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Journal of Life Sciences 2012年第3期6卷 335-341页

作者： christine amory-mazaudier LPP/UPMC/Polytechnique/CNRS 4 Avenue de Neptune 94107 Saint-Maur-des-Fossds France

It was in 1995 that, at the end of the international project IEEY （International Equatorial Electrojet Year）, African and European scientists decided to create the IRGGEA （International Group in Geophysics Europe Africa） in order to pursue the scientific work started during the IEEY project, The main objective of IRGGEA was to introduce new fields of research in Africa and built teams of African scientists recognized at an international level in these new fields. To reach this goal, we developed days after days methods to manage smoothly a large network of scientists from developed and developing countries. After a short introduction on the field of research developed in the IRGGEA, we present the organization of the work based on sharing practices and the results obtained in terms of scientific publications and socio-cultural aspects as the increase of the number of women and positions for students in their countries. Such an experience is easy to reproduce.

关键词： Scientific network ethical rules geophysics sustainable research Africa.

Study of Ionospheric Variability Using GNSS Observations

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Positioning 2018年第4期9卷 79-96页

作者： Jouan Taoufiq Bouziani Mourad Azzouzi Rachid christine amory-mazaudier Institute of Agronomy and Veterinary Medicine Rabat Morocco Université Pierre et Marie Curie (UPMC) Paris France T/ICT4D Abdus Salam ICTP Trieste Italy

With the increasing number of applications of Global navigation satellite system, the modeling of the ionosphere is a crucial element for precise positioning. Indeed, the ionosphere delays the electromagnetic waves which pass through it and induces a delay of propagation related to the electronic density (TEC) Total Electronic Content and to the frequency of the wave. The impact of this ionospheric error often results in a poor determination of the station’s position, particularly in strong solar activity. The first part of this paper focuses on a bibliographic study oriented first of all on the study of the ionosphere in relation to solar activity and secondly on the determination of the total electron content using GNSS measurements from the IGS network reference stations. Measurements were made on two permanent stations “RABT”, “TETN”. We selected years of GNSS measurements to evaluate the geomagnetic impact on the ionosphere, 2001, 2009 and 2013. A description of the ionospheric disturbances and geomagnetic storms was analyzed by determination of TEC, especially in high solar activity. The results show a strong dependence of the ionospheric activity with the geomagnetic activity.

关键词： GNSS TEC IGS

Solar Activity, Solar Wind and Geomagnetic Signatures

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Atmospheric and Climate Sciences 2013年第4期3卷 610-617页

作者： Jean-Louis Zerbo Frédéric Ouattara christine amory mazaudier Jean-Pierre Legrand John D. Richardson Ecole Normale Supérieure de l’Université de Koudougou Koudougou Burkina Faso Institut National des Sciences de l’Univers (INSU) Paris France Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology Cambridge USA LPP-Laboratoire de Physique des Plasmas/UPMC/Polytechnique/CNRS Saint-Maur-des-Fossés France Université Polytechnique de Bobo-Dioulasso Bobo-Dioulasso Burkina Faso

The present study investigates solar events through geomagnetic activity and physical processes on the Sun: 1) Quiet activity (QA) related to the slow solar wind, 2) Recurrent activity (RA) related to high and moderate speed solar wind streams from coronal holes, 3) Shock activity (SA) identified by observations of SSCs and 4) Unclear activity (UA) which contains all activity not covered by the first three cases. For recent cycles, we analyze and emphasize some important results: Quiet activity is predominant for cycle 23, comprising 40% of the total activity and over 80% of the activity near solar minimum. Shock and recurrent activity contributions to total geomagnetic activity are largest in cycle 20. The most fluctuating events are observed during cycles 21 and 22. Throughout solar cycle 23, the contribution, from each type of activity, differs from recent solar cycles, with larger percentages of quiet and recurrent activity and less unclear activity. These percentages are similar to those in solar cycles observed in the late 1800s. Since 1963, solar wind data are available. We analyze the distribution of the solar wind velocity for each geomagnetic class of activity and find that: 1) Within each activity type aa does not depend on V, 2) Approximately 80% of the solar wind has V 450 km/s for RA, 3) SA and UA both have 60% of the solar wind V > 450 km/s. We found the following conditions for all four solar cycles: 1) For QA 95% of solar wind speeds are in the range 399 ± 69 km/s, 2) For RA 95% of the solar wind speeds range from 582 ± 110 km/s, 3) For SA 95% of the solar wind velocities are order of 482 ± 101.4 km/s, and 4) For UA 95% of solar wind speeds are 480 ± 85.82 km/s. These results confirm the classification scheme that QA reflects slow wind effects, RA effects high wind stream and UA answers to the fluctuations between high wind stream (~60%) and slow wind (~40%). The study shows that high wind stream (

关键词： Solar Wind Geomagnetic Activity Solar Activity Geomagnetic Index aa

Climatology of Guinea： Study of Climate Variability in N＇zerekore

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Journal of Agricultural Science and Technology(A) 2017年第4期7卷 215-233页

作者： Rene Tato Loua Maoro Beavogui Hassan Bencherif Alpha Boubacar Barry Zoumana Bamba christine amory Mazodier Guinea Weather Service (DNM) Conakry BP 566 Guinea Laboratoire de l'Atmosphere et des Cyclones Universite de La Reunion UMR 8105 CNRS La Reunion France School of Chemistry and Physics University of KwaZulu-Natal Westville Durban South Africa Scientific Research Center of Conakry Rogbane (CERESCOR) Conakry BP 1615 Guinea Laboratoire de Physique du Plasma Universitd Pierre et Marie Curie UMR 7648 Paris France International Center for Theoretical Physics (CTP) Strada Costiera 11 1-34151 Trieste Italy

N＇zerekore is a geographical region of Guinea, which houses a weather observatory located at longitude 8.8°, latitude 7.7° and altitude 475 m. This region is of major socio-economic interest for the Country. The climatological study of this region shows the variability of each parameter. The objective of this study was to analyze meteorological parameters trends and to assess the space-time evolution of some agro-climatic risks related to the main trends observed in the meteorological parameters regime of this region. In this study, programming tools were used for processing and analyzing meteorological parameters data, including temperatures, rains, wind, evaporation and storms measured in this observatory from 1931 to 2014. The interannual, annual and daily variations of these parameters were obtained, as well as temperature, precipitation anomalies and agroclimatic indexes trends. The analyzing of these variations explained that September is the rainiest months, and the year 1932, 1957 and 1970 are normal, rainy and dry year, respectively. The evaporation increased since 1971 from January to March and November to December. A positive temperature anomaly was observed since 1973 with the maximum 26-33 ℃ and the minimum 16-21 ℃. A dominant westerly wind with a speed of 2.6 m/s was determined. Agro-climatic parameters in N＇zerekore have high variability. From 1931 to 2014, three major periods can be distinguished： a wet period from 1931 to 1977, a dry period from 1978 to 1994 and rainfall variability from 1995 to 2014. The trend of these parameters explains the impact of climate change in this part of the world. This is exacerbated by human activity （deforestation）, thus mitigation measures are necessary. It would be useful to extend this study throughout the country.

关键词： Climate change N'zerekore agroclimatic index.