Collaborative Research: Laboratory and Modeling Studies to Resolve a Grand Challenge for Upper Atmospheric Science

这个合作项目将利用空间观测、大气建模和基于激光的实验室实验的协同作用来解决二氧化碳15微米排放的来源。它的目的是通过多学科研究和教育活动，促进更广泛地认识行星大气中热能平衡的复杂性，通过红外辐射更好地量化高层大气辐射冷却。该项目将改进对从卫星观测的二氧化碳15微米排放中提取的大气温度分布的确定，并促进我们对地球、火星和金星大气中辐射平衡的理解。这项工作有可能为MLT的辐射能量学增加新的知识，并解决长期存在的二氧化碳15微米激发和去激发过程的问题。它还将促进与其他研究领域有关的新知识，如分子能量转移、化学激光、太阳系外行星大气、航天器再入过程中产生的冲击波的极端环境以及化学反应动力学和动力学。这项研究的结果使太阳系内外行星大气的建模人员、理论家和实验者受益，并提高了地面和空间遥感观测的科学回报。该项目还将有助于一名博士后研究生和一名或多名博士后研究员和暑期本科生的教育和形成性研究经验。控制二氧化碳(NU-2)数量的最重要过程被认为是二氧化碳与基态热化原子氧O(3P)碰撞时的激发和松弛。尽管过去几十年来进行了大量研究，但人们对这一过程知之甚少。有迹象表明，我们对潜在过程的理解存在重大的根本性缺陷。这项合作研究工作结合了(1)地面和空间观测分析，以量化以前未被识别的15微米二氧化碳排放源，(2)基于激光的O+CO2相互作用的实验室实验研究，以及(3)最先进的非LTE大气模拟计算，以重新评估15微米二氧化碳波段的MLT的全球热平衡。该团队将进行O+CO2碰撞的实验室研究，以1)测量O原子对CO2(010)振动能级的驰豫速率常数，2)确定其在150K到600K之间的温度依赖关系，3)研究与O原子碰撞中CO2振动激发的碰撞能量依赖关系，以及4)表征O原子在相互作用区的浓度及其在观测体积之外的扩散。他们还将进行SABER和LIDAR数据的观测分析，O+CO2碰撞的理论和非LTE建模研究。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This collaborative project will exploit the synergy of space-based observations, atmospheric modeling, and laser-based laboratory experiments to resolve the origins of the CO2 15-um emission. It aims to provide a better quantification of upper atmospheric radiative cooling by IR emissions through multi-disciplinary research and educational activities that promote a broader appreciation of the complexity of thermal energy balance in planetary atmospheres. The project will enable improved determination of atmospheric temperature profile retrievals from satellite observations of the CO2 15-um emission and advance our understanding of radiative balance in the atmospheres of Earth, Mars, and Venus. The work has the potential to add new knowledge to the radiative energetics of the MLT and address the long-standing question of CO2 15-um excitation and deexcitation processes. It will also advance new knowledge relevant to other research areas such as molecular energy transfer, chemical lasers, extrasolar planetary atmospheres, the extreme environments in the shock waves generated during space vehicle reentry, as well as chemical reaction dynamics and kinetics. The results of this research benefit modelers of planetary atmospheres within and beyond our solar system, theoreticians, and experimentalists, and enhance the scientific returns of ground- and space-based remote sensing observations. This project will also contribute to the education and formative research experiences of a Ph.D. graduate student and one or more postdoctoral fellows and summer undergraduate students.The most important process controlling the population of CO2(nu-2) is assumed to be its excitation and relaxation in collisions of CO2 with thermalized atomic oxygen in its ground state, O(3P). This process is poorly understood despite numerous studies over the past several decades. There are telltale signs of a major fundamental deficiency in our understanding of the underlying processes. This collaborative research effort combines (1) analysis of ground- and space based observations to quantify previously unrecognized sources of the CO2 15-µm emission, (2) laser-based laboratory experimental studies of the O + CO2 interaction, and (3) state-of-the-art, non-LTE atmospheric modeling calculations to reevaluate the global thermal balance of the MLT in the 15-µm CO2 band. The team will conduct laboratory studies of O + CO2 collisions to 1) measure the rate constant for relaxation of the CO2(010) vibrational level by O atoms, 2) determine its temperature dependence from 150 K to 600 K, 3) investigate the collision energy dependence of CO2 vibrational excitation in collisions with O atoms, and 4) characterize the concentration of O atoms in the interaction region and their diffusion out of the observation volume. They will also perform observation analysis of SABER and LIDAR data, theory, and Non-LTE modeling studies of O + CO2 Collisions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.