Physics
Scientific paper
May 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002agusmsm21b..04n&link_type=abstract
American Geophysical Union, Spring Meeting 2002, abstract #SM21B-04
Physics
7843 Numerical Simulation Studies, 7863 Turbulence, 2407 Auroral Ionosphere (2704), 2411 Electric Fields (2712), 2451 Particle Acceleration
Scientific paper
Recent 1-D open boundary simulations and their theoretical interpretation have demonstrated that a strong double layer can develop from a density depression in an initially field-free current-carrying plasma.1 The unipolar field of the double layer accelerates particles into unstable distributions which drive waves. The waves in turn saturate by trapping, leading to phase space holes and corresponding turbulent parallel bipolar fields. The electric fields generated in these 1-D simulation agree surprisingly well with recent FAST measurements2 in the downward current region of the auroral ionosphere. Despite this agreement between the simulations and the observations, it is desirable to verify and generalize these findings to higher dimensions. We present preliminary results of simulations and theoretical studies in 2-D with emphasis on spatial variation in the direction perpendicular to the geomagnetic field. These 2-D studies include simulations that address the coherence and stability of electron phase space holes with structure perpendicular to B and the effects of velocity shear on the formation of electron holes. Results of theoretical studies of the instability of low frequency magnetized waves---such as ion cyclotron waves---and how these instabilities might affect ion hole formation3 will also be presented. Challenges involved in future 2-D simulations will be discussed---including issues associated with initial and boundary conditions. Research supported by NSF, NASA, and DOE. 1 D. L. Newman, M. V. Goldman, R. E. Ergun, and A. Mangeney, Phys.~Rev.~Lett.}, 87, 255001 (2001). 2 R. E. Ergun, et al., Phys.~Rev.~Lett.}, 87, 045003 (2001). 3 M. V. Goldman, D. L. Newman, and R. E. Ergun, ``Phase-space holes due to electron and ion beams accelerated by a current-driven potential ramp,'' Nonlin.~Process.~Geophys.}, in press (2002).
Ergun Robert E.
Goldman Martin V.
Newman D. L.
No associations
LandOfFree
Double Layers, Phase-Space Holes, and Waves in the Auroral Downward-Current Region does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Double Layers, Phase-Space Holes, and Waves in the Auroral Downward-Current Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Double Layers, Phase-Space Holes, and Waves in the Auroral Downward-Current Region will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1724126