Devastating droughts that have occurred in the United States in the 30 years of the twentieth century were caused by an unusual temperature of surface water, a new study of climate. The researchers modeled the climate on the basis of the temperature of the surface water in the tropical Pacific and Atlantic oceans, and accurately predicted the drought affecting three-quarters of the U.S. between 1931 and 1929.
In the thirties of the 20th century Pacific was on average a few degrees cooler than usual, and the Atlantic, on the contrary, a little warmer. It was enough to turn some of Colorado, Texas, Kansas, Oklahoma and New Mexico into a giant dust bowl showed Siegfried Schubert of NASA Goddard Space Flight Center (USA). Then, more than two million farmers were forced to abandon their lands. According to some estimates, in 1935, erosion has carried away with the Southern Plains nearly a billion tons of soil. When the soil is dry, fewer fumes, and therefore less rainfall. This increased the scale of the drought nearly doubled, according to Schubert.
The great plains of the United States most of the moisture produced in the spring and summer. Western trade winds that blow on the equator, here usually bring moisture from the Gulf of Mexico. But at higher temperatures the Atlantic heated air directly above the water surface, whereby the density decreases and it begins to climb up. This makes it possible to penetrate the colder and denser than air, rush to the east of the American continent. Then, humid air from the Gulf instead of the west goes to the east.
The same trade winds usually blow in a westerly direction over the continent and the Pacific Ocean, collecting in the ocean moisture and attributing it to the United States in the upper atmosphere. Cold snap Pacific violated this cycle, so returning to the U.S. air was dry land, took place at a lower altitude and did not bring rain on the Plains.
News.Battery.Ru — Accumulator News, 24.03.2004 18:08