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3. Surface Temperature Trend Estimation over 12 Sites in Guinea Using 57 Years of Ground-Based Data

Author

Loua, René Tato, Bencherif, Hassan, Bègue, Nelson, Mbatha, Nkanyiso, Portafaix, Thierry, Hauchecorne, Alain, Sivakumar, Venkataraman, and Bamba, Zoumana

Subjects
Physics - Atmospheric and Oceanic Physics
Abstract

Trend-Run model was performed to estimate the trend in surface temperatures recorded at 12 sites in Guinea from 1960 to 2016 and to examine the contribution of each climate forcing. The coefficient of determination (R 2) calculated varies between 0.60 and 0.90, it provides total information about the simulation capability of the model. The decadal trend values also calculated show an upward trend (between 0.04 {\textdegree}C $\pm$ 0.06 {\textdegree}C decade --1 and 0.21 {\textdegree}C $\pm$ 0.06 {\textdegree}C decade --1). In addition, forcings' contributions were quantified, and the annual oscillation (AO) contribution is higher for most of the stations, followed by semiannual oscillation (SAO). Among the forcings, the tropical Northern Atlantic (TNA) contribution is greater than that of the sunspot number (SSN), Ni{\~n}o3.4 and Atlantic Ni{\~n}o (AN). Moreover, the Mann-Kendall test revealed a positive significant trend for all stations except at the Macenta site. Additionally, with sequential Mann-Kendall test, trend turning points were found only for the stations of Mamou, Koundara and Macenta at different dates. The temperature anomalies depict warming episodes (1970s, 1980s, 1984 and 1990s). Since then, the temperature is consistently increasing over the country. A significant warming has been shown, which might be further investigated using these models with additional contributing factors.

Published
2020
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4. Observations, Remote Sensing, and Model Simulation to Analyze Southern Brazil Antarctic Ozone Hole Influence

Author

Peres, Lucas Vaz, primary, Pinheiro, Damaris Kirsh, additional, Bencherif, Hassan, additional, Begue, Nelson, additional, Bageston, José Valentin, additional, Bittencourt, Gabriela Dorneles, additional, Portafaix, Thierry, additional, Schuch, Andre Passaglia, additional, Anabor, Vagner, additional, da Silva, Rodrigo, additional, Neves, Theomar Trindade de Araujo Tiburtino, additional, Silva, Raphael Pablo Tapajós, additional, dos Reis, Gabriela Cacilda Godinho, additional, dos Reis, Marco Antônio Godinho, additional, Martins, Maria Paulete Pereira, additional, Toihir, Mohamed Abdoulwahab, additional, Mbatha, Nkanyiso, additional, Steffenel, Luiz Angelo, additional, and Mendes, David, additional

Published
2024
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5. First-time calculation of the spatial distribution of concentration and air quality index over South Africa using TROPOMI data.

Author

Shikwambana, Lerato, Kganyago, Mahlatse, Mbatha, Nkanyiso, and Mhangara, Paidamwoyo

Subjects
AIR quality indexes, AIR pollutants, CARBON monoxide, AIR quality, NITROGEN dioxide, POLLUTANTS
Abstract

The release of toxic gases into the atmosphere may reach concentrations that can cause undesirable health, economic, or aesthetic effects. It is therefore important to monitor the amounts of pollutants injected into the atmosphere from various sources. Most countries have a ground network with multiple measuring sites and instruments, that can measure the air quality index (AQI). However, the main challenge with the networks is the low spatial coverage. In this work, satellite data is used to calculate for the first time the spatial distribution of AQI and pollutant concentration over South Africa. The TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinel-5P data is used to calculate AQI from carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide (SO2) gases. The results that the month of June has the worst air quality distribution throughout the country, while March has the best air quality distribution. Overall, the results clearly show that TROPOMI has the capability to measure air quality at a country and city level. Implications: In this work, satellite data is used to calculate for the first time the spatial distribution of the air quality index (AQI) and pollutant concentration over South Africa. The TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinel-5P data is used to calculate AQI from carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide (SO2) gases. Currently, South Africa has a ground network of instruments that measure AQ, however, the network does not cover the whole country. In this work, we show that the use of TROPOMI can compliment the current network and provide data for the areas not covered. [ABSTRACT FROM AUTHOR]

