Cloud bursts have become a pressing concern with their devastating impact and increasing frequency over the Himalayan region. Therefore, understanding the physical mechanisms associated with their occurrence is essential and urgent. Our investigation into the physical mechanisms of a cloud burst over Sauni Binsar, Uttarakhand, India, which occurred on 10 June 2021 around 06 UTC, is a step towards addressing this urgency. On the day of the cloud burst, there was a continuous accumulation/stagnation (at 850 hPa) of moist air over Sauni Binsar due to the northward propagation of the southwest monsoon, leading to atmospheric column supersaturation. The advection of warm air (dry) from the monsoon heat low at higher (700 hPa) caused potential instability over this region. Orographic lifting and a gradual increase in convergence over this region caused moist convection. Further, the analysis of Richardson's number indicated that turbulence was maximum in the middle and upper troposphere. Just a few hours before the cloud burst event (02–06 UTC 10 June 2021), the decrease in potential vorticity indicates the squashing of the moist columns and the decrease in the vorticity. The sudden squashing of the supersaturated atmospheric column might have caused enormous rainfall (Cloud burst) over the Sauni Binsar region.

中文翻译：

---

印度北阿坎德邦 Sauni Binsar 暴雨事件期间的天气强迫和热力学过程


云爆发因其破坏性影响和喜马拉雅地区日益频繁的发生而成为一个紧迫的问题。因此，了解与其发生相关的物理机制至关重要且紧迫。我们对 2021 年 6 月 10 日世界标准时间 6 点左右发生的印度北阿坎德邦 Sauni Binsar 上空云爆发的物理机制进行了调查，这是解决这一紧迫问题的一步。暴云当天，由于西南季风向北传播，Sauni Binsar上空的湿空气持续积聚/停滞（850 hPa），导致大气柱过饱和。季风高温（700 hPa）带来的暖空气（干燥）平流导致该地区潜在的不稳定。地形抬升和该地区辐合的逐渐增加引起了潮湿对流。此外，理查森数的分析表明，对流层中上层的湍流最大。就在云爆发事件（2021 年 6 月 10 日 02-06 UTC）前几个小时，位涡的减少表明湿柱的挤压和涡度的减少。过饱和大气柱的突然挤压可能导致 Sauni Binsar 地区出现大量降雨（云爆发）。