The link: Dust, specifically phosphorous and other nutrients, picked up by the wind from the Sahara Desert and spread half a world away. Much of this falls into the ocean, but about 27.7 million tons settles over the Amazon River basin. Even though the Amazon has plenty of nutrients, rain and flooding washes away a lot of the phosphorous in the soil, a fertilizing nutrient critical to plant growth. The phosphorous that reaches Amazon soils from Saharan dust, an estimated 22,000 tons per year, is about the same amount as that lost from rain and flooding.
The amount of dust transported varied wildly from year to year, with an 86% difference between the highest and lowest years. The study said the fluctuation may depend on the amount of rainfall in the Sahel, a small strip of semi-arid land south of the Sahara. Rainfall fluctuations there have been linked to boom and bust cycles in Atlantic hurricane activity, too, since rainstorms drifting off the west coast of Africa often go on to form tropical cyclones.
Each particle of dust is no bigger than a tenth of the width of a human hair. But in aggregate, they form large plumes that can be seen from space. The study is part of a larger effort to understand the effects of dust and small particles known as aerosols on local and global climate.
Picture Credit : Google
