Degradation of Methyl Bromide and Methyl Chloride in the Oceans

海洋中溴甲烷和氯甲烷的降解

• 批准号: 0221472
• 负责人: Eric Saltzman
• 金额: $ 45万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-15 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0221472&HistoricalAwards=false
• 关键词: Degradation; Methyl; Bromide; Chloride; Oceans

ABSTRACTOCE-0221472The importance of tropospheric halocarbons as a source for stratospheric halogens and ozone depletion is well recognized. Industrial production of longer-lived CFC's have been banned under the Montreal Protocol and Clean Air Act, however the time scale for recovery of the ozone layer from such molecules is on the order of decades. As a result, attention has shifted towards the shorter-lived halocarbons that respond more rapidly to changes in emissions. In this project, researchers at the University of California at Irvine will continue their ongoing efforts to understand the role of the oceans in the biogeochemical cycling of low molecular-weight halocarbons, like methyl bromide (CH3Br) and methyl chloride (CH3Cl). In this phase of their research, oceanic degradation studies will be continued in order to extend prior spatial and temporal coverage of the oceans, and to include methyl chloride (CH3Cl). The degradation of other natural halogenated compounds such as dibromomethane (CH2Br2), bromoform (CHBr3), and methyl iodide (CH3I) will also be studied in coastal seawater. The proposed measurements will result in revised estimates for the uptake of atmospheric halocarbons by the oceans, the extent to which the oceans can buffer atmospheric halocarbon concentrations, and the production rate for these gases in the surface oceans.

对流层卤烃作为平流层卤素和臭氧消耗源的重要性已得到公认。根据《蒙特利尔议定书》和《清洁空气法》，已经禁止了较长寿命的CFC的工业生产，但是从这种分子中恢复臭氧层的时间尺度是几十年。因此，人们的注意力转向了寿命较短的卤烃，因为它们对排放量的变化反应更快。在这个项目中，位于欧文的加州大学的研究人员将继续他们正在进行的努力，以了解海洋在低分子量卤烃（如甲基溴（CH3Br）和甲基氯（CH3Cl））的地球化学循环中的作用。在这一阶段的研究中，将继续进行海洋退化研究，以扩大先前对海洋的空间和时间覆盖范围，并将氯甲烷（CH3Cl）包括在内。 还将研究其他天然卤代化合物，如二溴甲烷（CH2Br2）、溴仿（CHBr3）和碘甲烷（CH3I）在沿海海水中的降解情况。拟议的测量将导致对海洋吸收大气中卤化碳的估计数、海洋缓冲大气中卤化碳浓度的程度以及这些气体在表层海洋中的生产率进行修订。