Articles | Volume 37, issue 4
https://doi.org/10.5194/angeo-37-603-2019
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the Creative Commons Attribution 4.0 License.
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https://doi.org/10.5194/angeo-37-603-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Converging photospheric vortex flows close to the polarity inversion line of a fully emerged active region
Universidade Tecnológica Federal do Paraná, Curitiba, Paraná, Brazil
Cristiano M. Wrasse
Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil
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Prosper K. Nyassor, Cristiano M. Wrasse, Igo Paulino, Cosme A. O. B. Figueiredo, Ricardo A. Buriti, Hisao Takahashi, Delano Gobbi, and Gabriel A. Giongo
EGUsphere, https://doi.org/10.5194/egusphere-2024-1982, https://doi.org/10.5194/egusphere-2024-1982, 2024
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This work studies the dynamics of momentum and energy of upward and downward GW. From photometer, the vertical component of GWs were observed and horizontal component from an all-sky imager. Using these parameters from these two instruments and wind from meteor radar, the momentum flux and energy of the waves were determined and studied. It was observed that the dynamics of the downward GWs is opposite to that of the upward GWs.
Cristiano M. Wrasse, Prosper K. Nyassor, Ligia A. da Silva, Cosme A. O. B. Figueiredo, José V. Bageston, Kleber P. Naccarato, Diego Barros, Hisao Takahashi, and Delano Gobbi
Atmos. Chem. Phys., 24, 5405–5431, https://doi.org/10.5194/acp-24-5405-2024, https://doi.org/10.5194/acp-24-5405-2024, 2024
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This present work investigates the propagation dynamics and the sources–source mechanisms of quasi-monochromatic gravity waves (QMGWs) observed between April 2017 and April 2022 at São Martinho da Serra. The QMGW parameters were estimated using a 2D spectral analysis, and their source locations were identified using a backward ray-tracing model. Furthermore, the propagation conditions, sources, and source mechanisms of the QMGWs were extensively studied.
Hisao Takahashi, Cosme A. O. B. Figueiredo, Patrick Essien, Cristiano M. Wrasse, Diego Barros, Prosper K. Nyassor, Igo Paulino, Fabio Egito, Geangelo M. Rosa, and Antonio H. R. Sampaio
Ann. Geophys., 40, 665–672, https://doi.org/10.5194/angeo-40-665-2022, https://doi.org/10.5194/angeo-40-665-2022, 2022
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We observed two different wave propagations in the earth’s upper atmosphere: a gravity wave in the mesosphere and the ionospheric disturbances. We investigated the wave propagations by using airglow imaging techniques. It is found that there was a gravity wave generation from the tropospheric convection spot, and it propagated upward in the ionosphere. This reports observational evidence of gravity wave propagation from the troposphere to ionosphere.
Prosper K. Nyassor, Cristiano M. Wrasse, Igo Paulino, Eliah F. M. T. São Sabbas, José V. Bageston, Kleber P. Naccarato, Delano Gobbi, Cosme A. O. B. Figueiredo, Toyese T. Ayorinde, Hisao Takahashi, and Diego Barros
Atmos. Chem. Phys., 22, 15153–15177, https://doi.org/10.5194/acp-22-15153-2022, https://doi.org/10.5194/acp-22-15153-2022, 2022
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This work investigates the sources of concentric gravity waves (CGWs) excited by a moving system of clouds with several overshooting regions on 1–2 October 2019 at São Martinho da Serra. The parameters of these waves were estimated using 2D spectral analysis and their source locations identified using backward ray tracing. Furthermore, the sources of these waves were properly identified by tracking the individual overshooting regions in space and time since the system of clouds was moving.
Igo Paulino, Ana Roberta Paulino, Amauri F. Medeiros, Cristiano M. Wrasse, Ricardo Arlen Buriti, and Hisao Takahashi
Ann. Geophys., 39, 1005–1012, https://doi.org/10.5194/angeo-39-1005-2021, https://doi.org/10.5194/angeo-39-1005-2021, 2021
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In the present work, the lunar semidiurnal tide (M2) was investigated in the equatorial plasma bubble (EPB) zonal drifts over Brazil from 2000 to 2007. On average, the M2 contributes 5.6 % to the variability of the EPB zonal drifts. A strong seasonal and solar cycle dependency was also observed, the amplitudes of the M2 being stronger during the summer and high solar activity periods.
Ana Roberta Paulino, Fabiano da Silva Araújo, Igo Paulino, Cristiano Max Wrasse, Lourivaldo Mota Lima, Paulo Prado Batista, and Inez Staciarini Batista
Ann. Geophys., 39, 151–164, https://doi.org/10.5194/angeo-39-151-2021, https://doi.org/10.5194/angeo-39-151-2021, 2021
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Long- and short-period oscillations in the lunar semidiurnal tidal amplitudes in the ionosphere derived from the total electron content were investigated over Brazil from 2011 to 2014. The results showed annual, semiannual and triannual oscillations as the dominant components. Additionally, the most pronounced short-period oscillations were observed between 7 and 11 d, which suggest a possible coupling of the lunar tide and planetary waves.
Oluwakemi Dare-Idowu, Igo Paulino, Cosme A. O. B. Figueiredo, Amauri F. Medeiros, Ricardo A. Buriti, Ana Roberta Paulino, and Cristiano M. Wrasse
Ann. Geophys., 38, 507–516, https://doi.org/10.5194/angeo-38-507-2020, https://doi.org/10.5194/angeo-38-507-2020, 2020
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Some strong gravity wave activity occurred and was observed on 8 April 2005. This work reports the spectral characteristics of these waves using OH airglow images captured by the all-sky imager installed at São João do Cariri (7.4° S, 36.5° W). A preferential propagation direction was observed due to the positioning of the source and also due to the wind filtering effect. Furthermore, the source of these waves was identified by performing reverse-ray tracing analysis.
Igo Paulino, Ana Roberta Paulino, Ricardo Y. C. Cueva, Ebenezer Agyei-Yeboah, Ricardo Arlen Buriti, Hisao Takahashi, Cristiano Max Wrasse, Ângela M. Santos, Amauri Fragoso de Medeiros, and Inez S. Batista
Ann. Geophys., 38, 437–443, https://doi.org/10.5194/angeo-38-437-2020, https://doi.org/10.5194/angeo-38-437-2020, 2020
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In this paper, an extensive study has been done in order to investigate periodic oscillations in the start times of equatorial plasma bubbles observed over Brazil. Using OI6300 airglow images and ionograms, it was possible to detect semimonthly oscillations in the start times of equatorial plasma bubbles (EPBs) and equatorial Spread-F. This semimonthly oscillation is likely related to the lunar tide, which represents an important mechanism acting in the day-to-day variability of EPBs.
Patrick Essien, Igo Paulino, Cristiano Max Wrasse, Jose Andre V. Campos, Ana Roberta Paulino, Amauri F. Medeiros, Ricardo Arlen Buriti, Hisao Takahashi, Ebenezer Agyei-Yeboah, and Aline N. Lins
Ann. Geophys., 36, 899–914, https://doi.org/10.5194/angeo-36-899-2018, https://doi.org/10.5194/angeo-36-899-2018, 2018
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Present work reports seasonal characteristics of small- and medium-scale gravity waves in the mesosphere and lower thermosphere region. All-sky images of the hydroxyl airglow emission layer over São João do Cariri (7.4° S, 36.5° W) were observed from September 2000 to December 2010, during a total of 1496 nights and obtained 2343 SSGW and 537 MSGW events. The horizontal propagation directions of SSGWs and MSGWs showed clear seasonal variations based on the influence of the wind filtering process.
Amauri Fragoso Medeiros, Igo Paulino, Cristiano Max Wrasse, Joaquim Fechine, Hisao Takahashi, José Valentin Bageston, Ana Roberta Paulino, and Ricardo Arlen Buriti
Ann. Geophys., 36, 311–319, https://doi.org/10.5194/angeo-36-311-2018, https://doi.org/10.5194/angeo-36-311-2018, 2018
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On 3 October 2005, a mesospheric front was observed over São João do Cariri (7.4° S, 36.5° W) propagating to the northeast in the OH airglow images. One and a half hours later, it disappeared completely and ripples were observed in the eastern part of the images. After studying the background atmosphere, the main conclusion of this work was that the instability in the airglow layer did not allow the propagation of the front to the other side of the local zenith.
Igo Paulino, Joyrles F. Moraes, Gleuson L. Maranhão, Cristiano M. Wrasse, Ricardo Arlen Buriti, Amauri F. Medeiros, Ana Roberta Paulino, Hisao Takahashi, Jonathan J. Makela, John W. Meriwether, and José André V. Campos
Ann. Geophys., 36, 265–273, https://doi.org/10.5194/angeo-36-265-2018, https://doi.org/10.5194/angeo-36-265-2018, 2018
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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.
Gabriel Augusto Giongo, José Valentin Bageston, Paulo Prado Batista, Cristiano Max Wrasse, Gabriela Dornelles Bittencourt, Igo Paulino, Neusa Maria Paes Leme, David C. Fritts, Diego Janches, Wayne Hocking, and Nelson Jorge Schuch
Ann. Geophys., 36, 253–264, https://doi.org/10.5194/angeo-36-253-2018, https://doi.org/10.5194/angeo-36-253-2018, 2018
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This work presents four events of mesosphere fronts observed on King George Island, Antarctic Peninsula, in the year 2011. The atmospheric background environment was analyzed to investigate the propagation conditions for all cases. To investigate the sources for such cases, satellite images were used. In two cases, we found that strong tropospheric instabilities were potential sources, and in the other two cases, it was not possible to associate them with tropospheric sources.
Diego Barros, Hisao Takahashi, Cristiano M. Wrasse, and Cosme Alexandre O. B. Figueiredo
Ann. Geophys., 36, 91–100, https://doi.org/10.5194/angeo-36-91-2018, https://doi.org/10.5194/angeo-36-91-2018, 2018
I. Paulino, A. F. Medeiros, S. L. Vadas, C. M. Wrasse, H. Takahashi, R. A. Buriti, D. Leite, S. Filgueira, J. V. Bageston, J. H. A. Sobral, and D. Gobbi
Ann. Geophys., 34, 293–301, https://doi.org/10.5194/angeo-34-293-2016, https://doi.org/10.5194/angeo-34-293-2016, 2016
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Periodic waves have been observed over São João do Cariri during almost one solar cycle. Similarities between the characteristics of these events with observations at other places around the world were noted, primarily the spectral parameters. Most observed waves have appeared during magnetically quiet nights, and the occurrence of those waves followed the solar activity. Due to their characteristics, most of them must have had different generation mechanisms from the Perkins instability.
A. F. Medeiros, I. Paulino, M. J. Taylor, J. Fechine, H. Takahashi, R. A. Buriti, L. M. Lima, and C. M. Wrasse
Ann. Geophys., 34, 91–96, https://doi.org/10.5194/angeo-34-91-2016, https://doi.org/10.5194/angeo-34-91-2016, 2016
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This paper reports two consecutive mesospheric bores observed in the airglow emissions (OH and OI5577). Both bores propagated to the east and showed similar spectral characteristics. However, the first one exhibited a dark leading front with several trailing waves behind and progressed into a brighter airglow region. However, the second bore, observed in the OH layer, was comprised of several bright waves propagating into a darker airglow region.
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Short summary
We describe a technique used to locate and classify critical points in 2-D flow fields at the solar photosphere obtained from the evolution of the line-of-sight magnetic field in a region close to the magnetic polarity inversion line of a fully emerged active region. We apply this technique to locate a particular kind of critical point associated to vortex flows, which are considered important, since they can twist and interweave the foot points of flux tubes and generate magnetic reconnection.
We describe a technique used to locate and classify critical points in 2-D flow fields at the...
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