Sahara dust blows over the United States.Summertime haze over Verb 1. haze over - make less visible or unclear; "The stars are obscured by the clouds"; "the big elm tree obscures our view of the valley" becloud, befog, fog, obnubilate, obscure, mist, cloud the eastern United States often contains bits of the Sahara Desert blown clear across the Atlantic Ocean Across the Atlantic Ocean is the twenty-eighth episode[1] of Mobile Suit Gundam. Plot summary Amuro and Sayla manage to reduce their time in docking the Gundam and the G-Fighter to fifteen seconds. , report researchers from the University of California, Davis The University of California, Davis, commonly known as UC Davis, is one of the ten campuses of the University of California, and was established as the University Farm in 1905. . When Thomas A. Cahill and his colleagues started studying microscopic dirt particles in the atmosphere, they believed that dust storms from the Great Plains supplied much of the dirt in the air over the Midwest and the East. But the proportions of various elements in the airborne soil did not match those of U.S. dirt. The floating dust particles did, however, resemble samples of dirt collected from air filters in the Virgin Islands. This led Cahill and his colleagues to suspect a Saharan source, because previous research indicated that air over the Virgin Islands contains African dust. In fact, Cahill calls the Virgin Islands the dustiest place in the United States, judging from the concentration of fine particles less than 2.5 micrometers in diameter. "The Virgin Islands have more dust than the Grand Canyon, the Badlands badlands, area of severe erosion, usually found in semiarid climates and characterized by countless gullies, steep ridges, and sparse vegetation. Badland topography is formed on poorly cemented sediments that have few deep-rooted plants because short, heavy showers , or Death Valley," he says. The tiny Saharan dirt particles may reduce visibility in normally clear places, such as the Virgin Islands or South Florida. But most eastern states cannot blame their perpetual summer haze on the African dust, says Cahill. Rather, their air pollution comes from burning sulfur-rich coal and other fossil fuels, which creates tiny sulfuric acid sulfuric acid, chemical compound, H2SO4, colorless, odorless, extremely corrosive, oily liquid. It is sometimes called oil of vitriol. Concentrated Sulfuric Acid droplets. Cahill warns that the African dust could confound efforts by the Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and to limit pollution from airborne fine particles. The agency is considering setting standards for particles below 2.5 micrometers in size. Natural sources could violate such standards on days when air currents carry large amounts of Saharan dust, says Cahill. "It just shows that when it comes to fine particles, we're all one world," he says. Indeed, researchers from Mauna Loa Observatory The Mauna Loa Observatory (MLO) is an atmospheric baseline station on Mauna Loa volcano, on the big island of Hawaii. Since 1957 MLO has been continuously monitoring and collecting data relating to atmospheric change, and is known especially for their continuous monitoring of on Hawaii find that dust storms from China and Mongolia reach Hawaii about 20 times a year, cutting down on visibility there. |
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