南大洋海冰区二甲基硫海-气交换过程及其对含硫气溶胶组成的影响研究

DMS (Dimethylsulphide) is a biological source compound and play a significant role of global sulphur cycle and climate change through emissting to the atmopshere and transforming into the sulphur aerosols. However, there have not had any researches about the seawater DMS been carried out in the Southern Ocean in China and ouly few from other countries due to very harsh sea conditions. This proposal will conduct a continuing investigation of DMS in air and surface water using a underway DMS and its species measurements adapted from our group, especially focusing in ice zone and polynya regions in the Southern Ocean. Characteristics of DMS and DMSP as well as their driving factors would be explained in comparison with routine observational data from Chinese Antarctic Atations of Zhongshan and Changcheng. An assessment will be made for contribution of oceanic DMS to aerosols in large scale based on remote sensing data to be dedected in situ measurred data and to simulate the seasonal variabilities and evaluate sea to air fluxes as to reduce the uncertainty for DMS's appraisal in the global sulphur cycle and enhance confidence level in estimate their effects on climate change.

海洋中二甲基硫（DMS）被认为是参与形成含硫气溶胶的重要生物来源的硫化物，对全球生物硫循环和气候变化有着重要的影响。然而，占世界大洋1/4的南大洋由于恶劣海况和极端环境而因观测数据稀缺使DMS研究评估出现很大的不确定性。本研究将应用自研发的DMS的走航观测系统，连续获取表层海水和大气DMS原位数据，结合采集分析上覆大气气溶胶的MSA等含硫化学物种相关数据，突出在南大洋海冰区和冰间湖的关键海区、关键断面和海冰芯的调查，深入了解南大洋海区DMS，DMSP分布特征及控制因子；并与走航、南极洲中山站及长城站的常年连续观测含硫气溶胶数据进行比对，分析南大洋生源DMS对气溶胶中硫组成影响特征；同时利用卫星遥感技术，结合现场观测数据的订正，反演南大洋海域表层海水DMS的季节性分布，估算DMS海-气通量，实现南大洋生源DMS对大气硫循环影响的深入评估，以期降低不确定性和提高其对气候变化影响评价的可信度。

本项目通过建立及改进DMS走航观测方法，先后参加中国第30次、31次，32次、34次等4个航次的南极科学考察，获取了大量的现场数据，取得了一些研究成果和创新认知，具体如下：建立了船载表层海水和大气DMS走航连续观测方法；获取了南大洋表层海水和大气DMS时空分布特征；发现了大气DMS的变化较海水DMS变化更为剧烈；发现了海洋DMS和pCO2具有很强的相关性；发现了南大洋浮游动物在藻华期间会对DMS释放产生重要影响；证实了中山站上空含硫气溶胶与临近冰间湖浮游植物的活动释放的DMS相关；发现航线上空含硫气溶胶与DMS海气交换通量数值很难保持一致；初步探索了中山站临近固定冰区海冰DMS的分布特征等。项目共发表相关论文17篇，2项发明专利，其中有10篇SCI发表在国际权威学术等期刊。培养博士生2名，硕士生2名。