Journal cover Journal topic
Annales Geophysicae Sun, Earth, planets, and planetary systems An interactive open-access journal of the European Geosciences Union
Ann. Geophys., 36, 231-241, 2018
https://doi.org/10.5194/angeo-36-231-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Regular paper
21 Feb 2018
Ultrafast Kelvin waves in the MLT airglow and wind, and their interaction with the atmospheric tides
Fabio Egito1, Ricardo Arlen Buriti2, Amauri Fragoso Medeiros2, and Hisao Takahashi3 1Centro de Formação de Professores, Universidade Federal do Recôncavo da Bahia, Amargosa, 45.300-000, Brazil
2Unidade Acadêmica de Física, Universidade Federal de Campina Grande-UFCG, Campina Grande, Brazil
3Aeronomy Division, National Institute for Space Research, São José dos Campos, 12227-010, Brazil
Abstract. Airglow and wind measurements from the Brazilian equatorial region were used to investigate the presence and the effects of the 3–4-day ultrafast Kelvin waves in the MLT. The airglow integrated intensities of the OI557.7 nm, O2b(0-1) and OH(6-2) emissions, as well as the OH rotational temperature, were measured by a multichannel photometer, and the zonal and meridional wind components between 80 and 100 km were obtained from a meteor radar. Both instruments are installed in the Brazilian equatorial region at São João do Cariri (7.4° S, 36.5° W). Data from 2005 were used in this study. The 3–4-day oscillations appear intermittently throughout the year in the airglow. They were identified in January, March, July, August and October–November observations. The amplitudes induced by the waves in the airglow range from 26 to 40 % in the OI557.7 nm, 17 to 43 % in the O2b(0-1) and 15 to 20 % in the OH(6-2) emissions. In the OH rotational temperature, the amplitudes were from 4 to 6 K. Common 3–4-day oscillations between airglow and neutral wind compatible with ultrafast Kelvin waves were observed in March, August and October–November. In these cases, the amplitudes in the zonal wind were found to be between 22 and 28 m s−1 and the vertical wavelength ranges from 44 to 62 km. Evidence of the nonlinear interaction between the ultrafast Kelvin wave and diurnal tide was observed.

Citation: Egito, F., Buriti, R. A., Fragoso Medeiros, A., and Takahashi, H.: Ultrafast Kelvin waves in the MLT airglow and wind, and their interaction with the atmospheric tides, Ann. Geophys., 36, 231-241, https://doi.org/10.5194/angeo-36-231-2018, 2018.
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