Articles | Volume 25, issue 19
https://doi.org/10.5194/acp-25-12357-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-25-12357-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Oct 2025
Research article |
| 08 Oct 2025
| 08 Oct 2025
Modulation of tropical stratospheric gravity wave activity and the ITCZ position by modes of climate variability using radio occultation and reanalysis data
Toyese Tunde Ayorinde
CORRESPONDING AUTHOR
Space Weather Division, National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
Cristiano Max Wrasse
Space Weather Division, National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
Hisao Takahashi
Space Weather Division, National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
Luiz Fernando Sapucci
Instituto Nacional de Pesquisas Espaciais (INPE), Centro de Previsão de Tempo e Estudos Climáticos, Rodovia Presidente Dutra, km 40, Cachoeira Paulista, SP, Brazil
Mohamadou A. Diallo
Institute of Climate and Energy Systems – Stratosphere (ICE-4), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
Cosme Alexandre Oliveira Barros Figueiredo
Unidade Acadêmica de Física, Universidade Federal de Campina Grande, Campina Grande, PB, Brazil
Diego Barros
Space Weather Division, National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
Ligia Alves da Silva
Space Weather Division, National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
Patrick Essien
Department of Physics, Meteorology and Atmospheric Research Lab, University of Cape Coast, Cape Coast, Ghana
Anderson Vestena Bilibio
Unidade Acadêmica de Física, Universidade Federal de Campina Grande, Campina Grande, PB, Brazil
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Atmos. Chem. Phys., 25, 9719–9736, https://doi.org/10.5194/acp-25-9719-2025, https://doi.org/10.5194/acp-25-9719-2025, 2025
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This study explores intense concentric gravity waves (CGWs) based on ground-based and multi-satellite observations over southern Brazil, revealing significant airglow perturbations and strong momentum release. Triggered by deep convection and enabled by weaker wind fields, these CGWs reached the mesopause and thermosphere. Consistent detection via OI and OH airglow emissions confirms their vertical propagation, while asymmetric thermosphere propagation is linked to Doppler-induced wavelength changes.
Gabriel Augusto Giongo, Cristiano Max Wrasse, Pierre-Dominique Pautet, José Valentin Bageston, Prosper Kwamla Nyassor, Cosme Alexandre Oliveira Barros Figueiredo, Anderson Vestena Bilibio, Tracy Moffat-Griffin, Damian John Murphy, Toyese Tunde Ayorinde, Delano Gobbi, and Hisao Takahashi
EGUsphere, https://doi.org/10.5194/egusphere-2025-3114, https://doi.org/10.5194/egusphere-2025-3114, 2025
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This work analyzes the medium-scale atmospheric gravity waves observed by ground-based airglow imaging over the Antarctic continent. Medium-scale gravity waves refer to waves larger than 50 km of horizontal wavelength, and have not been analyzed in that region so far. Wave parameters and horizontal propagation characteristics were obtained by a recently improved methodology and are described thoroughly.
Prosper K. Nyassor, Cristiano M. Wrasse, Igo Paulino, Erdal Yiğit, Vera Y. Tsali-Brown, Ricardo A. Buriti, Cosme A. O. B. Figueiredo, Gabriel A. Giongo, Fábio Egito, Oluwasegun M. Adebayo, Hisao Takahashi, and Delano Gobbi
Atmos. Chem. Phys., 25, 4053–4082, https://doi.org/10.5194/acp-25-4053-2025, https://doi.org/10.5194/acp-25-4053-2025, 2025
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This work explores the dynamics of the momentum and energy of propagating mesospheric gravity waves (GWs). A photometer was used to observe the vertical component of the GWs, whereas the horizontal component was observed by an all-sky imager. Using the parameters from these two instruments and background wind from meteor radar, the momentum flux and potential energy of the GWs were determined and studied. It is noted that the dynamics of the downward-propagating GWs were controlled by observed ducts.
Jingyu Wang, Gabriel Chiodo, Timofei Sukhodolov, Blanca Ayarzagüena, William T. Ball, Mohamadou Diallo, Birgit Hassler, James Keeble, Peer Nowack, Clara Orbe, and Sandro Vattioni
EGUsphere, https://doi.org/10.5194/egusphere-2025-340, https://doi.org/10.5194/egusphere-2025-340, 2025
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We analyzed the ozone response under elevated CO2 using the data from CMIP6 DECK experiments. We then looked at the relations between ozone response and temperature and circulation changes to identify drivers of the ozone change. The climate feedback of ozone is investigated by doing offline calculations and comparing models with and without interactive chemistry. We find that ozone-climate interactions are important for Earth System Models, thus should be considered in future model development.
