume scan data of X-band dual-polarization radar with high resolution, this paper improves the CVP (Column Vertical Profile) algorithm by varying the target area selection for applying it to rapidly developing convective clouds and locally generating clouds with small horizontal scales. The comparison with cloud radar indicates that for the local precipitation in the plateau area, the basic reflectivity (Z_H) vertical profile reconstructed using modified CVP with a small area comprising 5 km (radial range) × 10° (azimuth coverage) can reasonably reflect the characteristics of generating cells in the high level of clouds. Gradual decreasing of Z_H from high layer, and gradual increasing of Z_H toward low layer are indicated by the corresponding Z_H time-height series. For the vigorously developed convective cloud in North China, the area selection strategy of the original CVP was enhanced by adopting variations in the selected radial range for high and low-elevation layers. The new vertical profile of Z_H considerably avoids the “zig-zag” structure caused by the uneven horizontal distribution of the low-level echo while retaining the primary characteristics of the high-level echoes of convective cloud in the vigorously developing stage and the transformation of cloud structure at different stages. Moreover, by comparing the reconstructed results of modified CVP with the original CVP, a new time-height series is obtained for different polarization parameters, which shows the changing cloud microphysical characteristics over time, thereby revealing convection-generated cells mechanisms of formation and its seeding effect on the plateau. In the mature stage of convective cloud in North China, vertical distribution characteristics of polarization variables that vary with time could also be depicted.