One of the worst environmental catastrophes of the past century was the Dust Bowl during the 1930s in America. Now, new computer simulations show wind-driven dust made the drought even more severe.
Scientists have known poor land use and natural atmospheric conditions led to the dust storms in the Great Plains in the 1930s. Climate models in the past few years also have revealed the effect of sea surface temperatures on the Dust Bowl.
"What is new and what had not been done before is to work out whether the dust storms from the drought and land use had any impact on the drought," said Richard Seager of Lamont-Doherty Earth Observatory (LDEO) in New York.
"You had dust storms that were unprecedented in the recent historical record," said lead researcher Benjamin Cook of NASA Goddard Institute for Space Studies. "So it was on the level of dust emissions that nobody in living memory and probably much before that had ever seen."
Using computer simulations, Cook, Seager and Ronald Miller of LDEO found the "black blizzards" exacerbated the drought and pushed it northward into the Great Plains.
The airborne dust particles reflected sunlight back into space, leading to cooler surface temperatures. As temperatures dipped, so did evaporation. "You basically cut off the moisture source to clouds and precipitation," Cook said.
The researchers say global warming and an increased pressure to expand agriculture in light of a possible food crisis are creating conditions ripe for dust storms in regions worldwide.
"This is the type of phenomenon that potentially we could start seeing in places like China," Cook told LiveScience, "where you're having some desertification problems, and you're having a lot of land degradation."
Source:Xinhua/Agencies
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