How the dust of the Sahara desert saves the Atlantic Ocean and the Gulf of Mexico from devastating tropical storms
In recent decades, climatologists and economists raise the alarm over the negative impact on human life of dust storms and hurricanes. Of course, concerns about harm to health and economic damage are quite fair and justified. However, the nature, full of mysteries, has enclosed a rational sense even in this negative phenomenon in some parts of the world. The Sahara desert is one of the largest sources of dust storms. Every year, wind from the African continent around the world exports from 907 million to 4 billion tons of sand, sometimes turning entire settlements into orange landscapes. A group of scientists from the Texas A&M University studied the impact of the Saharan dust on the environment. The outcomes of the research were published recently in the journal of the American meteorological society "Journal of Climate". Staff at the Department of Atmospheric Sciences analyzed recent NASA satellite images and computer models of the movement of Saharan dust over the Atlantic ocean, transported by air currents up to the Gulf of Mexico. It was found that the air masses saturated with desert sand and mineral particles, contributes to lowering temperatures, and this, in turn, prevents the formation of clouds, and as a consequence, the emergence of hurricanes and storms. So, every cloud has a silver lining. In addition, the Saharan dust reflects and absorbs sunlight, thereby reducing the amount of solar radiation reaching the earth's surface and water. The sea surface temperature decreases accordingly, which also reduces the chances for storms. That is, if there is dust in the air above the sea, the probability that a storm will hit or a storm will blow is very low. The discovery seems life-saving, given that severe tropical storms and powerful hurricanes, formed by overheating of the water in the summer, annually cause natural disaster for the coastal areas of the Gulf. For example, about 80% of New Orleans' territory sank to water by hurricane Katrina (USA, 2005). - Our results show significant impacts of dust on the radiative budget, hydrological cycle, and large-scale environments relevant to tropical cyclone activity over the Atlantic, said one of the members of the research team Renyi Zhang. Sandstorms, originated from Sahara, over the Atlantic ocean and the Gulf of Mexico also minimize radiation, scientists proved. And the dust particles themselves, heated in the air, leading to more stable atmosphere.
