[A-CG43] Science in the Arctic Region

[ACG43-P09] Interannual changes of settling particle flux in shelf-slope area of the western Arctic Ocean from 2010 to 2021

*Jonaotaro Onodera¹, EIJI WATANABE¹, Kohei Mizobata², Miaki Muramatsu¹, Motoyo Itoh¹, Yuichiro Tanaka³, Eun-Jin Yang⁴, Naomi Harada¹ (1.Japan Agency for Marine-Earth Science and Technology, 2.Tokyo University of Marine Science and Technology, 3.National Institute of Advanced Industrial Science and Technology, 4.Korea Polar Research Institute)

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.