Geomagnetic-pulsation studies using the AFGL Magnetometer Network. Final Report, 1 Dec 1983-28 February 1987

Technical Report · Mon Jun 01 04:00:00 EDT 1987

OSTI ID:5965413

Hughes, W J

This contract funded a study of geomagnetic pulsations, the lowest-frequency waves that occur naturally in the Earth's magnetosphere. The study used as its primary data source the AFGL Magnetometer Network, which recorded midlatitude and subauroral magnetic variations continuously for six years. The major aim of the study was to develop Pi2 pulsations which occur at substorm onset, as monitors and locators of magnetospheric activity. Other aims of the study were to study the higher-frequency types of continuous pulsation, which are believed to be generated via ion-cyclotron resonance in the radiation belt, and to develop data management and analysis software. These latter aims were in preparation for the upcoming CRRES mission. The midlatitude Pi2's are in a reliable indicator of substorms and their polarization pattern provides a good method of finding the local time of the main activity of a particular substorm. For small isolated substorms the center of the polarization pattern and the center of the midlatitude geomagnetic bay pattern produce by the dc substorm currents, coincide, but during more disturbed intervals this is not always true, as consecutive bays are not well separated from one another. The midlatitude signatures spatially relate the other various signatures of substorm onset seen at geosynchronous orbit and in the auroral zone. The main auroral surge forms about an hour west of the center of the Pi2 polarization pattern and the longitude at which the surge forms separates the region of space near geosynchronous orbit where the geomagnetic field becomes more dipolar from that where it becomes more taillike.

• Research Organization: Boston Univ., MA (USA). Dept. of Astronomy
• OSTI ID: 5965413
• Report Number(s): AD-A-183748/3/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
CHARGED PARTICLES
CURRENTS
CYCLOTRON RESONANCE
DIRECT CURRENT
DISASTERS
ELECTRIC CURRENTS
GEOMAGNETIC FIELD
INDICATORS
IONS
MAGNETIC FIELDS
MAGNETIC STORMS
MAGNETOMETERS
MEASURING INSTRUMENTS
MONITORS
ORBITS
POLARIZATION
PULSATIONS
RADIATION BELTS
RELIABILITY
RESONANCE
STORMS