One minute mean values OH(3-1) airglow rotational temperatures from the mesopause region obtained with GRIPS 9 located at the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR), Norway

• Main Authors: Schmidt, Carsten, Wüst, Sabine, Bittner, Michael
• Format: Dataset
• Language: English
• Published: World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT) 2018
• Subjects: Temperature; Arctic; Norway; Alomar; Wüst
• Online Access: https://dx.doi.org/10.1594/wdcrsat.r3os740z; https://wdc.dlr.de/wdcservices/doi.php?doi=10.1594/WDCRSAT.R3OS740Z

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 9) located at the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR: 69.28°N, 16.01°E) – a measurement station of the international Network of Mesospheric Change (NDMC). The instrument 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. Since the initial data set recorded with 15 s temporal resolution is not strictly equidistant a one minute mean value is derived, if there are two or more high precision temperature values available within the respective interval of −30 s and +29.999 s around a UTC full minute time stamp. The corresponding precision of the one minute mean value follows from Gaussian error propagation and typically lies between ±2.5 K and ±8 K. Data were gathered at ALOMAR during each night between 23 Nov 2010 and 2 May 2014; no data are available during Arctic summer conditions. Thus, there are 934 nights of airglow observations available for this data set. : GRIPS 9 is equipped with a Czerny-Turner spectrograph and a thermoelectrically cooled InGaAs array. Only the P1(2), P1(3) and P1(4) rotational lines of the (3-1) vibrational transition are used for the derivation of temperatures. Intensities are only read out at the line centers of the smoothed spectra due to residual overlapping of the lines at their wings. Important physical constants applied during the processing are taken from Mies (1974) (Einstein coefficients) and Krassovsky et al. (1962) (rotational term values). Further details concerning the derivation of rotational temperatures are presented in Schmidt, C., Höppner, K. and Bittner, M. (2013): A ground-based spectrometer equipped with an InGaAs array for routine observations of OH(3-1) rotational temperatures in the mesopause region. Journal of Atmospheric and Solar-Terrestrial Physics (JASTP) 102 (2013) 125–139. https://dx.doi.org/10.1016/j.jastp.2013.05.001. Details concerning specifically the observations at ALOMAR are presented in Schmidt, C., Dunker, T., Lichtenstern, S., Scheer, J., Wüst, S. and Bittner, M. (2018): Derivation of vertical wavelengths of gravity waves in the MLT-region from multispectral airglow observations, JASTP, https://doi.org/10.1016/j.jastp.2018.03.002.