[A-AS22_1PO1] 大気化学

[AAS22-P31] 北西太平洋上の大気中ラドン濃度の時空間変動

*坪井 一寛¹、松枝 秀和¹、澤 庸介¹、丹羽 洋介¹、村山 昌平² (1.気象研究所、2.産業技術総合研究所)

キーワード：ラドン

A new compact radon measuring system has been developed for high-resolution observation of low-level radon-222 (Rn) for the remote sites, in collaboration with the MRI and AIST. The Rn measuring system was installed at 4 stations of Minamitorishima (MNM), Yonagunijima (YON), Chichijima (CCJ) and Ryori (RYO) operated by Japan Meteorological Agency (JMA) since 2007 . The Rn measurements clearly show that distinct seasonal variations as well as frequent episodic events with Rn enhancement peaks on a synoptic scale are successfully captured at all 4 stations. Although the seasonal cycles depended on the stations, significant correlations between the Rn and other trace gases were found for the most of the synoptic-scale events, indicating a large impact of widespread pollutions from the East-Asian countries on the regional air quality over the western North Pacific.