Photochemical Measurements of Virtual Atmospheres

该项目将进行实验室反应堆实验，寻求重建高层大气的光化学，以解决关于最近和新的大气测量的建模和理解方面的现有困境。虽然较低的压力和较长的时间适用于真实大气，但计算机建模我们可以用来设计虚拟大气实验，使它们对相同的化学和光解反应敏感。该研究探索的上层平流层和中间层的化学成分主要是含活性氧和含氢物质，我们将使用一系列激光诊断技术以极高的灵敏度和选择性测量其中的许多物质。这一概念将提供一种新的技术来验证我们对难以接近区域的光化学的理解，并揭示任何未知的特征。实验将在一个大型反应堆灯泡中进行，该灯泡具有量化的氧气，氮气，臭氧和水的进出口流量，在1托附近运行，停留时间为3至6分钟，并在特性良好的灯或激光辐射下进行紫外线光解。适当的操作条件和诊断将结合起来，以解决当前感兴趣、争论或测量活动的特定主题，包括当前中间层模型预测观测到的OH和HO2水平的失败，以及激发氧和羟基状态在高层大气加热、特征和化学中的作用。

The project will undertake laboratory reactor experiments that seek to recreate the photochemistry of the upper atmosphere in order to solve existing dilemmas regarding the modeling and understanding of recent and new atmospheric measurements. Although lower pressures and longer times pertain to the real atmosphere, computer modeling we can be used to design the virtual atmosphere experiments so that they are sensitive to the same chemistry and photolysis. The chemistry of the upper stratosphere and mesosphere to be explored by the study is dominated by reactive oxygen- and hydrogen-containing species, many of which we will measure with great sensitivity and selectivity using a series of laser diagnostics. This concept will provide a new technique to validate our understanding of the photochemistry of hard-to-access regions and uncover any unknown features. The experiments will be conducted in a large reactor bulb with quantified inlet and outlet flows of oxygen, nitrogen, ozone, and water, operating near 1 torr with 3- to 6-minute residence times, and subject to ultraviolet photolysis with well-characterized lamp or laser radiation. The appropriate operating conditions and diagnostics will be combined to address specific topics of current interest, debate, or measurement activity, including the failure of current mesospheric models to predict observed OH and HO2 levels, and the role of excited oxygen and hydroxyl states in the heating, signatures, and chemistry of the upper atmosphere.