获得真实的日面观测图像,是用户基于太阳望远镜开展科学和应用研究的基础,而平场定标是科学数据生产过程中的必要步骤之一,因为平场定标可以扣除太阳望远镜在成像过程中产生的不均匀性.“夸父一号”又名先进天基太阳天文台(Advanced Spa...获得真实的日面观测图像,是用户基于太阳望远镜开展科学和应用研究的基础,而平场定标是科学数据生产过程中的必要步骤之一,因为平场定标可以扣除太阳望远镜在成像过程中产生的不均匀性.“夸父一号”又名先进天基太阳天文台(Advanced Space-based Solar Observatory,ASO-S)卫星的载荷之一,莱曼阿尔法太阳望远镜(Lyman-alpha Solar Telescope,LST),包括3台科学仪器,具体来说是由一个双波段太阳日冕仪(Solar Corona Imager,SCI)以及白光太阳望远镜(White-light Solar Telescope,WST)和莱曼阿尔法全日面太阳成像仪(Solar Disk Imager,SDI)这两个全日面太阳望远镜构成.WST和SDI的探测器是互补金属氧化物半导体(Complementary Metal-Oxide-Semiconductor,CMOS),其平场本身的主要特征是由于激光退火造成的条纹结构,当CMOS探测器在紫外波段使用时会产生一定的衰减与辐射损伤,并且探测器上的水汽凝结和有机物的积累等污染,也会对所得平场产生一定影响.主要展示了ASO-S卫星发射两年多来,载荷LST的两个仪器WST和SDI在轨平场定标时使用的偏摆方案及其优化以及获得的平场图像和其随时间的演化情况等,并简要地介绍了WST和SDI探测器随时间的衰减和辐射损伤情况.展开更多
莱曼阿尔法太阳望远镜(Lyα Solar Telescope, LST)是先进天基太阳天文台(Advanced Space-based Solar Observatory, ASO-S,中文名为“夸父一号”)卫星上的有效载荷之一,它包括白光太阳望远镜(Whitelight Solar Telescope, WST)、莱曼...莱曼阿尔法太阳望远镜(Lyα Solar Telescope, LST)是先进天基太阳天文台(Advanced Space-based Solar Observatory, ASO-S,中文名为“夸父一号”)卫星上的有效载荷之一,它包括白光太阳望远镜(Whitelight Solar Telescope, WST)、莱曼阿尔法全日面成像仪(Solar Disk Imager, SDI)和日冕仪(Solar Corona Imager, SCI) 3台科学仪器.其中WST工作在(360±2) nm(近白光)波段, SDI工作在(121.6±4.5) nm(紫外莱曼阿尔法)波段,两者的观测视场均为1.2 R⊙(R⊙为太阳半径,整个视场相当于38.4′).通过WST和SDI的成像数据可以探索太阳爆发活动在低层大气(光球、色球及过渡区)中的触发和响应,比如研究太阳耀斑的触发机制、白光耀斑的物理性质以及爆发暗条/日珥的形态演化和运动学,并推导出太阳大气的物理参数等.若要获得WST和SDI观测的太阳大气不同特征的物理参数,如耀斑能量、日珥温度和密度等,则需要把它们观测的计数值(Digital Number, DN)转化为物理单位(如erg·cm-2·s-1·sr-1),这个过程即称为辐射定标.辐射定标是WST和SDI科学数据生产过程中的必要步骤之一.目前, WST和SDI在轨辐射定标均以太阳为参考源,其中前者使用美国材料与测试协会(American Society for Testing and Materials, ASTM)于2020年发布的太阳光谱数据,后者则使用地球同步环境系列卫星(Geostationary Operational Environmental Satellite R, GOESR)上搭载的极紫外传感器(Extreme Ultraviolet Sensors, EUVS)观测的数据.给出了WST和SDI在2023年8月到2024年2月正常观测期间的在轨辐射定标系数及其不确定度.通过拟合WST在轨辐射定标系数日平均值得到其经验公式.利用辐射定标后的数据,能够计算太阳耀斑在白光和莱曼阿尔法波段辐射出的能量以及获得日珥密度等,有利于实现WST和SDI的科学目标.展开更多
针对低空经济发展涉及的安全管理问题,在总结低空经济相关技术路线原理及落地方案的运行经验,分析低空安防普适性的4个建设方案:雷达与通感一体技术融合方案、广播式自动相关监视技术方案、远程识别技术方案和基于TDOA(time difference ...针对低空经济发展涉及的安全管理问题,在总结低空经济相关技术路线原理及落地方案的运行经验,分析低空安防普适性的4个建设方案:雷达与通感一体技术融合方案、广播式自动相关监视技术方案、远程识别技术方案和基于TDOA(time difference of arrival)无线电技术的多源融合方案的基础上,构建无人飞行器探测技术评价指标体系,并建立了一种基于决策试验评估实验室(decision-making trial and evaluation laboratory, DEMATEL)和优劣解距离法(technique for order preference by similarity to an ideal solution, TOPSIS)的多属性评价方法。结果发现,以TDOA为基础的多源融合方案是构建城市低空安防体系的有效路径和普适性方案。研究表明,低空安防体系的建设是一个系统性工程,需要政府、企业和社会各方的共同努力,在技术、数据、运营等多个层面进行整合,以适应未来低空经济的发展需求。展开更多
Using the new soft X-ray data from the Macao Science Satellite-1,we studied a solar flare that occurred on 22 June 2023.We found that the centroids of the Ca(around 3.9 keV)and Fe(around 6.7 keV)line features exhibit ...Using the new soft X-ray data from the Macao Science Satellite-1,we studied a solar flare that occurred on 22 June 2023.We found that the centroids of the Ca(around 3.9 keV)and Fe(around 6.7 keV)line features exhibit a rapid shift toward higher energy channels during the flare's rising phase,followed by a gradual decrease during the decay phase.Through precise energy calibration,the centroids are determined with high accuracy.Temperature and velocity are then self-consistently derived by comparing the centroids with those calculated from the synthesized line features using the latest CHIANTI atomic database(ver.10.1).The calculated maximum velocity reaches up to 710±60 km s-1,which significantly exceeds the previously reported values.Our results suggest that the entire shift of soft X-ray lines may occur during the process of chromospheric evaporation.展开更多
