检索结果-南通市图书馆

Extreme space weather events caused by super active regions during solar cycles 21-24

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2021年第5期21卷 296-300,302页

作者： Gui-Ming Le Gui-Ang Liu Ming-Xian Zhao Tian Mao Ping-Guo Xu School of Physics Science&Technology Lingnan Normal UniversityZhanjiang 524048China Key Laboratory of Space Weather National Center for Space WeatherChina Meteorological AdministrationBeijing 100081China Beijing Engineering Research Center of Smart Mechanical Innovation Design Service Beijing 100020China

Extreme space weather events including≥X5.0 flares,ground level enhancement(GLE)events and super geomagnetic storms(Dst≥-250 nT)caused by super active regions(SARs)during solar cycles 21-24 were *** total number ofX5.0 solar flares was 62,among which 41 were X5.0-X9.9 flares and 21 were≥X10.0 *** found that 83.9%of the≥X5.0 flares were produced by SARs;78.05%of the X5.0-X9.9 and 95.24%of the≥X10.0 solar flares were produced by SARs;46 GLEs were registered during solar cycles 21-24,and 25 GLEs were caused by SARs,indicating that 54.3%of the GLEs were caused by SARs;24 super geomagnetic storms were recorded during solar cycles 21-24,and 12 of them were caused by SARs,namely 50%of the super geomagnetic storms were caused by *** ascertained that only 29 SARs produced≥X5.0 flares,15 SARs generated GLEs and 10 SARs triggered super geomagnetic *** the 51 SARs,only 33 SARs produced at least one extreme space weather event,while none of the other 18 SARs could trigger an extreme space weather *** were only four SARs and each of them generated not only a≥X5.0 flare,but also a GLE event and a super geomagnetic *** of the extreme space weather events caused by the SARs appeared during solar cycles 22 and 23,especially for GLE events and super geomagnetic *** longitudinal distributions of source locations for the extreme space weather events caused by SARs were also studied.

关键词： Sun:sunspots Sun:flares Sun:particle emission Sun:solar-terrestrial relations

Large solar energetic particle event that occurred on 2012 March 7 and its VDA analysis

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2016年第8期16卷 33-42页

作者： Liu-Guan Ding Xin-Xin Cao Zhi-Wei Wang Gui-Ming Le School of Physics and Optoelectronic Engineering Institute of Space WeatherNanjing University of Information Science and Technology National Center for Space Weather China Meteorological Administration

On 2012 March 7, the STEREO Ahead and Behind spacecraft, along with near-Earth spacecraft （e.g. SOHO, Wind） situated between the two STEREO spacecraft, observed an extremely large global solar energetic particle （SEP） event in Solar Cycle 24. Two successive coronal mass ejections （CMEs） have been detected close in time. From the multi-point in-situ observations, it can be found that this SEP event was caused by the first CME, but the second one was not involved. Using velocity dispersion analysis （VDA）, we find that for a well magnetically connected point, the energetic protons and electrons are released nearly at the same time. The path lengths to STEREO-B （STB） for protons and electrons have a distinct difference and deviate remarkably from the nominal Parker spiral path length, which is likely due to the presence of interplanetary magnetic structures situated between the source and STB. Also, the VDA method seems to only obtain reasonable results at well-connected locations and the inferred release times of energetic particles in different energy channels are similar. We suggest that good-connection is crucial for obtaining both an accurate release time and path length simultaneously, agreeing with the modeling result of Wang ＆ Qin （2015）.

关键词： Sun particle emission -- Sun coronal mass ejection (CME) -- method velocity dispersionanalysis (VDA)

Latitudinal and Solar Cycle Distribution of Extreme(≥X5) Flares During1976–2018

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第12期24卷 63-70页

作者： Qi Li Xi-Wen Zhang Gui-Ming Le Institute of Geophysics China Earthquake Administration Key Laboratory of Space Weather National Satellite Meteorological Center (National Center for Space Weather)China Meteorological Administration Innovation Center for FengYun Meteorological Satellite (FYSIC)

