Observations of the seasonal dependence of the thermal plasma density in the Southern Hemisphere auroral zone and polar cap at 1 R (sub E)

M. T Johnson; J. R Wygant; C Cattell; F. S Mozer; M Temerin; J Scudder

doi:10.1029/2000JA900147

Back

Observations of the seasonal dependence of the thermal plasma density in the Southern Hemisphere auroral zone and polar cap at 1 R (sub E)

Journal article

Peer reviewed

Observations of the seasonal dependence of the thermal plasma density in the Southern Hemisphere auroral zone and polar cap at 1 R (sub E)

M. T Johnson, J. R Wygant, C Cattell, F. S Mozer, M Temerin and J Scudder

Journal of Geophysical Research, Vol.106, pp.19,023-19,033

09/01/2001

DOI: 10.1029/2000JA900147

View Online

Abstract

Synoptic maps of the thermal plasma density in the auroral zone and polar cap around 1 R (sub E ) altitude are produced from measurements of Polar spacecraft floating potential during 1 year of perigee passes. The densities are accurate to around a factor of 2 in this region of space. These measurements, which provide the first comprehensive maps of the thermal plasma density over the polar cap and auroral oval, show clear variations in plasma density due to solar illumination of the ionosphere. Number density increases by a factor of 5 for illuminated verses nonilluminated ionospheric conditions over the entire auroral oval and polar cap. The maps delineate the global extent of the large-scale auroral density cavity near 70 degrees + or - 5 degrees invariant latitude. These maps further show that the depth of the density cavity is strongly influenced by solar illumination. The minimum average density ( approximately 0.1 cm (super -3) ) occurs in darkness near 1900 magnetic local time. Copyright 2001 by the American Geophysical Union.

Antarctica

Ionosphere

Remote Sensing

Southern Hemisphere

auroral zone

magnetic field

mapping

Miscellaneous

polar caps

satellite methods

seasonal variations

solar illumination

spatial variations

thermal plasma density

Details

Title: Subtitle: Observations of the seasonal dependence of the thermal plasma density in the Southern Hemisphere auroral zone and polar cap at 1 R (sub E)
Creators: M. T Johnson - University of Minnesota
J. R Wygant - Physics and Astronomy (Twin Cities)
C Cattell - Physics and Astronomy (Twin Cities)
F. S Mozer - University of California, Berkeley
M Temerin - University of California, Berkeley
J Scudder - University of Iowa
Resource Type: Journal article
Publication Details: Journal of Geophysical Research, Vol.106, pp.19,023-19,033
DOI: 10.1029/2000JA900147
ISSN: 0148-0227
eISSN: 2156-2202
Publisher: American Geophysical Union
Language: English
Date published: 09/01/2001
Academic Unit: Physics and Astronomy
Record Identifier: 9984199835502771

Metrics

6 Record Views

27 Times Cited - Web of Science