Blar i forfatter "Dunker, Tim"

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    • The airglow layer emission altitude cannot be determined unambiguously from temperature comparison with lidars 

      Dunker, Tim (Journal article; Peer reviewed; Tidsskriftartikkel, 2018)
      I investigate the nightly mean emission height and width of the OH*(3–1) layer by comparing nightly mean temperatures measured by the ground-based spectrometer GRIPS 9 and the Na lidar at ALOMAR. The data set contains 42 coincident measurements taken between November 2010 and February 2014, when GRIPS 9 was in operation at the ALOMAR observatory (69.3° N, 16.0° E) in northern Norway. To closely ...

    • Corrigendum to "Development of the mesospheric Na layer at 69 degrees N during the Geminids meteor shower 2010", published in Ann.Geophys., 31, 61-73, 2013 

      Dunker, Tim; Hoppe, Ulf-Peter; Stober, Gunter; Rapp, Markus (Journal article; Tidsskriftartikkel; Peer reviewed, 2015)

    • Derivation of vertical wavelengths of gravity waves in the MLT-region from multispectral airglow observations 

      Schmidt, Carsten; Dunker, Tim; Lichtenstern, Sabrina; Scheer, Jürgen; Wüst, Sabine; Hoppe, Ulf-Peter; Bittner, Michael (Journal article; Tidsskriftartikkel; Peer reviewed; Preprint; Manuskript, 2018-03-06)
      <p>We present the derivation of gravity wave vertical wavelengths from OH airglow observations of different vibrational transitions. It utilizes small phase shifts regularly observed between the OH(3-1) and OH(4-2) intensities in the spectra of the GRIPS (GRound-based Infrared P-branch Spectrometer) instruments, which record the OH airglow emissions in the wavelength range from 1.5  μm to 1.6  μm ...

    • Development of the mesospheric Na layer at 69 degrees N during the Geminids meteor shower 2010 

      Dunker, Tim; Hoppe, Ulf-Peter; Stober, Gunter; Rapp, Markus (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      The ECOMA sounding rocket campaign in 2010 was performed to investigate the charge state and number density of meteoric smoke particles during the Geminids meteor shower in December 2010. The ALOMAR Na lidar contributed to the campaign with measurements of sodium number density, temperature and line-of-sight wind between 80 and 110 km altitude over Andøya in northern Norway. This paper ...

    • Mesospheric temperatures and sodium properties measured with the ALOMAR Na lidar compared with WACCM 

      Dunker, Tim; Hoppe, Ulf-Peter; Feng, Wuhu; Plane, John M.C.; Marsh, Daniel R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-16)
      We present a comparison of the temperature and sodium layer properties observed by the ALOMAR Na lidar (69.3°N, 16.0°E) and simulated by the Whole Atmosphere Community Climate Model with specified dynamics and implemented sodium chemistry (WACCM-Na). To constrain the meteorological fields below 60 km, we use MERRA and GEOS-5. For the years 2008 to 2012, we analyse daily averages of temperature ...

    • Retrieval of sodium number density profiles in the mesosphere and lower thermosphere from SCIAMACHY limb emission measurements 

      Langowski, M.P.; von Savigny, C.; Burrows, J.P.; Rozanov, V.V.; Dunker, Tim; Hoppe, Ulf-Peter; Sinnhuber, M; Aikin, A.C. (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-28)
      An algorithm has been developed for the retrieval of sodium atom (Na) number density on a latitude and altitude grid from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) limb measurements of the Na resonance fluorescence. The results are obtained between 50 and 150 km altitude and the resulting global seasonal variations of Na are analyzed. The retrieval approach ...

    • Simultaneous observations of a Mesospheric Inversion Layer and turbulence during the ECOMA-2010 rocket campaign 

      Szewczyk, Artur; Strelnikov, Boris; Rapp, Markus; Strelnikova, Irina; Baumgarten, Gerd; Kaifler, Natalie; Dunker, Tim; Hoppe, Ulf-Peter (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      From 19 November to 19 December 2010 the fourth and final ECOMA rocket campaign was conducted at Andøya Rocket Range (69 N, 16 E) in northern Norway. We present and discuss measurement results obtained during the last rocket launch labelled ECOMA09 when simultaneous and true common volume in situ measurements of temperature and turbulence supported by ground-based lidar observations reveal ...

    • Spatial and temporal variability in MLT turbulence inferred from in situ and ground-based observations during the WADIS-1 sounding rocket campaign 

      Strelnikov, Boris; Szewczyk, Artur; Strelnikova, Irina; Latteck, Ralph; Baumgarten, Gerd; Lübken, Franz-Josef; Rapp, Markus; Fasoulas, Stefanos; Löhle, Stefan; Eberhart, Martin; Hoppe, Ulf-Peter; Dunker, Tim; Friedrich, Martin; Hedin, Jonas; Khaplanov, Mikhail; Gumbel, Jörg; Barjatya, Aroh (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-10)
      In summer 2013 the WADIS-1 sounding rocket campaign was conducted at the Andøya Space Center (ACS) in northern Norway (69 N, 16 E). Among other things, it addressed the question of the variability in mesosphere/lower thermosphere (MLT) turbulence, both in time and space. A unique feature of the WADIS project was multi-point turbulence sounding applying different measurement techniques including ...