Volumes and Issues  Contents of Issue 10  Special Issue

Ann. Geophys., 16, 1355-1366, 1998
www.ann-geophys.net/16/1355/1998/
© European Geosciences Union 1998

Mesospheric observations with the EISCAT UHF radar during polar cap absorption events:
3. Comparison with simultaneous EISCAT VHF measurements

P. N. Collis¹ and M. T. Rietveld^2
1EISCAT Scientific Association, Box 812, S-981 28 Kiruna, Sweden
²EISCAT Scientific Association, Ramfjordmoen, N-9020 Tromsdalen, Norway

Abstract. 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

Full Article (PDF, 476 KB)

Citation: Collis, P. N. and Rietveld, M. T.: Mesospheric observations with the EISCAT UHF radar during polar cap absorption events:
3. Comparison with simultaneous EISCAT VHF measurements, Ann. Geophys., 16, 1355-1366, 1998.   Bibtex   EndNote   Reference Manager