Hydroxyl and Nitric Oxide Chemistry Relevant to Mesospheric and Lower Thermospheric Energy Budget

该项目将对高层大气中的羟基和一氧化氮化学进行详细调查。氢原子和臭氧之间的反应产生的OH具有高达9个量子的振动激发。被激发的振动能级主要是由O和O2的碰撞而淬灭的。用精确的量子和半经典计算来确定在中间层中与O原子碰撞使OH振动能级v = 1 - 5和与O2分子碰撞使能级v = 1 - 9猝灭的速率系数。得到的振动松弛率系数数据库将在世界范围的网络上提供。一氧化氮是低层热层的主要辐射物质，它是由O2和氮原子在基态和电子激发态之间的反应在高度旋转和振动激发水平上产生的。通过对精确分子势的量子散射计算，提出的工作将提供特定振动和旋转水平下一氧化氮的产生速率作为热层高度的函数。原子氧对NO的碰撞激发及其随后通过与O原子的碰撞去激发也将采用量子力学方法定量描述NO在5.3 - m的基本振动-旋转带发射。结果可用于高层大气的能量平衡和化学结构模型。该项目的更广泛的影响包括它对一些中层大气科学主题的适用性。该研究将为中间层和低层热层能量收支的空气经济学模型中的关键反应提供速率系数。作为教育部分的一部分，该项目将培养一名博士研究生和两到三名大气化学专业的本科生。将优先考虑来自代表性不足社区的候选人。该项目还将支持一名博士后学者，他将负责该项目的大部分工作。

This project will undertake detailed investigations of hydroxyl and nitric oxide chemistry in the upper atmosphere. The reaction between hydrogen atoms and ozone produces OH with up to nine quanta of vibrational excitation. The excited vibrational levels are quenched predominantly by collisions with O and O2. Rate coefficients for quenching of OH vibrational levels v = 1 - 5 by collisions with O atoms and levels v = 1 - 9 by collisions with O2 molecules at temperatures of interest in the mesosphere will be determined using accurate quantum and semiclassical calculations. The resulting database of vibrational relaxation rate coefficients will be made available over the world-wide web. Nitric oxide is the key radiating species in the lower thermosphere and it is produced in highly rotationally and vibrationally excited levels by the reaction between O2 and nitrogen atoms in the ground and electronically excited states. Through quantum scattering calculations on accurate molecular potentials, the proposed work will provide the rate of production of nitric oxide in specific vibrational and rotational levels as functions of the altitude in the thermosphere. Collisional excitation of NO by atomic oxygen and its subsequent deexcitation through collisions with O atoms will also be undertaken using quantum mechanical approaches to quantitatively describe the NO fundamental vibration-rotation band emission at 5.3 - m. The results can be used in models of the energy balance and chemical structure of the upper atmosphere. The broader impacts of the project includes its applicability to a number of middle atmosphere science topics. The research will provide rate coefficients for key reactions in aeronomic models of the mesospheric and lower thermospheric energy budget. As part of the educational component, the project will train a Ph. D. level graduate student and two or three undergraduate students in atmospheric chemistry. Preference will be given to candidates from under-represented communities. The project will also support a postdoctoral scholar who will be responsible for a large portion of the project.