Variations in atmospheric composition and density during a geomagnetic storm
Document ID: 35
Philbrick, C. Russell1
McIsaac, J. P.1
Faucher, Gerard A.1
1 USAF, Geophysics Laboratory, Hanscom AFB, Bedford, MA, U.S.A.
Abstract
Data from a mass spectrometer, accelerometer and density gauge are examined during a geomagnetic storm to study the atmospheric variations in the region near 160 km. The S3-1 satellite perigee was located between 600N and 700N during the geomagnetic storm which reached a peak Kp of 7 and included a sustained period with Kp between 5 and 6. The density increased by more than 500 above quiet conditions at 160 km and the O/N2 ratio varied from 1.1 to 0.3 during the storm period. The density increases at lower altitudes are caused by molecular nitrogen. The atomic oxygen exhibits variations during the storm period but these changes do not contribute substantially to the mass density changes. The density of argon exhibits strong variations during a geomagnetic storm, with increases exceeding a factor of 10 at 160 km. Localized heating during the storm produces structure in both the total density and the density profiles of individual species, with the largest variations at highest geomagnetic latitudes. The composition variations, latitudinal structure, and atmospheric response indicate the importance of the thermospheric circulation system developed during geomagnetic storm periods.
Keywords: satellite instruments, mass spectrometer data, density, atmospheric dynamics, thermosphere
| Citation: | "Variations in atmospheric composition and density during a geomagnetic storm", Philbrick, C. R., J. P. McIsaac, G. A. Faucher, COSPAR SPACE RESEARCH, Vol. XVII, Pergamon Press, Oxford, United Kingdom, 1977, pp. 349 - 353 |