THE IONOSPHERIC ABSORPTION OF THE VLF EMISSIONS AT THE AURORAL ZONE

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Journal of Geomagnetism and Geoelectricity (Japan)

DOI:https://doi.org/10.5636/jgg.15.90· OSTI ID:4080823

Ondoh, T

Ionospheric absorptions of v-l-f emissions at the auroral zone were calculated along a geomagnetic line of force connecting with the earth's surface at geomagnetic latitude of 64 deg by using the longitudinal approximation of the AppletonHartree formula and data of rocket sounding and of auroral luminosity profiles. Ionospheric absorptions at 4 kc between 50 and 170 km height are of 33.1, 15.4, 16.9, and 2.2 db for a daytime ionosphere during total polar black- out, a quiet ionosphere near noon, a midnight ionosphere during diffuse aurora, and a quiet ionosphere at winter midnight, respectively. Therefore the lack of v- l-f emissions during total polar black-out at high latitudes may be due to the marked increase of the absorption in the ionosphere, especially in the D layer. On the other hand, it seems likely that particles producing auroras and geomagnetic disturbances around the E layer do not cause considerable absorption of the v-l-f emissions, and that the power of v-l-f emissions is originally weak in the exosphere on night side at the auroral zone. The absorption of 15.4 db in the quiet ionosphere near noon suggests that the original power of v-l-f emissions in the exosphere is of the order of 3.5 x 10/sup -13/ approximates 3.5 x 10/sup 15/ wm/sup -1/ (c)/sup -1/ in the daytime. The diurnal variation in maximum chorus frequency at high latitudes may be explained by relative increase of ionospheric absorption during the daytime for frequencies above a few kilo- cycles. (auth)

• Research Organization: Radio Research Labs., Nakaminato, Ibaragi, Japan
• Sponsoring Organization: USDOE
• NSA Number: NSA-18-011077
• OSTI ID: 4080823
• Journal Information: Journal of Geomagnetism and Geoelectricity (Japan), Journal Name: Journal of Geomagnetism and Geoelectricity (Japan) Vol. Vol: 15; ISSN JGEGA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
AURORAE
DISTRIBUTION
EARTH
EFFICIENCY
ELECTROMAGNETIC WAVES
EMISSION
EQUATIONS
FREQUENCY
IONOSPHERE
LAYERS
LIGHT
MAGNETIC FIELDS
NUMERICALS
PHYSICS
RADIO WAVES
ROCKETS
VARIATIONS