Transient composite electric field disturbances near dip equator associated with auroral substorms

Journal Article · Fri Jul 24 00:00:00 EDT 1992 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/92GL01447· OSTI ID:7012720

Hanumath Sastri, J; Ramesh, K B; Ranganath Rao, H N ^[1]

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1. Indian Inst. of Astrophysics, Bangalore (India)

Ionosonde data of Kodaikanal and Huancayo are used to show the simultaneous occurrence of a transient disturbance in F region height of composite polarity in day and night sectors near the dip equator during the auroral substorm activity on 20 August 1979. At Kodaikanal which is on the nightside at the time of the substorm activity, h[prime]F first underwent an abrupt and rapid decrease (80km in 1 hr) followed by a much larger increase (120km in 1 hr). Perturbation in hpF2 of exactly opposite polarity was simultaneously seen at Huancayo which is on the dayside. The decrease in h[prime]F at Kodaikana (increase in hpF2 at Huancayo) occurred in association with an increase in polar cap potential drop, [phi] (estimated from IMF parameters), and the subsequent increase (decrease at Huancayo) with a decrease in polar cap potential. The F-region height disturbance is interpreted as the manifestation of a global transient composite disturbance in equatorial zonal electric field caused by the prompt penetration of substorm-related high latitude electric fields into the equatorial ionosphere. The polarity pattern of the electric field disturbance is consistent with the global convection models which predict westward (eastward) electric fields at night (by day) near the geomagnetic equator in response to an increase in polar cap potential drop, and fields of opposite signs for a decrease in polar cap potential.

• OSTI ID: 7012720
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 19:14; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
F REGION
ELECTRIC FIELDS
DATA
DISTURBANCES
EARTH MAGNETOSPHERE
ELECTRIC POTENTIAL
GEOMAGNETIC EQUATOR
IONOSONDES
LATITUDE EFFECT
MAGNETIC BAYS
PLASMA DRIFT
POLAR REGIONS
EARTH ATMOSPHERE
ELECTRONIC EQUIPMENT
EQUIPMENT
GEOGRAPHICAL VARIATIONS
INFORMATION
IONOSPHERE
PLANETARY IONOSPHERES
RADIO EQUIPMENT
VARIATIONS
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)