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

Journal Article · Sat Dec 01 04:00:00 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), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:A12; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

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