Results 131 to 140 of about 1,202,402 (151)

Night-Time Behavior of 630 NM Emission in Mid-Latitude Auroras During Strong Magnetic Storms

COSPAR Colloquia Series, 2002
ABSTRACT Using experimental observations of the airglow in upper atmosphere over East Siberia (52 N, 104 E), an analysis is made of the night behavior of the oxygen line OI 630 nm emission in mid-latitude auroras during severe magnetic storms. Two types of the night behavior of the OI 630 nm emission are found out in mid-latitude auroras during ...
exaly   +2 more sources

energetic oxygen in a mid‐latitude aurora

Journal of Geophysical Research: Space Physics, 1984
On the night of September 21/22, 1982, ground‐based observations were made of an aurora which extended as far equatorward as Logan, Utah (41°N, 111°W). An imaging spectrometer was used to obtain spectral images over the wavelength range 3300–5300 Å at a spectral resolution of 2.7 Å.
Marsha R. Torr, D. G. Torr
openaire   +1 more source

Very low brightness fluctuations in the mid-latitude aurora

Journal of Geophysical Research, 1977
From ground-based photometric observations made near Dunedin, New Zealand, at L = 2.71, weak mid-latitude electron precipitation is detected through the appearance of a characteristic signature in the cross correlogram of λ3914 and λ5577 brightness fluctuations. The method is sufficiently sensitive to detect rms brightness fluctuations at 3914 A, σ(Bv),
G. R. Stanley, P. J. Edwards
openaire   +1 more source

Energetic He⁺ precipitation in a mid‐latitude aurora

Journal of Geophysical Research: Space Physics, 1987
Optical spectra of a mid‐latitude aurora on September 21–22 indicated that the observed emissions were caused by energetic ions (O+ or He+). In an earlier paper it was shown that the spectral features could be fairly well explained by a flux of precipitating energetic O+ with characteristics similar to O+ fluxes that have been observed in large ...
M. Ishimoto, M. R. Torr
openaire   +1 more source

Dynamic effects of aurora-generated gravity waves on the mid-latitude ionosphere

Journal of Atmospheric and Terrestrial Physics, 1979
Abstract This paper gives a brief review of aurora-generated large-scale traveling ionospheric disturbances, and presents results of numerical simulations of one such event. Numerous observations and several theoretical studies have shown that large-scale gravity waves are generated in the high-latitude thermosphere during geomagnetic disturbances ...
A.D. Richmond, R.G. Roble
openaire   +1 more source

The role of energetic O⁺ precipitation in a mid‐latitude aurora

Journal of Geophysical Research: Space Physics, 1986
We show that fluxes of precipitating energetic O+ that have been observed by satellites in the topside ionosphere can explain the magnitude of the N2+(1 N) (first negative) 3914‐Å and N2(2 P) (second positive) 3371‐Å emission rate observed during a mid‐latitude aurora over Logan, Utah (41° N, 111°W), on September 21–22, 1982.
M. Ishimoto, M. R. Torr, P. G. Richards, D. G. Torr   +3 more
openaire   +1 more source

Mid-latitude pulsating auroras

Planetary and Space Science, 1974
Pulsating auroras were recorded at Bedford, Massachusetts, cgm lat. 55.4°, 24 March 1969 during a worldwide magnetic storm, the only known published observations of pulsating auroras at such low magnetic latitudes. Spectral density analysis of several minutes of 5577A pulsations indicated a dominant period of 7.2 sec at 0300 EST.
openaire   +1 more source

Mid-latitude auroras and SAR arcs observed from the Isis 2 spacecraft during the August 1972 geomagnetic storm

Journal of Geophysical Research, 1976
Optical and particle measurements made from the Isis 2 spacecraft during August 1972 geomagnetic storm are reported for August 4, 5, and 6. Soon after the two sudden commencements which initiated the storm on August 4 a bright optical aurora was detected in the range of 60degree--65degree invariant in the dawn sector.
G. G. Shepherd, L. L. Cogger, J. R. Burrows   +2 more
openaire   +1 more source

Mid-latitude auroras of the Solar cycle 25 according to optical instruments of the National Heliogeophysical Complex

PHYSICS OF AURORAL PHENOMENA
Mid-latitude auroras (MA) are a rare geophysical phenomenon, however, according to some researches subvisual MA are observed more often. In addition, the observation of stable red auroral arcs (SAR arcs) in mid-latitudes was previously considered an extremely rare phenomenon.
A.B. Beletsky, T.E. Syrenova, A.V. Mikhalev, R.A. Marchuk, S.V. Podlesnyi, R.V. Vasiliev   +5 more
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 Aurora-Associated Ionospheric Disturbances at European Mid-Latitudes During the May 10, 2024, Geomagnetic Storm

The extreme geomagnetic storm on May 10, 2024, caused an unprecedented expansion of auroral activity toward the equator over Europe. This provided a unique opportunity to study ionospheric disturbances associated with auroras at mid-latitudes. In this study, we analyze the ionosphere's response based on observations from a dense network of Global ...
Grzegorz Nykiel, Joanna Kanska, Hiroatsu Sato, Shin-ichiro Oyama, David Themens   +4 more
openaire   +1 more source