Saharan air layer

[4] Disturbances such as large thunderstorm complexes over North Africa periodically result in vast dust and sand storms, some of which extend as high as 6,000 metres (20,000 ft).

The layer is transported westwards cross the Atlantic by a series of broad anticyclonic eddies that are typically found 1,500–4,500 metres (4,900–14,800 ft) above sea level.

[5] An estimated 60-200 million tons of dust particles are carried from the Sahara Desert region of North Africa, where it originates, and moves westward annually.

[citation needed] Scientists believe the July 2000 measurements made in Puerto Rico, nearly 8 million tonnes, equaled about one-fifth of the year's total dust deposits.

[citation needed] The clouds of dust SAL creates are visible in satellite photos as a milky white to gray shade, similar to haze.