Dust Deposition - Mineral Dust: A Key Player in the Earth System - page 188

Fig. 8.3 Annual dust deposition fluxes measured over North Africa and in the Mediterranean
basin. The data from Banizoumbou, Cinzana, and M'Bour (1) are unpublished data provided by
LISA (B. Chatenet, B. Marticorena, J.L. Rajot) from measurements performed in the framework
of the Sahelian Dust Transect, (2) O'Hara et al. ( 2006 ), (3) Breuning-Madsen and Awadzi
( 2005 ), and (4) Avila ( 1996 ), Bergametti et al. ( 1989 ), Kubilay et al. ( 2000 ), and Mattsson and
Nihlen ( 1996 )
the existing measurements in this region. These measurements show that the annual
dust deposition fluxes measured in or close to the source regions (Banizoumbou
(Niger), Cinzana (Mali), M'Bour (Senegal), in Libya) are very high with values on
the order of 100 g m 2 year 1 . They also show a clear decrease of the deposition
flux as a function of the distance from the Saharan dust source regions. In the Sahel,
the dust deposition decreases only slowly along the main transport pathways of
Saharan dust (see Chap. 7 ) : from east (Banizoumbou) to west (M'Bour) and from
north (Banizoumbou and Cinzana) to south (Ghana). On the opposite, the annual
dust deposition fluxes measured in the Mediterranean Sea are lower by about one
order of magnitude than those measured in the Sahara and Sahel, showing that a
large part of the dust mass is deposited before reaching the Mediterranean basin.
Total deposition of atmospheric mineral particles (wet plus dry) has also been
measured during consecutive two-week sampling intervals from January 1981 to
March 1982 at four island stations (Midway, Oahu, Enewetak, and Fanning) of the