Distribution and Sea to Air Flux of Biogenic Sulfur Compounds in the Northeastern South China Sea During Summer and Their Response to Mesoscale Eddies
Biogenic sulfur compounds play a crucial role in the marine sulfur cycle and have significant implications for global climate change.A field investigation was conducted in the northeastern South China Sea during July—August 2020,to investigate the spatial and temporal distributions of dimethyl-sulfide(DMS),β-dimethylsulfoniopropionate(DMSP),and dimethylsulfoxide(DMSO)in seawater.and study the influence of mesoscale eddies on their distribution and production.The results indicate that the average concentrations of DMS,dissolved DMSP(DMSPd),particulate DMSP(DMSPp),dis-solved DMSO(DMSOd),and particulate DMSO(DMSOp)in surface seawater were(2.93±2.39),(2.89±2.11),(6.56±3.41),(10.84±7.58),and(7.44±4.88)nmol·L-1,respectively.The con-centrations of biogenic sulfur compounds in cyclonic eddy-controlled region were significantly higher than those in anticyclonic eddy-controlled region,with higher concentrations observed at the edges of mesoscale eddies compared to their interiors.Biogenic sulfur compounds showed strong correlations with chlorophyll a(Chl a),indicating that phytoplankton biomass is a crucial factor influencing the dis-tributions of organic sulfur compounds in the South China Sea.Air masses passing through regions with high Chl a values were found to bring higher atmospheric mixing ratios of DMS over the northeastern South China Sea.The sea-to-air flux of DMS ranged from 0.16 to 19.88 μmol·m-2·d-1,with an av-erage of(5.86±6.16)μmol·m-2·d-1,in the study area during summer.Due to the higher seawater DMS concentrations in cyclonic eddy-controlled region,the sea-to-air flux((5.86±6.16)μmol·m-2·d-1)was higher than those in anticyclonic eddy-controlled region((3.71±4.73)μmol·m-2·d-1)and the region without mesoscale eddy control((4.61±4.77)μmol·m-2·d-1),highlighting the signifi-cant role of mesoscale eddies in controlling the production and release of biogenic sulfur compounds.
biogenic sulfurdistributionsea-to-air fluxmesoscale eddySouth China Sea
万方数据
维普
