@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 = "14 fev. 2025"
}