Atmospheric Transport Inferred from Seasonal Variations in Cosmogenic Be7 Concentrations
Atmospheric Transport Inferred from Seasonal Variations in Cosmogenic Be7 Concentrations
复制标题
从宇宙成因 Be7 浓度的季节变化推断的大气传输
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
F. Sánchez
中科院分区：
文献类型：
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作者：
F. Sánchez
宇宙成因放射性核素Be-7（半衰期53.3天）是银河宇宙射线在地球大气层中的核相互作用的结果。大部分Be-7产生于平流层下部，并缓慢地输送到地面。Be-7是一种大气示踪剂，它的测量为研究大气质量运动提供了重要线索。自2002年以来，我们一直在测量东京的Be-7浓度。2002-2006年的数据显示，每年春季和秋季Be-7浓度都有明显的增加。的季节变化是不相关的清除降水，因为表面Be-7浓度与降雨量不相关。我们提出了一种可能性，平流层的Be-7被带到对流层上层之间的平流层和对流层之间的大规模的空气质量交换。据推测，在春季和秋季，日本上空的一对移动高压和对流层外低压的周期性通道（几天的周期）与空气质量交换有关。
A cosmogenic radionuclide Be-7 (half life 53.3 days) results from nuclear interactions of galactic cosmic rays in the Earth’s atmosphere. Most of Be-7 is produced in the lower stratosphere and slowly transported to the surface. Be-7 plays a role of atmospheric tracer and its measurements provide an important clue on atmospheric air mass motions. We have continuously measured the Be-7 concentrations in Tokyo since 2002. The data in 2002-2006 indicated clear enhancements of Be-7 concentrations in spring and autumn every year. The seasonal variations are not associated with scavenging by precipitation because the surface Be-7 concentrations do not correlate with rainfall. We suggested a possibility that the stratospheric Be-7 are brought to the upper troposphere through a large-scale air mass exchange between the stratosphere and troposphere. The air mass exchange is inferred to occur in association with a periodic passage (a period of a few days) of a pair of traveling high pressure and extratropical low pressure over Japan in spring and autumn.