Observations of auroral breakup.

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...

Observations of Auroral Plasma Lines

AKR breakup and auroral particle acceleration at substorm onset

[1] The dynamical behavior of auroral kilometric radiation (AKR) is investigated in connection with auroral particle acceleration at substorm onsets using high-time-resolution wave spectrograms provided by Polar/PWI electric field observations. AKR develops explosively at altitudes above a preexisting low-altitude AKR source at substorm onsets. This ‘‘AKR breakup’’ suggests an abrupt formation ...

First VHF auroral radarinterferometer observations

The radar interferometer technique on two separate antennas. The coherence first used at the magnetic equator in Peru is (amplitude) of the cross spectrum at each also a very powerful means for studying auroral frequency is a measure of how localized the plasma instabilities. We present here the first scattering target corresponding to that results, obtained with a 49.92 MHz, 20-25 KW peak part...

Wilson Bentley’s Auroral Observations S

Wilson Bentley’s aurora1 observations in northern Vermont were made over the period from 1883 to 1931, thus encompassing the solar activity minimum at the beginning of the twentieth century. Long term series of aurora1 observations by a single observer in a region of reasonable frequency of occurrence are rare, and are important for the study of solar-terrestrial relationships. Bentley’s data h...