Millstone Hill radar was performing a mid-latitude survey of ionospheric parameters versus latitude during the time of intensification of activity near 2300 on 3 Nov 93. Radar recorded prompt onset of precipitation-produced ionization (due to soft precitiation component) at lower F region heights in a latitudinally-narrow region (2 deg) near L=4 in the evening sector. This occurred immediately poleward of a deep trougn formed nearly overhead at Millstone at L=3.5. Phase perturbation of VLF propagation delineated a coincident region of hard precipitation in the region at L=4 and this coincided with the region of a sharp depletion of the outer-zone radiation belt particle population (dumping) observed by SAMPEX.
An uplifting of the ionospheric F region equatorward of the trough at 0030 UT on 4 Nov indicates the time of a deep penetration of disturbance electric fields to very low latitude (L<2).
Unusual low-latitude effects near the Atlantic magnetic anomaly were recorded during the event.
Back to J.Foster Web Page