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第十一届全国日地空间物理学术讨论会

作者： H.V. Malova D.A.Ovodkov L.M.Zelenyi D.C.Delcourt space Research Institute Moscow Russia space Research Institute Moscow Russia space Research Institute Moscow Russia cetp-cnrs saint-maur des fossés France

＜正＞We examine the non-linear dynamics of charged particles in double-humped （"bifurcated"） current sheets. It was shown in previous studies that dynamical regimes in this case contrast with those obtained in single-humped （Harris-like） current sheets. In particular, it was demonstrated that quasi-adiabatic motion with negligible magnetic moment change may be obtained when the adiabaticity parameter approaches unity, a behavior that is at odds with the prominent magnetic moment scattering achieved in the single-humped case. Using single particle simulations, we demonstrate that dynamical behaviors in single-and double-humped current sheets actually differ throughout the whole adiabatic-nonadiabatic transition （i.e., for between 1 and 3）, with alternatively weak and enhanced diffusion in the latter case. Prominent bunching of the particles in gyration phase is also obtained that leads to the formation of nongyrotropic distribution functions. We show that, downstream of bifurcated current sheets, accelerated ion beams in the parallel direction may form even though one has 1 which is usually associated with enhanced particle trapping.

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The International Research Group in Geophysics Europe Africa： A Laboratory without Borders in the Earth science and Environment

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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.

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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 s for QA and 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

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