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IELTS Academic Reading Sample 43 - Arctic Haze

Để đạt kết quả cao trong kì thi sắp tới, các bạn có thể tham khảo và tải về IELTS Academic Reading Sample 43 - Arctic Haze được TaiLieu.VN chia sẻ dưới đây để có thêm tư liệu ôn tập, luyện tập giải đề thi nhanh và chính xác giúp các bạn tự tin đạt điểm cao trong kì thi này. Chúc các bạn thi tốt! | Arctic Haze In the 1950 s pilots traveling on weather reconnaissance flights in the Canadian high Arctic reported seeing bands of haze in the springtime in the Arctic region. It was during this time that the term Arctic haze was first used referring to this smog of unknown origin. But it was not until 1972 that Dr. Glenn Shaw of the Geophysical Institute at the University of Alaska first put forth ideas of the nature and long-range origin of Arctic haze. The idea that the source was long range was very difficult for many to support. Each winter cold dense air settles over the Arctic. In the darkness the Arctic seems to become more and more polluted by a buildup of mid-latitude emissions from fossil fuel combustion smelting and other industrial processes. By late winter the Arctic is covered by a layer of this haze the size of the continent of Africa. When the spring light arrives in the Arctic there is a smog-like haze which makes the region at times looks like pollution over such cities as Los Angeles. This polluted air is a well-known and well-characterized feature of the late winter Arctic environment. In the North American Arctic episodes of brown or black snow have been traced to continental storm tracks that deliver gaseous and particulate-associated contaminants from Asian deserts and agricultural areas. It is now known that the contaminants originate largely from Europe and Asia. Arctic haze has been studied most extensively in Point Barrow Alaska across the Canadian Arctic and in Svalbard Norway . Evidence from ice cores drilled from the ice sheet of Greenland indicates that these haze particles were not always present in the Arctic but began to appear only in the last century. The Arctic haze particles appear to be similar to smog particles observed in industrial areas farther south consisting mostly of sulfates mixed with particles of carbon. It is believed the particles are formed when gaseous sulfur dioxide produced by burning sulfur-bearing coal is .