High accuracy transition intensities for ozone

臭氧的高精度转变强度

• 批准号: NE/N001508/1
• 负责人: Jonathan Tennyson
• 金额: $ 44.22万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN001508%2F1
• 关键词: accuracy; transition; intensities; ozone

Ozone is present in low concentrations throughout the Earth's atmosphere. In the troposphere ozone is a pollutant which largely results from human activity. However, ozone is harmful to humans, animals and plants at even trace concentrations. Conversely stratospheric ozone, the ``ozone layer'', provides an extremely important shield of solar ultraviolet radiation. Human activity has resulted in a significant reduction in stratospheric ozone and this loss has lead to increased holes at the poles. Studies of atmospheric ozone concentrations rely heavily on the use of spectroscopic remote sensing from a mixture of ground-based, airborne and satellite instruments. These instruments observe the characteristic absorption features of ozone either in the infrared or the ultraviolet. Retrievals based on these observations require accurate laboratory data to make them useful. In particular the many studies of atmospheric currently being conducted require intensity / cross section data for both ultraviolet (UV) and infrared (IR) which is accurate to 1% or better.Unfortunately, as has been extensively documented in the scientific literature, the situation with the laboratory intensity determinations is far from satisfactory. Firstly, there are many measurements showing systematic differences between atmospheric studies performed at infrared and ultraviolet wavelengths at the 4 to 5 % level. Secondly, while laboratory measurements of the ultraviolet cross sections show a measure of agreement, those for the infrared do not. A recent (2012) analysis concluded that for the key 10 micron region agreement between measurements was only at best 4% with intensity discrepancies much higher than this. There are other discrepancies within the infrared region. There is an urgent need for a solution to this problem for missions such as TES+OMI on Aura satellite mission (NASA), IASI+GOME-2 on Metop satellite (ESA) AIRS on the Auqa satellite (NASA). The proposal will use high accuracy, first principles quantum mechanical methods to compute the transition intensities for both the IR and UV portions of the spectrum. For the IR region, methods of computing high accuracy dipole moment surfaces already used successful for water and CO2, will be employed. These will be combined with measured transition frequencies to complete line lists with intensities accurate to about 0.5%.New methodologies will be developed to transfer the experience gained computing IR vibration-rotation intensities (which require electronically diagonal dipole moments) to electronic transitions in the UV. Initial work will focus on the Huggins band and will also require further development of the methods used for treating nuclear motion.These calculations will provide complete independent assessment of the absolute line intensities / cross sections removed from experimental issues such as the ozone concentration. Results will be made widely available via the web, databases and submitted for inclusion in standard compilations used for atmospheric studies such as HITRAN. HITRAN will be a project partner on the proposal and undertake independent evaluation of the results.

地球大气层中的臭氧浓度很低。对流层中的臭氧是一种主要由人类活动造成的污染物。然而，即使是微量浓度的臭氧也对人类、动物和植物有害。相反，平流层臭氧，即“臭氧层”，提供了极其重要的太阳紫外线辐射屏蔽。人类活动导致平流层臭氧显着减少，这种损失导致两极空洞增加。大气臭氧浓度的研究在很大程度上依赖于地面、机载和卫星仪器的光谱遥感。这些仪器观察臭氧在红外线或紫外线下的特征吸收特征。基于这些观察的检索需要准确的实验室数据才能发挥作用。特别是，目前正在进行的许多大气研究都需要紫外线 (UV) 和红外线 (IR) 的强度/截面数据，其精确度为 1% 或更高。不幸的是，正如科学文献中广泛记录的那样，实验室强度测定的情况远不能令人满意。首先，许多测量结果表明，在红外和紫外波长下进行的大气研究之间存在 4% 至 5% 水平的系统差异。其次，虽然实验室对紫外线横截面的测量显示出一定程度的一致性，但对红外线横截面的测量结果却不然。最近 (2012) 的一项分析得出结论，对于关键的 10 微米区域，测量之间的一致性最多仅为 4%，强度差异远高于此。红外区域内还存在其他差异。对于诸如Aura卫星任务（NASA）上的TES+OMI、Metop卫星（ESA）上的IASI+GOME-2、Auqa卫星（NASA）上的AIRS等任务，迫切需要解决这个问题。该提案将使用高精度、第一原理量子力学方法来计算光谱的红外和紫外部分的跃迁强度。对于红外区域，将采用已成功用于水和二氧化碳的高精度偶极矩表面计算方法。这些将与测量的跃迁频率相结合，以完成强度精确到约 0.5% 的谱线列表。将开发新的方法，将计算红外振动旋转强度（需要电子对角偶极矩）所获得的经验转移到紫外线中的电子跃迁。最初的工作将集中在哈金斯带上，还需要进一步开发用于处理核运动的方法。这些计算将为从臭氧浓度等实验问题中去除的绝对线强度/横截面提供完整的独立评估。结果将通过网络、数据库广泛提供，并提交纳入用于大气研究的标准汇编（例如 HITRAN）。 HITRAN 将作为该提案的项目合作伙伴，并对结果进行独立评估。

项目成果

ExoMol line lists - XV. A new hot line list for hydrogen peroxide

ExoMol 系列列表 - XV。

• DOI: 10.1093/mnras/stw1295
• 发表时间: 2016
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Al-Refaie A

Determination of approximate quantum labels based on projections of the total angular momentum on the molecule-fixed axis

根据总角动量在分子固定轴上的投影确定近似量子标签

• DOI: 10.48550/arxiv.2106.03597
• 发表时间: 2021
• 作者: Conway E

Accurate line intensities for water transitions in the infrared: Comparison of theory and experiment

红外水跃迁的精确线强度：理论与实验的比较

• DOI: 10.1016/j.jqsrt.2017.03.040
• 发表时间: 2017
• 期刊: Journal of Quantitative Spectroscopy & Radiative Transfer
• 影响因子: 2.3
• 作者: Birk M;Wagner G;Loos J;Lodi L;Polyansky OL;Kyuberis AA;Zobov NF;Tennyson J
• 通讯作者: Tennyson J

A New Near-IR C-2 Linelist for an Improved Chemical Analysis of Hydrogen-deficient, Carbon-rich Giants

用于改进缺氢、富碳巨星化学分析的新近红外 C-2 系列列表

• 发表时间: 2018
• 期刊: Astronomical Society of the Pacific Conference Series
• 作者: D A Garcia-Hernandez

Current State of Astrophysical Opacities: A White Paper

天体物理不透明性的现状：白皮书

• 发表时间: 2018
• 期刊: Astronomical Society of the Pacific Conference Series
• 作者: A E Lynas-Gray