Triple dip La-Nina, unorthodox circulation and unusual spin in air quality of India

Beig, G and Anand, V and Korhale, N and Sobhana, SB and Harshitha, KM and Kripalani, RH (2024) Triple dip La-Nina, unorthodox circulation and unusual spin in air quality of India. In: Science of the Total Environment, 920 .

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Abstract

The recent La-Nina phase of the El Nino Southern Oscillation (ENSO) phenomenon unusually lasted for third consecutive year, has disturbed global weather and linked to Indian monsoon. However, our understanding on the linkages of such changes to regional air quality is poor. We hereby provide a mechanism that beyond just influencing the meteorology, the interactions between the ocean and the atmosphere during the retreating phase of the La-Niña produced secondary results that significantly influenced the normal distribution of air quality over India through disturbed large-scale wind patterns. The winter of 2022�23 that coincided with retreating phase of the unprecedented triple dip La-Niña, was marred by a mysterious trend in air quality in different climatological regions of India, not observed in recent decades. The unusually worst air quality over South-Western India, whereas relatively cleaner air over the highly polluted North India, where levels of most toxic pollutant (PM2.5) deviating up to about ±30 from earlier years. The dominance of higher northerly wind in the transport level forces influx and relatively slower winds near the surface, trapping pollutants in peninsular India, thereby notably increasing PM2.5 concentration. In contrast, too feeble western disturbances, and unique wind patterns with the absence of rain and clouds and faster ventilation led to a significant improvement in air quality in the North. The observed findings are validated by the chemical-transport model when forced with the climatology of the previous year. The novelty of present research is that it provides an association of air quality with climate change. We demonstrate that the modulated large-scale wind patterns linked to climatic changes may have far-reaching consequences even at a local scale leading to unusual changes in the distribution of air pollutants, suggesting ever-stringent emission control actions. © 2024 Elsevier B.V.

Item Type:	Journal Article
Publication:	Science of the Total Environment
Publisher:	Elsevier B.V.
Additional Information:	The copyright for this article belongs to The Authors.
Keywords:	Atmospheric pressure; Climate change; Emission control; Normal distribution; Particles (particulate matter), El nino-southern oscillation phenomenons; Indian monsoon; La nina; La Nina phase; Large-scales; North India; Particulate Matter; Regional air quality; Transport modelling; Wind patterns, Air quality, rain, air quality; atmospheric pollution; climate change; climatology; El Nino-Southern Oscillation; emission control; La Nina; meteorology; particulate matter; ventilation, air pollutant; air pollution; air quality; Article; atmosphere; climate; climate change; cloud; controlled study; El Nino; India; meteorology; model; particulate matter 2.5; sea; surface property; wind; winter; air pollution; air pollution control; article; climate; human; meteorology; particulate matter; weather, India
Department/Centre:	Others
Date Deposited:	23 Apr 2024 10:15
Last Modified:	23 Apr 2024 10:15
URI:	https://eprints.iisc.ac.in/id/eprint/84619

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