Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.490 IF 1.490
  • IF 5-year value: 1.445 IF 5-year
    1.445
  • CiteScore value: 2.9 CiteScore
    2.9
  • SNIP value: 0.789 SNIP 0.789
  • IPP value: 1.48 IPP 1.48
  • SJR value: 0.74 SJR 0.74
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 88 Scimago H
    index 88
  • h5-index value: 21 h5-index 21
Volume 16, issue 10
Ann. Geophys., 16, 1180–1189, 1998
https://doi.org/10.1007/s00585-998-1180-9
© European Geosciences Union 1998

Special issue: VIIIe EISCAT

Ann. Geophys., 16, 1180–1189, 1998
https://doi.org/10.1007/s00585-998-1180-9
© European Geosciences Union 1998

  31 Oct 1998

31 Oct 1998

Application of tomographic inversion in studying airglow in the mesopause region

T. Nygrén1, M. J. Taylor2, M. S. Lehtinen3, and M. Markkanen3 T. Nygrén et al.
  • 1Department of Physical Sciences, University of Oulu, FIN-90570 Oulu, Finland
  • 2Space Dynamics Laboratory and Physics Department, Utah State University, Logan, UT, 84322, USA
  • 3Sodankylä Geophysical Observatory, FIN-99600 Sodankylä , Finland

Abstract. It is pointed out that observations of periodic nightglow structures give excellent information on atmospheric gravity waves in the mesosphere and lower thermosphere. The periods, the horizontal wavelengths and the phase speeds of the waves can be determined from airglow images and, using several cameras, the approximate altitude of the luminous layer can also be determined by triangulation. In this paper the possibility of applying tomographic methods for reconstructing the airglow structures is investigated using numerical simulations. A ground-based chain of cameras is assumed, two-dimensional airglow models in the vertical plane above the chain are constructed, and simulated data are calculated by integrating the models along a great number of rays with different elevation angles for each camera. After addition of random noise, these data are then inverted to obtain reconstructions of the models. A tomographic analysis package originally designed for satellite radiotomography is used in the inversion. The package is based on a formulation of stochastic inversion which allows the input of a priori information to the solver in terms of regularization variances. The reconstruction is carried out in two stages. In the first inversion, constant regularization variances are used within a wide altitude range. The results are used in determining the approximate altitude range of the airglow structures. Then, in the second inversion, constant non-zero regularization variances are used inside this region and zero variances outside it. With this method reliable reconstructions of the models are obtained. The number of cameras as well as their separations are varied in order to find out the limitations of the method.

Key words. Tomography · Airglow · Mesopause · Gravity waves

Publications Copernicus
Special issue
Download
Citation