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Statistical Study of the Geoeffectivity of Halo Coronal Mass Ejections Associated with X-Class Flares during Solar Cycles 23 and 24

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Open Journal of Applied Sciences 2024年第4期14卷 950-960页

作者： Younoussa Diakite Christian Zoundi M’Bi Kabore jean louis zerbo Laboratoire de Chimie Analytique de Physique Spatiale et Energ&#233tique (L@CAPSE) Physics Department Universit&#233 Norbert Zongo Koudougou Burkina Faso Laboratoire de Maté riaux d&#8217H&#233liophysique et Environnement (LAMHE) Physics Department Universit&#233 Nazi Boni Bobo-Dioulasso Burkina Faso

By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 December 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth.

关键词： CME Halo (X) Geoeffectivity Geomagnetic Storm Solar Flare Solar Cycle

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Rainfall and Temperature Variations over Burkina Faso: Possible Influence of Geomagnetic Activity, Solar Activity and Associated Energies from 1975 to 2020

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Atmospheric and Climate Sciences 2022年第4期12卷 603-612页

作者： Yacouba Sawadogo Somaïla Koala jean louis zerbo Laboratoire de Matériaux d’Héliophysique et Environnement (La.M.H.E) Université Nazi Boni Bobo-Dioulasso Burkina Faso Unité de Formation et de Recherche en Sciences Exactes et Appliquées (UFR/SEA) Université Nazi Boni Bobo-Dioulasso Burkina Faso

This study investigates climatic parameters (rainfall, and temperature) over Burkina Faso and the possible role of solar activity and its induced energies. Through morphological investigations, we analyzed solar activity indices (sunspot number, IMF, PC index, Cosmic rays) over the last three solar cycles (1975-2020). Results about interplanetary heating show that joule heating is well correlated with the dynamic pressure of the solar plasma. Climate parameters (rainfall, Temperature) variabilities are modulated by disturbances in solar activity: 1) quiet solar characterized by a drop in solar plasma’s parameters is associated with important cloud cover and consequently bring important rainfall which chills terrestrial atmosphere, 2) active solar characterized by important input energy is associated with weak incident cosmic ray consequently with low cloudiness which brings warming. Thus, the possible natural link can be suggested between solar activity and climatic parameters even if it is not the only factor of global warming.

关键词： Temperature Rainfall Solar Activity Geomagnetic Activity Climate Burkina Faso

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Seasonal Variations of Solar Wind Parameters during Solar Cycles 23 and 24

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Open Journal of Applied Sciences 2022年第9期12卷 1527-1546页

作者： Somaïla Koala Yacouba Sawadogo jean louis zerbo Laboratoire de Matériaux d’Héliophysique et Environnement (La.M.H.E) ED/ST Université Nazi BONI Bobo-Dioulasso Burkina Faso Unité de Formation et de Recherche en Sciences Exactes et Appliquées (UFR/SEA) Université Nazi BONI Bobo-Dioulasso Burkina Faso

In this paper, we analyzed diurnal and annual seasonal variations of solar wind parameters such as interplanetary magnetic field (IMF), proton density (N), solar wind speed (V) and solar wind dynamic pressure (Pdym), during the solar cycles 23 and 24. Our study shows that strong geomagnetic disturbances are observed at the equinoxes during both solar cycles. The highest proton densities are observed at solstices during both solar cycles. The greatest solar wind speeds are observed at the equinoxes of solar cycle 23 and at the solstices of solar cycle 24. The highest solar wind dynamic pressures are observed at the solstices of both solar cycles. We also observed an asymmetrical evolution of the seasonal diurnal values of the solar wind parameters during the two cycles, except for the proton density. Our investigations also highlight the fact that the seasonal diurnal values of the solar wind parameters are significant at solar cycle 23 compared to solar cycle 24 characterized by a global weak in solar plasma conditions since the deep minimum that followed the solar cycle 23 leading to an absence of a persistent polar coronal hole. The drop observed in polar field and solar winds parameters during solar cycle 24 is reproduced on seasons (solstices and equinoxes). The solar cycle 23 and 24 appear to be two magnetically opposite solar cycles regardless the time scales.

