探测高层大气的粒子浓度具有重要的科学意义.本文利用安装在中国西安城区(海拔457m,34.23°N,109.01°E)的自制地基气辉成像干涉仪 GBAVTII(Ground-based atmosphere VER & temperature imaging interferometer)对峰值高度在94 km处的867.7 nmO2(0-1)夜气辉长期定点观测,反演得到O2(0-1)的柱浓度,并根据大气温度及O2(0-1)粒子柱浓度的扰动提取得到大气重力波、行星波周期.本文首先阐述了地基GBAVTII探测气辉的原理,并从气辉辐射理论及地基探测模式导出气辉强度表达式,建立地基仪器探测得到的气辉的积分体发射率IER(Integrated Emission Rate)与大气中O2(0-1)柱浓度的关系,然后利用2019年以来的多日观测数据,得到西安地区上空O2(0-1)粒子的柱浓度量级为104cm-2;经对比发现2020年9月17日GBAVTII探测O2(0-1)柱浓度结果与NRLMSISE-00模型数据的相对误差在0.5％～30％.我们从GBAVTII整夜拍摄气辉成像干涉图中反演出西安上空90～100 km的大气温度和O2(0-1)柱浓度及扰动特征,得到周期在8～10 h左右的潮汐波,去掉潮汐趋势的温度和柱浓度残差序列,利用小波分析提取得到周期为2.3 h的重力波.最后我们利用2022年4月21 日-2022年5月6日期间的O2(0-1)柱浓度探测序列得到日平均柱浓度并提取准2日的行星波周期.GBAVTII所探测得到大气波动的周期尺度与其他已有中纬度地区的探测结果相吻合.
Study of O2(0-1)column concentration detected by GBAVTII and wave parameters over Xi'an
Detection of the column concentration of particles in the upper atmosphere is a great scientific significance.In this paper,a ground-based airglow imaging interferometer,GBAVTII(Ground-based atmosphere VER & temperature Imaging Interferometer),installed in the Xi'an urban area of China(altitude 457 m,34.23°N,109.01°E),was used to capture long-term fixed-point images of O2(0-1)night airglow at a peak altitude of 94 km,and the column concentration of O2(0-1)was obtained.Based on the disturbance of the O2(0-1)column concentration and rotation temperature,atmospheric gravity waves and planetary waves were extracted.This paper first derives the expression of O2(0-1)column concentration between the ground-based instrument GBAVTII's detection intensity based on O2(0-1)airglow.After establishing the relationship of IER(Integrated Emission Rate)and O2(0-1)column concentration,the magnitude of column concentration of O2(0-1)above the Earth's atmosphere was determined to be 104/cm2 using multi-day observation data since 2019.After comparison,it was found that the relative error between the O2(0-1)column concentration results detected by GBAVTII and the NRLMSISE-00 model data on Sep.17,2020,was from 0.5％to 30％.By inverting the airglow imaging interferometry images captured by GBAVTII throughout the night,the atmospheric temperature,column concentration,and perturbation characteristics at 90～100 km above Xi'an were obtained,revealing tidal waves with a period of about 8～10 hours.By subtracting the tidal trend from the temperature and column concentration residual sequences,gravity waves period of 2.3 hours was extracted using wavelet analysis.Finally,the O2(0-1)column concentration detection sequence during the period from April 21,2022,to May 6,2022,was used to obtain the daily average column concentration and extract the quasi 2-day planetary wave period.The periodic scale of atmospheric fluctuations detected by GBAVTII are consistent with the detection results of other existing mid-latitude regions.
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