Published
2024
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7. Ozone Trend Analysis in Natal (5.4°S, 35.4°W, Brazil) Using Multi-Linear Regression and Empirical Decomposition Methods over 22 Years of Observations

Author

Bencherif, Hassan, primary, Pinheiro, Damaris Kirsch, additional, Delage, Olivier, additional, Millet, Tristan, additional, Peres, Lucas Vaz, additional, Bègue, Nelson, additional, Bittencourt, Gabriela, additional, Martins, Maria Paulete Pereira, additional, Raimundo da Silva, Francisco, additional, Steffenel, Luiz Angelo, additional, Mbatha, Nkanyiso, additional, and Anabor, Vagner, additional

Published
2024
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10. Observations, Remote Sensing and Model Simulation to Ana-lyze Southern Brazil Antarctic Ozone Hole Influence

Author

Peres, Lucas Vaz, primary, Pinheiro, Damaris Kirsch, additional, Bencherif, Hassan, additional, Bègue, Nelson, additional, Bageston, José Valentin, additional, Bittencourt, Gabriela Dornelles, additional, Portafaix, Thierry, additional, Schuch, André Passaglia, additional, Anabor, Vagner, additional, Da Silva, Rodrigo, additional, Neves, Theomar Trindade, additional, Silva, Raphael Tapajós, additional, Dos Reis, Gabriela Godinho, additional, Dos Reis, Marco Godinho, additional, Martins, Maria Paulete, additional, Toihir, Mohamed A., additional, Mbatha, Nkanyiso, additional, Steffenel, Luiz Angelo, additional, and Mendes, David, additional

Published
2023
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14. Aerosol Optical Properties and Types over Southern Africa and Reunion Island Determined from Ground-Based and Satellite Observations over a 13-Year Period (2008–2021)

Author

Ranaivombola, Marion, primary, Bègue, Nelson, additional, Bencherif, Hassan, additional, Millet, Tristan, additional, Sivakumar, Venkataraman, additional, Duflot, Valentin, additional, Baron, Alexandre, additional, Mbatha, Nkanyiso, additional, Piketh, Stuart, additional, Formenti, Paola, additional, and Goloub, Philippe, additional

Published
2023
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21. Ozone Variability and Trend Estimates from 20-Years of Ground-Based and Satellite Observations at Irene Station, South Africa

Author

Bencherif, Hassan, Toihir, Abdoulwahab M., Mbatha, Nkanyiso, Sivakumar, Venkataraman, Preez, David Jean du, Bègue, Nelson, Coetzee, Gerrie, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, University of KwaZulu-Natal (UKZN), Agence nationale de l'aviation Civile et de la Météorologie, University of Pretoria [South Africa], South African Weather Service (SAWS), and This research was funded jointly by the CNRS (Centre National de la Recherche Scientifique) and the NRF (National Research Foundation) in the framework of the IRP ARSAIO and by the South Africa/France PROTEA Program (project No. 42470VA), and by Université de la Réunion through the OMNCG (Observatoire des Milieux Naturels et des Changements Globaux) federation of the OSU-Reunion (Observatoire des Sciences de l’Univers—La Réunion)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, South Africa, atmospheric composition, southern tropics, lcsh:Meteorology. Climatology, ddc:610, ozone trend, lcsh:QC851-999
Abstract

While the stratospheric ozone protects the biosphere against ultraviolet (UV) radiation, tropospheric ozone acts like a greenhouse gas and an indicator of anthropogenic pollution. In this paper, we combined ground-based and satellite ozone observations over Irene site (25.90&deg, S, 28.22&deg, E), one of the most ancient ozone-observing stations in the southern tropics. The dataset is made of daily total columns and weekly profiles of ozone collected over 20 years, from 1998 to 2017. In order to fill in some missing data and split the total column of ozone into a tropospheric and a stratospheric column, we used satellite observations from TOMS (Total Ozone Mapping Spectrometer), OMI (Ozone Monitoring Instrument), and MLS (Microwave Limb Sounder) experiments. The tropospheric column is derived by integrating ozone profiles from an ozonesonde experiment, while the stratospheric column is obtained by subtracting the tropospheric column from the total column (recorded by the Dobson spectrometer), and by assuming that the mesospheric contribution is negligible. Each of the obtained ozone time series was then analyzed by applying the method of wavelet transform, which permitted the determination of the main forcings that contribute to each ozone time series. We then applied the multivariate Trend-Run model and the Mann&ndash, Kendall test for trend analysis. Despite the different analytical approaches, the obtained results are broadly similar and consistent. They showed a decrease in the stratospheric column (&minus, 0.56% and &minus, 1.7% per decade, respectively, for Trend-Run and Mann&ndash, Kendall) and an increase in the tropospheric column (+2.37% and +3.6%, per decade, respectively, for Trend-Run and Mann&ndash, Kendall). Moreover, the results presented here indicated that the slowing down of the total ozone decline is somewhat due to the contribution of the tropospheric ozone concentration.

