Free-tropospheric aerosols contribute to large aerosol optical depth at a remote, inland location with insignificant anthropogenic emissions

Ajay, A and Anand, N and Adithya Kaushik, YA and Ilavazhagan, G and Sunilkumar, K (2023) Free-tropospheric aerosols contribute to large aerosol optical depth at a remote, inland location with insignificant anthropogenic emissions. In: Journal of Atmospheric and Solar-Terrestrial Physics, 253 .

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Abstract

In-situ measurements of atmospheric aerosols from remote environments marked with negligible human activities are required to reduce the uncertainties associated with natural aerosols in pre-industrial climate forcings (particularly the aerosol-cloud interactions). In this study, we present long-term continuous aerosol measurements, carried out using ground-based and satellite observations, both close to the surface and in the vertical column, over a remote, rural, inland location in southern peninsular India. The near-surface aerosol concentrations were low, in general conformity to the typical pattern expected for a remote location, with the temporal changes being primarily governed by the background meteorology. However, the columnar aerosol optical depth (AOD) was surprisingly high and resembled that of a typical semi-urban continental location, with an yearly mean AOD of 0.47 ± 0.06. Spaceborne lidar observations in conjunction with ground-based radiometer measurements revealed that around 60 of this AOD was contributed by free-tropospheric aerosol layers during summer and monsoon seasons. Airmass back-trajectory analysis along with particle depolarisation ratio profiles indicate that these aerosol layers are mostly associated with long-range transported dust aerosols. Our findings indicate that benign surface concentration of aerosols at a location need not necessarily be sufficient to consider it as an optimal choice for studying background aerosols. © 2023 Elsevier Ltd

Item Type:	Journal Article
Publication:	Journal of Atmospheric and Solar-Terrestrial Physics
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to Publisher
Keywords:	Atmospheric aerosols; Carbon; Industrial emissions; Optical properties; Optical radar; Troposphere; Uncertainty analysis, Aerosol layers; Aerosol optical depths; Anthropogenic emissions; Black carbon; CALIOP; Free-tropospheric aerosol; In-situ measurement; Measurements of; Remote environment; Tropospheric aerosols, Location
Department/Centre:	Division of Information Sciences (Doesn't exist now) > BioInformatics Centre UG Programme Others
Date Deposited:	29 Feb 2024 05:56
Last Modified:	29 Feb 2024 05:56
URI:	https://eprints.iisc.ac.in/id/eprint/83731

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