关键词： Diurnal Seasonal Solar Winds Parameters Variation Solar Cycle

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Total Electron Content Diurnal and Seasonal Variations and Response to Solar Events at Koudougou Station in Burkina Faso

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International Journal of Geosciences 2023年第9期14卷 827-839页

作者： Yacouba Sawadogo M’Bi Kaboré Somaïla Koala Arouna Mandé jean louis zerbo Laboratoire de Matériaux d’Héliophysique et Environnement (La.M.H.E) Université Nazi BONI Bobo-Dioulasso Burkina Faso

In this paper, we studied the seasonal behavior of the total electron content (TEC) during a part of solar cycle 24 ascending, maximum and decreasing phases at Koudougou station (Latitude: 12°15'09"N Longitude: 2°21'45"W). Response of TEC to solar recurrent events is presented. The highest values of the TEC in 2014, 2015 and 2016 were recorded on March and October, while in 2013 they were recorded on April and November, corresponding to equinox months. This observation shows that TEC values at the equinoxes are higher than those of solstices. Moreover, the monthly TEC varies in phase with the sunspots number showing a linear dependence of the TEC on solar activity. The ionospheric electron contents are generally very low both before noon and during the night, but quite high at noon and after noon. This pattern of TEC variation is due to the fluctuation of incident solar radiation on the Earth’s equatorial ionosphere. During quiet periods, the number of free electrons generated is lower than that generated during recurrent periods, which shows a positive contribution of recurrent activity to the level of the TEC. Investigations have also highlighted a winter anomaly and equinoctial asymmetry in TEC behavior at Koudougou station.

关键词： Total Electron Content (TEC) Recurrent Activity Quiet Activity Seasonal Variation

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Distributions and Structure of the Solar Wind during Solar Cycles 23 and 24

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International Journal of Geosciences 2023年第9期14卷 813-826页

作者： Somaïla Koala Wendkouni Paulin Bere Yacouba Sawadogo Issamaïl Ki jean louis zerbo Laboratoire de Matériaux d’Héliophysique et Environnement (La.M.H.E) Université Nazi BONI Bobo-Dioulasso Burkina Faso

To observe the level of interaction between the solar wind and the geomagnetic activity, we analyzed the distribution of the solar wind speeds according to the different classes of geomagnetic activity and the different phases of solar activity. We found that, the magnetic quiet activity reccord 80% of the solar wind speeds V s observed 88% of solar wind speeds V > 450 km/s. The shock activity observes 82% of the solar wind speeds V > 450 km/s. About 70% of the solar wind speeds V > 450 km/s, are observed in the corotating activity class. The cloud shock activity and fluctuating activity classes observed respectively 37% and 55% of the wind speeds V > 450 km/s. Furthermore, slow solar winds are mainly observed at the minimum phase of each solar cycle;but exceptionally the solar maximum phase of solar cycle 24, records a significant rate of slow solar wind. Shock winds are mainly observed around the solar maximum and recurrent winds are mainly observed at the descending phase of the solar cycle. Corotating stable winds and moderate shock winds dominate respectively at the descending phase and at the maximum phase.

关键词： Solar Wind Solar Activity Geomagnetic Activity Solar Cycle

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Effect of High-Speed Solar Winds Turbulence Upstream of the Earth’s Magnetosphere: Case of the Outer Minima of Solar Cycles 20, 21, 22, 23 and 24

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Open Journal of Applied Sciences 2023年第7期13卷 1145-1162页

作者： Inza Gnanou Salfo Kabore Aristide Marie Frédéric Gyebre Christian Zoundi jean-louis zerbo Frédéric Ouattara É cole Normale Supérieure Koudougou Burkina Faso Department of Physics Laboratoire de Recherche en énergétique et Météorologie de l’Espace (LAREME) Université Norbert ZONGO Koudougou Burkina Faso Department of Physics Laboratoire de Matériaux d’Héliophysique et Environnement (LaMHE) Université Nazi BONI Bobo-Dioulasso Burkina Faso

Highly turbulent environment, the solar wind is a stream of very energetic particles mainly made of protons and electrons. During its trip in the interplanetary space, this solar flow becomes more accelerated during the outer minima (descending phases) of the solar cycles and can therefore influence all of humanity and its technology. These disturbances lead to socio-economic consequences requiring a precise knowledge of the climate variability. Using a statistical approach, we evaluate the response of the Earth’s magnetosphere to the High-Speed Solar Winds (HSSW) forcing during the peaks of the last five outer minima. To do so, 1UA data of solar wind and magnetic field parameters were extracted from OMNI browser. Analysis of the energetic solar plasma particles shows that strong geomagnetic field variations can occur even in the absence of large solar disturbances. While the normalized reconnection rate was estimated to be ~21% of the total variance of the magnetospheric variables, the upstream of the magnetic cavity was perturbed 80% of the time with large energies recorded. As a result, Earth’s magnetosphere becomes denser (i.e., more drag), which is a problem for spacecraft. Thus, the coupled solar wind-magnetosphere system follows scale-invariant dynamics and is in a state far from equilibrium. Our analysis provides insight into the main cause of geomagnetic storms with more than 97% of HSSW imposed in the range 300 - 850 km/s. These high-speeds lead to auroras that can disrupt electrical and communication systems.

