Optical emissions and ionization profiles during an intense pulsating aurora

Journal Article · Sat Aug 01 00:00:00 EDT 1981 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA086iA08p06853· OSTI ID:5881148

Sears, R D; Vondrak, R R

Coordinated spectrophotometric and incoherent scatter radar measurements were made of an intense early-morning pulsating aurora at Chatanika, Alaska. Both instruments were operated simultaneously with temporal resolution of 1 s and were boresighted at geomagnetic zenith. The goals of the collaborative experimental were to determine the total energy flux E/sub t/ and the characteristic energy parameter ..cap alpha.. of the precipitating electrons on a time scale smaller than the pulsation duration and to investigate the response of the ionospheric electron density on a comparable time scale. The relationship between total energy flux and the characteristic energy parameter suggests that during these observations the pulsations were caused by a modulation of ..cap alpha.. rather than by a modulation of the total precipitating particle flux. The values of E/sub t/ and ..cap alpha.. derived from photometric data were used to model the electron density versus altitude in the ionosphere for comparison with the incoherent scatter radar measurements. Measured altitude profiles of ionization did not change significantly on the time scale of the pulsations. The E region maximum electron density typically was 7 x 10/sup 5/ at an altitude of 99 km. Variations in ionospheric conductivity were less than 15% on the pulsation time scale. These results suggest that a magnetospheric modulation mechanism is required to explain diffuse pulsating auroras.

• Research Organization: Lockheed Palo Alto Research Laboratories, Palo Alto, California 94304
• OSTI ID: 5881148
• Journal Information: J. Geophys. Res.; (United States), Vol. 86:A8
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
PULSATIONS
ALTITUDE
CHARGED-PARTICLE PRECIPITATION
ELECTRIC CONDUCTIVITY
ELECTRON DENSITY
ION DENSITY
IONOSPHERE
MAGNETOSPHERE
EARTH ATMOSPHERE
ELECTRICAL PROPERTIES
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena