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A 45-year time series of dune mobility indicating constant windiness over the central Sahara

Vermeesch, P. and Leprince, S. (2012) A 45-year time series of dune mobility indicating constant windiness over the central Sahara. Geophysical Research Letters, 39 . Art. No. L14401. ISSN 0094-8276. doi:10.1029/2012GL052592.

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Although evidence is mounting that links global warming to changes in atmospheric dynamics over the Atlantic realm, similar studies over the African continent are lacking. And even if such models would exist, it would be difficult to verify their validity due to the paucity of meteorological observations and anemometers in the central Sahara. A pragmatic way around this problem is to monitor barchan dune velocity as a proxy for the windiness of desert areas. Dune migration rates are a measure of the amount of work done by the wind which does not require field measurements but can be observed from space instead. This paper presents a novel application of the remote sensing tool COSI-Corr for the construction of time series of dune mobility from sequences of optical satellite imagery. The technique has been applied to the Bodélé Depression in northern Chad, to demonstrate that dune migration rates in the central Sahara have been remarkably constant for nearly half a century, leading us to conclude that wind velocities have not changed more than 0.2% per year over that period. It is therefore unlikely that the frequency and intensity of dust storms originating from this ‘hot spot’ has significantly changed over the past decades either.

Item Type:Article
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Leprince, S.0000-0003-4555-8975
Additional Information:© 2012 American Geophysical Union. Received 1 June 2012; accepted 8 June 2012; published 19 July 2012. Part of this research was done during an academic visit of P.V. to Caltech, sponsored by a grant from the Keck Institute for Space Studies (KISS) awarded to S.L. We would like to thank the help of two anonymous reviewers, one of whom suggested equation (2) to us. The Editor thanks the anonymous reviewer.
Group:Keck Institute for Space Studies
Funding AgencyGrant Number
Keck Institute for Space Studies (KISS)UNSPECIFIED
Subject Keywords:COSI-Corr; Sahara; bodele; dunes; dust; wind
Classification Code:Index Terms: Hydrology: Remote sensing (1640, 4337) Hydrology: Sediment transport (4558)
Record Number:CaltechAUTHORS:20120824-130941964
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Official Citation:Vermeesch, P. and S. Leprince (2012), A 45-year time series of dune mobility indicating constant windiness over the central Sahara, Geophys. Res. Lett., 39, L14401, doi:10.1029/2012GL052592.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:33516
Deposited On:24 Aug 2012 21:38
Last Modified:09 Nov 2021 21:35

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