AUTHOR=Yan Shi-Bo , Li Xiao-Jun , Xu Feng , Zhang Hong-Hai , Wang Jian , Zhang Yueqi , Yang Gui-Peng , Zhuang Guang-Chao , Chen Zhaohui TITLE=High-resolution distribution and emission of dimethyl sulfide and its relationship with pCO2 in the Northwest Pacific Ocean JOURNAL=Frontiers in Marine Science VOLUME=10 YEAR=2023 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1074474 DOI=10.3389/fmars.2023.1074474 ISSN=2296-7745 ABSTRACT=

Ocean-derived dimethyl sulfide (DMS) is widely concerning because of its hypothesized influence on global climate change. This study aims to explore the distribution characteristics and influencing factors of DMS and partial pressure of carbon dioxide (pCO₂) in the Northwest Pacific Ocean, as well as the potential relationship between DMS and pCO₂. A high-resolution, underway, shipboard measurement device was used to determine the DMS and pCO₂ of the surface seawater and atmosphere in the Northwest Pacific and its marginal seas during November 2019. The result show that atmospheric and surface seawater DMS concentrations ranged from 3 to 125 pptv and 0.63 to 2.28 nmol L^-1, respectively, with mean values of 46 ± 19 pptv and 1.08 ± 0.34 nmol L^-1. The average sea surface pCO₂ was 371 ± 16 μatm (range from 332 to 401 μatm). The trends in the surface seawater DMS in different current systems were primarily associated with phytoplankton abundance and composition. Biological activity and physical processes such as cooling jointly influenced the sea surface pCO₂. A cold eddy along the transect in the Northwest Pacific Ocean increased DMS at the sea surface by 10% and CO₂ uptake by 3%. We found a significant negative correlation between DMS and pCO₂ in the Northwest Pacific Ocean at the 0.1° resolution [DMS]_seawater = -0.0161[pCO₂]_seawater + 7.046 (R² = 0.569, P < 0.01). The DMS and pCO₂ sea-air fluxes were estimated to range from 0.04 to 25.3 μmol m^-2·d^-1 and from -27.0 to 4.22 mmol m^-2·d^-1 throughout the survey area. The Northwest Pacific Ocean, especially the Oyashio Current, is an important sink of CO₂ and a source of DMS.