Biogeochemical Cycling of Dimethylsulfide in Seawater

二甲基硫是从海洋排放到大气中的挥发性还原性硫的主要形式。DMS的通量对大气化学甚至全球气候都有重要影响。控制海水中DMS浓度的生物地球化学过程是复杂的，人们对其知之甚少。DMS是由b -二甲基磺酰丙酸酯（DMSP）降解产生的，DMSP是某些海洋浮游植物的天然产物。然而，最近的调查表明，只有一小部分。海水中总dmsp硫的一半可能会逃逸到大气中。本研究将探讨海水DMS循环的几个关键方面；1)海水中DMS降解的机制和速率，主要集中在生物过程，其次是光化学过程；2) DMSP生成DMS并检测两种不同途径是否参与DMSP降解。

Dimethyl sulfide is the major form of volatile reduced sulfur which is emitted form the oceans to the atmosphere. The flux of DMS has an important impact on atmospheric chemistry and possibly global climate. The biogeochemical processes which control DMS concentrations in seawater are complex and poorly understood. DMS is produced from the degradation of B-dimethylsulfoniopropionate (DMSP), a natural product of certain marine phytoplankton. However, recent investigations, suggest that only a small fraction. of the total DMSP-sulfur in seawater is likely to escape to the atmosphere. This research will investigate several key aspects of the seawater DMS cycle; 1) The mechanisms and rates of DMS degradation in seawater, concentrating mainly upon biological processes, and to a lesser extent photochemical processes; and 2) The production of DMS from DMSP and testing whether two different pathways are involved in DMSP degradation.