Contributions of Dynamic and Thermodynamic Scaling in Subdaily Precipitation Extremes in India

• Published in: Geophysical research letters Vol. 45; no. 5; pp. 2352 - 2361
• Main Authors: Ali, Haider, Mishra, Vimal
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 16-03-2018
• Subjects: Atmospheric moisture; Atmospheric motion; Climate; Climate change; Daily precipitation; dynamic and thermodynamic scaling; Dynamic response; Extreme weather; Flooding; Global warming; India; Moisture content; Precipitation; precipitation extremes; Scaling; scaling relationship; subdaily; Urban areas; Vertical velocities; Water content; India
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2018GL077065

Despite the importance of subdaily precipitation extremes for urban areas, the role of dynamic and thermodynamic scaling in changes in precipitation extremes in India remains poorly constrained. Here we estimate contributions from thermodynamic and dynamic scaling on changes in subdaily precipitation extremes for 23 urban locations in India. Subdaily precipitation extremes have become more intense during the last few decades. Moreover, we find a twofold rise in the frequency of subdaily precipitation extremes during 1979–2015, which is faster than the increase in daily precipitation extremes. The contribution of dynamic scaling in this rise in the frequency and intensity of subdaily precipitation extremes is higher than the thermodynamic scaling. Moreover, half‐hourly precipitation extremes show higher contributions from the both thermodynamic (~10%/K) and dynamic (~15%/K) scaling than daily (6%/K and 9%/K, respectively) extremes indicating the role of warming on the rise in the subdaily precipitation extremes in India. Our findings have implications for better understanding the dynamic response of precipitation extremes under the warming climate over India.
Plain Language Summary
Understanding the changes in precipitation extremes in urban areas with warming climate can be valuable in mitigating the adverse social and financial consequences. India has witnessed a twofold rise in the frequency of subdaily precipitation extremes during 1979–2015. This increase in the subdaily frequency of extreme precipitation events is higher than the frequency of daily precipitation extremes. Urban areas in India witness flooding due to increasing extreme precipitation events, which caused enormous damage to infrastructure. Despite the increase in subdaily extreme precipitation in India, the contribution of thermodynamic and dynamic scaling remains largely unexplored. We show that subdaily precipitation extremes have substantially larger contribution from thermodynamic and dynamic scaling than that of daily precipitation extremes. We find that subdaily precipitation extremes are more strongly related to changes in variations in the atmospheric motion and increase in vertical velocity than the rise in atmospheric moisture content. Our work will help in understanding the subdaily precipitation extremes in India under the warming climate.
Key Points
The frequency and intensity of subdaily precipitation extremes has increased in India
The contribution from the dynamic scaling is higher than the thermodynamic scaling
Subdaily precipitation extremes show higher regression slopes (against dew point temperature) than daily regression slopes