Air-sea exchange of dimethylsulfide in the Southern Ocean: Measurements from SO GasEx compared to temperate and tropical regions
Air-sea exchange of dimethylsulfide in the Southern Ocean: Measurements from SO GasEx compared to temperate and tropical regions
复制标题
DOI：
10.1029/2010jc006526
复制
发表时间：
2011-04
影响因子：
--
通讯作者：
Mingxi Yang;B. Blomquist;C. Fairall;S. Archer;B. Huebert
中科院分区：
文献类型：
--
作者：
Mingxi Yang;B. Blomquist;C. Fairall;S. Archer;B. Huebert
在南大洋气体交换实验（SO GasEx）中，我们测得大气二甲硫醚（DMS）浓度为118±54 pptv (1σ)， DMS海气通量为2.9±2.1 μmol m−2 d−1，海水DMS浓度为1.6±0.7 nM。用通量除以同时存在的海气浓度差得到DMS的传递速度（kDMS）。南大洋的kDMS显著低于赤道东太平洋、马尾藻海、东北大西洋和东南太平洋的实测数据。对水侧扩散率和溶解度的温度依赖性进行标准化的kDMS结果在各种实地研究中得到了更好的一致性，并表明南大洋的低kDMS主要是由于较冷的温度。DMS在较低温度下的较高溶解度导致更大的空侧控制和由破碎波形成的气泡较少的气体转移。最终归一化的DMS传递速度与低至中风中二氧化碳等难溶气体的k相似；在大风条件下，由于气泡介导的传递减少，DMS传递速度明显降低。
[1] In the Southern Ocean Gas Exchange Experiment (SO GasEx), we measured an atmospheric dimethylsulfide (DMS) concentration of 118 ± 54 pptv (1σ), a DMS sea-to-air flux of 2.9 ± 2.1 μmol m−2 d−1 by eddy covariance, and a seawater DMS concentration of 1.6 ± 0.7 nM. Dividing flux by the concurrent air-sea concentration difference yields the transfer velocity of DMS (kDMS). The kDMS in the Southern Ocean was significantly lower than previous measurements in the equatorial east Pacific, Sargasso Sea, northeast Atlantic, and southeast Pacific. Normalizing kDMS for the temperature dependence in waterside diffusivity and solubility results in better agreement among various field studies and suggests that the low kDMS in the Southern Ocean is primarily due to colder temperatures. The higher solubility of DMS at a lower temperature results in greater airside control and less transfer of the gas by bubbles formed from breaking waves. The final normalized DMS transfer velocity is similar to k of less soluble gases such as carbon dioxide in low-to-moderate winds; in high winds, DMS transfer velocity is significantly lower because of the reduced bubble-mediated transfer.