Deep convective activity in tropical cyclones and Its Impact on cirrus clouds: using lightning as a proxy

Saha, J., Routray, A., Price, C., Hunt, K. M. R. ORCID: https://orcid.org/0000-0003-1480-3755, Hari Prasad, K. B. R. R. and Guha, A. (2026) Deep convective activity in tropical cyclones and Its Impact on cirrus clouds: using lightning as a proxy. Pure and Applied Geophysics. ISSN 0033-4553 doi: 10.1007/s00024-025-03908-7

Abstract/Summary

This study examines the impact of deep convective activity in intense tropical cyclones (TCs) on cirrus clouds, specifically in terms of modulating cloud ice water content in the upper atmosphere. Cirrus clouds play a crucial role in Earth’s radiation budget. The study considers three major TCs (Fani, Tauktae, and Mocha) in the North Indian Ocean (NIO) basin to examine lightning activity within a 500 km radial distance from the TC eye, as a proxy for convective activity, and assess its contribution to Specific Cloud Ice Water Content (SCIWC). It reveals positive correlations between daily lightning strike counts and daily mean SCIWC, with correlation coefficients (r) reaching 0.76, 0.63, and 0.81 at 200 hPa for TCs Fani, Tauktae, and Mocha, respectively. It is found that the SCIWC consistently peaks near the 200 hPa level for all three TCs, highlighting this level as a key region for the accumulation of upper-tropospheric cloud ice. Lightning stroke counts and SCIWC at 200 hPa at the 500 km radial distance from the TC eye on the maximum lightning activity day possess strong positive correlations with correlation coefficients (r) = 0.64, 0.60, and 0.55 for Fani (with a 12-h latency), Tauktae, and Mocha (with a 12-h latency), respectively. Additionally, a multi-scale analysis across latitude–longitude grids further confirms that as lightning intensifies, cloud ice content increases significantly at high altitudes. Regression analysis shows that for every 100% increase in daily stroke counts within a 500 km radius from the TC eye, the daily SCIWC could rise by more than 60% in different TC cases, with a stronger response between 300 to 200 hPa. It highlights the role of deep convection in the formation of cirrus clouds. The study deduces that the lightning activity in TCs serves as a key indicator of convective strength, modulating cirrus cloud development through enhanced cloud ice water content.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/128504
Identification Number/DOI	10.1007/s00024-025-03908-7
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Springer
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