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

点击翻译按钮获取中文摘要

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.