Polarization and amplitude characteristics of Pc 3 pulsations in conjugate area around L = 1. 3-2. 1

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA093iA07p07386· OSTI ID:5153170

Yumoto, K; Saito, T ^[1]; Tanaka, Y ^[2]; Lynn, K J.W. ^[3]; Menk, F W; Fraser, B J ^[4]

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1. Tohoku Univ., Sendai (Japan)
2. Nagoya Univ., Toyokawa (Japan)
3. Defence Research Centre, Adelaide, South Australia (Australia)
4. Univ. of Newcastle, New South Wales (Australia)

In order to extend both theoretical and experimental investigations of low-latitude Pc 3 mangetic pulsations, the authors conducted conjugate magnetic observations at Asahikawa and Onagawa in Japan and Birdsville, i.e., the conjugate point of ASH, Dalby and St. Kilda in Australia, during the period from July 20 to September 16, 1986. From the analysis of these conjugate-area data, ocurrence and polarization characteristics of low-latitude Pc 3 pulsations can be summarized as follows: (1) the average amplitude at SKD (L = 2.1) is about twice that at BSV (1.55); (2) the H component amplitude as BSV in the winter hemisphere is larger than that at ASH in the summer hemisphere; (3) the polarizations at all stations switch statistically from left-handed in the morning to right-handed in the afternoon, where polarization senses are defined with reference to the direction of the main geomagnetic field; (4) however, the switch from L-H to R-H polarization at the conjugate stations (L = 1.55) does not always occur near local noon, but sometimes near 0500 and 1700 LT; (5) the abrupt changes of major axis orientations of Pc 3 polarization ellipses appear to coincide with the ionospheric conductivity enhancement and depression, respectively, associated with local sunrise and sunset. These observational facts suggest that a standing field line resonance in the Pc 3 frequency range is situated at L > 2.1, and that at lower latitudes (L {approx lt} 1.5) Pc 3 magnetic pulsations could arise predominantly from compressional mode waves propagating transverse to the Earth's magnetic field through the low-latitude ionosphere.

• OSTI ID: 5153170
• Journal Information: Journal of Geophysical Research; (United States), Vol. 93:A7; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH MAGNETOSPHERE
HYDROMAGNETIC WAVES
AMPLITUDES
COMPRESSION
DATA ANALYSIS
ELECTRIC CONDUCTIVITY
GEOMAGNETIC FIELD
IONOSPHERE
MAGNETOPAUSE
MAGNETOSHEATH
POLARIZATION
WAVE PROPAGATION
EARTH ATMOSPHERE
ELECTRICAL PROPERTIES
MAGNETIC FIELDS
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena