检索结果-南通市图书馆

Research in Astronomy and Astrophysics 2020年第1期20卷 27-34页

作者： Juan Miao Xin Wang Ting-Ling Ren Zhi-Tao Li National Space Science Center Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Predictions of the strength of solar cycles are important and are necessary for planning long-term missions.A new solar cycle 25 is coming soon,and the amplitude is needed for space weather *** predictions have been made using different methods and the values are drastically ***,since 2015 July 1,the original sunspot number data have been entirely replaced by the Version 2.0 data series,and the sunspot number values have changed *** this paper,using Version 2 smoothed sunspot numbers and aa indices,we verify the predictions for cycles 18-24 based on Ohl’s Precursor *** a similar-cycles method is used to evaluate the aa minimum of 9.7(±1.1)near the start of cycle 25 and based on the linear regression relationship between sunspot maxima and aa minima,our predicted Version 2maximum sunspot number for cycle 25 is 121.5(±32.9).

关键词： solar cycle sunspot geomagnetic aa indices

Anomalous pattern of ocean heat content during different phases of the solar cycle in the tropical Pacific

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2017年第1期10卷 9-16页

作者： HUO Wen-Juan XIAO Zi-Niu State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China College of Earth Science University of Chinese Academy of Sciences Beijing China

solar radiation is a forcing of the climate system with a quasi-11-year *** a quasi-period forcing,the influence of the phase of the solar cycle on the ocean system is an interesting topic of *** this paper,the authors investigate a particular feature,the ocean heat content（OHC）anomaly,in different phases of the total solar irradiance（TSI） *** results show that almost opposite spatial patterns appear in the tropical Pacific during the ascending and declining phases of the TSI *** analysis reveals the presence of the quasi-decadal（11-year） solar signal in the SST,OHC and surface zonal wind anomaly field over the tropical Pacific with a high level of statistical confidence（95%）.It is noted that the maximum centers of the ocean temperature anomaly are trapped in the upper ocean above the main pycnocline,in which the variations of OHC are related closely with zonal wind and ocean currents.

关键词： Ocean heat content anomaly total solar irradiance solar cycle tropical Pacific

Distributions and Structure of the solar Wind during solar cycles 23 and 24

在线全文

学校读者我要写书评

暂无评论

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

Statistical Study of the Occurrence of Coronal Mass Ejections (CMEs) from 1996 to 2018 (solar cycles 23-24)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Physics 2024年第12期15卷 2238-2255页

作者： Salfo Kaboré Abdoul Kader Segda Aristide Marie Frédéric Gyébré Frédéric Ouattara Laboratory of Analytical Chemistry Space and Energy Physics (L@CAPSE) Koudougou Burkina Faso Norbert ZONGO University (UNZ) Koudougou Burkina Faso

The objective of this article was to carry out a statistical study of the occurrences of CMEs from solar cycles 23 and 24 and to deduce interpretations as a contribution to a greater understanding of heliosphere dynamics. Thus, from the statistical examination of the occurrences according to the phases it appeared that solar cycle 23 (SC23) counted 13207 occurrences of CMEs while 16510 were counted for solar cycle 24 (SC24). These occurrences of CMEs are correlated to the sunspot cycle because in each of these cycles we would note the predominance of the phase maximum (1478 for SC23 and 2338 for SC24) over the ascending phases (550 for SC23 and 1559 for the SC24) and descending (1197 for the SC23 and 1178 for the SC24) and these predominate on the minimum phase (206 for the SC23 and 834 for the SC24). However, the percentages per phase in each cycle show that SC23 was only predominant over SC24 at the maximum phase (43.08% for SC23 and 39.57% for SC24). From this correlation, some authors therefore suggest that the toroidal magnetic field would be the cause of the ejections of these CMEs. The annual statistical examination confirms the correlation with the sunspot cycle but nevertheless reveals in the descending phase of SC23 two unusual peaks in 2005 and 2007 and a drop-in sunspot activity of 42% from SC23 to SC24 while that we would note an increase in the activity of CME occurrences of 36% at SC24, thus suggesting that CMEs can occur without the toroidal magnetic field being the cause, particularly from the coronal holes. The seasonal statistical examination shows for its part that out of the total of 29717 occurrences of CMEs of the two cycles that spring (28%) was the most active than summer (25%) and summer over autumn (24%) and finally autumn over winter (23%) thus revealing that: The ascending phase of the cycle was only the most active during the winter seasons in spring and the descending phase only during the rest of the seasons. Finally, the monthly stat

