Physics
Scientific paper
Dec 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufmsm24b..08d&link_type=abstract
American Geophysical Union, Fall Meeting 2010, abstract #SM24B-08
Physics
[2407] Ionosphere / Auroral Ionosphere, [2431] Ionosphere / Ionosphere/Magnetosphere Interactions, [2439] Ionosphere / Ionospheric Irregularities, [2736] Magnetospheric Physics / Magnetosphere/Ionosphere Interactions
Scientific paper
During periods of intense geomagnetic activity, strong electric fields and currents penetrate from the magnetosphere into the high-latitude E region ionosphere where they dissipate a significant fraction of their energy. In this region, electrons are magnetized while ions are demagnetized due to frequent collisions with the neutral atmosphere causing the strong electric fields to generate intense electrojets that excite plasma instabilities. These instabilities give rise to plasma density turbulence coupled to electrostatic field fluctuations, which, in turn, induce nonlinear currents and strong anomalous electron heating. These two effects modify the global ionospheric conductances that play an important role in magnetosphere-ionosphere coupling. Our recent theoretical analysis, along with 2-D and 3-D fully kinetic, particle-in-cell, massively-parallel, computer simulations allow one to quantify the energy deposition in the ionosphere, particle heating, and effects of the anomalous conductivities. Figures below show examples of theoretically predicted anomalous Pedersen conductivities for two values of strong convection electric field. The regular Pedersen conductivity is modified by ionospheric irregularities which are generated by the Farley-Buneman instability. Our estimates show that during strong geomagnetic storms the inclusion of the instability-induced anomalous effects may double the total Pedersen conductance. This helps explain why existing global MHD codes developed for predictive modeling of space weather systematically overestimate the cross-polar cap potentials by approximately a factor of two. Altitude profiles of a theoretically predicted anomalous Pedersen conductivity for two values of the convection electric field. Curves 0 show the regular conductivities; curves 1 include the effect of a nonlinear current caused by instability-driven density irregularities; curves 2 additionally include plasma density elevation due to recombination changes in the anomalously heated E-region ionosphere.
Dimant Ya. S.
Oppenheim Meers M.
No associations
LandOfFree
Magnetosphere-Ionosphere Coupling: Effects of E-Region Plasma Turbulence on Ionospheric Conductances 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 Magnetosphere-Ionosphere Coupling: Effects of E-Region Plasma Turbulence on Ionospheric Conductances, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetosphere-Ionosphere Coupling: Effects of E-Region Plasma Turbulence on Ionospheric Conductances will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1470036