Global atmospheric black carbon mixing ratios and direct radiative effect based on GEOS-Chem model

Kohei Ikeda
Earth System Division, National Institute for Environmental Studies (NIES)
Researcher Info (URL):https://researchmap.jp/ikeda_kohei?lang=en

2026/06/26

2009/01/01 - 2022/12/31

NIES
Email: cgerdb_admin(at)nies.go.jp

NetCDF

7.2 GB

ver.1.0 (Last updated: 2026/06/26)

English

Atmospheric black carbon concentration, Direct radiative effect

Global

Monthly

Latitude: 2 degrees, Longitude: 2.5 degrees, Vertical: 47 layers from the surface to 0.01 hPa

The atmospheric mixing ratios of black carbon (BC) were simulated using the GEOS-Chem global chemistry transport model (version 13.1.2; Bey et al., 2001; Ikeda et al., 2017) with a tagged tracer approach. The model was run at a horizontal resolution of 2° × 2.5° with 47 vertical layers extending from the surface to 0.01 hPa. Meteorological inputs were provided by the Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2). Biomass burning emissions were based on the Global Fire Emissions Database with small fires (GFED v4.1s; van der Werf et al., 2017), which has a spatial resolution of 0.25° × 0.25° and daily temporal resolution. Anthropogenic emissions were taken from the ECLIPSEv6b inventory (Klimont et al., 2017), which provides total annual emissions at five-year intervals and monthly emission shares at 0.5° × 0.5° resolution; emissions for intermediate years were linearly interpolated. To assess the influence of potential changes in transport efficiency under climate change on China’s contribution to Arctic BC, we also performed sensitivity simulations in which China’s emissions were fixed at the 2010 level, referred to as chn2010. The direct radiative effects (DRE) of BC and other atmospheric species were simulated using the full-chemistry GEOS-Chem model coupled with the Rapid Radiative Transfer Model for GCMs (RRTMG; Heald et al., 2014; Ikeda et al., 2023). These simulations were conducted at a horizontal resolution of 4° × 5° under both the standard BC emission configuration and the chn2010 scenario. Each scenario was simulated for two periods: 2009–2011 and 2020–2022. Within GEOS-Chem, RRTMG computed time-averaged, all-sky radiation at the top of the atmosphere for both shortwave and longwave components on a monthly basis. The BC DRE was estimated as the difference between the total radiative flux and the flux from a simulation in which BC concentrations were set to zero.

[Free keywords]

[2026/06/26]

Yange Deng ( orcid.org/0000-0002-2185-6372)
Earth System Division, National Institute for Environmental Studies (NIES)

This work is a contribution to the Minutes of Cooperation (MoC) between the National Institute for Environmental Studies, Japan and the Finnish Environment Institute (SYKE) on Black Carbon and SLCP Research, since 2017.

This study was supported by the Environment Research and Technology Development Fund of the ERCA (JPMEERF20252001) funded by the Ministry of the Environment.

Deng, Y., Ikeda, K., Tanimoto, H., Andrews, E., Chan, T., Krejci, R., et al. (2026). China's contribution to arctic black carbon declined from 2009 to 2022. Earth's Future, 14, e2025EF007441, doi:10.1029/2025EF007441.

CC BY 4.0（Creative Commons Attribution 4.0 International）

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