Concentrations and radiative forcing of anthropogenic aerosols from 1750 to 2014 simulated with the Oslo CTM3 and CEDS emission inventory
<p>We document the ability of the new-generation Oslo chemistry-transport model, Oslo CTM3, to accurately simulate present-day aerosol distributions. The model is then used with the new Community Emission Data System (CEDS) historical emission inventory to provide updated time series of an...
Main Authors: | , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2018-12-01
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Series: | Geoscientific Model Development |
Online Access: | https://www.geosci-model-dev.net/11/4909/2018/gmd-11-4909-2018.pdf |
Summary: | <p>We document the ability of the new-generation Oslo
chemistry-transport model, Oslo CTM3, to accurately simulate present-day
aerosol distributions. The model is then used with the new Community Emission
Data System (CEDS) historical emission inventory to provide updated time
series of anthropogenic aerosol concentrations and consequent direct
radiative forcing (RFari) from 1750 to 2014.</p><p>Overall, Oslo CTM3 performs well compared with measurements of surface
concentrations and remotely sensed aerosol optical depth. Concentrations are
underestimated in Asia, but the higher emissions in CEDS than previous
inventories result in improvements compared to observations. The treatment
of black carbon (BC) scavenging in Oslo CTM3 gives better agreement with
observed vertical BC profiles relative to the predecessor Oslo CTM2. However,
Arctic wintertime BC concentrations remain underestimated, and a range of
sensitivity tests indicate that better physical understanding of processes
associated with atmospheric BC processing is required to simultaneously
reproduce both the observed features. Uncertainties in model input data,
resolution, and scavenging affect the distribution of all aerosols species,
especially at high latitudes and altitudes. However, we find no evidence of
consistently better model performance across all observables and regions in
the sensitivity tests than in the baseline configuration.</p><p>Using CEDS, we estimate a net RFari in 2014 relative to 1750 of
−0.17 W m<sup>−2</sup>, significantly weaker than the IPCC AR5 2011–1750
estimate. Differences are attributable to several factors, including stronger
absorption by organic aerosol, updated parameterization of BC absorption, and
reduced sulfate cooling. The trend towards a weaker RFari over recent years
is more pronounced than in the IPCC AR5, illustrating the importance of
capturing recent regional emission changes.</p> |
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ISSN: | 1991-959X 1991-9603 |