Marsham, JH orcid.org/0000-0003-3219-8472, Knippertz, P, Dixon, NS et al. (2 more authors) (2011) The importance of the representation of deep convection for modeled dust‐generating winds over West Africa during summer. Geophysical Research Letters, 38 (16). L16803. ISSN 0094-8276
Abstract
West Africa is the world's largest source of airborne mineral dust, which affects weather, climate, and biogeochemical processes. We use continental-scale ten-day simulations from the UK Met Office Unified Model to study the effects of the representation of deep convection on modeled dust-generating winds in summertime West Africa. To isolate the role of meteorology from the land surface we use a new diagnostic parameter "uplift potential", which represents the dependency of dust uplift on wind-speed for an idealized land surface. Runs permitting explicit convection suggest that cold pool outflows from moist convection (so called "haboob" dust storms) potentially generate on the order of half the dust uplift. Simulations with parameterized convection show substantially less haboob uplift, but compensating increased uplift from low-level jets associated with a stronger Saharan heat low (SHL). This leads to reduced dust emission on convectively active days, in the afternoon and evening hours, and in the Sahel. The common practice of tuning coarse-resolution dust models cannot resolve these problems. A realistic representation of the dust cycle, as well as of the SHL, requires targeted efforts to develop computationally inexpensive ways to incorporate the effects of cold-pool outflows from deep convection.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | An edited version of this paper was published by AGU. Copyright (2011) American Geophysical Union. Marsham, JH, Knippertz, P, Dixon, NS, Parker, DJ and Lister, GMS The importance of the representation of deep convection for modeled dust-generating winds over West Africa during summer. Geophysical Research Letters, 38 (16). L16803. To view the published open abstract, go to http://dx.doi.org/10.1029/2011GL048368 |
Keywords: | Intertropical Discontinuity Region; Diurnal Cycle; Monsoon; Emissions; Circulation; Rainfall; System; Scheme |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Oct 2013 10:31 |
Last Modified: | 13 Jan 2021 12:01 |
Published Version: | http://dx.doi.org/10.1029/2011GL048368 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1029/2011GL048368 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76607 |