Assessment of austral autumn air–sea CO2 exchange in the Pacific sector of the Southern Ocean and dominant controlling factors

Frontiers in Marine Science

Marine Science

Doshik Hahm¹  Keyhong Park²  Jisoo Park²  Ahra Mo²  Jung-Ok Choi²  José Luis Iriarte³  Young Ho Ko⁴  Tae-Wook Kim⁵  Kitae Kim⁶ 

[1] Department of Oceanography, Pusan National University, Busan, Republic of Korea;Division of Ocean Sciences, Korea Polar Research Institute, Incheon, Republic of Korea;Instituto de Acuicultura, Universidad Austral de Chile, Los Lagos, Chile;OJEong Resilience Institute, Korea University, Seoul, Republic of Korea;OJEong Resilience Institute, Korea University, Seoul, Republic of Korea;Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea;Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon, Republic of Korea;

关键词: Southern Ocean;    p;    carbon cycle;    air-sea CO flux;    western Antarctic Peninsula;   

DOI  :  10.3389/fmars.2023.1192959

 received in 2023-03-24, accepted in 2023-05-10,  发布年份 2023

来源: Frontiers

【 摘 要 】

The factors that control the partial pressure of carbon dioxide (pCO2) in the Pacific sector of the Southern Ocean were investigated in April 2018, onboard the icebreaker, ARAON. The mean (± 1σ) of the sea surface pCO2 was estimated to be 431 ± 6 μatm in the north of the Ross Sea (NRS), 403 ± 18 μatm in the Amundsen–Bellingshausen Sea (ABS), and 426 ± 16 μatm in the western Antarctic Peninsula and Weddell Sea (WAP/WS). The controlling factors for pCO2 in the NRS appeared to be meridionally different based on the southern boundary of the Antarctic Circumpolar Current (SB; ~62.5°S in the Ross Sea). The sea surface pCO2 exhibited a strong correlation with salinity and the difference between the O2/Ar (ΔO2/Ar) values of the sample and air-saturated water in the north and south of the SB, respectively. The pCO2 in the ABS and western WAP/WS displayed a strong correlation with salinity. Furthermore, ΔO2/Ar and sea ice formation appear to be the dominant factors that control pCO2 in the Confluence Zone (CZ) and northern parts of WAP/WS. The estimated air–sea CO2 fluxes (positive and negative values indicate the source and sink for atmospheric CO2, respectively) range from 3.1 to 18.8 mmol m−2 d−1 in the NRS, −12.7 to 17.3 mmol m−2 d−1 in the ABS, and −59.4 to 140.8 mmol m−2 d−1 in the WAP/WS. In addition, biology-driven large variations in the air–sea CO2 flux were observed in the CZ. Our results are the most recent observation data acquired in austral autumn in the Southern Ocean.

【 授权许可】

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Copyright © 2023 Mo, Park, Park, Hahm, Kim, Ko, Iriarte, Choi and Kim