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=Volume 10 - 2023

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. We conducted a survey of the Northwest Pacific Ocean and its marginal sea in November 2019 using high-resolution, underway, shipboard measurements of DMS and partial pressure of carbon dioxide (pCO2) in the surface seawater and atmospheric. 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:332 to 401 μatm). The trends in the surface seawater DMS in different current systems were primarily associated with phytoplankton biomass 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.