关键词： CMEs Occurrence solar cycle Phase of the solar cycle Seasons Months

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Seasonal Variations of solar Wind Parameters during solar cycles 23 and 24

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Concept of the solar ring mission:An overview

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2020年第9期63卷 1699-1713页

作者： WANG YuMing JI HaiSheng WANG YaMin XIA LiDong SHEN ChengLong GUO JingNan ZHANG QuanHao HUANG ZhengHua LIU Kai LI XiaoLei LIU Rui WANG JingXiu WANG Shui CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of China(USTC)Hefei230026China CAS Center for Excellence in Comparative Planetology USTCHefei230026China Purple Mountain Observatory Chinese Academy of SciencesNanjing210034China CAS Key Lab of Microsatellite Innovation Academy for MicrosatellitesChinese Academy of SciencesShanghai201203China Shanghai Engineering Center for Microsatellites Shanghai201203China Shandong Provincial Key Laboratory of Optical Astronomy and solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai264209China Univeristy of Chinese Academy of Sciences Beijing100049China

The concept of the solar Ring mission was gradually formed from L5/L4 mission concept, and the proposal of its pre-phase study was funded by the National Natural Science Foundation of China in November 2018 and then by the Strategic Priority Program of Chinese Academy of Sciences in space sciences in May 2019. solar Ring mission will be the first attempt to routinely monitor and study the Sun and inner heliosphere from a full 360-degree perspective in the ecliptic plane. The current preliminary design of the solar Ring mission is to deploy six spacecraft, grouped in three pairs, on a sub-AU orbit around the Sun. The two spacecraft in each group are separated by about 30?and every two groups by about 120?. This configuration with necessary science payloads will allow us to establish three unprecedented capabilities:(1) determine the photospheric vector magnetic field with unambiguity,(2) provide 360-degree maps of the Sun and the inner heliosphere routinely, and(3) resolve the solar wind structures at multiple scales and multiple longitudes. With these capabilities, the solar Ring mission aims to address the origin of solar cycle, the origin of solar eruptions, the origin of solar wind structures and the origin of severe space weather events. The successful accomplishment of the mission will advance our understanding of the star and the space environment that hold our life and enhance our capability of expanding the next new territory of human.

关键词： space mission concept solar cycle solar eruptions solar wind space weather

Starspots, stellar cycles and stellar flares： Lessons from solar dynamo models

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2017年第1期60卷 1-16页

作者： Amab Rai Choudhuri Department of Physics Indian Institute of Science Bangalore 560012 India

In this review, we discuss whether the present solar dynamo models can be extrapolated to explain various aspects of stellar activity. We begin with a summary of the following kinds of data for solar-like stars:(i) data pertaining to stellar cycles from Ca H/K emission over many years;(ii) X-ray data indicating hot coronal activity;(iii) starspot data(especially about giant polar spots); and(iv) data pertaining to stellar superflares. Then we describe the current status of solar dynamo modelling—giving an introduction to the flux transport dynamo model, the currently favoured model for the solar cycle. While an extrapolation of this model to solar-like stars can explain some aspects of observational data, some other aspects of the data still remain to be theoretically explained. It is not clear right now whether we need a different kind of dynamo mechanism for stars having giant starspots or producing very strong superflares.

