MATRIX-VBS (v1.0): implementing an evolving organic aerosol volatility in an aerosol microphysics model
The gas-particle partitioning and chemical aging of semi-volatile organic aerosol are presented in a newly developed box model scheme, where its effect on the growth, composition, and mixing state of particles is examined. The volatility-basis set (VBS) framework is implemented into the aerosol micr...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-02-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/10/751/2017/gmd-10-751-2017.pdf |
| Summary: | The gas-particle partitioning and chemical aging of
semi-volatile organic aerosol are presented in a newly developed box model
scheme, where its effect on the growth, composition, and mixing state of
particles is examined. The volatility-basis set (VBS) framework is
implemented into the aerosol microphysical scheme MATRIX (Multiconfiguration
Aerosol TRacker of mIXing state), which resolves mass and number aerosol
concentrations and in multiple mixing-state classes. The new scheme,
MATRIX-VBS, has the potential to significantly advance the representation of
organic aerosols in Earth system models by improving upon the conventional
representation as non-volatile particulate organic matter, often also with
an assumed fixed size distribution. We present results from idealized cases
representing Beijing, Mexico City, a Finnish forest, and a southeastern US forest,
and investigate the evolution of mass concentrations and volatility
distributions for organic species across the gas and particle phases, as
well as assessing their mixing state among aerosol populations. Emitted
semi-volatile primary organic aerosols evaporate almost completely in the
intermediate-volatility range, while they remain in the particle phase in
the low-volatility range. Their volatility distribution at any point in time
depends on the applied emission factors, oxidation by OH radicals, and
temperature. We also compare against parallel simulations with the original
scheme, which represented only the particulate and non-volatile component of
the organic aerosol, examining how differently the condensed-phase organic
matter is distributed across the mixing states in the model. The results
demonstrate the importance of representing organic aerosol as a
semi-volatile aerosol, and explicitly calculating the partitioning of
organic species between the gas and particulate phases. |
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| ISSN: | 1991-959X 1991-9603 |