[A-CG46] Biogeochemical linkages between the surface ocean and atmosphere

[ACG46-P02] Atmosphere–sea ice–ocean interaction study in Saroma-ko Lagoon, Hokkaido, Japan 2021

*Daiki Nomura¹, Hiroki Ikawa², Yusuke Kawaguchi³, Naoya Kanna³, Tatsuya Kawakami⁴, Yuichi Nosaka⁵, Sachi Umezawa⁴, Manami Tozawa⁴, Takahito Horikawa⁴, Reishi Sahashi⁴, Taichi Noshiro⁴, Ibuki Kaba⁴, Makoto Ozaki⁴, Fumiyoshi Kondo⁶, Keisuke Ono⁷, Itsuka S. Yabe³, Eun Yae Son³, Takahiro Toyoda⁸, Sohiko Kameyama⁴, Changqing Wang⁴, Hajime Obata³, Atsushi Ooki⁴, Hiromichi Ueno⁴, Akihide Kasai⁴ (1.Faculty of Fisheries Sciences, Hokkaido University, 2.Hokkaido Agricultural Research Center, NARO, 3.The University of Tokyo, 4.Hokkaido University, 5.Tokai University, 6.Japan Coast Guard Academy, 7.Institute for Agro-Environmental Sciences, NARO, 8.Japan Meteorological Agency)

An atmosphere–sea ice–ocean interaction study was conducted at the Saroma-ko Lagoon, Hokkaido, Japan from 27 February to 9 March 2021. Air–sea ice CO2 flux measurements were conducted by eddy covariance and chamber methods together with meteorological observations. Sea ice cores were collected to understand the interaction between the atmosphere and under-ice water with respect to fluxes of heat and biogeochemical components. Physical and biogeochemical parameters such as temperature, salinity, ice structure, environmental DNA, and concentrations of gases, nutrients, and trace metals were measured. Under-ice water properties were monitored to quantify heat budgets and interactions with sea ice biogeochemical properties. Incubation experiments with ice algae were conducted. Equipment such as air–sea ice CO2/CH4 flux chambers, an eddy covariance system, a trace metal analyzer, and a pump and sampler for environmental DNA were tested and compared to prepare for future Arctic and Antarctic expeditions. In addition, movies and pictures were taken under the auspices of the educational program of Hokkaido University (LASBOS) to enhance educational programs in ocean science. The field campaign activities provided useful information for inter-comparison research and future studies of sea ice in polar oceans.