We studied the latitudinal and solar cycle distribution of extreme(≥X5) solar flares spanning 1976–2018. We found that all such flares were confined within the latitudinal range of [S30, N35]. Nonetheless, the majority of these flares during different solar cycles were confined in different latitudinal scopes. Statistical results showed that the southeast quadrant experienced the highest activity of extreme flares. 47.5% of the extreme flares occurred within the latitudes ≤15° of the two hemispheres, with 26.2%, 31.1%, and 42.6% in the latitudinal bands [5°, 10°],>20° and [11°, 20°] of both hemispheres, respectively. Significant N–S asymmetries were observed in the ascending phase of SC 21, the descending phase of SC 23, and both phases of SC 24. Other phases showed asymmetries primarily in latitudinal distribution. The proportion of extreme flares in the ascending phases of SCs21–24 was 22.2%, 33.3%, 38.9%, and 50%, respectively. Stronger flares(≥X10) were more likely to occur in the descending phase, with 39% of X5–X9 flares and 20% of(≥X10) flares occurring in the ascending phase. On average, 83.6% of extreme flares occurred within a period extending from two years prior to three years following the solar peak, according to our statistical analysis, with specific percentages for each cycle being 88.9%, 100%,61.1%, and 75%.

关键词： (Sun:) sunspots Gamma-rays Sun: flares Sun: X-rays

Dependence of E ≥ 100 MeV protons on the associated flares and CMEs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第7期17卷 99-108页

作者： Gui-Ming Le Chuan Li Xue-Feng Zhang Key Laboratory of Space Weather National Center for Space WeatherChina Meteorological Administration School of Computer Science Anhui University of Technology School of Astronomy and Space Science Nanjing University

To investigate the possible solar source of high-energy protons, correlation coefficients between the peak intensities of E ≥ 100 MeV protons, I100, and the peak flux and fluence of solar soft X-ray（SXR） emission, and coronal mass ejection（CME） linear speed in the three longitudinal areas W0-W39, W40-W70 and W71-W90 have been calculated respectively. Classical correlation analysis shows that the correlation coefficients between CME speeds and I100 in the three longitudinal areas are0.28±0.21, 0.35±0.21 and 0.04±0.30 respectively. The classical correlation coefficients between I100 and SXR peak flux in the three longitudinal areas are 0.48±0.17, 0.72±0.13 and 0.02±0.30 respectively, while the correlation coefficients between I100 and SXR fluence in the three longitudinal areas are 0.25±0.21, 0.84±0.07 and 0.10±0.30 respectively. Partial correlation analysis shows that for solar proton events with source location in the well connected region（W40-W70）, only SXR fluence can significantly affect the peak intensity of E ≥ 100 MeV protons, but SXR peak flux has little influence on the peak intensities of E ≥ 100 MeV protons; moreover, CME speed has no influence on the peak intensities of E ≥ 100 MeV protons. We conclude that these findings provide statistical evidence that E ≥ 100 MeV protons may be mainly accelerated by concurrent flares.

关键词： Sun coronal mass ejections (CMEs) --Sun flares - (Sun:) particle emission

Dependence of large SEP events with different energies on the associated flares and CMEs

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第12期17卷 41-52页

作者： Gui-Ming Le Xue-Feng Zhang Key Laboratory of Space Weather National Center for Space WeatherChina Meteorological Administration School of Computer Science Anhui University of Technology

To investigate the dependence of large gradual solar energetic particle（SEP） events on the associated flares and coronal mass ejections（CMEs）, the correlation coefficients（CCs） between peak intensities of E 〉 10 MeV（I10）, E 〉 30 MeV（I30） and E 〉 50 MeV（I50） protons and soft X-ray（SXR） emission of associated flares and the speeds of associated CMEs in the three longitudinal areas W0–W39, W40–W70（hereafter the well connected region） and W71–W90 have been *** correlation analysis shows that CCs between SXR emission and peak intensities of SEP events always reach their largest value in the well connected region and then decline dramatically in the longitudinal area outside the well connected region, suggesting that they may contribute to the production of SEPs in large SEP events. Both classical and partial correlation analyses show that SXR fluence is a better parameter describing the relationship between flares and SEP events. For large SEP events with source location in the well connected region, the CCs between SXR fluence and I10, I30 and I50 are0.58±0.12, 0.80±0.06 and 0.83±0.06 respectively, while the CCs between CME speed and I10, I30 and I50 are 0.56±0.12, 0.52±0.13 and 0.48±0.13 respectively. The partial correlation analyses show that in the well connected region, both CME shock and SXR fluence can significantly affect I10, but SXR peak flux makes no additional contribution. For E 〉 30 MeV protons with source location in the well connected region, only SXR fluence can significantly affect I30, and the CME shock makes a small contribution to I30, but SXR peak flux makes no additional contribution. For E 〉 50 MeV protons with source location in the well connected region, only SXR fluence can significantly affect I50, but both CME shock and SXR peak flux make no additional contribution. We conclude that these findings provide statistical evidence that for SEP events with source locations in the well connected region, a CME shock is only an effect

