[A-CG43] 北極域の科学

[ACG43-P09] 2010年から2021年にかけての西部北極海陸棚斜面域における沈降粒子フラックスの経年変動

*小野寺 丈尚太郎¹、渡邉 英嗣¹、溝端 浩平²、村松 美幌¹、伊東 素代¹、田中 裕一郎³、Yang Eun-Jin⁴、原田 尚美¹ (1.海洋研究開発機構、2.東京海洋大学、3.産業技術総合研究所、4.韓国極地研究所)

In the changing environments of the Arctic Ocean, the dynamics of upper ocean circulation around shelf-slope areas affect lower-trophic marine ecosystem and basin-shelf interaction such as transportation of materials. To observe the relationships between particle transportation and oceanographic condition, multi-year observation of setting particles have been conducted by the deployment of bottom-tethered moorings with time-series sediment trap in the southern Northwind Abyssal Plain (2010-2014, 2018-2021), northern Hanna Canyon (2015-2017), and north of the Barrow Canyon (2015-2019). The collected particles by sediment trap are mainly composed of lithogenic matter with silt grain size in addition to biogenic matter, suggesting advection of re-suspended particles from shelf to basin. The setting particle flux in this study showed maxima in not only the productive summer season but also physical oceanographic events like the passing of oceanic eddies over the mooring position area. In an interannual comparison of obtained results from 2010 to 2021, total mass flux shows a recent increase in the southern Northwind Abyssal Plain. In a large sense, the recent increase of setting particles probably reflects the interannual position shift of oceanic Beaufort Gyre to the southeast (shelf side) and the intensification of westward shelf-slope current along the shelf edge of Chukchi Sea.