Nocturnal means of OH(3-1) airglow rotational temperatures from the mesopause region obtained with GRIPS 8 located at the Environmental Research Station “Schneefernerhaus”

The temperatures are derived from the rotational vibrational transition of the OH molecule originating from a thin layer in approximately 87 km centroid height. The spectra have been obtained with the Ground-based Infrared P-branch Spectrometer (GRIPS 8) located at the Environmental Research Station “Schneefernerhaus” (UFS: 10.98°E, 47.42°N) - a measurement station of the international Network for the Detection of Mesospheric Change (NDMC). It is operated by the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR). During routine operation one spectrum is obtained every 15 s, originating from a field of view of approximately 15.5° x 15.5° which corresponds to ca. 1600 km2 in 87 km height, because the instruments points southwards with a zenith angle of 45°. The covered wavelength range allows the observation of the OH(3-1) Q- and P-branches as well as of the OH(4-2) R- and Q-branches. Rotational temperatures are calculated using OH(3-1) P-branch emissions between 1520 nm and 1550 nm. For the estimation of a nocturnal mean value all samples of the nightly temperature time series are weighted according to their individual precision. Thus, mean temperatures between 1 and 2 K are lower compared to the unweighted arithmetic mean. A mean is only calculated, when at least two hours of observation time are available.

本次所用温度数据源自羟基（OH）分子的转动-振动跃迁信号，其探测层的质心高度约为87千米。相关光谱数据由安装于施内费纳豪斯环境研究站（UFS：东经10.98°，北纬47.42°）的地基红外P支光谱仪（Ground-based Infrared P-branch Spectrometer，GRIPS 8）获取，该站点隶属于国际中层变化探测网络（Network for the Detection of Mesospheric Change，NDMC）。该站点由德国航空航天中心（German Aerospace Center，DLR）下属的德国遥感数据中心（German Remote Sensing Data Center，DFD）负责运维。日常运行模式下，仪器每15秒即可获取一组光谱数据，其视场范围约为15.5°×15.5°，在87千米高度处对应的探测面积约为1600平方千米，这是由于仪器以45°天顶角指向南方。本次探测覆盖的波长范围可同时观测OH(3-1)的Q支与P支跃迁，以及OH(4-2)的R支与Q支跃迁。转动温度通过1520 nm至1550 nm波段内的OH(3-1) P支发射光谱计算得到。在计算夜间平均温度时，所有夜间温度时间序列的样本均会根据其自身的测量精度进行加权处理，因此加权后的平均温度相较于未加权的算术平均值低1~2开尔文。仅当有效观测时长不少于2小时时，方可计算夜间平均温度。