Evidence for an OH≠ N2≠ CO2(ν3) → CO2 +hν (4.3 μm) mechanism for 4.3-μm airglow
Evidence for an OH≠ N2≠ CO2(ν3) → CO2 +hν (4.3 μm) mechanism for 4.3-μm airglow
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4.3 μm 气辉的 OH≠ N2≠ CO2(ν3) → CO2 +hν (4.3 μm) 机制的证据
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
D. Baker
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文献类型：
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作者：
J. Kumer;A. T. Stair;N. B. Wheeler;K. Baker;D. Baker
在这项研究之前，我们曾认为，在ν3模式下产生CO_2振动激发的唯一未受干扰的夜间机制是(1)热碰撞的振动激发和(2)CO_2对4.3um地光的吸收。在本文中，我们提供了详细的证据，证明了在85公里高空地区产生CO_2(υ-3)的主要激发机制可能是OH(→)+N_2υ-1+N_2≠，其次是N_2≠+CO_2→N_2+CO_2(ν_3)。证据基于1974年4月11日通过火箭搭载的液氮冷却圆形可变滤光式辐射计获得的4.3微米天顶辐射数据。火箭于夜间从阿拉斯加的扑克平原研究靶场发射。这些数据是在极光活动基本为零的条件下获得的。这些数据在85公里高度附近有一个特征，这可以用机制来解释。要解释这一特征，需要0.12±0.025 erg/cm？S从OH-≠到N_2的柱子转移。根据上面引用的机制1和2的另一种解释是，1974年4月11日晚上存在一种非常不可能的中间层温度廓线。在1973年3月27日、1974年2月25日、1975年3月6日和1975年3月12日获得的初步4.3微米天顶数据中，类似的非极光特征一直出现在85公里附近，从而进一步证明，这种特征很可能是OH机制的结果，而不是一种奇怪的中温分布。这些数据是从空军地球物理实验室和犹他州立大学获得的，作为红外化学实验的一部分，该计划由国防核机构支持。在这篇文章中，我们只关注对1974年4月11日数据的分析。
Prior to the study we report here it had been thought that the sole undisturbed nighttime mechanisms for producing CO2 vibrationally excited in the ν3 mode were (1) vibrational excitation by thermal collisions and (2) absorption of 4.3-µm earthshine by CO2. In this paper we show detailed evidence that the mechanism OH(υ) + N2 → OH(υ - 1) + N2≠, followed by N2≠ + CO2 → N2 + CO2(ν3), may be the dominant excitation mechanism for producing CO2(ν3) in the 85-km altitude region. The evidence is based on 4.3-µm zenith radiance data obtained on April 11, 1974, via a rocket-borne liquid N2 nitrogen cooled circular variable-filtered radiometer. The rocket was launched at night from the Poker Flat Research Range, Alaska. The data were obtained under conditions of essentially zero auroral activity. There is a feature in these data near 85-km altitude which can be explained by the mechanism . A column transfer of 0.12 ± 0.025 erg/cm² s from OH≠ to N2 is required to explain the feature. An alternate explanation on the basis of just the mechanisms 1 and 2 which are cited above requires that there existed a very unlikely mesospheric temperature profile on the evening of April 11, 1974. A similar nonauroral feature appears consistently near 85 km in preliminary 4.3-µm zenith data obtained on March 27, 1973, February 25, 1974, March 6, 1975, and March 12, 1975, thus providing further evidence that the feature most likely results from the OH mechanism rather than a strange mesopheric temperature profile. These data were obtained from the Air Force Geophysics Laboratory and Utah State University as part of the Infrared Chemistry Experiments, Coordinated Auroral Program supported by the Defense Nuclear Agency. In this article we confine our attention to analysis of the April 11, 1974, data.