HR: 0800h
AN: SA31A-0365 [Abstracts]
TI: Observations of isolated polar cap patches by the EISCAT Svalbard and SuperDARN Finland
radars
AU: Moen, J I
SA31A-0365
AF: Department of Physics, University of Oslo, P.O.Box 1048, Blindern, OSLO, N-0316
Norway
AU: * Oksavik, K
EM: kjellmar.oksavik@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, Mailstop MP3-W189,
11100 Johns Hopkins Road, Laurel, MD 20723
United States
AU: Ruohoniemi, J M
SA31A-0365
AF: Johns Hopkins University Applied Physics Laboratory, Mailstop MP3-W189,
11100 Johns Hopkins Road, Laurel, MD 20723
United States
AU: Greenwald, R A
SA31A-0365
AF: Johns Hopkins University Applied Physics Laboratory, Mailstop MP3-W189,
11100 Johns Hopkins Road, Laurel, MD 20723
United States
AU: Baker, J B
SA31A-0365
AF: Johns Hopkins University Applied Physics Laboratory, Mailstop MP3-W189,
11100 Johns Hopkins Road, Laurel, MD 20723
United States
AU: Carlson, H C
SA31A-0365
AF: AFOSR, 875 North Randolph Street, Arlington, VA 22203
United States
AU: Yeoman, T K
SA31A-0365
AF: Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH
United Kingdom
AU: Lester, M
SA31A-0365
AF: Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH
United Kingdom
AB:
In this paper we present new observations of the F-region cusp ionosphere from the SuperDARN Finland and EISCAT Svalbard
radars in a new joint experiment. On 16 December 2002 the EISCAT Svalbard radar was operated in a fast elevation scan along
beam 9 of the SuperDARN Finland radar giving altitude/latitude profiles of the SuperDARN Finland backscatter volume every two
minutes. Combining the two independent data sets we monitor the formation of an isolated polar cap patch of high electron
density (1011.5 m-3) that slowly formed in the dark cusp ionosphere during an interval of northward interplanetary
magnetic field. The patch formed on a stirred lobe cell, excluding the possibility for solar EUV ionized plasma to drift in
from the south. This data set represents an unparalleled example of patch formation within the polar cap, locally by particle
impact ionization. After the interplanetary magnetic field turned southward and By changed polarity the patch started to
move poleward into the polar cap. Enhanced velocity gave rise to enhanced HF backscatter power and enhanced spectral widths,
consistent with gradient drift instability as the formation mechanism of HF backscatter targets.
DE: 2407 Auroral ionosphere (2704)
DE: 2455 Particle precipitation
DE: 2467 Plasma temperature and density
DE: 2475 Polar cap ionosphere
DE: 2706 Cusp
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005