LOCAL AND NON-LOCAL BEHAVIOUR OF SUBSTORM RADAR SIGNATURES

P. Eglitis¹, E. Boralv¹,U. Hager¹, H. J. Opgenoorth^1,2,
M. Uspensky^2,3

1. Swedish Institute of Space Physics, Uppsala, Sweden
2. Finnish Meteorological Institute, Helsinki, Finland
3. On leave from Murmansk State Technical University

Abstract:

Field-aligned irregularity backscatter radars have unique capabilities for studying magnetospheric substorms. They are a sensitive monitor of substorm growth phase features and, in contrast, challenging instruments for the study of substorm onset and expansion since this often leads to the loss of backscatter. A comparison is made between HF (CUTLASS Finland) and VHF (STARE) radar observations of local substorm features. In addition, substorms are now being considered as a more global magnetospheric process than before and ionospheric signatures are visible at other local times than just near the location of the substorm current wedge. Observations by SuperDARN of these non-local signatures are illustrated and discussed.