Nocturnal means of OH(3-1) airglow rotational temperatures from the mesopause region obtained with GRIPS 9 located at ALOMAR, Norway

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 9) located at the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR: 16.01°E, 69.28°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. 24 x 24 km2 in zenith direction at 87 km height. 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.

本次温度数据源自质心高度约87 km处薄层内羟基（OH）分子的振转跃迁。
光谱数据由安装于北极中层大气研究激光雷达观测站（Arctic Lidar Observatory for Middle Atmosphere Research，ALOMAR：东经16.01°，北纬69.28°）的地基红外P支光谱仪（Ground-based Infrared P-branch Spectrometer，GRIPS 9）获取，该站点为国际中层大气变化监测网（Network for the Detection of Mesospheric Change，NDMC）的实测站点之一。
该设备由德国宇航中心（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。
常规运行模式下，每15秒采集一组光谱，其视场角约为15.5°×15.5°，对应87 km高度处天顶方向约24 km×24 km的观测区域。
本次观测覆盖的波长范围可同时获取羟基（OH）(3-1)振转带的Q支、P支辐射信号，以及OH(4-2)振转带的R支、Q支辐射信号。
转动温度通过1520 nm至1550 nm波段内的OH(3-1) P支辐射强度计算得到。
在估算夜间平均温度时，需依据各样本的自身测量精度对夜间温度时间序列的全部数据进行加权处理。经加权后的平均温度较未加权的算术平均值低1~2 K。
仅当有效观测时长不少于2小时时，方可计算得到平均温度值。