Articles | Volume 36, issue 2
Ann. Geophys., 36, 301–310, 2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue: Space weather connections to near-Earth space and the...
Regular paper 05 Mar 2018
Regular paper | 05 Mar 2018
Mesopause region temperature variability and its trend in southern Brazil
Mateus S. Venturini et al.
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Juliano Moro, Jiyao Xu, Clezio Marcos Denardini, Laysa Cristina Araújo Resende, Régia Pereira Silva, Sony Su Chen, Giorgio Arlan da Silva Picanço, Liu Zhengkuan, Hui Li, Chunxiao Yan, Chi Wang, and Nelson Jorge Schuch
Ann. Geophys., 38, 457–466,Short summary
The monthly averages of the F2 critical frequency (foF2), its peak height (hmF2), and the E-region critical frequency (foE) acquired by the DPS4-D installed in Santa Maria, Brazil, is compared to the International Reference Ionosphere (IRI-2016) model predictions. It is important to test the performance of the IRI over Santa Maria because it is located in the SAMA, which is a region particularly important for high-frequency (HF) ground-to-satellite navigation signals.
Nelson Bègue, Lerato Shikwambana, Hassan Bencherif, Juan Pallotta, Venkataraman Sivakumar, Elian Wolfram, Nkanyiso Mbatha, Facundo Orte, David Jean Du Preez, Marion Ranaivombola, Stuart Piketh, and Paola Formenti
Ann. Geophys., 38, 395–420,Short summary
This study investigates the influence of the 2015 Calbuco eruption (41.2°S, 72.4°W; Chile) on the total columnar aerosol optical properties in the Southern Hemisphere. The well-known technique of sun photometry was applied to the investigation of the transport and the spatio-temporal evolution of the optical properties of the volcanic plume. The CIMEL sun photometer measurements performed over six South American and three African sites were statistically analyzed.
Emilia Correia, Luis Tiago Medeiros Raunheitte, José Valentin Bageston, and Dino Enrico D'Amico
Ann. Geophys., 38, 385–394,Short summary
Here the investigation of gravity wave (GW) properties in the low ionosphere using very low frequency (VLF) radio signals is presented. The VLF technique is a powerful tool to obtain the wave period and duration of GW events in the low ionosphere. It can be used independent of sky conditions, during daytime and year-round, which is an advantage in comparison with airglow all-sky imagers.
Gabriela Dornelles Bittencourt, Damaris Kirsch Pinheiro, José Valentin Bageston, Hassan Bencherif, Luis Angelo Steffenel, and Lucas Vaz Peres
Ann. Geophys., 37, 1049–1061,Short summary
The Antarctic ozone hole (AOH) directly influences the Antarctic region, where its levels can reach values below 220 DU. The temporary depletion of ozone in Antarctica generally occurs between the beginning and middle of August, during the austral spring, and extends to November, when a temporary reduction in ozone content is observed in a large region over Antarctica. However, masses of ozone-depleted air can break away from the ozone hole and reach mid-latitude regions.
Kévin Lamy, Thierry Portafaix, Béatrice Josse, Colette Brogniez, Sophie Godin-Beekmann, Hassan Bencherif, Laura Revell, Hideharu Akiyoshi, Slimane Bekki, Michaela I. Hegglin, Patrick Jöckel, Oliver Kirner, Ben Liley, Virginie Marecal, Olaf Morgenstern, Andrea Stenke, Guang Zeng, N. Luke Abraham, Alexander T. Archibald, Neil Butchart, Martyn P. Chipperfield, Glauco Di Genova, Makoto Deushi, Sandip S. Dhomse, Rong-Ming Hu, Douglas Kinnison, Michael Kotkamp, Richard McKenzie, Martine Michou, Fiona M. O'Connor, Luke D. Oman, Giovanni Pitari, David A. Plummer, John A. Pyle, Eugene Rozanov, David Saint-Martin, Kengo Sudo, Taichu Y. Tanaka, Daniele Visioni, and Kohei Yoshida
Atmos. Chem. Phys., 19, 10087–10110,Short summary
In this study, we simulate the ultraviolet radiation evolution during the 21st century on Earth's surface using the output from several numerical models which participated in the Chemistry-Climate Model Initiative. We present four possible futures which depend on greenhouse gases emissions. The role of ozone-depleting substances, greenhouse gases and aerosols are investigated. Our results emphasize the important role of aerosols for future ultraviolet radiation in the Northern Hemisphere.
