Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season.
The air over major cities and rural regions of the Nile Delta is highly polluted during autumn which is the biomass burning season, locally known as black cloud. Previous studies have attributed the increased pollution levels during the black cloud season to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. Here we show, for the first time, the evidence of long range transport of dust at high altitude (2.5-6 km) from Western Sahara and its deposition over the Nile Delta region unlike current Models. The desert dust is found to be a major contributor to the local air quality which was previously considered to be due to pollution from biomass burning enhanced by the dominant northerly winds coming from Europe.
Prasad
Anup K
AK
Chapman University, Orange, CA 92866, USA. aprasad@chapman.edu
El-Askary
Hesham
H
Kafatos
Menas
M
D000352:Africa, Northern; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D000531:Altitude; D001272:Atmosphere / Q000737:chemistry*; D018533:Biomass; D003889:Desert Climate; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D017745:Incineration; D008956:Models, Chemical; D045483:Rivers; D012621:Seasons; D014919:Wind
D000393:Air Pollutants; D004391:Dust