Abstract The characteristic features of inter-seasonal variability of precipitation microphysics for the year 2019 over Mumbai and Chennai – the two urban-coastal cities of Indian sub-continent have been studied in this paper. The importance of choosing the regions lies in the fact that these two cities are well-known for the occurrences of severe rainfall events due to the effect of south-west and north-east monsoon during the summer and winter season of Indian sub-continent respectively. It has been observed that raindrops of diameter 2–4 mm dominate the summer rainfall over Chennai with respect to winter rainfall. Correspondingly, while comparing the two cities together, the impact of the south-west and north-east monsoon in conjunction with the interplay of the continental and maritime effect on the microphysics of precipitation over these cities is strongly visible in the analysis. The study reveals that the rainfall evolving from the continental clouds along with contrasting surface temperature produces distinct diurnal variation for the summer (winter) rainfall over Chennai (Mumbai) while such variations are not visible for the maritime clouds. It has been observed that the drops of larger diameter along with higher radar reflectivity dominated the summer rainfall of Chennai with respect to Mumbai. While for the winter rainfall, such distinct variations are visible only for higher rainfall regimes from 16 mm/h and above where the domination of larger drops is visible for the Mumbai rainfall. Thus the difference in surface temperature which in turn escalates the convective environment in the atmosphere can be termed as one of the important factors responsible for this inter-seasonal variability of precipitation microphysics.

中文翻译：

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揭示孟买和金奈夏季和冬季季风降水微物理特征——印度次大陆的两个沿海城市

摘要 本文研究了印度次大陆两个沿海城市孟买和金奈2019年降水微物理的季节间变化特征。选择地区的重要性在于，这两个城市因印度次大陆夏季和冬季分别受西南季风和东北季风的影响，以发生强降雨事件而闻名。 . 据观察，与冬季降雨量相比，直径 2-4 毫米的雨滴在金奈的夏季降雨量中占主导地位。相应地，将两个城市放在一起比较时，在分析中，西南和东北季风的影响以及大陆和海洋对这些城市降水微观物理学的相互作用的影响非常明显。该研究表明，从大陆云演变而来的降雨以及对比鲜明的表面温度对金奈（孟买）的夏季（冬季）降雨产生明显的日变化，而海洋云则看不到这种变化。据观察，较大直径的水滴和较高的雷达反射率主导了金奈相对于孟买的夏季降雨。而对于冬季降雨量，这种明显的变化仅在 16 毫米/小时及以上的较高降雨量情况下可见，而孟买降雨量较大的降雨量占主导地位。