关键词： sunspots solar dynamo solar cycle stellar dynamo, stellar activity

Silver fir tree-ring fluctuations decrease from north to south latitude—total solar irradiance and NAO are indicated as the main influencing factors

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2023年第6期10卷 717-731页

作者： Vaclav Simůnek Anna Prokůpkova Zdenek Vacek Stanislav Vacek Jan Cukor Jirí Remes Vojtech Hajek Giuseppe D'Andrea Martin Salek Paola Nola Osvaldo Pericolo Sarka Holzbachova Francesco Ripullone Faculty of Forestry and Wood Sciences Czech University of Life Sciences PragueKamýcka 129CZ—16500Prague 6SuchdolCzech Republic Forestry and Game Management Research Institute v.v.iStrnady 13625202JílovisteCzech Republic Czech Academy of Sciences Institute of Vertebrate BiologyKvetna 860365BrnoCzech Republic Department of Earth and Environmental Sciences University of PaviaVia S.Epifanio 14I-27100PaviaItaly Forests of the Czech Republic SOEPremyslova 1106/19NovýHradec Kralove50008Hradec KraloveCzech Republic School of Agricultural Forestry and Environmental SciencesUniversity of BasilicataViale dell’Ateneo Lucano 10I-85100PotenzaItaly Faculty of Environmental Sciences Czech University of Life Sciences PragueKamýcka 129CZ—16500PragueSuchdolCzech Republic

Silver fir(Abies alba Mill.)is a flexible European tree species,mainly vegetating within the mountainous regions of Europe,but its growth responses across its latitudinal and longitudinal range have not yet been satisfactorily verified under changing environmental *** study describes the tree-ring increment of silver fir in research plots across a latitudinal gradient from the northern range in Czechia(CZ),through Croatia(HR)to the southernmost range in Italy(IT).The research aims to analyze in detail the dynamics and cyclicity of the ringwidth index(RWI)and how it relates to climatic factors(temperature and precipitation),the North Atlantic Oscillation(NAO),and total solar irradiance(TSI),including the determination of *** results show that the main drivers affecting fir growth are the seasonal NAO index and *** temperatures affect RWI early in the vegetation season,while lack of precipitation during the summer is a limiting factor for fir growth,especially in *** temperatures and temperatures in June and July negatively impact,while seasonal precipitation totals in the same months positively influence the RWI in all research plots across *** longest growth cycles in fir RWI were recorded in the northernmost studied plots in *** cyclical fluctuations recede approaching the *** cyclic increase in RWI is related to the TSI,which decreases its effect from north to *** TSI's effects vary,positively impacting CZ but negatively influencing HR while remaining relatively neutral in *** the other hand,seasonal NAO tends to negatively affect silver fir growth in HR and CZ but has a mildly positive effect in *** conclusion,the TSI and the influence of the seasonal NAO index are prevalent in the fir RWI and are accompanied by a greater cyclicity of RWI in Central Europe(temperature optimum)than in the Italian Mediterranean region,where this tree species is limited by climatic conditions,especially lack of pre

关键词： Abies alba Mill Tree-rings solar cycle North Atlantic oscillation Precipitation Temperature

Analysis of the correlation between horizontal wind and 11-year solar activity over Langfang, China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2021年第3期5卷 270-279页

作者： Bing Cai QingChen Xu Xiong Hu Xuan Cheng JunFeng Yang Wen Li Key Laboratory of Science and Technology on Environmental Space Situation Awareness National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China

In this study,long term observations of medium frequency(MF)radar at Langfang site(39.4°N,116.7°E)from 2009 to 2020 have been used to analyze the dependence of the 11-year solar cycle on horizontal winds in the local mesosphere and lower thermosphere(MLT).The results show that the zonal wind is positively correlated with solar activity during spring at 80–84 km,and during summer at 80–82 km;the meridional wind is positively correlated with solar activity during spring at 84–88 km and during summer at 84–90 *** contrast,the results show no correlation between the horizontal wind and solar activity in autumn and *** attempt to explain the correlations in terms of the changes in stratospheric temperature and the net flux of gravity waves during solar *** addition,annual and semiannual oscillations of the zonal/meridional wind were found by using the least squares fitting method on daily horizontal winds,which show negative correlations with solar activity at heights of 80–90 km.

关键词： MF radar MLT horizontal wind solar cycle