@Article{FagundesSahaBittTaka:1995:ObThNe,
author = "Fagundes, Paulo Roberto and Sahai, Yogeshwar and Bittencourt, Jose
Augusto and Takahashi, Hisao",
title = "Observation of thermospheric neutral winds and temperatures at
Cachoeira Paulista (23 degree S, 45 degree W) during a geomagnetic
storm",
journal = "Advances in Space Research",
year = "1995",
volume = "16",
number = "5",
pages = "527--530",
keywords = "AERONOMIA, tempestades magn{\'e}ticas, interferometros Fabry
Perot, termosfera, energia, magnetic storms, Fabry Perot
interferometers, thermosphere, energy.",
abstract = "Observations of nighttime thermospheric neutral wind velocities
and temperatures from measurements of Doppler shifts and widths,
respectively, of the OI 630.0 nm airglow emission line, using a
Fabry-Perot interferometer, have been carried out at Cachoeira
Paulista (23 degrees S, 45 degrees W), Brazil, since 1988. In this
paper we present observations of thermospheric neutral winds and
temperatures during the period July 6-10, 1991, which included the
strong magnetic disturbance of July 8-9, 1991 when the Kp value
reached 8. During this storm the meridional and zonal neutral wind
velocity patterns were strongly modified. On July 9-10, the
observed meridional wind during the storm shows a behaviour
opposite to that observed during winter and the observed zonal
wind at the beginning of the night shows a behaviour similar to
its quiet time behaviour (to the east), but at 01:15 LT the zonal
wind changes its direction rapidly to the west and at 03:45 LT it
reverses to east again. Also, from the observed thermospheric
temperatures, inferred from the thermal broadening of the 630.0 nm
line emission, we find that during this event there is
thermospheric cooling over Cachoeira Paulista. This result is
surprising, because we would normally expect thermospheric heating
during geomagnetic storms, since a large amount of energy is
deposited in the thermosphere at high latitudes.",
issn = "0273-1177",
label = "7146",
targetfile = "5755.pdf",
urlaccessdate = "2025, Feb. 14"
}