Accession Number : ADA140507

Title :   A Study of Geomagnetic Pulsations Using the AFGL (Air Force Geophysics Laboratory) Magnetometer Network.

Descriptive Note : Final rept. 15 Nov 80-14 Nov 83,

Corporate Author : BOSTON UNIV MA DEPT OF ASTRONOMY

Personal Author(s) : Hughes,W J ; Singer,H J ; Lester,M

PDF Url : ADA140507

Report Date : 13 Jan 1983

Pagination or Media Count : 56

Abstract : The objective of this work has been to study the midlatitude magnetic signatures of magnetospheric substorm onsets with the aim of using these signals to time and locate substorm onsets. The primary data source was the AFGL Magnetometer Network, a unique facility in that it spans over four hours in local magnetic time, a far greater extent than any other high-time-resolution network. Using this capability we have found that pi2 pulsation polarizations are ordered in longitude or local time. The direction of the major axis of the polarizations ellipse varies with longitude, and points due north on the central meridian of the D.C. substorm current system. We have made use of this pattern to locate particular substorms. We have also shown that substorm onset signatures near geostationary orbit are far more localized that at midlatitudes on the ground. The geostationary orbit signature is usually localized to within the two meridians on which the main substorm field-aligned currents flow, whereas the ground signature is usually seen over the entire nightside of the earth. The latter we have shown by using data from Northern Europe in conjunction with the AFGL data. In addition to these studies, we have also made some theoretical contributions and participated in two data analysis.

Descriptors :   *MAGNETIC STORMS, MAGNETOSPHERE, GEOMAGNETISM, POLARIZATION, VARIATIONS

Subject Categories : Geomagnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE