Measuring Methyl Halide Fluxes in Temperate Grasslands Using Stable Isotope Tracers

使用稳定同位素示踪剂测量温带草原中的卤代甲烷通量

• 批准号: 0526750
• 负责人: Robert Rhew
• 金额: --
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-10-01 至 2009-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0526750&HistoricalAwards=false
• 关键词: Measuring; Methyl; Halide; Fluxes; Temperate

This project seeks to quantify fluxes of atmospheric methyl halides in temperate North American grassland ecosystems, employing a recently developed stable isotope tracer technique to separate simultaneous production and consumption fluxes. Methyl halides are major carriers of halogens in the atmosphere and consequently play important roles in stratospheric ozone chemistry. Field measurements will be conducted in three different types of grasslands ecosystems located in California, Colorado, and Kansas. The primary objectives of this work are: (1) to determine whether or not temperate grasslands are net sources or net sinks of methyl halides; (2) to separately quantify the production and consumption fluxes of methyl bromide and methyl chloride using a stable isotope tracer technique, and (3) to investigate the environmental, biological and biogeochemical drivers of the fluxes, ultimately improving our understanding of their atmospheric lifetimes and ozone depletion potentials.Four undergraduate students and a post-doctoral researcher will participate in this research. At least two undergraduate researchers will be from underrepresented groups in the sciences, as selected through the Berkeley Leadership Excellence through Advanced Degrees program. Methyl bromide is a broad-spectrum agricultural fumigant whose use is scheduled to be phased out in accordance with the Montreal Protocol. Understanding the biogeochemistry of methyl halides is prerequisite to understanding how changes in policy, climate, and land use will affect the halogen loading in the atmosphere.

该项目旨在量化温带北美草地生态系统中大气甲基卤化物的通量，采用最近开发的稳定的同位素示踪技术来分开同时生产和消费通量。甲基卤化物是大气中卤素的主要载体，因此在平流层臭氧化学中起着重要作用。现场测量将在位于加利福尼亚，科罗拉多州和堪萨斯州的三种不同类型的草原生态系统中进行。这项工作的主要目标是：（1）确定温带草原是甲基卤化物的净来源还是净水槽； (2) to separately quantify the production and consumption fluxes of methyl bromide and methyl chloride using a stable isotope tracer technique, and (3) to investigate the environmental, biological and biogeochemical drivers of the fluxes, ultimately improving our understanding of their atmospheric lifetimes and ozone depletion potentials.Four undergraduate students and a post-doctoral researcher will participate in this research.至少有两名本科研究人员将来自科学中代表性不足的小组，这是通过高级学位课程卓越的伯克利领导力卓越。甲基溴化物是一种广谱农业烟雾，其用途计划根据蒙特利尔方案逐步淘汰。了解甲基卤化物的生物地球化学是理解政策，气候和土地使用变化如何影响大气中的卤素载荷的前提。