关键词： Sun:coronal mass ejections(CMEs) Sun:flares (Sun:)particle emission

在线全文

学校读者我要写书评

暂无评论

太阳质子事件与太阳耀斑的关系

空间科学学报 2018年第4期38卷 437-443页

作者：乐贵明王鸿雁白铁男中国气象科学研究院北京100081 中国气象局空间天气重点开放实验室北京100081 国家空间天气监测预警中心北京100081

通过对0°W-39°W,40°W-70°W,71°W-90°W经度范围内太阳质子事件与太阳耀斑的相关性计算分析,发现太阳质子事件与太阳耀斑的相关系数依赖于经度.太阳耀斑积分与地球磁链接区域(40°W-70°W)太阳质子事件强度的相关系数最大.相关系数... 详细信息

通过对0°W-39°W,40°W-70°W,71°W-90°W经度范围内太阳质子事件与太阳耀斑的相关性计算分析,发现太阳质子事件与太阳耀斑的相关系数依赖于经度.太阳耀斑积分与地球磁链接区域(40°W-70°W)太阳质子事件强度的相关系数最大.相关系数的这种特点与耀斑加速粒子的最大流量只出现在磁链接区域的特征相吻合.计算结果表明,太阳耀斑对太阳质子事件具有贡献,即耀斑对E≥10 MeV的质子加速有贡献.耀斑和CME在磁链接区域对太阳质子事件的贡献相同,这说明太阳质子事件是混合型事件.

关键词：太阳耀斑日冕物质抛射太阳质子事件

What Can We Learn from the Geoeffectiveness of the Magnetic Cloud on 2012 July 15–17?

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第1期22卷 14-18页

作者： Gui-Ang Liu Ming-Xian Zhao Gui-Ming Le Tian Mao School of Physics Science and Technology Lingnan Normal UniversityZhanjiang 524048China Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Key Laboratory of Space Weather National Center for Space WeatherChina Meteorological AdministrationBeijing100081China

An interplanetary shock and a magnetic cloud(MC) reached the Earth on 2012 July 14 and 15 one after *** shock sheath and the MC triggered an intense geomagnetic *** find that only small part of the MC from06:45 UT to 10:05 UT on 2012 July 15 made contribution to the intense geomagnetic storm,while the rest part of the MC made no contribution to the intense geomagnetic *** averaged southward component of interplanetary magnetic field(Bs) and duskward-electric fields(Ey) within the MC from 10:05 UT,2012 July 15 to09:08 UT,2012 July 16(hereafter MC2),are 15.11 nT and 8.01 my m-1,*** to the empirical formula established by Burton et al.(hereafter Burton equation),the geoeffectiveness of MC2 should be-655.42 nT,while the geoeffectiveness of MC2 is-324.68 nT according to the empirical formula established by O’Brien & McPherron(hereafter OM equation).However,the real geoeffectiveness of MC2 is 39.74 *** results indicate that the Burton equation and the OM equation cannot work *** geoeffectiveness of MC2 shows that large and long duration of Bs or Ey cannot guarantee the occurrence of an intense geomagnetic storm if the solar wind dynamic pressure is very *** we use 0.52 as γ,the geoeffectiveness of MC2 is 40.36 nT according to the empirical formula established by Wang et al.,which is very close to the observed value,indicating that the empirical formula established by Wang et *** much better than the Burton equation and the OM equation.