Pablo Facundo Orte, Elian Wolfram, Jacobo Salvador, Akira Mizuno, Nelson Bègue, Hassan Bencherif, Juan Lucas Bali, Raúl D'Elia, Andrea Pazmiño, Sophie Godin-Beekmann, Hirofumi Ohyama, and Jonathan Quiroga
Ann. Geophys., 37, 613–629,Short summary
We analysed an event of short-term ozone variability due to the passage of the polar vortex over Río Gallegos (southern Argentina) with the aim of highlighting the capability of a millimetre-wave radiometer to observe ozone in the stratosphere and the low mesosphere with a high temporal resolution. It is particularly important in this subpolar region due to the high variation that this gas can suffer as a consequence of the passage of the polar vortex and the ozone hole during spring.
Nelson J. Schuch, Rodrigo P. Marques, Otávio S. C. Durão, Marlos R. da Silva, Odim Mendes, Fátima Mattiello-Francisco, Andrei P. Legg, André L. da Silva, Fernando S. Pedroso, and Eduardo E. Bürger
Ann. Geophys. Discuss.,
Preprint withdrawnShort summary
The Brazilian INPE-UFSM NANOSATC-BR CubeSats Development Program consists of two CubeSats, NANOSATC-BR1 (1U) & NANOSATC-BR2 (2U). NANOSATC-BR2 is expected to operate in orbit for at least 12 months, while NANOSATC-BR1 this year has completed more than four years in orbit operation. This paper focuses on the future development of NANOSATC-BR3 & NANOSATC-BR4, in a partnership with the UFSM's Aerospace Engineering Course and on the launching of NANOSATC-BR2.
David J. du Preez, Jelena V. Ajtić, Hassan Bencherif, Nelson Bègue, Jean-Maurice Cadet, and Caradee Y. Wright
Ann. Geophys., 37, 129–141,Short summary
Reduced atmospheric ozone results in increased solar ultraviolet radiation (UVR) at the surface which may potentially negative impact public health. We aimed to assess whether or not the break-up of the Antarctic ozone hole had an impact on ozone and UVR at Cape Point (South Africa). We found a moderate inverse relationship between ozone and UVR at midday on clear-sky days. The Antarctic ozone hole had a limited effect on ozone levels while tropical air masses more frequently affected the site.
Abdoulwahab Mohamed Toihir, Thierry Portafaix, Venkataraman Sivakumar, Hassan Bencherif, Andréa Pazmiño, and Nelson Bègue
Ann. Geophys., 36, 381–404,
Caroline Bresciani, Gabriela Dornelles Bittencourt, José Valentin Bageston, Damaris Kirsch Pinheiro, Nelson Jorge Schuch, Hassan Bencherif, Neusa Paes Leme, and Lucas Vaz Peres
Ann. Geophys., 36, 405–413,Short summary
This paper investigates the passage of the ozone secondary effect (OSE) over southern Brazil and Uruguay in October 2016 by using multi-instrumental data, i.e. ozonesonde, satellites and ground-based instruments, and the large OSE influence on the ozone concentration and on the temperature was shown.
Gabriela Dornelles Bittencourt, Caroline Bresciani, Damaris Kirsch Pinheiro, José Valentin Bageston, Nelson Jorge Schuch, Hassan Bencherif, Neusa Paes Leme, and Lucas Vaz Peres
Ann. Geophys., 36, 415–424,Short summary
Ozone-poor air mass can be released and leave through the Antarctic ozone hole, thus reaching midlatitude regions. The objective of this study is to show how tropospheric and stratospheric dynamics behaved during the event. The ozone-poor air mass began to operate in the region on 20 October 2016. A reduction of ozone content of approximately 23 % was observed in relation to the climatology average. The advance of the ozone-poor air mass caused intense reductions in total ozone content.
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,Short summary
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.
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,Short summary
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.
Kévin Lamy, Thierry Portafaix, Colette Brogniez, Sophie Godin-Beekmann, Hassan Bencherif, Béatrice Morel, Andrea Pazmino, Jean Marc Metzger, Frédérique Auriol, Christine Deroo, Valentin Duflot, Philippe Goloub, and Charles N. Long
Atmos. Chem. Phys., 18, 227–246,Short summary
This work focuses on solar radiation in the tropics, more specifically on ultraviolet radiation. From ground-based and satellite observations of the chemical state of the atmosphere, we were able to model the ultraviolet measurements measured in the southern tropics with a very small error. This is a first step to modelling and predicting future ultraviolet levels in the tropics from chemistry-climate projections.
Nelson Bègue, Damien Vignelles, Gwenaël Berthet, Thierry Portafaix, Guillaume Payen, Fabrice Jégou, Hassan Benchérif, Julien Jumelet, Jean-Paul Vernier, Thibaut Lurton, Jean-Baptiste Renard, Lieven Clarisse, Vincent Duverger, Françoise Posny, Jean-Marc Metzger, and Sophie Godin-Beekmann
Atmos. Chem. Phys., 17, 15019–15036,Short summary
The space–time evolutions of the Calbuco plume are investigated by combining satellite, in situ aerosol counting and lidar observations, and a numerical model. All the data at Reunion Island reveal a twofold increase in the amount of aerosol with respect to the values observed before the eruption. The dynamic context has favored the spread of the plume exclusively in the Southern Hemisphere. This study highlights the role played by dynamical barriers in the transport of atmospheric species.
Nelson Bègue, Nkanyiso Mbatha, Hassan Bencherif, René Tato Loua, Venkataraman Sivakumar, and Thierry Leblanc
Ann. Geophys., 35, 1177–1194,Short summary
In this investigation a statistical analysis of the characteristics of mesospheric inversion layers (MILs) over tropical regions is presented. This study involves the analysis of 16 years of lidar observations recorded at Reunion (20.8° S, 55.5° E) and 21 years of lidar observations recorded at Mauna Loa (19.5° N, 155.6° W) together with SABER observations at these two locations. Results presented in this study confirm that SAO contributes to the formation of MILs over the tropical region.
Lucas Vaz Peres, Hassan Bencherif, Nkanyiso Mbatha, André Passaglia Schuch, Abdoulwahab Mohamed Toihir, Nelson Bègue, Thierry Portafaix, Vagner Anabor, Damaris Kirsch Pinheiro, Neusa Maria Paes Leme, José Valentin Bageston, and Nelson Jorge Schuch
Ann. Geophys., 35, 25–37,Short summary
In this paper, we analyze the total ozone column over the Southern Space Observatory, Brazil, between 1992 and 2014 by Brewer spectrometer and TOMS and OMI satellite instruments, finding good agreement between the two. In addition, the seasonal TOC variation is dominated by an annual cycle, and the Quasi-Biennial Oscillation modulation was the main mode of interannual variability and in opposite phase to the total ozone column anomaly time series.
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,Short summary
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.
In the past years, the study of the temperature trend and its variability in the upper atmosphere has increased. However, most works were conducted in regions of medium and high latitude. Therefore, we aim to analyze a low-latitude region, the south of Brazil and surrounding areas. Using data from the TIMED/SABER instrument and applying the Trend-Run model for temperature trend analyses, no substantial temperature trend was found in the MLT region (80–100 km) from the years 2003 to 2014.
In the past years, the study of the temperature trend and its variability in the upper...