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Multiple dust sources in the Sahara Desert: The importance of sand dunes
Author(s) -
Crouvi Onn,
Schepanski Kerstin,
Amit Rivka,
Gillespie Alan R.,
Enzel Yehouda
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052145
Subject(s) - aeolian processes , silt , sand dune stabilization , geology , storm , abrasion (mechanical) , debris , dust storm , mineral dust , geomorphology , hydrology (agriculture) , environmental science , aerosol , geotechnical engineering , oceanography , meteorology , mechanical engineering , engineering , physics
We determine the current sources of dust in the Sahara Desert using quantitative correlation between the number of days with dust storms (NDS), derived from remote‐sensing data of high temporal resolution, with the distribution of the soil types and geomorphic units. During 2006–8 the source of over 90% of the NDS was found to be sand dunes, leptosols, calcisols, arenosols, and rock debris. In contrast to previous studies, only few dust storms originated from playas and dry lake beds. Land erodibility was estimated by regressing the NDS to the number of days with high‐speed wind events, and was found to be high for sand dunes. Clay and fine‐silt grains and aggregates are scarce in sand dunes, which most likely produce dust particles through aeolian abrasion of sand grains. Thus, saltating sand grains impacting clay aggregates on playa surfaces cannot be the sole process for generating dust in the Sahara.