Five minute means of OH(3-1) airglow rotational temperatures from the mesopause region obtained with GRIPS 14 located at the German Remote Sensing Data Center, Oberpfaffenhofen

Temperatures are derived from the rotational vibrational transition of the OH molecule originating from a thin layer in approximately 87km centroid height. The spectra have been obtained with the GRound-based Infrared P-branch Spectrometer (GRIPS 14) located at the German Remote Sensing Data Center of the German Aerospace Center (DLR-DFD) at Oberpfaffenhofen (OPN: 48.09°N, 11.28°E) – a measurement station of the international Network of Mesospheric Change (NDMC).
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. In addition to the field of view (FoV) in zenith direction, the instrument is successively pointed into three more directions at 30° zenith angle: 90°(E), 210°(SSW), 330°(NNW) azimuth angles, increasing the effective FoV in these directions to approximately 880 km².
Regular observations with the scanning GRIPS 14 were performed at Oberpfaffenhofen from 17 July 2015 until 10 November 2015 and with the identical setup again from 13 April 2016 until 19 April 2018.
Since data are recorded for each FoV successively, the initial data are not directly comparable, therefore a five minute mean value is derived for each FoV, if there are two or more high precision temperature values available within the respective interval of −150 s and +149.999 s around a UTC full five minute time stamp. The corresponding precision of the five minute mean value follows from Gaussian error propagation and typically lies between ±2.5 K and ±8 K.