Characteristics of hydrometeor budget and the microphysical processes responsible for heavy precipitation are studied based on the WRF model simulations of two representative Meiyu frontal rainstorms that are associated with two distinct atmospheric circulation patterns. Case 1 is characterized by the coupling of the Eastward Propagating Mesoscale Vortex (EPMV) and Meiyu front, while Case 2 is dominated by the interaction between the Low‐Level Wind Shear (LLWS) and Meiyu front. The temporal and spatial characteristics of the hydrometeor budget are validated against observations and assimilation products including those obtained during the 2018 Integrative Monsoon Frontal Rainfall Experiment (IMFRE) campaign and discussed in the context of contrasting the precipitation intensification and dissipation stage. Specifically, the ice‐dependent cloud processes, rather than the liquid‐dependent cloud processes, are predominantly responsible for the variation of precipitation. These terms include the deposition from water vapor to the ice phase hydrometeors, the accretion from cloud liquid water to the ice phase hydrometeors in the upper troposphere, and the melting of the ice phase hydrometeors into raindrops in the mid‐lower troposphere. Then three major ice cloud conversion pathways and two minor warm cloud conversion pathways for the formation of raindrops are extracted from the overall microphysical processes active in both Case 1 and Case 2. One of the key findings is that ice‐dependent cloud processes are significantly more active in the case characterized by the coupling of EPMV and Meiyu front, and this difference is at least partly explained by the differences in dynamical and thermodynamic conditions dominated by the circulation patterns.

中文翻译：

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两种不同大气环流方式引起的梅雨锋暴雨的水文收支。

基于两次有代表性的梅雨锋暴雨的WRF模型模拟，研究了造成大量降水的水凝物收支特征和微物理过程，这与两种不同的大气环流模式有关。案例1的特征是向东传播的中尺度涡旋（EPMV）和梅雨锋的耦合，而案例2则以低空风切变（LLWS）和梅雨锋之间的相互作用为主导。对照观测和同化产品（包括在2018年季风前锋正面降雨实验（IMFRE）活动中获得的观测和同化产品）验证了水流预算的时空特征，并在对比降水集约和消散阶段的背景下进行了讨论。特别，与冰有关的云过程，而不是与液体有关的云过程，主要是造成降水变化的原因。这些术语包括在对流层上部从水蒸气到冰相水凝物的沉积，从云状液态水到冰相氢凝物的吸积，以及在对流层中下部的冰相水凝物融化成雨滴。然后，从案例1和案例2中活跃的整个微物理过程中提取了三个主要的冰云转换路径和两个次要的暖云转换路径。在EPMV和Meiyu Front耦合的情况下很活跃，