关键词： Solar Wind Outer Minimum Magnetosphere Geomagnetic Field Solar Disturbances

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Scanning transmission electron microscopy and atom probe tomography analysis of non-stoichiometry long-period-stacking-ordered structures in Mg-Ni-Y/Sm alloys

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Journal of Magnesium and Alloys 2024年第3期12卷 954-965页

作者： Yimeng Chen Manuel Legrée jean-louis Bobet Alexander Kvit CAMECA Instruments Inc MadisonWI 53711USA ICMCB Universitéde BordeauxPessacCEDEX 33608France NIAC&Materials Science Department University of WisconsinMadisonWI 53706USA

The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg *** current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-Ni-Y/Sm ternary alloys after extended isothermal *** on the alloying elements and their concentrations,Mg-Ni-Y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg ***-STEM and APT indicate non-stoichiometric LPSO with incomplete Ni_(6)(Y/Sm)_(8) *** addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of Ni within the Mg bonding *** results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.

关键词： Magnesium alloys Long-range ordering Atom probe tomography(APT) STEM HAADF Hydrolysis properties.

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Annual and Diurnal Variabilities in the Critical Frequency (foF2) during Geomagnetic Fluctuating Activity over Solar Cycles 21 and 22 at Ouagadougou

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Atmospheric and Climate Sciences 2018年第4期8卷 435-445页

作者： Abidina Diabaté Frédéric Ouattara jean louis zerbo Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) Université Norbert Zongo Koudougou Burkina Faso Université Nazi Boni Bobo Dioulasso Burkina Faso Laboratoire d’Energies Thermiques Renouvelables (L.E.T.RE) Université Ouaga 1 Pr Joseph Ki-Zerbo Ouagadougou Burkina Faso

Geomagnetic activity is characterized by four solar wind conditions. Each condition has specific impact on ionosphere. This paper review on fluctuating activity effects on ionosphere F2 layer through its critical frequency foF2 variations. Under fluctuating wind conditions, we have investigated on annual, diurnal and seasonal variations of foF2 during solar cycles 21 and 22 phases covered by Ouagadougou ionosonde station data (Lat: 12.5°N;Long: 358.5°E;dip: 1.43°). Our investigations show that foF2 annual’ variability is in phase with solar cycle. The diurnal variation is “noon bite out” most of the time except for the solar maximum where we have a morning peak testifying to the fact that the vertical drift E × B is disturbed. The seasonal variations show that the fluctuating activity has no particular effect on certain characteristics of the equatorial ionosphere such as electrojet and vertical drift E × B. However, the increase of the electric field pre-reversal phenomenon in autumn is a characteristic effect observed during the fluctuating activity.

关键词： Critical Frequency Solar Cycle Seasonal Diurnal Fluctuating Activity

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Solar Activity and Meteorological Fluctuations in West Africa: Temperatures and Pluviometry in Burkina Faso, 1970-2012

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International Journal of Astronomy and Astrophysics 2013年第4期3卷 408-411页

作者： jean-louis zerbo Frédéric Ouattara Emmanuel Nanéma LERSEM University of Koudougou Koudougou Burkina Faso UFR/ST Polytechnic University of Bobo Dioulasso Bobo-Dioulasso Burkina Faso

In this paper we investigate the fluctuations of solar activity and their links with climatic parameters in West Africa. We achieve our research by investigating several data plotted using averages. Mean to our results we can assume that active solar is associated with weak incident cosmic ray consequently with low cloudiness which brings warming. Likewise, quiet solar is associated with important cloud cover and consequently brings important precipitations and chills terrestrial atmosphere. This implies the necessity to deal with space phenomenon by considering the severe interconnection between solar activity indices for interplanetary and earth environment weather forecasting.

关键词： Solar Activity Temperatures Precipitations Cloud Cover Solar Cycle

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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 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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