科学家相信他们已发现了地球上最干净的空气。研究人员发现，该区域大气圈并未因为人类活动而改变，大气边界层也没有人类活动所制造的气胶微粒。
scientists have discovered what they believe to be the cleanest air on earth. researchers from colorado state university and the australian bureau of meteorology conducted research on the purity of the air above antarctica. they found a region over the southern ocean, between the south of australia and antarctica, that was "unaffected" by human activity. the scientists said the area they researched formed the atmosphere in the lower clouds. the analysis of the air showed that it was totally free from "anthropogenic
2". these are
3 or particles
4 from human activity, or dust from other continents. the scientists called this pollution-free area, "truly
5".
the scientists analysed the structure of airborne microbes in the lower clouds over the southern ocean. they looked at the
6 of the microbes and tracked where they came from. their analysis included monitoring wind
7 to detect how far the microbes may have travelled. they found that the
8 eco-system was very much "isolated," self-contained, and free from contaminants from elsewhere in the world. the source of the microbes was the southern ocean, rather than airborne pollutants from other continents. the researchers concluded that the southern ocean is one of very few places on earth that has been "
9 1 by anthropogenic activities".
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