Observations of NO in the upper mesosphere and lower thermosphere during ECOMA 2010
Observations of NO in the upper mesosphere and lower thermosphere during ECOMA 2010
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ECOMA 2010 期间中层上部和热层下部 NO 观测
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发表时间：
2012
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通讯作者：
G. Witt
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作者：
J. Hedin;M. Rapp;M. Khaplanov;J. Stegman;G. Witt
2010年12月，德国-挪威探空火箭项目ECOMA（中层大气中流星烟雾粒子的存在和电荷状态）的最后一次活动在挪威北方的Andoya火箭靶场（北纬69度，东经16度）进行，与双子座流星雨有关。火箭有效载荷上的主要仪器是ECOMA探测器，用于通过主动光电离研究流星烟雾粒子，随后探测产生的电荷（粒子和光电子）。除了光致电离MSP之外，ECOMA闪光灯发出的光子的能量也足够高以光致电离一氧化氮（NO）。因此，在NO层的峰值周围，在主MSP层处和上方，预期由NO的光电离产生的光电子有助于或甚至主导主MSP层上方的总测量光电子电流。在船上的其他仪器中，有一套两个的光度计，用于研究O2（B 1 6 + g X 3 6 g）大气波段和NO2连续夜光排放。在极光发射的情况下，这两个夜光功能可以一起使用来推断NO数密度。这将提供一种方法来量化NO光电子对ECOMA测量的光电子电流的贡献，并且在MSP层上方，用两种不同且独立的技术同时测量NO。由于不确定性，特别是从ECOMA光电子流定量推断NO密度的努力，以及缺乏用于光测研究的温度和密度的同时测量，这项工作仍在进行中。在本文中，我们描述了这两种技术来推断NO密度和讨论的不确定性。在99 km左右的高度上，由两台光度计测得的NO数密度峰值为3.9Dad 10 8 cm 3，而由ECOMA光电子测量结果测得的浓度值则小5倍。
In December 2010 the last campaign of the German-Norwegian sounding rocket project ECOMA (Exis- tence and Charge state Of Meteoric smoke particles in the middle Atmosphere) was conducted from Andoya Rocket Range in northern Norway (69 N, 16 E) in connection with the Geminid meteor shower. The main instrument on board the rocket payloads was the ECOMA detector for studying meteoric smoke particles (MSPs) by active photoionization and subsequent detection of the produced charges (particles and photoelectrons). In addition to photoionizing MSPs, the energy of the emitted photons from the ECOMA flash-lamp is high enough to also photoionize nitric oxide (NO). Thus, around the peak of the NO layer, at and above the main MSP layer, photoelectrons produced by the photoionization of NO are expected to contribute to, or even dominate above the main MSP-layer, the total measured photoelectron current. Among the other instruments on board was a set of two pho- tometers to study the O2 (b 1 6 + g X 3 6g ) Atmospheric band and NO2 continuum nightglow emissions. In the absence of auroral emissions, these two nightglow features can be used together to infer NO number densities. This will provide a way to quantify the contribution of NO photoelectrons to the photoelectron current measured by the ECOMA instru- ment and, above the MSP layer, a simultaneous measure- ment of NO with two different and independent techniques. This work is still on-going due to the uncertainties, especially in the effort to quantitatively infer NO densities from the ECOMA photoelectron current, and the lack of simultane- ous measurements of temperature and density for the photo- metric study. In this paper we describe these two techniques to infer NO densities and discuss the uncertainties. The peak NO number density inferred from the two photometers on as- cent was 3.9◊ 10 8 cm 3 at an altitude of about 99 km, while the concentration inferred from the ECOMA photoelectron measurement at this altitude was a factor of 5 smaller.