Gabriel Augusto Giongo, Cristiano Max Wrasse, Pierre-Dominique Pautet, José Valentin Bageston, Prosper Kwamla Nyassor, Cosme Alexandre Oliveira Barros Figueiredo, Anderson Vestena Bilibio, Delano Gobbi, and Hisao Takahashi
EGUsphere, https://doi.org/10.5194/egusphere-2024-3344, https://doi.org/10.5194/egusphere-2024-3344, 2024
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A new algorithm for medium-scale gravity waves analysis was developed for studies of gravity waves observed by airglow imaging. With this procedure, observation datasets can be analyzed to extract the gravity waves parameters for climatological purposes. The procedure showed reliable performance and are ready to be used in other observation sites.
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.
Livia R. Alves, Márcio E. S. Alves, Ligia A. da Silva, Vinicius Deggeroni, Paulo R. Jauer, and David G. Sibeck
Ann. Geophys., 41, 429–447, https://doi.org/10.5194/angeo-41-429-2023, https://doi.org/10.5194/angeo-41-429-2023, 2023
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We derive the wave–particle interaction time (IT) equation considering the effects of special relativity theory for whistler-mode chorus waves and relativistic electrons in Earth's radiation belt. Results show that IT has a non-linear dependence on the wave group velocity, electrons' energy, and initial pitch angle. Our results show that the interaction time is generally longer when applying the complete relativistic approach compared to a non-relativistic calculation.
Francis Nkrumah, Cornelia Klein, Kwesi Akumenyi Quagraine, Rebecca Berkoh-Oforiwaa, Nana Ama Browne Klutse, Patrick Essien, Gandomè Mayeul Leger Davy Quenum, and Hubert Azoda Koffi
Weather Clim. Dynam., 4, 773–788, https://doi.org/10.5194/wcd-4-773-2023, https://doi.org/10.5194/wcd-4-773-2023, 2023
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It is not yet clear which variations in broader atmospheric conditions of the West African monsoon may lead to mesoscale convective system (MCS) occurrences in southern West Africa (SWA). In this study, we identified nine different weather patterns and categorized them as dry-, transition-, or monsoon-season types using a method called self-organizing maps (SOMs). It was revealed that a warmer Sahel region can create favourable conditions for MCS formation in SWA.
Manfred Ern, Mohamadou A. Diallo, Dina Khordakova, Isabell Krisch, Peter Preusse, Oliver Reitebuch, Jörn Ungermann, and Martin Riese
Atmos. Chem. Phys., 23, 9549–9583, https://doi.org/10.5194/acp-23-9549-2023, https://doi.org/10.5194/acp-23-9549-2023, 2023
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Quasi-biennial oscillation (QBO) of the stratospheric tropical winds is an important mode of climate variability but is not well reproduced in free-running climate models. We use the novel global wind observations by the Aeolus satellite and radiosondes to show that the QBO is captured well in three modern reanalyses (ERA-5, JRA-55, and MERRA-2). Good agreement is also found also between Aeolus and reanalyses for large-scale tropical wave modes in the upper troposphere and lower stratosphere.
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.
Mohamadou A. Diallo, Felix Ploeger, Michaela I. Hegglin, Manfred Ern, Jens-Uwe Grooß, Sergey Khaykin, and Martin Riese
Atmos. Chem. Phys., 22, 14303–14321, https://doi.org/10.5194/acp-22-14303-2022, https://doi.org/10.5194/acp-22-14303-2022, 2022
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The quasi-biennial oacillation disruption events in both 2016 and 2020 decreased lower-stratospheric water vapour and ozone. Differences in the strength and depth of the anomalous lower-stratospheric circulation and ozone are due to differences in tropical upwelling and cold-point temperature induced by lower-stratospheric planetary and gravity wave breaking. The differences in water vapour are due to higher cold-point temperature in 2020 induced by Australian wildfire.
Ivette H. Banos, Will D. Mayfield, Guoqing Ge, Luiz F. Sapucci, Jacob R. Carley, and Louisa Nance
Geosci. Model Dev., 15, 6891–6917, https://doi.org/10.5194/gmd-15-6891-2022, https://doi.org/10.5194/gmd-15-6891-2022, 2022
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A prototype data assimilation system for NOAA’s next-generation rapidly updated, convection-allowing forecast system, or Rapid Refresh Forecast System (RRFS) v0.1, is tested and evaluated. The impact of using data assimilation with a convective storm case study is examined. Although the convection in RRFS tends to be overestimated in intensity and underestimated in extent, the use of data assimilation proves to be crucial to improve short-term forecasts of storms and precipitation.
Laysa C. A. Resende, Yajun Zhu, Clezio M. Denardini, Sony S. Chen, Ronan A. J. Chagas, Lígia A. Da Silva, Carolina S. Carmo, Juliano Moro, Diego Barros, Paulo A. B. Nogueira, José P. Marchezi, Giorgio A. S. Picanço, Paulo Jauer, Régia P. Silva, Douglas Silva, José A. Carrasco, Chi Wang, and Zhengkuan Liu
Ann. Geophys., 40, 191–203, https://doi.org/10.5194/angeo-40-191-2022, https://doi.org/10.5194/angeo-40-191-2022, 2022
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This study showed the ionospheric response over low-latitude regions in Brazil predicted by Martínez-Ledesma et al. (2020) for the solar eclipse event on 14 December 2020. We used a multi-instrumental and modeling analysis to observe the modifications in the E and F regions and the Es layers over Campo Grande and Cachoeira Paulista. The results showed that solar eclipses can cause significant ionosphere modifications even though they only partially reach the Brazilian low-latitude regions.
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.
Manfred Ern, Mohamadou Diallo, Peter Preusse, Martin G. Mlynczak, Michael J. Schwartz, Qian Wu, and Martin Riese
Atmos. Chem. Phys., 21, 13763–13795, https://doi.org/10.5194/acp-21-13763-2021, https://doi.org/10.5194/acp-21-13763-2021, 2021
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Details of the driving of the semiannual oscillation (SAO) of the tropical winds in the middle atmosphere are still not known. We investigate the SAO and its driving by small-scale gravity waves (GWs) using satellite data and different reanalyses. In a large altitude range, GWs mainly drive the SAO westerlies, but in the upper mesosphere GWs seem to drive both SAO easterlies and westerlies. Reanalyses reproduce some features of the SAO but are limited by model-inherent damping at upper levels.
Felix Ploeger, Mohamadou Diallo, Edward Charlesworth, Paul Konopka, Bernard Legras, Johannes C. Laube, Jens-Uwe Grooß, Gebhard Günther, Andreas Engel, and Martin Riese
Atmos. Chem. Phys., 21, 8393–8412, https://doi.org/10.5194/acp-21-8393-2021, https://doi.org/10.5194/acp-21-8393-2021, 2021
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We investigate the global stratospheric circulation (Brewer–Dobson circulation) in the new ECMWF ERA5 reanalysis based on age of air simulations, and we compare it to results from the preceding ERA-Interim reanalysis. Our results show a slower stratospheric circulation and higher age for ERA5. The age of air trend in ERA5 over the 1989–2018 period is negative throughout the stratosphere, related to multi-annual variability and a potential contribution from changes in the reanalysis system.
Mohamadou Diallo, Manfred Ern, and Felix Ploeger
Atmos. Chem. Phys., 21, 7515–7544, https://doi.org/10.5194/acp-21-7515-2021, https://doi.org/10.5194/acp-21-7515-2021, 2021
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Despite good agreement in the spatial structure, there are substantial differences in the strength of the Brewer–Dobson circulation (BDC) and its modulations in the UTLS and upper stratosphere. The tropical upwelling is generally weaker in ERA5 than in ERAI due to weaker planetary and gravity wave breaking in the UTLS. Analysis of the BDC trend shows an acceleration of the BDC of about 1.5 % decade-1 due to the long-term intensification in wave breaking, consistent with climate predictions.
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.
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Short summary
We studied how the Intertropical Convergence Zone (ITCZ) interacts with atmospheric gravity waves high in the sky and how global climate patterns like El Niño affect them. Using RO, ERA5, and NCEP reanalysis data, we found that the ITCZ shifts with season but stays strong year-round, influencing weather and energy flow. Our findings show how climate patterns shape weather systems and help predict changes, improving understanding of the atmosphere and its effects on global climate.
We studied how the Intertropical Convergence Zone (ITCZ) interacts with atmospheric gravity...
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