Methyl Bromide Degradation in the Oceans

甲基溴作为平流层溴的重要来源，作为《蒙特利尔议定书》和《清洁空气法》的一部分，已计划逐步淘汰其作为农业熏蒸剂的用途。然而，对流层甲基溴的全球收支以及海洋作为来源或汇的作用存在很大的不确定性。甲基溴的海洋寿命是全球模式中的一个重要参数，旨在预测大气对甲基溴排放变化的响应。在这个项目中，迈阿密大学和康涅狄格大学的研究人员将进行实验室实验和海上研究，以确定从表层海水中生物去除甲基溴的速度是否足以影响这种化合物的海洋寿命。目前的知识水平允许通过纯化学（非生物）途径预测其周转率；人们对微生物的影响知之甚少。如果生物去除效果显著，它将改变我们目前对甲基溴全球循环的概念和定量建模。

ABSTRACT The importance of methyl bromide as a source for stratospheric bromine has led to its planned phase-out as an agricultural fumigant as part of the Montreal Protocol and Clean Air Act. However, there is significant uncertainty regarding the global budget of tropospheric methyl bromide and the role of the ocean as a source or sink. The oceanic lifetime of methyl bromide is an important parameter in global models seeking to predict the atmospheric response to proposed changes in emissions of methyl bromide. In this project, investigators at the University of Miami and the University of Connecticut will conduct laboratory experiments as well as studies at sea to determine whether biological removal of methyl bromide from surface seawater proceeds ar rates sufficient to affect the oceanic lifetime of this compound. The current state of knowledge allows prediction of its turnover rate through purely chemical (non-biological) pathways; little is known of microbiological impacts. If biological removal is significant, it will alter our current concept and quantitative modeling of the global cycling of methyl bromide.