AerSett v1.0: a simple and straightforward model for the settling speed of big spherical atmospheric aerosols
<p>This study introduces AerSett v1.0 (AERosol SETTling version 1.0), a model giving the settling speed of big spherical aerosols in the atmosphere without going through an iterative equation resolution. We prove that, for all spherical atmospheric aerosols with diameter <span class="i...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-02-01
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| Series: | Geoscientific Model Development |
| Online Access: | https://gmd.copernicus.org/articles/16/1119/2023/gmd-16-1119-2023.pdf |
| Summary: | <p>This study introduces AerSett v1.0 (AERosol SETTling version 1.0), a model giving the settling speed of big spherical aerosols in the atmosphere without going through an iterative equation resolution. We prove that, for all spherical atmospheric aerosols with diameter <span class="inline-formula"><i>D</i></span> up to <span class="inline-formula">1000 µm</span>, this direct and explicit method including the drag coefficient formulation of <span class="cit" id="xref_text.1"><a href="#bib1.bibx5">Clift and Gauvin</a> (<a href="#bib1.bibx5">1971</a>)</span> and the <span class="cit" id="xref_text.2"><a href="#bib1.bibx7">Davies</a> (<a href="#bib1.bibx7">1945</a>)</span> slip correction factor gives results within 2 % of the exact solution obtained from the numerical resolution of a non-linear fixed-point equation. This error is acceptable considering the uncertainties on the drag coefficient formulations themselves. For <span class="inline-formula"><i>D</i><100 µm</span>, the error is below 0.5 %. We provide a Fortran implementation of this simple and straightforward model, hoping that more chemistry–transport models (CTMs) and general circulation models will be able to take into account large-particle drag correction to the settling speed of big spherical aerosol particles in the atmosphere, without performing an iterative and time-consuming calculation.</p> |
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| ISSN: | 1991-959X 1991-9603 |