关键词： Solar coronal mass ejections Solar-terrestrial interactions Solar wind

Properties of the Main Phases of the Super Geomagnetic Storms(ΔSYM-H≤-250 nT)with Different Heliolongitudes

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2023年第1期23卷 76-82页

作者： Ming-Xian Zhao Gui-Ming Le Yong-Hua Liu Key Laboratory of Space Weather National Satellite Meteorological Center(National Center for Space Weather)China Meteorological AdministrationBeijing 100081China School of Physics Science&Technology Lingnan Normal UniversityZhanjiang 524048China Innovation Center for FengYun Meteorological Satellite(FYSIC) Beijing 100081China CAS Key Laboratory of Solar Activity National Astronomical ObservatoriesBeijing 100101China Polar Research Institute of China Shanghai 200136China

We studied the properties of the main phases of 24 super geomagnetic storms(SGSs)(ΔSYM-H≤-250 nT)since *** divided the SGSs into two subgroups:SGSs-Ⅰ(-400 nT<ΔSYM-H≤-250 nT)and SGSs-Ⅱ(ΔSYM-H≤-400 nT).Of the 24 SGSs,16 are SGSs-Ⅰand eight are SGSs-Ⅱ.The source locations of SGSs were distributed in the longitudinal scope of[E37,W66].95.8%of the SGSs were distributed in the longitudinal scope of[E37,W20].East and west hemispheres of the Sun had 14 and 10 SGSs,*** durations of the main phases for six SGSs ranged from 2 to 4 *** durations of the main phases for the rest 18 SGSs were longer than 6.5 *** duration of the SGSs with source locations in the west hemisphere varied from 2.22 to 19.58 *** duration for the SGSs with the source locations in the east hemisphere ranged from 2.1 to31.88 *** averaged duration of the main phases of the SGSs in the west and east hemispheres are 8.3 hr and13.98 hr,respectively.|ΔSYM-H/Δt|for six SGSs with source locations distributed in the longitudinal area ranging from E15 to W20 was larger than 1.0 nT·minute^(-1),while|ΔSYM-H/Δt|for the rest 18 SGSs was lower than 1.0 nT·minute^(-1).|ΔSYM-H/Δt|for SGSs-Ⅰvaried from 0.18 to 3.0 nT·minute^(-1).|ΔSYM-H/Δt|for eight SGSs-Ⅱvaried from 0.37 to 2.2 nT·minute^(-1)with seven SGSs-Ⅱfalling in the scope from 0.37 to0.992 nT·minute^(-1).

关键词： The Sun-(Sun:)solar-terrestrial relations-(Sun:)solar wind

第23太阳活动周行星际磁场扇形结构对中低纬地磁场的影响

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2017年第1期37卷 19-27页

作者：李仲怡乐贵明裴世鑫广西壮族自治区气象服务中心南宁530022 中国气象局空间天气重点实验室国家空间天气监测预警中心北京100081 南京信息工程大学数学与统计学院空间天气研究所南京210044 南京信息工程大学物理与光电工程学院南京210044

用特征向量分析法对第23太阳活动周天津静海磁场强度水平分量H的时均值进行研究,分析行星际磁场扇形结构的地磁效应(简称扇形效应)对中低纬地磁场H分量日变化的贡献.研究结果表明,中低纬扇形效应为3~11 nT,在太阳活动高年扇形效应达到... 详细信息

用特征向量分析法对第23太阳活动周天津静海磁场强度水平分量H的时均值进行研究,分析行星际磁场扇形结构的地磁效应(简称扇形效应)对中低纬地磁场H分量日变化的贡献.研究结果表明,中低纬扇形效应为3~11 nT,在太阳活动高年扇形效应达到最大值(约11 nT),低年达到最小值(约3 nT).太阳活动高年扇形效应引起的地磁H分量值变化与太阳活动低年的情况相反,但是扇形效应在夏季对地磁H分量的影响较小.太阳活动高年扇形效应日均值的增减与上升年的相反,与下降年相同,夏季扇形效应平均增量最小且无规律.春、夏和秋三个季节的扇形效应最大值都出现在太阳活动高年,冬季的扇形效应在太阳活动峰年一年后才出现最大值(约11 nT).在太阳活动低年(或高年),当扇形磁场背离(或指向)太阳时,夏季扇形效应白天引起地磁H分量增大(或减小),夜间导致地磁H分量减小(或增大),其他季节全天都会导致地磁H分量减小(或增大).用特征向量推断行星际磁场扇形极性的符合率在春夏秋三个季节高达60%,在冬季为55%.

关键词：行星际磁场扇形结构地磁效应特征向量