Impact of atmospheric transport on the evolution of microphysical and optical properties of Saharan dust

Ryder, C. L. ORCID: https://orcid.org/0000-0002-9892-6113, Highwood, E. J., Lai, T. M., Sodemann, H. and Marsham, J. H. (2013) Impact of atmospheric transport on the evolution of microphysical and optical properties of Saharan dust. Geophysical Research Letters, 40 (10). pp. 2433-2438. ISSN 0094-8276 doi: 10.1002/grl.50482

Abstract/Summary

Saharan dust affects the climate by altering the radiation balance and by depositing minerals to the Atlantic Ocean. Both are dependent on particle size. We present aircraft measurements comprising 42 profiles of size distribution (0.1–300 µm), representing freshly uplifted dust, regional aged dust, and dust in the Saharan Air Layer (SAL) over the Canary Islands. The mean effective diameter of dust in SAL profiles is 4.5 µm smaller than that in freshly uplifted dust, while the vertical structure changes from a low shallow layer (0–1.5 km) to a well-mixed deep Saharan dust layer (0–5 km). Size distributions show a loss of 60 to 90% of particles larger than 30 µm 12 h after uplift. The single scattering albedo (SSA) increases from 0.92 to 0.94 to 0.95 between fresh, aged, and SAL profiles: this is enough to alter heating rates by 26%. Some fresh dust close to the surface shows SSA as low as 0.85

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38377
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	dust; aircraft measurements; transport; saharan air layer; deposition; size distribution
Publisher	American Geophysical Union
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