Auroral Phenomena

Particle Acceleration and Wave Phenomena in the Auroral Region

1 I n t r o d u c t i o n The auroral region of the terrestrial magnetosphere is a fascinating part of space, and also a part that can be investigated in some detail with satellites, sounding rockets and groundbased instruments. The second EGS Alfv~n conference held in Stockholm May 3-7 1999 was devoted to auroral particle acceleration and related topics. This meeting produced a variety of inte...

Luminosity variations in several parallel auroral arcs before auroral breakup

Variation of the luminosity in two parallel auroral arcs before auroral breakup has been studied by using digitised TV-data with high temporal and spatial resolution. The intervals when a new arc appears near already existing one were chosen for analysis. It is shown, for all cases, that the appearance of a new arc is accompanied by fading or disappearance of another arc. We have named these ev...

Section III Auroral Region

Jupiter’s polar auroral emissions

[1] This paper reports a study of Jupiter’s polar auroral emissions observed in an extended series of FUV images. They were obtained on seven days, during winter 2000–2001, with the STIS camera on board the Hubble Space Telescope. The fixed pointing yielded highly accurate and consistent tracking of emisson features as Jupiter rotated, allowing the analysis of the auroral morphology and brightn...

Phenomena in the ionosphere-magnetosphere system induced by injection of powerful HF radio waves into nightside auroral ionosphere

Experimental results from three ionospheric HF pumping experiments in overdense E or F regions are summarized. The experiments were conducted by the use of the EISCAT HF Heating facility located near Tromsø, Norway, allowing HF pumping the ionosphere in a near geomagnetic field-aligned direction. Distinctive features related to auroral activations in the course of the experiments are identified...