Accession Number : AD0721200

Title :   Types Pc 1-2 and IPDP Micropulsations at the Auroral Zone.

Descriptive Note : Final rept. 1 Nov 67-31 Oct 70,

Corporate Author : ALASKA UNIV COLLEGE GEOPHYSICAL INST

Personal Author(s) : Heacock,Richard R.

Report Date : JAN 1971

Pagination or Media Count : 128

Abstract : A micropulsation recording program was carried out at College and Anchorage, Alaska and at Bar I, Canada, with induction magnetometers. The analysis program centered mainly on synoptic and polarization characteristics for types Pc 1-2, IPDP, and Pi burst micropulsation events. Summaries of the known morphological features for structured Pc 1 and structured Pc 1-2 micropulsations are given. The synoptic studies disclosed latitude relationships between unstructured Pc 1-2, IPDP, and Pi burst events. At the onset of a polar substorm, Pi bursts occur near midnight at 65 degrees - 70 degrees geomagnetic latitudes. IPDP events follow the Pi burst and are seen in evening hours at 60 degrees - 65 degrees latitudes. IPDP events seen in afternoon hours are often preceded by unstructured Pc 1-2 activity which maximizes a few degrees polewards of the IPDP. The IPDP events are seen in the evening bulge region of the plasmasphere. The proton plasma requirement for IPDP wave generation suggests that protons which are injected near midnight in the Pi burst event drift westwards into the bulge and generate unstructured Pc 1-2 and IPDPs there. (Author)

Descriptors :   (*MAGNETOSPHERE, *MAGNETIC STORMS), (*IONOSPHERIC DISTURBANCES, MAGNETIC STORMS), AURORAE, MAGNETOMETERS, SPECTRUM ANALYZERS, GRAPHICS, ALASKA, CANADA

Subject Categories : Atmospheric Physics
      Geomagnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE