We measured the concentration and turnover rates of dimethylsulfoxide (DMSO) across the northeast Subarctic Pacific (NESAP) to better understand the role of this compound in regional sulfur cycling and phytoplankton physiological ecology. Using ship‐track observations and Lagrangian drifter surveys, we examined the spatial and temporal components of DMS and DMSO variability, comparing rates of DMSO reduction with simultaneous measurements of dimethylsulfide (DMS) oxidation and dimethylsulfoniopropionate (DMSP) cleavage. Our results show high concentrations and rapid turnover of DMSO across much of our NESAP survey region. DMS and DMSO concentrations ranged from < 1 nM to maxima of 26 nM and 183 nM, respectively, and exhibited a nonlinear positive relationship. Rate constants for DMSO reduction to DMS ranged from < 1 to 6.5 d⁻¹ and were correlated to bacterial production and phytoplankton taxonomic composition. DMSO reduction rates exceeded dissolved DMSP cleavage at nearly all stations, and exceeded DMS oxidation rates at four stations where DMSO reduction and DMS oxidation were measured simultaneously. At these stations, net DMS production from DMSO ranged from 0.50 to 7.18 nM d⁻¹. During our Lagrangian survey, DMSO concentrations decreased during periods of peak mid‐day irradiance. A strong correlation between DMSO concentrations, non‐photochemical quenching and photochemical efficiency of photosystem II (F_v/F_m) suggest a potential role for DMSO in photo‐protection, supporting previous suggestions of an anti‐oxidant function for this molecule. Our findings highlight the potential contribution of DMSO to net DMS production in the NESAP, and suggest a role for this compound in phytoplankton physiological ecology.

中文翻译：

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二甲亚砜在东北亚太平洋太平洋区域硫循环和浮游植物生理生态中的潜在作用

我们测量了整个东北亚太平洋太平洋（NESAP）的二甲亚砜（DMSO）的浓度和周转率，以更好地了解该化合物在区域硫循环和浮游植物生理生态中的作用。我们使用船径观测和拉格朗日漂流仪调查，研究了DMS和DMSO变异性的时空成分，比较了DMSO还原率与同时测量二甲基硫醚（DMS）氧化和二甲基磺丙酸二甲酯（DMSP）裂解的情况。我们的结果表明，在我们的NESAP调查区域的大部分地区，DMSO的浓度很高且流动迅速。DMS和DMSO的浓度范围分别从<1 nM到最大值26 nM和183 nM，并表现出非线性正相关。DMSO还原为DMS的速率常数范围从<1到6.5 d^-1和与细菌产量和浮游植物分类学组成相关。DMSO还原率几乎在所有站均超过了溶解的DMSP裂解，并在同时测量DMSO还原和DMS氧化的四个站中超过了DMS氧化速率。在这些站点，DMSO的净DMS产量介于0.50至7.18 nM d ^-1之间。在我们的拉格朗日调查中，DMSO浓度在午间辐照度高峰期下降。DMSO浓度，非光化学猝灭和光系统II（F _v / F _m）暗示DMSO在光保护中的潜在作用，支持先前对该分子具有抗氧化功能的建议。我们的发现凸显了DMSO对NESAP中净DMS生产的潜在贡献，并暗示了该化合物在浮游植物生理生态中的作用。