Japan Geoscience Union Meeting 2025

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[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG52] Science in the Arctic Region

Thu. May 29, 2025 9:00 AM - 10:30 AM Exhibition Hall Special Setting (3) (Exhibition Hall 7&8, Makuhari Messe)

convener:Tatsuya Kawakami(Hokkaido University), Masatake Hori(University of Tokyo, Atmosphere Ocean Research Institute), Kazuki Yanagiya(Japan Aerospace Exploration Agency), Yota Sato(Japan Agency for Marine-Earth Science and Technology), Chairperson:Tatsuya Kawakami(Hokkaido University), Rigen Shimada(Japan Aerospace Exploration Agency)

10:15 AM - 10:30 AM

[ACG52-06] Effect of sediment loads on the biogeochemical properties of sea ice along the coast of Alaska, Arctic Ocean

*Ryota Akino1, Daiki Nomura1,2,3, Masaki Yoshimura1, Keigo D Takahashi1, Amane Fujiwara4, Mariko Hatta5, Hisatomo Waga5, Laura Whitmore5 (1.Faculty of Fisheries Sciences, Hokkaido University, 2.Field Science Center for Northern Biosphere, Hokkaido University, 3.Arctic Research Center, Hokkaido University, 4.Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 5.University of Alaska Fairbanks)


Keywords:sediment laden ice, nutrients, biogeochemistry

Sediment-laden sea ice is a common feature in the Arctic Ocean. Sediment laden ice is formed coastal area. It is transported by sea ice drift and spreads in Arctic Ocean. Sediment trapped in sea ice include mineral particles and organic matter. Over time, decomposition and dissolution of sediments within sea ice might influence the composition of biogeochemical parameters such as nutrients in sea ice. The role of sediment as a driver of sea ice biogeochemical cycles is not well-established. In this study, we conducted sea ice sampling at analyzed physical and biogeochemical parameters including nutrients, chlorophyll a, and SPM (Suspended particulate matter) concentrations. We observed brown sections in the ice core and SPM concentrations were higher in these sections than in other sections, indicating this section contained large amount of sediment. Nitrate and silicate Utqiagvik, Alaska during May 2024 and tended to be higher in the sediment sections. Chlorophyll a concentration was also high in the sediment sections, indicating that sediment load influences algal distribution in sea ice. SPM concentrations (sediment load) were correlated with phosphate and silicate concentrations. It suggested the possibility that decomposition of organic matters in sediment supplied nutrients. Thus, sediment load into sea ice is thought to have an important role in sea ice biogeochemistry.