Published
2020

22. Stratosphere–Troposphere Exchange and O3 Decline in the Lower Stratosphere over Irene SHADOZ Site, South Africa

Author

Mkololo, Thumeka, Mbatha, Nkanyiso, Venkataraman, Sivakumar, Begue, Nelson, Coetzee, Gerrie, and Labuschagne, Casper

Subjects
atmospheric_science
Abstract

This study aims to investigate the Stratosphere-Troposphere Exchange (STE) events and ozone trends over Irene (25.5°S, 28.1°E). Twelve years of ozonesondes data (2000–2007, 2012–2015) from Irene station operating in the framework of the Southern Hemisphere Additional Ozonesodes (SHADOZ) was used to study the troposphere (0–16 km) and stratosphere (17– 28 km) ozone (O3) vertical profiles. Ozone profiles were grouped into three categories (2000–2003, 2004–2007 and 2012–2015) and average composites were calculated for each category. Fifteen O3 enhancement events were identified over the study period. These events were observed in all seasons (one event in summer, four events in autumn, five events in winter and five events in spring), however, they predominantly occur in winter and spring. The STE events presented here are observed to be influenced by the Southern Hemisphere polar vortex. During the STE events, the advected potential vorticity maps assimilated using Modélisation Isentrope du transport Méso–échelle de l’Ozone Stratosphérique par Advection (MIMOSA) model for the 350 K (~12–13 km) isentropic level indicated a transport of high latitude air masses which seems to be responsible for the reduction of the O3 mole fractions at the lower stratosphere over Irene which takes place at the same time with the enhancement of ozone in the upper troposphere. In general, the stratosphere is dominated by higher Modern Retrospective Analysis for Research Application (MERRA-2) potential vorticity (PV) values compared to the troposphere. However, during the STE events, higher PV values from the stratosphere were observed to intrude the troposphere. Ozone decline was observed from 12 km to 24 km with highest decline occurring from 14 km to 18 km. An average decrease of 6.0 and 9.1% was calculated from 12 to 24 km in 2004–2007 and 2012–2015 respectively. The observed decline occurred in the upper troposphere and lower stratosphere with winter and spring showing more decline compared with summer and autumn.

Published
2020

23. Statistical analysis of the long-range transport of the 2015 Calbuco volcanic plume from ground-based and space-borne observations

Author

Bègue, Nelson, Shikwambana, Lerato, Bencherif, Hassan, Pallotta, Juan, Sivakumar, Venkataraman, Wolfram, Elian, Mbatha, Nkanyiso, Orte, Facundo, Du Preez, David Jean, Ranaivombola, Marion, Piketh, Stuart, Formenti, Paola, Laboratoire de l'Atmosphère et des Cyclones (LACy), Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), South African National Space Agency (SANSA), University of KwaZulu-Natal (UKZN), Centro de Investigaciones en Láseres y Aplicaciones [Buenos Aires] (CEILAP), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF), University of ZuluLand, University of Pretoria [South Africa], Unit for Environmental Sciences and Management, North-West University [South Aftrica] (NWU), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), The authors acknowledge the South African–French PROTEA programme (project no. 42470VA) and CNRS-NRF LIA ARSAIO (Atmospheric Research in Southern Africa and Indian Ocean) for supporting the research activities. This work was supported by the French–Argentine ECOS-Sud A16U01 project and the Université de la Réunion through the federation Observatoire des Milieux Naturels et des Changements Globaux (OMNCG) of the OSU-R (Observatoire des Sciences de l'Univers – La Reunion)., Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, School of Chemistry and Physics [Durban], University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), Departement of Geography [UniZulu], Department of Geography, Geoinformatics and Meteorology [Pretoria], North-West University [Potchefstroom] (NWU), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), This work was supported by the French–Argentine ECOS-Sud A16U01 project and the Université de la Réunion through the federation Observatoire des Milieux Naturels et des Changements Globaux (OMNCG) of the OSU-R (Observatoire des Sciences de l'Univers – La Reunion)., and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France

