Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
P. N. Collis; M. T. Rietveld (1998)
Publisher: Copernicus Publications
Journal: Annales Geophysicae
Languages: English
Types: Article
Subjects: Geophysics. Cosmic physics, Q, [ SDU.STU ] Sciences of the Universe [physics]/Earth Sciences, [ SDU.OCEAN ] Sciences of the Universe [physics]/Ocean, Atmosphere, Science, Physics, QC1-999, QC801-809

Classified by OpenAIRE into

arxiv: Physics::Space Physics, Physics::Atmospheric and Oceanic Physics
Mesospheric observations were obtained by the EISCAT UHF and VHF radars during the solar proton event of March 1990. We present the first comparison of incoherent-scatter spectral measurements from the middle mesosphere using simultaneous, co-located observations by the two radars. VHF spectra observed with a vertical antenna were found to be significantly narrower than model predictions, in agreement with earlier UHF results. For antenna pointing directions that were significantly away from the vertical, the wider VHF radar beam gave rise to broadening of the observed spectra due to vertical shears in the horizontal wind. In this configuration, UHF spectral measurements were found to be more suitable for aeronomical applications. Both radar systems provide consistent and reliable estimates of the neutral wind. Spectral results using both the multipulse and pulse-to-pulse schemes were intercompared and their suitability for application to combined mesosphere – lower thermosphere studies investigated.

Key words. Mesophere · Lower thermosphere · EISCAT UHF radar · EISCAT VHF radar
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Bauer, P., Theory of waves incoherently scattered, Phil. Trans. Roy. Soc., A280, 167±191, 1975.
    • Beynon, W. J. G. and P. J. S. Williams, Incoherent scatter of radio waves from the ionosphere, Rep. Prog. Phys., 41, 909±956, 1978.
    • Cho, J. Y. N., and J. R oÈttger, An updated review of polar mesosphere summer echoes: observation, theory, and their relationship to noctilucent clouds and subvisible aerosols, J. Geophys. Res., 102, 2001±2020, 1997.
    • Collis, P. N. and M. T. Rietveld, Mesospheric observations with the EISCAT UHF radar during polar cap absorption events: 1. Electron densities and negative ions, Ann. Geophysicae, 8, 809± 824, 1990.
    • Collis, P. N., and J. RoÈ ttger, Mesospheric measurements with the EISCAT UHF and VHF radars: a review of principles and experimental results, J. Atmos. Terr. Phys., 52, 569±584, 1990.
    • Collis, P. N., and J. R oÈttger, Correction to ``Mesospheric measurements with the EISCAT UHF and VHF radars: a review of principles and experimental results'', J. Atmos. Terr. Phys., 53, 463, 1991.
    • Collis, P. N., T. Turunen and E. Turunen, Evidence of heavy positive ions at the summer arctic mesopause from the EISCAT UHF incoherent- scatter radar, Geophys. Res. Lett., 15, 148± 151, 1988.
    • Collis, P. N., M. T. Rietveld, J. R oÈttger, and W. K. Hocking, Turbulence scattering layers in the middle-mesosphere observed by the EISCAT 224 MHz radar, Radio Sci., 27, 97±107, 1992.
    • Evans, J. V., Theory and practice of ionosphere study by Thomson scatter radar, Proc. IEEE, 57, 496±530, 1969.
    • Hall, C., U.-P. Hoppe, P.J.S. Williams, and G. O. L. Jones, Mesospheric measurements using the EISCAT VHF system: ®rst results and their interpretation, Geophys. Res. Lett., 14, 1187±1190, 1987.
    • Hansen, G., U-P. Hoppe, E. Turunen, and P. Pollari, Comparison of observed and calculated incoherent-scatter spectra from the D-region, Radio Sci., 26, 1153±1164, 1991.
    • Kofman, W., and C. Lathuillere, EISCAT multipulse technique and its contribution to auroral ionosphere and thermosphere description, J. Geophys. Res., 90, 3520±3524, 1985.
    • Kofman, W., F. Bertin, J. R oÈttger, A. Cremieux, and P. J. S. Williams, The EISCAT mesospheric measurements during the CAMP campaign, J. Atmos. Terr. Phys., 46, 565±575, 1984.
    • Mathews, J. D., Incoherent-scatter radar probing of the 60±100-km atmosphere and ionosphere, Proc. IEEE Trans. Geosc. Rem. Sensing, 24, 765±776, 1986.
    • Rietveld, M. T., and P. N. Collis, Mesospheric observations with the EISCAT UHF radar during polar cap absorption events: 2. spectral measurements, Ann. Geophysicae S, 11, 797±808, 1993.
    • Rietveld M. T., P. N. Collis and J. RoÈ ttger, Observations of atmospheric dynamics in the low- and middle-mesosphere with the EISCAT incoherent-scatter radar during solar proton events, Adv. Space Res., 12, (10)81±(10)84, 1992.
    • Solar Geophysical Data, Preliminary report and forecast of, SESC PRF 760, NOAA, 325 Broadway, Boulder, Colorado 80303± 3328, USA, 1990.
    • Turunen, E., EISCAT incoherent-scatter radar observations and model studies of day to twilight variations in the D-region during the PCA event of August, 1989, J. Atmos. Terr. Phys. 55, 767±781, 1993.
    • Turunen, E., Incoherent-scatter radar contributions to high-latitude D-region aeronomy, J. Atmos. Terr. Phys., 58, 707±725, 1996.
    • Turunen, E., P. N. Collis, and T. Turunen, Incoherent-scatter spectral measurements of the summertime high-latitude Dregion with the EISCAT UHF radar, J. Atmos. Terr. Phys., 50, 289±299, 1988.
    • Turunen, T., GEN-SYSTEM ± a new experimental philosophy for EISCAT radars, J. Atmos. Terr. Phys., 48, 777±785, 1986.
    • Turunen, T., and J. Sile n, Modulation patterns for the EISCAT incoherent scatter radar, J. Atmos. Terr. Phys., 46, 593±599, 1984.
    • Wu, Y.-F., H.-U. Widdel, and D. O€erman, First observation of a mesospheric wind shear as high as 330 m s)1km)1, Ann. Geophysicae, 13, 954±958, 1995.
  • No related research data.
  • No similar publications.