HR: 0800h
AN: SM51B-0537    [Abstracts]
TI: First Results on the Variability of Mid- and High-Latitude Ionospheric Electric Fields at 1- Second Time Scales
AU: * Ruohoniemi, J M
EM: mike.ruohoniemi@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 111000 Johns Hopkins Road, Laurel, MD 21042, United States
AU: Greenwald, R A
EM: ray.greenwald@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 111000 Johns Hopkins Road, Laurel, MD 21042, United States
AU: Oksavik, K
EM: kjellmar.oksavik@unis.no
AF: The University Centre in Svalbard, UNIS, Longyearbyen, XXX, Norway
AU: Baker, J B
EM: jo.baker@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 111000 Johns Hopkins Road, Laurel, MD 21042, United States
AB: The electric fields at high latitudes are often modeled as a static pattern in the absence of variation in solar wind parameters or geomagnetic disturbance. However, temporal variability in the local electric fields on time scales of minutes for stable conditions has been reported and characterized statistically as an intrinsic property amounting to turbulence. We describe the results of applying a new technique to SuperDARN HF radar observations of ionospheric plasma convection at middle and high latitudes that gives views of the variability of the electric fields at sub-second time scales. We address the question of whether there is a limit to the temporal scale of the electric field variability and consider whether the turbulence on minute time scales is due to organized but unresolved behavior. The basis of the measurements is the ability to record raw samples from the individual multipulse sequences that are transmitted during the standard 3 or 6–second SuperDARN integration period; a backscattering volume is then effectively sampled at a cadence of 200 ms. The returns from the individual sequences are often sufficiently well-ordered to permit a sequence-by-sequence characterization of the electric field and backscattered power. We attempt a statistical characterization of the variability at these heretofore inaccessible time scales and consider how variability is influenced by solar wind and magentospheric factors.
DE: 2437 Ionospheric dynamics
DE: 2463 Plasma convection (2760)
DE: 2704 Auroral phenomena (2407)
DE: 2712 Electric fields (2411)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting