新奇事件簿 科学家发现了世界上最干净的空气（在线收听）

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 aerosols". These are pollutants or particles derived from human activity, or dust from other continents. The scientists called this pollution-free area, "truly pristine".

The scientists analysed the structure of airborne microbes in the lower clouds over the Southern Ocean. They looked at the DNA of the microbes and tracked where they came from. Their analysis included monitoring wind trajectories to detect how far the microbes may have travelled. They found that the atmospheric 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 "minimally affected by anthropogenic activities".

科学家发现了他们认为是地球上最干净的空气。来自科罗拉多州立大学和澳大利亚气象局的研究人员对南极洲上空空气的纯净度进行了研究。他们发现，在澳大利亚南部和南极洲之间的南大洋上空有一块未受人类活动影响的区域。科学家们表示，他们研究的这片区域在较低云层中形成了大气层。对空气的分析表明，空气中完全没有“人为气溶胶”。这些污染物或颗粒来自人类活动或其他大陆上的灰尘。科学家将这片无污染区域为“真正的原始”。

科学家们分析了南大洋上空较低云层中空气微生物的结构。他们观察了微生物的DNA并追踪它们的来源。他们的分析包括监测风的轨迹，以检测微生物的传播距离。他们发现其大气生态系统非常“孤立”、独立，且没有来自世界其他地方的污染物。这些微生物来自南大洋，而不是其他大陆上的空气污染物。研究人员得出结论，南大洋是地球上为数不多的几个“受人为活动影响最小”的地方之一。