posted on 2017-01-24, 10:17authored byA. V. Koustov, D. W. Danskin, M. V. Uspensky, T. Ogawa, P. Janhunen, N. Nishitani, S. Nozawa, M. Lester, S. Milan
Two Doppler coherent radar systems are currently working at Hankasalmi, Finland, the STARE and CUTLASS radars operating at ~144 MHz and ~12 MHz, respectively. The STARE beam 3 is nearly co-located with the CUTLASS beam 5, providing an opportunity for echo velocity comparison along the same direction but at significantly different radar frequencies. In this study we consider an event when STARE radar echoes are detected at the same ranges as CUT-LASS radar echoes. The observations are complemented by EISCAT measurements of the ionospheric electric field and electron density behaviour at one range of 900 km. Two separate situations are studied; for the first one, CUTLASS observed F-region echoes (including the range of the EIS-CAT measurements), while for the second one CUTLASS observed E-region echoes. In both cases STARE E-region measurements were available. We show that F-region CUT-LASS velocities agree well with the convection component along the CUTLASS radar beam, while STARE velocities are typically smaller by a factor of 2–3. For the second case, STARE velocities are found to be either smaller or larger than CUTLASS velocities, depending on the range. Plasma physics of E-and F-region irregularities is discussed in attempt to explain the inferred relationship between various velocities. Special attention is paid to ionospheric refraction that is important for the detection of 12-MHz echoes.
Funding
CUTLASS Finland radar is supported by
PPARC, the Swedish Institute for Space Physics, Uppsala, and the
Finnish Meteorological Institute. The STARE system is operated
jointly by the Max Plank Institute for Aeronomie, Germany, and
the Finnish Meteorological Institute, Finland, in cooperation with
SINTEF, University of Trondheim, Norway. EISCAT is an international
facility supported by Finland, France, Germany, Japan, Norway,
Sweden and the UK. Data of the Sodankyla ionosonde are
acknowledged. A. V. K. acknowledges the Solar-Terrestrial Environment
Laboratory of Nagoya University for funding during his
stay in Japan. The work was also supported by Academy of Finland
to M.V.U.
History
Citation
Annales Geophysicae, 2002, 20 (10), pp. 1647-1661 (15)
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
Version
VoR (Version of Record)
Published in
Annales Geophysicae
Publisher
European Geosciences Union (EGU), Copernicus Publications, Springer Verlag (Germany)