Analysis of Indian Summer Monsoon Extreme Precipitation Events over the Himalayas

The Himalayan region is highly vulnerable to extreme rainfall-related hazards such as flash floods, river flooding, and cloudbursts. Extreme precipitation events (EPEs) aggravate loss of lives, property damage and significantly impact socio-economic activities in the region. Therefore, understanding and prediction of these events are important for flood risk assessment. However, due to the lack of reliable precipitation networks, it is challenging to predict the EPEs in the world's most extreme terrain. The existence of knowledge gaps about the factors responsible for EPEs and the dynamical changes associated with the atmospheric circulation pattern warrants in-depth investigations on this topic. Majorly, heavy rainfall over the region during the Indian summer monsoon occurs by convection followed by orographically locked system. The condition of the strong ridges of the Tibetan Plateau, combined with the low pressure of the monsoon in northern India, creates a strong moist flow from the Bay of Bengal and the Arabian Sea into the Himalayas. Along with this interaction of tropical monsoon depression with extratropical disturbances, lead to the formation of the EPEs condition over the region. The present study explored the dynamic and thermodynamic feedbacks responsible for the development of the EPEs over the Himalayas. Our result suggests that the Indian summer monsoon EPEs over the Himalayas are mostly associated with synoptic and sub-synoptic scale systems along with local scale convective systems. Finally, the current study aims to provide scientific insights to the possible impact of climate change on extreme events which can help the mitigation of the disasters in the Himalayan region. Detailed results attributed to the EREs mechanisms altering the atmospheric conditions will be discussed.