Page 180 - 《高原气象》2025年第6期

高 原 气 象 44 卷
1588

A Case Study on the Differences in Environmental Conditions for

Hail Clouds between Northern and Southern Regions and the
Characteristics of Hail Clouds Development and Evolution

WANG Qingyuan， GUO Fengxia， DENG Jie， HE Miao， FU Hanghang， CHEN Yutan
（Emergency Management College/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters，
Nanjing University of Information Science and Technology， Nanjing 210044， Jiangsu， China）

Abstract： Unstable energy， strong horizontal environmental wind shear and 0 °C layer height are important fac‐
tors affecting surface hailfall. To explore the differences in environmental stratification of hail clouds between
northern and southern China， this study compares the environmental characteristics before two hail events in Xu‐
nyi， Shaanxi， and northwestern Fujian. The three-dimensional hail cloud numerical model was used to simulate
the development characteristics of these two events under different disturbance temperatures through sensitivity
experiments， while also discussing the impact of strong wind shear on the Fujian hail case. The results show that
the Shaanxi case has a large Convective Available Potential Energy （CAPE） but very weak vertical wind shear，
whereas the Fujian case exhibits a relatively small CAPE but strong vertical wind shear. The height of the 0 °C
layer in both hail clouds is relatively consistent. The atmospheric water vapor content during the formation of the
Shaanxi hail cloud is lower， the cloud base height is higher， and the efficiency of CAPE transforming into up‐
draft kinetic energy is higher. In contrast， the southern hail cloud has higher lower atmospheric humidity and a
lower cloud base height， making it easier to release unstable energy. As the intensity of convection increases， the
peak values of vertical wind speed become greater and occur earlier， the content of hail increases and its duration
is prolonged， the intensity of solid-liquid precipitation intensifies， and the precipitation volume intensifies. The
strong wind shear in the Fujian case weakens the convective intensity and shortens its lifespan， the weaker the
convection is， the more obvious the effect is. Additionally， strong wind shear weakens solid-liquid precipitation.
When there is no wind shear， hail exhibits larger specific water content and number concentration， wider range
of existence， longer time and earlier occurrence time， but the hail range is smaller.
Key words： hail cloud； unstable energy； vertical shear of ambient wind； cloud numerical simulation