Line Shape Parameters and Their Temperature Dependence for Molecules of Importance in Earth's Atmosphere

首席研究员（PI）计划开发一个理论框架来计算地球大气中痕量气体的压力加宽半宽度和压力引起的线移。半宽度仍然是用于减少遥感数据的光谱参数和用于计算温室气体辐射强迫的逐行模式的主要误差来源。在剖面检索中包含线移也减少了过程中的误差。为了应用于地球大气层，需要数千次反振动跃迁的数据。因此，需要一种理论模型，它计算效率高，能够在光谱学和遥感界的需要范围内确定伽马和δ。在这项工作中，将研究半宽度和线移对温度的依赖关系。这些碰撞诱发参数的振动状态、旋转状态和温度依赖性将被研究。更广泛的影响包括在研究项目中培养一名博士后和三名本科生。这项工作还将为研究和教育提供资源。所有的计算结果将在网上公布（http://faculty.uml.edu/Robert_Gamache）。大气分子的线形信息将被纳入HITRAN分子吸收参数数据库，供社区使用。在科学和工程之外的贡献是，这些结果将被遥感界使用，并将使他们对自己的数据更有信心。这些结果将使我们更好地了解地球，它的能量平衡，臭氧和其他气体的浓度如何随时间变化，以及气候如何演变。这些知识将有助于更好地监管和管理地球上相互作用的系统，并将使信息更好地呈现给美国和世界公民。

The Principal Investigator (PI) plans to develop a theoretical framework to calculate pressure-broadened half-widths and pressure-induced line shifts for trace gases in the terrestrial atmosphere. The half-width remains the major source of error in the spectral parameters used for reducing remote sensing data and in line-by-line models used to calculate radiative forcing from greenhouse gases. The inclusion of the line shift in profile retrievals also reduces the error in the procedure. For applications to the Earth's atmosphere, data are needed for thousands of ro-vibrational transitions. Hence a theoretical model is needed that is computationally efficient and capable of determining gamma and delta within the needs of the spectroscopic and remote sensing communities. In this work the temperature dependence of the half-width and the line shift will be investigated. The vibrational state, rotational state, and temperature dependence of these collision-induced parameters will be investigated.Broader impacts include education of a postdoctoral student and three undergraduate students in the research project. The work will also provide resources for research and education. All the results of the calculations will be made available online (http://faculty.uml.edu/Robert_Gamache). The line shape information for atmospheric molecules will be incorporated into the HITRAN molecular absorption parameter database for use by the community. The contributions beyond science and engineering are that the results will be used by the remote sensing community and will allow them more confidence in their data. These results will allow a better understanding about planet Earth, its energy balance, how the concentration of ozone and other gases are changing with time, and how climate is evolving. This knowledge will allow for better regulation and stewardship of the planet's interacting systems and will allow better presentations of the information to the citizens of the United States and the world.