2020年8月11日至12日阿拉善地区暴雨螺旋度特征分析

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作者简介 陈艳萍（1992—），女，内蒙古阿拉善人，助理工程师，本科，主要从事地面综合观测、预报预测工作。

收稿日期 2023-06-30

Analysis of Helicity Characteristics of rainstorm in Alashan Area from August 11 to 12， 2020

Chen Yan-ping （Alxa League Meteorological Bureau of Inner Mongolia Autonomous Region， Alxa， Inner Mongolia 750306）

Abstract This paper used the surface observation data and NCEP reanalysis data in the Alashan area to analyze the vertical helicity of the rainstorm process that occurred in the Alashan area from August 11 to 12， 2020， providing a reference for the short-term heavy precipitation forecast and the rainstorm magnitude precipitation forecast in the future. Analysis results： Before the rainstorm， the hp center value was greater than 310 × 10-6 Pa/s2，

hxy strength 100 × 10-2 Pa/s2， as shown in the vertical helicity profile along 40.2°N， 700 hPa increases to 360 at the positive center of 105°E .There was a negative center near 10-6 Pa/s2 400 hPa， with a center value of -30×10-6 Pa/s2， low-level convergence， high-level divergence. From the perspective of divergence， vertical velocity， and relative humidity， the strongest convergence center is located near 850 hPa， with a divergence center value of -14×10-9 g/（cm2·hPa·s）

-1 500～650 hPa， with the strongest upward velocity occurring at 700 hPa and a vertical velocity of -8 Pa/s， 700 hPa， reaching 100% relative humidity at 104°E. The change in vertical helicity corresponds to the period of heavy precipitation， and when the center and intensity of the positive vertical helicity increase， the rainfall in the precipitation area also increases.

Key words Rainstorm; Vertical helicity; Horizontal helicity; Divergence; Vertical velocity

摘要 利用阿拉善地区地面观测资料和NCEP再分析资料分析2020年8月11日—12日阿拉善地区暴雨螺旋度特征，为今后短时强降水预报及其暴雨量级降水预报提供参考依据。（剩余5371字）