Subjects
purl.org/becyt/ford/1 [https], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, trasnporte, purl.org/becyt/ford/1.5 [https], cenizas, aerosoles
Abstract

This study investigates the influence of the 2015 Calbuco eruption (41.2∘ S, 72.4∘ W; Chile) on the total columnar aerosol optical properties over the Southern Hemisphere. The well-known technic of sun photometry was applied for the investigation of the transport and spatio-temporal evolution of the optical properties of the volcanic plume. The CIMEL sun photometer measurements performed at six South American and three African sites were statistically analysed. This study involves the use of the satellite observations and a back-trajectory model. The passage of the Calbuco plume is statistically detectable in the aerosol optical depth (AOD) observations obtained from sun photometer and MODIS observations. This statistical detection confirms that the majority of the plume was transported over the northeastern parts of South America and reached the South African region 1 week after the eruption. The plume impacted the southern parts of South America to a lesser extent. The highest AOD anomalies were observed over the northeastern parts of South America. Over the South African sites, the AOD anomalies induced by the spread of the plume were quite homogeneously distributed between the east and west coasts. The optical characteristics of the plume near the source region were consistent with an ash-bearing plume. Conversely, sites further from the Calbuco volcano were influenced by ash-free plume. The optical properties discussed in this paper will be used as inputs for numerical models for further investigation of the ageing of the Calbuco plume in a forthcoming study. Fil: Bègue, Nelson. Université de la Réunion; Francia. Centre National de la Recherche Scientifique; Francia Fil: Shikwambana, Lerato. University of Kwazulu Natal; Sudáfrica. South African National Space Agency; Sudáfrica Fil: Bencherif, Hassan. Université de la Réunion; Francia. University of Kwazulu Natal; Sudáfrica Fil: Pallotta, Juan Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina Fil: Sivakumar, Venkataraman. University of Kwazulu Natal; Sudáfrica Fil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina Fil: Mbatha, Nkanyiso. University Of Zululand; Sudáfrica Fil: Orte, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina Fil: Jean Du Preez, David. Université de la Réunion; Francia. University of Pretoria; Sudáfrica Fil: Ranaivombola, Marion. Université de la Réunion; Francia Fil: Piketh, Stuart. North-west University; Sudáfrica Fil: Formenti, Paola. Universite de Paris; Francia

Published
2020

25. Investigating the Long-Range Transport of Aerosol Plumes Following the Amazon Fires (August 2019): A Multi-Instrumental Approach from Ground-Based and Satellite Observations

Author

Bencherif, Hassan, primary, Bègue, Nelson, additional, Kirsch Pinheiro, Damaris, additional, du Preez, David Jean, additional, Cadet, Jean-Maurice, additional, da Silva Lopes, Fábio Juliano, additional, Shikwambana, Lerato, additional, Landulfo, Eduardo, additional, Vescovini, Thomas, additional, Labuschagne, Casper, additional, Silva, Jonatan João, additional, Anabor, Vagner, additional, Coheur, Pierre-François, additional, Mbatha, Nkanyiso, additional, Hadji-Lazaro, Juliette, additional, Sivakumar, Venkataraman, additional, and Clerbaux, Cathy, additional

Published
2020
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30. Statistical analysis of the long-range transport of the 2015 Calbuco volcanic eruption from ground-based and space-borne observations

Author

Bègue, Nelson, primary, Shikwambana, Lerato, additional, Bencherif, Hassan, additional, Pallota, Juan, additional, Sivakumar, Venkataraman, additional, Wolfram, Elian, additional, Mbatha, Nkanyiso, additional, Orte, Facundo, additional, Du Preez, David Jean, additional, Ranaivombola, Marion, additional, Piketh, Stuart, additional, and Formenti, Paola, additional

