Radar observations of cleft dynamics

Journal Article · Tue Jul 01 04:00:00 EDT 1980 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA085iA07p03453· OSTI ID:5096718

Foster, J C; Stiles, G S; Doupnik, J R

The ionospheric F region is perturbed by low-energy particle precipitation in the cleft. On January 28--29, 1977, UT an ionospheric density enhancement associated with the cleft was monitored continuously by the Chatanika incoherent scatter radar during a 6-hour period including an onset and recovery of global substorm activity. A strongly southward interplanetary magnetic field (IMF) brought the cleft into the field of view of the radar (invariant latitudes less than 75 /sup 0/). The observed motions of the cleft included a rapid equatorward excursion (approx.4 /sup 0/..lambda../h) to 70 /sup 0/ before occurrence of a major substorm intensification, continued location at low magnetic latitude during substorm expansion, and a poleward retreat to approx.73.5 /sup 0/..lambda.. during substorm recovery in response to a northward turning of the IMF. The latitudinal width of the cleft density enhancement varied from less than 1 /sup 0/ during the presubstorm equatorward motion to approx.4 /sup 0/ after substorm recovery. F region densities immediately poleward of the cleft were reduced by a factor of 10 from their quiet time value.

• Research Organization: Center for Atmospheric and Space Sciences, Utah State University, Logan, Utah 84322
• OSTI ID: 5096718
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 85:A7; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED-PARTICLE PRECIPITATION
EARTH ATMOSPHERE
F REGION
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC BAYS
MAGNETIC FIELDS
MAGNETOSPHERE
MEASURING INSTRUMENTS
PLANETARY IONOSPHERES
PLASMA DENSITY
RADAR
RANGE FINDERS