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Heacock, R. R.

Publications and source records attributed to Heacock, R. R..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Midday Pc 1-2 pulsations observed at a subcleft location

A class of unstructured Pc 1-2 pulsation activity, as identified on Bar I (70.2 N) records taken during 1968-1972, is found to be present in midday hours on about half of the days in summer months. The events have some tendency to occur in the later part of the ring current recovery phase, especially at times of moderate AE when the cleft lines are just poleward of Bar I. The source lines of the Pc 1-2 are found to lie essentially outside the plasmapause. In terms of the proton cyclotron resonance instability the most likely source regions of the Bar I Pc 1-2 are the detached plasma regions convecting sunward on the dayside and the portion of the cleft plasma on the last closed field lines.

Heacock, R. R.↗
NASA NTRS1971

Correlations of OGO-V plasmapause crossing with observations of type Pi micropulsations on the ground.

Comparison of plasmapause positions with Pi micropulsation events observed at College (L 5.4) or at Sodankyla (L 5.1), showing that in almost all cases the plasmapause was inside the field line of the observing site when the Pi event was recorded. Strong Pi events were seen at Nurmijaarvi (L 3.4) only when Kp was very high, when the plasmapause would be expected to be inside L 3.4. When Pi events and structure Pc 1 events were observed nearly simultaneously, the Pi activity was always more prominent at the poleward site. A demarcation line seems to exist, separating the Pi and structured Pc 1 source regions. This line may be the plasmapause, with structured Pc 1 inside and Pi outside.

Heacock, R. R.↗
NASA NTRS1971

Correlation between convection electric fields in the nightside magnetosphere and several wave and particle phenomena during two isolated substorms.

Correlation of several magnetoionospheric wave and particle phenomena previously linked observationally to magnetospheric substorms and inferred to involve convection electric fields with whistler measurements of convection activity during two relatively isolated substorms. The events occurred at about 0600 UT on July 15, 1965, and about 0500 UT on Oct. 13, 1965. The correlated phenomena include cross-L inward plasma drifts near midnight within the plasmaphere, diffuse auroral radar echoes observed near the dusk meridian, IPDP micropulsations (intervals of pulsations of diminishing period) in the premidnight sector, apparent contractions and expansions of the plasma sheet at about 20 earth radii in the magnetotail, and Pc 1/Pi 1 micropulsation events near or before midnight. Two new vlf phenomena occurred during the October 13 event - a noise band within the plasmasphere associated with a convecting whistler path, and ?hisslers,' falling-tone auroral-hiss forms repeated at intervals of about 2 sec.

Carpenter, D. L.↗