Storm time plasma transport at middle and high latitudes

Journal Article · Mon Feb 01 00:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JA02032· OSTI ID:6901012

Foster, J C ^[1]

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1. MIT Haystack Observatory, Westford, MA (United States)

Associated with the large-scale enhancement of the ionospheric convection electric field during disturbed geomagnetic conditions, solar-produced F region plasma is transported to and through the noontime cleft from a source region at middle and low latitudes in the afternoon sector. As a result of the offset between the geomagnetic and geographic poles, the afternoon sector region of strong sunward convection is shifted to increasingly lower geographic latitude throughout the interval between 12 UT and 24 UT. A snowplow effect occurs in which the convection cell continually encounters fresh corotating ionospheric plasma along its equatorward edge, producing a latitudinally narrow region of storm-enhanced plasma density (SED) and increased total electron content which is advected toward higher latitudes in the noon sector. The Millstone Hill incoherent scatter radar regularly observes SED as a spatially continuous, large-scale feature spanning local times between noon and midnight and at latitudes between the polar cap and its mid- or low-latitude source region. For local times away from noon, the latitude of most probable SED occurrence moves equatorward by 6[degrees] for an increase of 2 in the Kp index. During strong disturbances the topside SED is observed to be convecting sunward at [approximately]750 m s[sup [minus]1] with a flux of 10[sup 14] m[sup [minus]2] s[sup [minus]1]. This feature accounts for the pronounced enhancement of ionospheric density near dusk at middle latitudes observed during the early stages of magnetic storms (called the dusk effect) and constitutes a source for the enhanced F region plasma observed in the polar cap during disturbed conditions. 34 refs., 13 figs., 1 tab.

• OSTI ID: 6901012
• Journal Information: Journal of Geophysical Research; (United States), Vol. 98:A2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRIC FIELDS
CONVECTION
IONOSPHERE
MAGNETIC STORMS
PLASMA DRIFT
DISTURBANCES
EARTH MAGNETOSPHERE
F REGION
GEOMAGNETIC FIELD
PLASMA
PLASMA DENSITY
RADAR
EARTH ATMOSPHERE
ENERGY TRANSFER
HEAT TRANSFER
MAGNETIC FIELDS
MASS TRANSFER
MEASURING INSTRUMENTS
PLANETARY IONOSPHERES
RANGE FINDERS
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)