Location of Repository

Observations by the CUTLASS radar, HF Doppler, oblique ionospheric sounding, and TEC from GPS during a magnetic storm

By D. V. Blagoveshchensky, M. Lester, V. A. Kornienko, I. I. Shagimuratov, A. J. Stocker and E. Michael Warrington

Abstract

Multi-diagnostic observations, covering a significant area of northwest Europe, were made during the magnetic storm interval (28–29 April 2001) that occurred during the High Rate SolarMax IGS/GPS-campaign. HF radio observations were made with vertical sounders (St. Petersburg and Sodankyla), oblique incidence sounders (OIS), on paths from Murmansk to St. Petersburg, 1050 km, and Inskip to Leicester, 170 km, Doppler sounders, on paths from Cyprus to St. Petersburg, 2800 km, and Murmansk to St. Petersburg, and a coherent scatter radar (CUTLASS, Hankasalmi, Finland). These, together with total electron content (TEC) measurements made at GPS stations from the Euref network in northwest Europe, are presented in this paper. A broad comparison of radio propagation data with ionospheric data at high and mid latitudes, under quiet and disturbed conditions, was undertaken. This analysis, together with a geophysical interpretation, allow us to better understand the nature of the ionospheric processes which occur during geomagnetic storms. The peculiarity of the storm was that it comprised of three individual substorms, the first of which appears to have been triggered by a compression of the magnetosphere. Besides the storm effects, we have also studied substorm effects in the observations separately, providing an improved understanding of the storm/substorm relationship. The main results of the investigations are the following. A narrow trough is formed some 10h after the storm onset in the TEC which is most likely a result of enhanced ionospheric convection. An enhancement in TEC some 2–3 h after the storm onset is most likely a result of heating and upwelling of the auroral ionosphere caused by enhanced currents. The so-called main effect on ionospheric propagation was observed at mid-latitudes during the first two substorms, but only during the first substorm at high latitudes. Ionospheric irregularities observed by CUTLASS were clearly related to the gradient in TEC associated with the trough. The oblique sounder and Doppler observations also demonstrate differences between the mid-latitude and high-latitude paths during this particular storm

Publisher: European Geosciences Union (EGU)
Year: 2005
DOI identifier: 10.5194/angeo-23-1697-2005
OAI identifier: oai:lra.le.ac.uk:2381/7404

Suggested articles

Preview

Citations

  1. (1997). CUTLASS − A tool for co-ordinated Cluster/Ground Based investigations of the Solar Terrestrial System,
  2. (1995). Darn/Superdarn: A global view of the dynamics of high-latitude convection, doi
  3. (2003). Effect of solar wind pressure pulses on the size and strength of the auroral oval, doi
  4. (1994). et al.: What is a geomagnetic storm?, doi
  5. (1992). High-latitude ionospheric phenomena diagnostics by highfrequency radio wave propagation observations, doi
  6. (2002). In: book of abstracts of the International conference on problems of geocosmos,
  7. (1982). Interference methods in ionospheric radio sounding.
  8. (2003). Ionosphere dynamics over Europe and western Asia during magnetospheric substorms 1998–1999, doi
  9. (1999). Ionospheric storms − a review,
  10. (1995). Ionospheric wave processes during HF heating experiments, doi
  11. (2002). Monitoring and forecasting of ionospheric space weather - effects of geomagnetic storms, doi
  12. (1998). Observation of the reduction in the available HF band on four highlatitude paths during periods of geomagnetic disturbance, doi
  13. (1996). Preand after substorm situations in the ionosphere and decameter radio wave propagation (in Russian),
  14. (2000). Substorm effects of ionosphere and HF propagation, doi
  15. (2003). The high-latitude ionosphere and its effects on radio propagation. doi
  16. (2000). The synthesis of travelling ionospheric disturbance (TID) signatures in HF radar observations using ray tracing, doi
  17. (2004). The time-of-flight and direction of arrival of HF radio signals received over a path along the mid-latitude trough: theoretical considerations, Radio Science, doi
  18. (2004). The time-offlight and direction of arrival of HF radio signals received over a path along the mid-latitude trough: observations, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.