Cowie, SM, Marsham, JH orcid.org/0000-0003-3219-8472 and Knippertz, P (2015) The importance of rare, high-wind events for dust uplift in northern Africa. Geophysical Research Letters, 42 (19). pp. 8208-8215. ISSN 0094-8276
Abstract
Dust uplift is a nonlinear thresholded function of wind speed and therefore particularly sensitive to the long tails of observed wind speed probability density functions. This suggests that a few rare high-wind events can contribute substantially to annual dust emission. Here we quantify the relative roles of different wind speeds to dust-generating winds using surface synoptic observations of dust emission and wind from northern Africa. The results show that winds between 2 and 5m/s above the threshold cause the most emission. Of the dust-generating winds, 25% is produced by very rare events occurring only at 0.1 to 1.4% of the time, depending on the region. Dust-producing winds are underestimated in ERA-I, since it misses the long tail found in observations. ERA-I overpredicts (underpredicts) the frequency of emission strength winds in the southern (northern) regions. These problems cannot be solved by simple tunings. Finally, we show that rare
events make the largest contribution to interannual variability in dust-generating winds and that ERA severely underestimates this interannual variability.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015, The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. |
Keywords: | Northern Africa; dust emission; ERA-Interim; interannual variability; surface observations; thresholds |
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) |
Funding Information: | Funder Grant number EU - European Union 257543 |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 Oct 2015 09:56 |
Last Modified: | 17 Feb 2022 15:11 |
Published Version: | http://dx.doi.org/10.1002/2015GL065819 |
Status: | Published |
Publisher: | American Geophysical Union (AGU) |
Identification Number: | 10.1002/2015GL065819 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:90765 |