Published
2019
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31. Climatological analysis of temperature and pluviometry in Guinea 1960-2016

Author

Loua, René Tato, Bencherif, Hassan, Mbatha, Nkanyiso, Bègue, Nelson, BAMBA, ZOUMANA, Sivakumar, Venkataraman, Guinea Weather Service (DNM), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Scientifique de Conakry Rogbané (CERESCOR), Departement of Geography [UniZulu], University of ZuluLand, Scientific Research Center of Conakry (CERESCOR), School of Chemistry and Physics [Durban], University of KwaZulu-Natal (UKZN), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Pluviometry, Semi-annual cycle, Temperature, Climate normal, Climate variability in Guinea, Annual cycle
Abstract

International audience; The purpose of this study is to improve the understandings on climate variability in Guinea. The methodology used is based on climatological analysis. The pluviometry and temperature data recorded at 12 meteorological stations were used. The annual variability of temperature shows the semi-annual cycle, and the interannual evolution of monthly mean temperature is characterized by an increasing trend over the years. The pluviometry values seems to indicate a decrease since 1960s, and is characterized by an annual cycle. The northward distributions of the temperature and rainfall show an increase and decrease respectively for the country.

Published
2018

36. Economic growth and income inequality: a non-linear econometrics analysis of the SADC region, 1990–2015

Author

Zungu, Lindokuhle Talent, Greyling, Lorraine, and Mbatha, Nkanyiso

Abstract

Purpose: The authors investigate the growth–inequality relationship, using panel data from 13 Southern African Development Community (SADC) countries over the period 1990–2015, to test the validity of the Kuznets and Tribble theories. Furthermore, the authors seek to determine the threshold level at which excessive growth hampers inequality. Design/methodology/approach: The panel smooth transition regression (PSTR) model has several stages. The authors applied the Lagrange multiplier (LM) test to find the appropriate transition variable amongst all candidate variables, to assess the linearity between economic growth and income inequality and to find the sequence for selecting the order mof the transition function. The authors then estimated the PSTR model, but before facilitating the results, the authors first used the wild cluster bootstrap (WCB)–LM-type test to assess the appropriateness of the selected transition. Findings: The authors found that at lower growth, income inequality tends to be lower, while if growth increases above US$8,969, inequality tends to increase in the SADC region. The findings combine into a U-shaped relationship, contradicting the Kuznets and Tribble theories. Originality/value: The contribution of this paper is that it becomes the first to provide the threshold level at which excessive growth increases inequality in the selected countries. This study proposes that policymakers should focus on activities aimed at stimulating growth, in other words, activities such as spending more on infrastructure, drawing up a suitable investment portfolio and spending on technological investment for countries that are below US$8,969. An improvement in these activities will create job opportunities, which in turn will add to economic growth and thus lead to lower income inequality and better social cohesion.

Published
2020
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37. Measurements of the total ozone column using a Brewer spectrophotometer and TOMS and OMI satellite instruments over the Southern Space Observatory in Brazil

Author

Vaz Peres, Lucas, primary, Bencherif, Hassan, additional, Mbatha, Nkanyiso, additional, Passaglia Schuch, André, additional, Toihir, Abdoulwahab Mohamed, additional, Bègue, Nelson, additional, Portafaix, Thierry, additional, Anabor, Vagner, additional, Kirsch Pinheiro, Damaris, additional, Paes Leme, Neusa Maria, additional, Bageston, José Valentin, additional, and Schuch, Nelson Jorge, additional

Published
2017
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38. Studies on CO distribution over South Africa, Madagascar and Reunion Island using Tropospheric Emission Spectrometer (TES) data

Author

Abdoulwahab , Mohamed Toihir, Sivakumar, Venkataraman, Mbatha, Nkanyiso, Bencherif, Hassan, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), University of KwaZulu-Natal (UKZN), South African National Space Agency (SANSA), South African National Space Agency, and School of Chemistry and Physics [Durban]

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Studies on CO distribution over South Africa, Madagascar and Reunion Island using Tropospheric Emission Spectrometer (TES) data

