Analysis of the Satellite Nephogram Characteristic and Moist Potential Vorticity of Rainstorm on July 3, 2011
Abstract：A heavy rain process occurred in northwest Henan on July 2-3, 2011. There was two stations' 24 h rainfall achieved heavy rain, and the rainfall intensity was large and period was concentrat-ed, which presented obviously severe convection rainstorm characters. The circulation background analy-sis and physical diagnosis were studied to adopt NCEP 1°×1° reanalysis data. The result shows that : the middle and low-altitude low trough and shear line directly bring on the storm. Humidity unstable region continuously stabled has accumulated a large amount of unstable energy for the rain ; excited by the inva-sion of cold air, unstable energy release generates strong convective precipitation. The formation of cy-clonic circulation and the existence of cyclonic curvature in low-level are conducive to strengthen the up-ward motion; the water vapor transport and convergence as well as the strong upward motion cause the heavy precipitation continued. Dry potential vorticity in high-level propagating downstream perturbation to the lower troposphere prompts to cyclonic vortex formation and intensification. The propagation character-istics of potential vorticity match corresponding rain intensity in 4-6 h. Combined with the automatic sta-tion hourly precipitation, local heavy rain was analyzed by using FY-2E satellite data. The result shows: The rainstorm exists obviously cloud self-organization phenomena. The heavy precipitation is di-rectly occurred by two β-seale strong rain cloud, which is internal in one α-scale convective cloud after organization and combination. Cold cloud covered region (Tbb 〈 221 K) is corresponding to the heavy rainfall area.
Keywords：rainstormsatellite nephogramTbbmoist potential vorticity
Publication Date：2012-08-07
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：7( 1-7 )