Theoretical Studies of the Chemical Composition of the Earth's Atmosphere

ATM-9320778麦克尔罗伊 该研究项目旨在解决平流层和对流层化学中的关键问题。 对于平流层，（1）将利用实地观测来检验和改进我们对非均匀过程对平流层下部化学性质的作用的理解;（2）将开发和应用诊断模型来阐明造成臭氧长期趋势的化学和动力机制，特别注意火山气溶胶的全球影响;以及（3）作为澄清北极和南极臭氧损失差异的战略的一部分，将审查反硝化作用对极地臭氧损失的控制作用。 对于对流层，PI建议：（1）将使用最近实地考察的短寿命物种数据来测试和改进光化学机制;（2）将使用碳14标记的一氧化碳的观测来测试全球三维化学示踪剂模型（CTM）中羟基自由基的分布;（3）CTM将用于测试一氧化碳源的清单，一氧化碳是调节羟基自由基浓度的关键物质，利用碳13标记的一氧化碳和碳18标记的一氧化碳的新数据，包括乙烯和乙炔的额外研究，以及（4）CTM还将用于研究从1950年至今对流层氧化能力的变化。

ATM-9320778 McElroy This research project is aimed at addressing key issues in stratospheric and tropospheric chemistry. For the stratosphere, (1) field observations will be used to test and refine our understanding of the role of heterogenous processes on the chemistry of the lower stratosphere; (2) diagnostic models will be developed and applied to elucidate the chemical and dynamical mechanisms responsible for long-term trends in the ozone, with particular attention to global effects of volcanic aerosols; and (3) the role of denitrification will be examined as the controlling influence on loss of ozone in polar regions, as part of a strategy to clarify differences between ozone loss in the Arctic and Antarctic. For the troposphere, the PI proposes to: (1) data for short-lived species from recent field expeditions will be used to test and improve photochemical mechanisms; (2) to test the distribution of hydroxyl radical in a global three-dimensional Chemical Tracer Model (CTM) will be tested using observations of carbon 14 labeled carbon monoxide; (3) the CTM will be used to test inventory of sources for carbon monoxide, a key species regulating hydroxyl radical concentrations, taking advantage of new data for carbon 13 labeled carbon monoxide and carbon 18 labeled carbon monoxide and including additional studies of ethylene and acetylene and (4) the CTM will also be used to investigate changes in the oxidizing power of the troposphere from 1950 to the present.