Published
2012

39. Durban lidar for atmospheric studies : current status

Author

Sivakumar, Venkataraman, Mbatha, Nkanyiso, Bencherif, Hassan, Keckhut, Philippe, School of Chemistry and Physics [Durban], University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), South African National Space Agency (SANSA), South African National Space Agency, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Cardon, Catherine, University of KwaZulu-Natal (UKZN), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

In this paper, we briefly describe the Durban atmospheric lidar (Light Detection and Ranging) system for the measurements of vertical profiles of temperature and aerosol. The Durban lidar has been operated at University of KwaZulu-Natal (UKZN) as apart of co-operation between the Reunion University and the Service d'Aéronomie (CNRS, IPSL, Paris) for climate research studies. Here, we describe the present system details and important specification. Sample results are provided from the earlier collected datasets.

Published
2012

40. Simultaneous observation of aerosols using the Durban and Reunion lidar systems

Author

Bongumusa Mbatha, Nkanyiso, Sivakumar, Venkataraman, Bencherif, Hassan, Keckhut, Philippe, South African National Space Agency (SANSA), South African National Space Agency, University of KwaZulu-Natal (UKZN), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, and Cardon, Catherine

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDE.MCG] Environmental Sciences/Global Changes, [SDU.STU.CL] Sciences of the Universe [physics]/Earth Sciences/Climatology, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, [SDE.MCG]Environmental Sciences/Global Changes, [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

The observation of aerosols over Durban (29.9˚S, 31.0˚E, South Africa) and Reunion Island (20.8˚S, 55.5˚E) using Rayleigh-Mie lidar data collected during a coincident night of 21 May 2003 is presented in this paper. The temporal evolution of the Durban lidar backscatter signal for the corresponding night is used to study aerosols and clouds condition. The aerosol loading in the lower stratosphere is discussed in terms of aerosol extinction coefficient during this coincident night. A clear enhancement due to the presence of aerosols over Durban at the height level above 6 km is observed. The coincident profile of the aerosol extinction coefficient measured by the Durban and the Reunion lidar shows consistency during this day, with maximum observed at ~17 km for both lidars. However, the Reunion lidar shows higher aerosol extinction coefficient values.

Published
2012

42. Durban Rayleigh LiDAR measurments of stratospheric-mesospheric temperature structures

Author

Mbatha, Nkanyiso, Sivakumar, Venkataraman, Malinga, Sandile B., Bencherif, Hassan, Pillay, Sadhasivan R., Moorgawa, Ashokabose, Michaelis, Max M., South African National Space Agency (SANSA), South African National Space Agency, School of Chemistry and Physics [Durban], University of KwaZulu-Natal (UKZN), Laboratoire de l'Atmosphère et des Cyclones (LACy), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Durban Rayleigh LiDAR measurments of stratospheric-mesospheric temperature structures

Published
2010

43. Study on the impact of Sudden Stratospheric warming in the upper mesosphere and lower thermosphere region using satellite and HF radar measurements

Author

Mbatha, Nkanyiso, Malinga, Sandile B., Sivakumar, Venkataraman, Pillay, Sadhasivan R., Bencherif, Hassan, South African National Space Agency (SANSA), South African National Space Agency, School of Chemistry and Physics [Durban], University of KwaZulu-Natal (UKZN), Laboratoire de l'Atmosphère et des Cyclones (LACy), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Study on the impact of Sudden Stratospheric warming in the upper mesosphere and lower thermosphere region using satellite and HF radar measurements

Published
2009

44. LiDAR for Atmosphere Research over Africa (LARA)

Author

Sivakumar, Venkataraman, Moema, D., Bollig, C., Sharma, A., Mbatha, Nkanyiso, Malinga, Sandile B., Mengistu, G., Bencherif, Hassan, Keckhut, Philippe, Council for Scientific and Industrial Research [Pretoria] (CSIR), Tshwane University of Technology [Pretoria] (TUT), Hermanus Magnetic Observatory, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Addis Ababa University (AAU), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; This paper describes the LIDAR for atmosphere research over Africa and current initiatives being undertaken in South Africa. A mobile LIDAR system is being developed at the Council for Scientific and Industrial Research (CSIR) National Laser Centre (NLC), Pretoria (25°5 ′ S;28°2 ′ E), South Africa, for remote sensing the atmosphere. The initial results conclude that the system is capable of providing aerosol/cloud backscatter measurements for the height region from ground to 40 km with a 10 m vertical height resolution.

