Dissertation Research: "Environmental Controls over Methyl Halide Emissions from Agricultural Rice Paddy Ecosystems"

卤甲烷是大气化学中重要的痕量气体。 甲基溴和甲基氯向平流层提供大量的无机氯和溴，在平流层中它们催化臭氧损失。氯甲烷、溴甲烷和碘甲烷在低层大气化学中也很活跃，可能影响对流层的净化率。因此，甲基溴，一种广泛使用的农业熏蒸剂，在美国和国外受到管制。 由于管制，这些气体的人为来源随着时间的推移而减少，天然卤素来源将占主导地位。必须对这些气体的农业排放进行量化和了解，最近的实地研究表明，全球水稻农业产生了全球大量的甲基溴和甲基碘。 我们建议确定某些非生物因素（包括土壤卤化物量和光照水平）对水稻中卤代甲烷产生的影响，并研究植物反应的生理和生物化学基础。 这些研究将包括原位（季节性温室测量）和体内（叶盘酶测定）研究

Methyl halides are important trace gases in atmospheric chemistry. Methyl bromide and methyl chloride supply a significant amount of inorganic chlorine and bromine to the stratosphere where they catalyze ozone loss. Methyl chloride, methyl bromide and methyl iodide are also active in lower atmosphere chemistry and may impact the cleansing rate of the troposphere. Consequently, methyl bromide, a widely used agricultural fumigant, is being regulated in the U.S. and abroad. As anthropogenic sources of these gases decline with time due to regulation natural halogen sources will dominate. Agricultural emissions of these gases must be quantified and understood.Recent field research has shown that globally significant amounts of methyl bromide and methyl iodide are produced by worldwide rice agriculture. We propose to determine the effects of certain abiotic factors (including soil halide amounts and light levels) on methyl halide production in rice and to examine the underlying physiology and biochemistry of the plant response. These studies will incorporate in-situ (seasonal greenhouse measurements) and in-vivo (leaf-disk enzyme assays) studies