edu.ucar.opensky::articles:24626 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T23:06:24.854118 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7n301dv https://doi.org/10.5281/zenodo.2620535 https Related Software #1 geoschem/geos-chem: GEOS-Chem 12.3.0 Investigating carbonaceous aerosol and its absorption properties from fires in the Western United States (WE-CAN) and Southern Africa (ORACLES and CLARIFY) 2021-08-16T00:00:00Z publication https://n2t.org/ark:/85065/d7n301dv https://doi.org/10.1029/2021JD034984 Carter, T. S. author Heald, C. L. author Cappa, C. D. author Kroll, J. H. author Campos, Teresa author Coe, H. author Cotterell, M. I. author Davies, N. W. author Farmer, D. K. author Fox, C. author Garofalo, L. A. author Hu, L. author Langridge, J. M. author Levin, E. J. T. author Murphy, S. M. author Pokhrel, R. P. author Shen, Y. author Szpek, K. author Taylor, J. W. author Wu, H. author UCAR/NCAR - Library publisher Biomass burning (BB) produces large quantities of carbonaceous aerosol (black carbon and organic aerosol, BC and OA, respectively), which significantly degrade air quality and impact climate. BC absorbs radiation, warming the atmosphere, while OA typically scatters radiation, leading to cooling. However, some OA, termed brown carbon (BrC), also absorbs visible and near UV radiation; although, its properties are not well constrained. We explore three aircraft campaigns from important BB regions with different dominant fuel and fire types (Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen [WE-CAN] in the western United States and ObseRvations of Aerosols above CLouds and their intEractionS and Cloud-Aerosol-Radiation Interactions and Forcing for Year downwind of southern Africa) and compare them with simulations from the global chemical transport model, GEOS-Chem using GFED4s. The model generally captures the observed vertical profiles of carbonaceous BB aerosol concentrations; however, we find that BB BC emissions are underestimated in southern Africa. Our comparisons suggest that BC and/or BrC absorption is substantially higher downwind of Africa than in the western United States and, while the Saleh et al. (2014, https://doi.org/10.1038/ngeo2220) and FIREX parameterizations based on the BC:OA ratio improve model-observation agreement in some regions, they do not sufficiently differentiate absorption characteristics at short wavelengths. We find that photochemical whitening substantially decreases the burden and direct radiative effect of BrC (annual mean of +0.29 W m(-2) without whitening and +0.08 W m(-2) with). Our comparisons suggest that whitening is required to explain WE-CAN observations; however, the importance of whitening for African fires cannot be confirmed. Qualitative comparisons with the OMI UV aerosol index suggest our standard BrC whitening scheme may be too fast over Africa. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2021 American Geophysical Union. None eng geoscientificInformation