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, 265-273, 2018
https://doi.org/10.5194/angeo-36-265-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Regular paper
28 Feb 2018
Intrinsic parameters of periodic waves observed in the OI6300 airglow layer over the Brazilian equatorial region
Igo Paulino1, Joyrles F. Moraes1, Gleuson L. Maranhão1, Cristiano M. Wrasse2, Ricardo Arlen Buriti1, Amauri F. Medeiros1, Ana Roberta Paulino1,3, Hisao Takahashi2, Jonathan J. Makela4, John W. Meriwether5, and José André V. Campos1 1Universidade Federal de Campina Grande, Campina Grande, PB, Brazil
2Instituto Nacional de Pesquisas Espaciais, São José dos Campos, SP, Brazil
3Universidade Estadual da Paraíba, Campina Grande, PB, Brazil
4University of Illinois, Urbana-Champaign, IL, USA
5Clemson University, Clemson, SC, USA
Abstract. Periodic waves were observed in the OI6300 airglow images over São João do Cariri (36.5° W, 7.4° S) from 2012 to 2014 with simultaneous observations of the thermospheric wind using two Fabry–Pérot interferometers (FPIs). The FPIs measurements were carried out at São João do Cariri and Cajazeiras (38.5° W, 6.9° S). The observed spectral characteristics of these waves (period and wavelength) as well the propagation direction were estimated using two-dimensional Fourier analysis in the airglow images. The horizontal thermospheric wind was calculated from the Doppler shift of the OI6300 data extracted from interference fringes registered by the FPIs. Combining these two techniques, the intrinsic parameters of the periodic waves were estimated and analyzed. The spectral parameters of the periodic waves were quite similar to the previous observations at São João do Cariri. The intrinsic periods for most of the waves were shorter than the observed periods, as a consequence, the intrinsic phase speeds were faster compared to the observed phase speeds. As a consequence, these waves can easily propagate into the thermosphere–ionosphere since the fast gravity waves can skip turning and critical levels. The strength and direction of the wind vector in the thermosphere must be the main cause for the observed anisotropy in the propagation direction of the periodic waves, even if the sources of these waves are assumed to be isotropic.

Citation: Paulino, I., Moraes, J. F., Maranhão, G. L., Wrasse, C. M., Buriti, R. A., Medeiros, A. F., Paulino, A. R., Takahashi, H., Makela, J. J., Meriwether, J. W., and Campos, J. A. V.: Intrinsic parameters of periodic waves observed in the OI6300 airglow layer over the Brazilian equatorial region, Ann. Geophys., 36, 265-273, https://doi.org/10.5194/angeo-36-265-2018, 2018.
Publications Copernicus
Download
Short summary
This article presents characteristics of periodic waves observed in the thermosphere from airglow images collected in the Northeast of Brazil. Using simultaneous measurements of the background wind in the airglow emission altitudes, it was possible to estimate the intrinsic parameters and the role of the wind in the propagation of the waves into the thermosphere. An anisotropy in the propagation direction of the waves was observed and it could be explained by the wind filtering process.
This article presents characteristics of periodic waves observed in the thermosphere from...
Share