CEDAR: Critical Evaluation of the Hydroxyl Radical (OH) Meinel Band Einstein A Coefficients

CEDAR：羟基自由基 (OH) 梅尼尔带爱因斯坦 A 系数的批判性评估

• 批准号: 1651450
• 负责人: Daniel Matsiev
• 金额: $ 20.9万
• 依托单位: SRI International
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1651450&HistoricalAwards=false
• 关键词: CEDAR; Critical; Evaluation; Hydroxyl; Radical

The Meinel band nightglow emission from the OH molecule has been used for decades to characterize mesospheric temperatures. Aeronomers currently rely on emission coefficients ("A coefficients") that the PIs argue are in need of revision. Temperatures recovered using the existing set of A coefficients differ by up to 15 K from actual temperatures computed from first principles. Large uncertainty in the mesospheric temperature can have detrimental effects on modeling chemistry, transport and circulation of the mesosphere and lower thermosphere (MLT). The uncertainties also undermine efforts to monitor the long-term temperatures in the MLT. This proposal addresses the OH temperature determination by 1) using intensity-calibrated nightglow data that has been collected simultaneously over a large spectral range from astronomical sky spectra; 2) making comparisons between such recently obtained OH Meinel band line intensities, and the most recent first principles calculations of the emission coefficients. This research will contribute to understanding fundamental physical quantum processes, atmospheric motions on small and large scales, and long-term temperature change in the lower thermosphere.

数十年来，OH分子的Meinel带agi夜发射已被用来表征中层温度。 PIS认为需要修订的PIS认为的排放系数（“系数”）目前依靠排放系数（“系数”）。使用现有系数集回收的温度与根据第一原理计算的实际温度最多不同。中层温度的较大不确定性可能会对中层和较低热球（MLT）的化学，运输和循环产生有害影响。不确定性也破坏了监测MLT长期温度的努力。 该提案通过1）使用强度校准的噩梦数据来解决OH温度的确定，该数据已在天文学天空光谱中同时收集的较大光谱范围内； 2）在最近获得的OH Meinel带线强度与发射系数的最新第一原理计算之间进行比较。这项研究将有助于理解基本的物理量子过程，大小和大尺度上的大气运动以及较低热层的长期温度变化。