Shamjad, P. M. and Tripathi, S. N. and Aggarwal, S. G. and Mishra, S. K. and Joshi, Manish and Khan, Arshad and Sapra, B. K. and Ram, Kirpa (2012) Comparison of Experimental and Modeled Absorption Enhancement by Black Carbon (BC) Cored Polydisperse Aerosols under Hygroscopic Conditions. Environmental Science and Technology, 46 (15). pp. 8082-8089. ISSN 0013-936X

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Abstract

The quantification of the radiative impacts of light absorbing ambient black carbon (BC) particles strongly depends on accurate measurements of BC mass concentration and absorption coefficient (beta(abs)). In this study, an experiment has been conducted to quantify the influence of hygroscopic growth of ambient particles on light absorption. Using the hygroscopic growth factor (i.e., Zdanovskii-Stokes-Robinson (ZSR) approach), a model has been developed to predict the chemical composition of particles based on measurements, and the absorption and scattering coefficients are derived using a core-shell assumption with light extinction estimates based on Mie theory. The estimated optical properties agree within 7% for absorption coefficient and 30% for scattering coefficient with that of measured values. The enhancement of absorption is found to vary according to the thickness of the shell and BC mass, with a maximum of 2.3 for a shell thickness of 18 nm for the particles. The findings of this study underline the importance of considering aerosol-mixing states while calculating their radiative forcing.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Chemical Society.
Subjects:	Earth Sciences Engineering
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	06 Feb 2020 07:29
Last Modified:	06 Feb 2020 07:29
URI:	http://npl.csircentral.net/id/eprint/3669

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