Variations in the atmospheric composition and density during a geomagnetic storm
Document ID: 260
Philbrick, C. Russell1
McIsaac, J. P.1
Faucher, Gerard A.1
1 USAF, Geophysics Laboratory, Hanscom AFB, Bedford, MA, U.S.A.
Presented: 19th COSPAR Plenary Meeting
Philadelphia, Pennsylvania, June 8-19, 1976
Abstract
Data from a mass spectrometer, accelerometer, and density gauge during a geomagnetic storm are examined to study atmospheric variations in the region near 160 km. The storm reached a peak Kp of 7 and included a sustained period with Kp between 5 and 6. The density increased by more than 50% above quiet conditions at 160 km, and the O/N2 ratio varied from 1.1 to 0.3 during the storm period. Density increases at lower altitudes are caused by molecular nitrogen. Atomic oxygen exhibits variations during the storm period, but these do not contribute substantially to the mass-density changes at low altitudes. Argon exhibits strong variations during the geomagnetic storm, with increases exceeding a factor of 10 at 160 km. The composition variations, latitudinal structure, and atmospheric response indicate the importance of the thermospheric circulation system developed during geomagnetic-storm periods.
Keywords: atmospheric density, ionospheric composition, ionospheric disturbances, magnetic storms, accelerometer, Kp Index, mass spectroscopy, nitrogen, oxygen, satellite observation, thermosphere
| Citation: | "Variations in the atmospheric composition and density during a geomagnetic storm", Philbrick, C. R., J. P. McIsaac, G. A. Faucher, COSPAR (Committee on Space Research), June 1976, pp. 1 - 12 |