Improved parameterization for the vertical flux of dust aerosols emitted by an eroding soil
Abstract
The representation of the dust cycle in atmospheric circulation models hinges on an accurate parameterization of the vertical dust flux at emission. However, existing parameterizations of the vertical dust flux either require input parameters that are not normally available on regional or global scales, or do not sufficiently account for differences in erodibility between soils. To help overcome these problems, we present a physically-based theory for the vertical dust flux that is based on the concept that dust emission is a threshold effect. The theory yields a straightforward analytical expression for the vertical dust flux that depends only on the wind friction velocity and the soil's threshold friction velocity, and can therefore be readily implemented into atmospheric circulation models. We show that our parameterization is supported by a compilation of high-quality vertical dust flux measurements, and that it reproduces field measurements with substantially less scatter than existing parameterizations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A42E..02K
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 1631 GLOBAL CHANGE / Land/atmosphere interactions;
- 3311 ATMOSPHERIC PROCESSES / Clouds and aerosols