Premium
Variations in the FUV dayglow after intense auroral activity
Author(s) -
Craven J. D.,
Nicholas A. C.,
Frank L. A.,
Strickland D. J.,
Immel T. J.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl02458
Subject(s) - thermosphere , earth's magnetic field , brightness , atmospheric sciences , morning , local time , airglow , ionosphere , astrophysics , physics , environmental science , geophysics , astronomy , magnetic field , mathematics , statistics , quantum mechanics
A localized ∼55% decrease is observed in the brightness of Earth's FUV dayglow in the morning sector at 130.4 nm after an interval of intense geomagnetic activity. This large decrease is interpreted as being the consequence of auroral‐associated heating which reduces the thermospheric column density of O relative to that of N 2 . Spatial extent of the observed decrease exceeds 10 7 km² at the −25% level, and the depth of the decrease lessens during more than two hours of observations. These remote observations provide the first instantaneous, two‐dimensional measurement of the large‐scale spatial extent of such a change in thermospheric composition.