HR: 0800h
AN: SA21C-0362    [Abstracts]
TI: High latitude structuring of plasma patches: present and future
AU: * Guzdar, P N
EM: guzdar@umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742
AU: Gondarenko, N A
EM: ngondare@glue.umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742
AB: Results from the three-dimensional nonlinear simulations of the gradient drift instability to study structuring in high latitude plasma patches are presented. The high-resolution simulation data have a dynamic range that allows us to make detailed comparisons with the observed density and velocity fluctuation spectra. We use the measured ion density and horizontal velocity data from the Dynamic Explorer 2 (DE 2) spacecraft examined by Kivanc and Heelis [1997] to compare them with our simulations. We have demonstrated that the existence of the mesoscale structures on the edges and inside a patch is due to the nonlinear evolution of the gradient drift instability, which occurs initially on the trailing edge and penetrates through the entire patch. The magnitudes of the density and electric field fluctuations and their spectra were studied and compared with the simultaneous density and electric field spectra obtained from the noon-midnight and dawn-dusk orbit data of the DE 2 satellite [Basu et al., 1990]. The observed asymmetry in the simulated electric field spectra in these two directions was demonstrated. The spectral slope for the simulated density fluctuations is steeper when compared with the spectral index from the observations [Basu et al., 1990]. We will discuss the future directions for our simulations of mesoscale structures in high-latitude plasma patches.
DE: 2407 Auroral ionosphere (2704)
DE: 2439 Ionospheric irregularities
DE: 2475 Polar cap ionosphere
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting