Berlin 2005 – wissenschaftliches Programm
EP 1.7: Vortrag
Freitag, 4. März 2005, 11:30–11:45, TU BH349
Energy Conversion in the Auroral Magnetosphere — •Octav Marghitu1,2, Maria Hamrin3, Berndt Klecker1, Mats André4, Stephan Buchert4, James McFadden5, and Hans Vaith1 — 1Max-Planck-Institut für extraterrestrische Physik, Garching, Germany — 2Institute for Space Sciences, Bucharest, Romania — 3Physics Department, University of Umeå, Sweden — 4Swedish Institute of Space Physics, Uppsala, Sweden — 5Space Sciences Lab., University of California at Berkeley, USA
The energy dissipated in the auroral ionosphere is believed to come from generator regions located far away in the magnetosphere. Several studies have addressed the auroral generator by using analytical, semi-analytical, and numerical tools. However, in the literature there is a lack of observational investigations of the generator region; for example, to our knowledge, an analysis of the power density, E·J (with E the electric field and J the current density vector), is missing.
In this paper we examine conjugated night-side data from the four CLUSTER satellites (in the magnetotail, at an altitude of ∼20 RE) and the FAST satellite (above the auroral oval, at ∼0.5 RE). Because of its four simultaneous measuring points, CLUSTER makes possible the complete evaluation of J; in addition, we use estimates of E from two different instruments, which improves on the reliability of these data. At the same time FAST offers a ’snapshot’ over the electron precipitation and energy flux into the ionosphere.