Nocturnal means of OH(3-1) airglow rotational temperatures (version 1.0) from the mesopause region obtained at the Environmental Research Station “Schneefernerhaus” between 2009 and 2020, Germany

The temperatures are derived from the rotational vibrational transition of the OH molecule originating from a thin layer in approximately 86-87 km centroid height. The spectra have been obtained with the Ground-based Infrared P-branch Spectrometers (GRIPS 5, GRIPS 7 and GRIPS 8) located at the Environmental Research Station “Schneefernerhaus” (UFS: 47.42°N, 10.98°E) - a measurement station of the international Network for the Detection of Mesospheric Change (NDMC). The instruments are operated by the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR). 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. During routine operation one spectrum is obtained every 15s, originating from a field of view of approximately 15° x 15°, which corresponds to ca. 660 km2 in 87 km height, as the instruments point southwards with a zenith angle of 45°. GRIPS 7 usually acquires one spectrum every 10s due to its outstanding performance. Both GRIPS 5 and GRIPS 7 were also operated with different field of views in the context of various sensitivity studies. Systematic differences due these changes were identified and accounted for in the calculation of the site mean temperature. The data set covers the time period from 1 July 2009 until 30 June 2020, i.e. 4018 nights / 11 years and thus it allows for a thorough investigation of the decade 2010-2019.