A MU radar-based study of mid-latitude F region response to a geomagnetic disturbance

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Journal of Geophysical Research; (United States)

OSTI ID:5376914

Reddy, C A; Fukao, S; Takami, T; Yamamoto, M; Tsuda, T; Nakamura, T; Kato, S ^[1]

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1. Kyoto Univ., Uji (Japan)

During the night of January 20-21, 1989, ionospheric incoherent scatter power measurements were made with the MU (middle and upper atmosphere) radar at Shigaraki (geographic latitude 34.85 N, longitude 136.10 E; geomagnetic latitude 24.9{degree}, longitude 204.3{degree}). Japan, and the electron density profiles in the 180- to 1,000-km height range were derived at 8-min intervals. The observations showed the presence of three F region disturbances during the night. During the very large first disturbance, which lasted from 2,300 to 0240 LT approximately, the height of maximum electron density N{sub m} increased by 220 km in 2 hours to reach an altitude of 600 km. The other two, smaller disturbances occurred during 0300-0500 LT and 0530-0700 LT approximately. A detailed interpretation of the above F region disturbances is given. Examination of some high- and middle-latitude magnetograms showed the beginning of an intense geomagnetic substorm at auroral latitudes at the start of the first F region disturbance, and a less intense substorm around the starting time of the second F region disturbance. On the basis of this evidence, the first two F region disturbances are interpreted as the result of large vertical drifts of F region ionization due to the substorm-generated east-west electric fields appearing at mid-latitudes. The patterns of h{prime}F variations during this night at five ionospheric stations in Japan support the above interpretation. Additionally, during the second disturbance the possible presence of a wind perturbation due to the equatorward propagation of a wave disturbance, generated probably by the first major substorm, is indicated by the MU radar data and the ionosonde data. The third F region disturbance is attributed to a neutral wind perturbation associated with a gravity wave traveling equatorward, the wave being generated most plausibly by the Joule heating during the first major substorm.

• OSTI ID: 5376914
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A12; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
F REGION
DISTURBANCES
MAGNETIC BAYS
IONOSPHERIC EFFECTS
ELECTRIC FIELDS
ELECTRON DENSITY
GRAVITY WAVES
HEIGHT
IONIZATION
IONOSONDES
JOULE HEATING
RADAR
WIND
DIMENSIONS
EARTH ATMOSPHERE
ELECTRIC HEATING
ELECTRONIC EQUIPMENT
EQUIPMENT
HEATING
IONOSPHERE
MEASURING INSTRUMENTS
PLANETARY IONOSPHERES
PLASMA HEATING
RADIO EQUIPMENT
RANGE FINDERS
RESISTANCE HEATING
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena