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

甲基卤化物是大气化学中重要的微量气体。甲基溴和甲基氯向平流层提供大量的无机氯和溴，在平流层中催化臭氧损失。氯甲烷、甲基溴和碘化甲基在低层大气化学中也很活跃，可能影响对流层的净化速率。因此，甲基溴，一种广泛使用的农业熏蒸剂，正在美国和国外受到监管。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。农业排放的这些气体必须加以量化和了解。最近的实地研究表明，全球范围内的水稻农业生产了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）对水稻甲基卤化物产量的影响，并研究植物对甲基卤化物反应的潜在生理生化机制。这些研究将包括现场（季节性温室测量）和体内（叶盘酶分析）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