Publication Abstracts
Karambelas et al. 2022
Karambelas, A., A.M. Fiore, , V.F. McNeill, C.A. Randles, C. Venkataraman, J.R. Pierce, K.R. Bilsback, and G.P. Milly, 2022: Investigating drivers of particulate matter pollution over India and the implications for radiative forcing with GEOS-Chem-TOMAS15. J. Geophys. Res. Atmos., 127, no. 24, e2021JD036195, doi:10.1029/2021JD036195.
Ambient fine particulate matter (PM2.5) concentrations in India frequently exceed 100 µg/m3 during fall and winter pollution episodes. We use the GEOS-Chem chemical transport model with the TwO-Moment Aerosol Sectional microphysics scheme with 15 size bins (TOMAS15) to assess PM2.5 composition and impacts on radiation and cloud condensation nuclei (CCN) during pollution episodes as compared to the seasonal (October-December) average. We conduct high resolution (0.25°×0.3125°) nested-domain simulations over India for short-duration, high-PM2.5 episodes in fall 2015 and 2017. The simulations capture the magnitude and spatial patterns of pollution episodes measured by surface monitors (r2PM2.5=0.69) although aerosol optical depth is underestimated. During the episodes, near-surface organic matter (OM), black carbon (BC), and secondary inorganic aerosol concentrations increase from seasonal averages by up to 36, 7, and 7 µg/m3, respectively. Episodic aerosol increases enhance cooling by lowering the top-of-atmosphere clear-sky direct radiative effect (DRETOA) during the 2015 episode (-6 W/m2), with a smaller impact during the 2017 episode (-1 W/m2). Differences in DRETOA reflect larger increases in scattering aerosols in the column during the 2015 episode (+17 mg/m2) than in 2017 (+13 mg/m2), while absorbing aerosol column enhancements are smaller (+3 mg/m2) in both years. Changes in shortwave radiation at the surface (SWsfc) are spatially similar to DRETOA and mostly negative during both episodes. CCN enhancements (0.2% supersaturation) during these episodes occur across the western Indo-Gangetic Plain, coincident with higher PM2.5 concentrations. Changes in DRETOA, SWsfc, and CCN during high-PM2.5 episodes may have implications for crops, the hydrologic cycle, and surface temperature.
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BibTeX Citation
@article{ka05400t,
author={Karambelas, A. and Fiore, A. M. and Westervelt, D. M. and McNeill, V. F. and Randles, C. A. and Venkataraman, C. and Pierce, J. R. and Bilsback, K. R. and Milly, G. P.},
title={Investigating drivers of particulate matter pollution over India and the implications for radiative forcing with GEOS-Chem-TOMAS15},
year={2022},
journal={Journal of Geophysical Research: Atmospheres},
volume={127},
number={24},
pages={e2021JD036195},
doi={10.1029/2021JD036195},
}
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RIS Citation
TY - JOUR ID - ka05400t AU - Karambelas, A. AU - Fiore, A. M. AU - Westervelt, D. M. AU - McNeill, V. F. AU - Randles, C. A. AU - Venkataraman, C. AU - Pierce, J. R. AU - Bilsback, K. R. AU - Milly, G. P. PY - 2022 TI - Investigating drivers of particulate matter pollution over India and the implications for radiative forcing with GEOS-Chem-TOMAS15 JA - J. Geophys. Res. Atmos. JO - Journal of Geophysical Research: Atmospheres VL - 127 IS - 24 SP - e2021JD036195 DO - 10.1029/2021JD036195 ER -
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