ItemArticle

Australian bushfire emissions result in enhanced polar stratospheric clouds

Title
Australian bushfire emissions result in enhanced polar stratospheric clouds
Creator
Prasanth, Srinivasan; Anand, Narayana Sarma; Sunilkumar, Kudilil; Jose, Subin; Arun, Kenath; Satheesh, Sreedharan K.; Moorthy, Krishnaswamy Krishna
Description
Extreme bushfire events amplify climate change by emitting greenhouse gases and destroying carbon sinks. They also cause economic damage, through property destruction, and even fatalities. One such bushfire occurred in Australia in 20192020, and this event injected large amounts of aerosols and gases into the stratosphere and depleted the ozone layer. While previous studies have focused on the drivers behind ozone depletion, the bushfire impact on polar stratospheric clouds (PSCs), a paramount factor in ozone depletion, has not been extensively investigated so far. Therefore, this study focuses on the effects of bushfire aerosols on the dynamics and stratospheric chemistry related to PSC formation and its pathways. An analysis from Auras Microwave Limb Sounder revealed that the enhanced hydrolysis of dinitrogen pentoxide significantly increased nitric acid (HNO3) in the high-latitude lower stratosphere in early 2020. This resulted in an anomalously high areal coverage of PSCs with ice, exceeding 3 standard deviations with respect to background period. Based on Lagrangian backward-trajectory analysis, we find that a predominant fraction (79 %) of the liquidnitric acid trihydrate (NAT) mixture formed via the ice-free nucleation pathway. These NAT particles subsequently acted as nuclei for ice formation, accounting for 95 % of the observed ice PSCs. This rapid conversion from NAT to ice likely contributed to the strong positive anomaly in ice PSC. This highlights the primary formation pathways of ice and liquidNAT mixtures and possibly helps us to simulate PSC formation and denitrification process better in climate models. These findings will contribute significantly to a deeper understanding of the impacts of extreme wildfire events on stratospheric chemistry and PSC dynamics. Author(s) 2025.
Source
Atmospheric Chemistry and Physics;Volume;25;Issue;13;pp.7161-7186
Date
01-01-2025
Publisher
Copernicus Publications
Coverage
Prasanth S., Department of Physics and Electronics, Christ University, Karnataka, Bengaluru, India, Divecha Centre for Climate Change, Indian Institute of Science, Karnataka, Bengaluru, India; Anand N.S., School of Earth, Environmental and Sustainability Sciences, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, Vithura, India; Sunilkumar K., Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Karnataka, Bengaluru, India; Jose S., Department of Physics, Newman College, Kerala, Thodupuzha, India; Arun K., Department of Physics and Electronics, Christ University, Karnataka, Bengaluru, India; Satheesh S.K., Divecha Centre for Climate Change, Indian Institute of Science, Karnataka, Bengaluru, India, Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Karnataka, Bengaluru, India, DST-Centre of Excellence in Climate Change, Indian Institute of Science, Karnataka, Bengaluru, India; Moorthy K.K., Divecha Centre for Climate Change, Indian Institute of Science, Karnataka, Bengaluru, India
Rights
All Open Access; Gold Open Access; Green Open Access
Relation
ISSN: 16807316;
Format
online
Language
English
Type
Article

Citation

Prasanth, Srinivasan; Anand, Narayana Sarma; Sunilkumar, Kudilil; Jose, Subin; Arun, Kenath; Satheesh, Sreedharan K.; Moorthy, Krishnaswamy Krishna, “Australian bushfire emissions result in enhanced polar stratospheric clouds,” CHRIST (Deemed To Be University) Institutional Repository, accessed June 18, 2026, https://archives.christuniversity.in/items/show/23656.

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