Coordinated satellite and ground-based study of an intense electron precipitation spike over the southern polar cap

Journal Article · Sun Dec 01 04:00:00 EST 1946 · J. Geophys. Res.; (United States)

OSTI ID:6047702

Imhof, W L; Reagan, J B; Voss, H D; Datlowe, D W; Kilner, J R; Gaines, E E; Mobilia, J; Rosenberg, T J; Lanzerotti, L J; Joiner, R G

An electron precipitation event has been investigated with bremsstrahlung X ray mapping data taken from two satellites and with ground-based riometer and magnetometer data. The event occurred near 2300 UT on June 27, 1982, in the vicinity of South Pole Station, which was in the dusk-midnight local time sector. The main precipitation was associated with a poleward-moving westward electrojet and produced the largest riometer absorption (exceeding 10 d at 30 MHz) recorded during 1982 at that station. The feature examined in detail here is an intense spike of approx.10 s duration and limited spatial extent that occcurred as a short-lived eastward ionospheric current developed equatorward of the west-ward electrojet. At the time of the spike, two sensors on the P78-1 satellite essentially simultaneously measured X rays from the region viewed by the ground-based instruments. Movement of the spike precipitation region toward the pole was indicated by the measurements. From ratios of the riometer absorption at different frequencies it is concluded that the spike precipitation region is consistent with a strip of width approx.25 km and length greater than 100 km. The total flux of the precipitating electrons in the spike was approx.4 x 10/sup 23/el/s(approx.2 x 10/sup 16/ ergs/s) with an e-fold energy of approx.40 keV. The fluxes and energy spectra of X rays emitted from a large area, as measured by the spacecraft, were about the same before and after the spike. However, following the spike there was a pronounced decrease in riometer absorption, which suggests a movement of the main precipitation region away from the south pole at that time.

• Research Organization: Lockheed Palo Alto Research Laboratory, California
• OSTI ID: 6047702
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 89:A12; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTARCTIC REGIONS
BREMSSTRAHLUNG
CHARGED-PARTICLE PRECIPITATION
CURRENTS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTROJETS
ELECTROMAGNETIC RADIATION
ELECTRON PRECIPITATION
ENERGY SPECTRA
IONOSPHERE
PLANETARY IONOSPHERES
POLAR CUSP
POLAR REGIONS
RADIATIONS
SPECTRA