Published
2008

45. Mesosphere-Lower Thermosphere (MLT) atmospheric structure, coupling and dynamics using ground-based and satellite instruments

Author

Mbatha, Nkanyiso, Malinga, Sandile B., Sivakumar, Venkataraman, Pillay, Sadhasivan R., Bencherif, Hassan, South African National Space Agency (SANSA), South African National Space Agency, School of Chemistry and Physics [Durban], University of KwaZulu-Natal (UKZN), Laboratoire de l'Atmosphère et des Cyclones (LACy), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about Mesosphere-Lower Thermosphere (MLT) atmospheric structure, coupling and dynamics using ground-based and satellite instruments

Published
2008

46. LIDAR for atmosphere Research over Africa: A trilateral research programme (LARA-TRIP)

Author

Sivakumar, Venkataraman, Moema, D., Sharma, A., Mbatha, Nkanyiso, Bollig, C., Malinga, Sandile B., Mengistu, G., Bencherif, Hassan, Keckhut, Philippe, National Laser Centre [Pretoria] (NLC), Council for Scientific and Industrial Research [Pretoria] (CSIR), Tshwane University of Technology [Pretoria] (TUT), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Hermanus Magnetic Observatory, South African National Space Agency (SANSA), South African National Space Agency, School of Chemistry and Physics [Durban], University of KwaZulu-Natal [Durban, Afrique du Sud] (UKZN), Addis Ababa University (AAU), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, and University of KwaZulu-Natal (UKZN)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; This paper describes the importance of LIDAR for atmosphere research over Africa and the initiatives being undertaken to foster such research. A mobile LIDAR system is to be employed for field campaign measurements over different locations around South Africa and Africa.

Published
2008

47. LIDAR for atmosphere Research over Africa (LARA) : A trilateral research programme

Author

Sivakumar, Venkataraman, Mbatha, Nkanyiso, Moema, D., Sharma, A., Bollig, C., Malinga, Sandile B., Mengistu, G., Bencherif, Hassan, Keckhut, Philippe, Council for Scientific and Industrial Research [Pretoria] (CSIR), Hermanus Magnetic Observatory, South African National Space Agency (SANSA), Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Tshwane University of Technology [Pretoria] (TUT), Addis Ababa University (AAU), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about LIDAR for atmosphere Research over Africa (LARA) : A trilateral research programme

Published
2008

48. Measurements of the total ozone column using a Brewer spectrophotometer and TOMS and OMI satellite instruments over the Southern Space Observatory in Brazil.

Author

Peres, Lucas Vaz, Bencherif, Hassan, Mbatha, Nkanyiso, Schuch, André Passaglia, Toihir, Abdoulwahab Mohamed, Bègue, Nelson, Portafaix, Thierry, Anabor, Vagner, Pinheiro, Damaris Kirsch, Paes Leme, Neusa Maria, Bageston, José Valentin, and Schuch, Nelson Jorge

Subjects
SPECTROPHOTOMETERS, OZONE layer, WAVELET transforms, QUASI-biennial oscillation (Meteorology), TIME series analysis
Abstract

This paper presents 23 years (1992-2014) of quasi-continuous measurements of the total ozone column (TOC) over the Southern Space Observatory (SSO) in São Martinho da Serra, Brazil (29.26° S, 53.48° and 488m altitude). The TOC was measured by a Brewer spectrometer, and the results are also compared to daily and monthly observations from the TOMS (Total Ozone Mapping Spectrometer) and OMI (Ozone Monitoring Instrument) satellite instruments. Analyses of the main interannual modes of variability computed using the wavelet transform method were performed. A favorable agreement between the Brewer spectrophotometer and satellite datasets was found. The seasonal TOC variation is dominated by an annual cycle, with a minimum of approximately 260DU in April and a maximum of approximately 295DU in September. The wavelet analysis applied in the SSO TOC anomaly time series revealed that the Quasi-Biennial Oscillation (QBO) modulation was the main mode of interannual variability. The comparison between the SSO TOC anomaly time series with the QBO index revealed that the two are in opposite phases. [ABSTRACT FROM AUTHOR]

Published
2017
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