HR: 0800h
AN: SA31A-0363    [Abstracts]
TI: Comparison of Plasma Velocities derived by the EISCAT Svalbard Radar and the SuperDARN Network
AU: * Loevhaug, U P
EM: Unni.Pia.Lovhaug@phys.uit.no
AF: University of Tromsoe, Auroral Observatory, Tromsoe, 9037 Norway
AU: Moen, M N
EM: mariann@phys.uit.no
AF: University of Tromsoe, Auroral Observatory, Tromsoe, 9037 Norway
AU: van Eyken, A P
EM: tony.van.eyken@eiscat.se
AF: EISCAT Scientific Association, PO Box 432, Longyearbyen, 9171 Norway
AU: Gallop, P
EM: p.gallop@rl.ac.uk
AF: Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX United Kingdom
AU: Grocott, A
EM: a.grocott@ion.le.ac.uk
AF: Leicester University, University Road, Leicester, LE1 7RH United Kingdom
AU: Stroemme, A
EM: anja.stromme@eiscat.se
AF: EISCAT Scientific Association, PO Box 432, Longyearbyen, 9171 Norway
AB: A systematic difference between high latitude measured plasma convection velocities determined by the EISCAT Svalbard Radar and those routinely produced by the SuperDARN network has been detected using data from a period where both systems provided data over a substantial interval. The EISCAT Svalbard Radar was operated continuously for one month in October and November 2002 using a mode which combined a cycle of three local measurements on the steerable 32m antenna with interleaved measurements on the fixed, 42m, field-aligned antenna. The three, non-field aligned, line of sight velocity estimates were combined using a general purpose computer code (VELCOM) to derive field aligned and field perpendicular velocity components. The field perpendicular component was then compared directly with the corresponding velocities interpolated from SuperDARN high latitude convection plots. A systematic difference between the two velocities estimates is evident, with the greatest differences being found in the morning sector. The differences appear to arise from the choice of magnetic field models chosen to organise the two data sets. The observed discrepancies are most severe when the chosen models differ over the local azimuth of magnetic north. Casting the EISCAT Svalbard Radar data into the co-ordinate system routinely used in the SuperDARN maps results in close agreement, but the implications in terms of the local appearance of e.g. cusp related flows requires careful evaluation.
DE: 2447 Modeling and forecasting
DE: 2475 Polar cap ionosphere
DE: 2494 Instruments and techniques
DE: 2760 Plasma convection (2463)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005