Indirect X-ray modulation imaging has been adopted in a number of solar missions and provided reconstructed X-ray images of solar flares that are of great scientific importance.However,the assessment of the image qual...Indirect X-ray modulation imaging has been adopted in a number of solar missions and provided reconstructed X-ray images of solar flares that are of great scientific importance.However,the assessment of the image quality of the reconstruction is still difficult,which is particularly useful for scheme design of X-ray imaging systems,testing and improvement of imaging algorithms,and scientific research of X-ray sources.Currently,there is no specified method to quantitatively evaluate the quality of X-ray image reconstruction and the point-spread function(PSF)of an X-ray imager.In this paper,we propose percentage proximity degree(PPD)by considering the imaging characteristics of X-ray image reconstruction and in particular,sidelobes and their effects on imaging quality.After testing a variety of imaging quality assessments in six aspects,we utilized the technique for order preference by similarity to ideal solution to the indices that meet the requirements.Then we develop the final quality index for X-ray image reconstruction,QuIX,which consists of the selected indices and the new PPD.QuIX performs well in a series of tests,including assessment of instrument PSF and simulation tests under different grid configurations,as well as imaging tests with RHESSI data.It is also a useful tool for testing of imaging algorithms,and determination of imaging parameters for both RHESSI and ASO-S/Hard X-ray Imager,such as field of view,beam width factor,and detector selection.展开更多
Imaging observations of solar X-ray bursts can reveal details of the energy release process and particle acceleration in flares.Most hard X-ray imagers make use of the modulation-based Fourier transform imaging method...Imaging observations of solar X-ray bursts can reveal details of the energy release process and particle acceleration in flares.Most hard X-ray imagers make use of the modulation-based Fourier transform imaging method,an indirect imaging technique that requires algorithms to reconstruct and optimize images.During the last decade,a variety of algorithms have been developed and improved.However,it is difficult to quantitatively evaluate the image quality of different solutions without a true,reference image of observation.How to choose the values of imaging parameters for these algorithms to get the best performance is also an open question.In this study,we present a detailed test of the characteristics of these algorithms,imaging dynamic range and a crucial parameter for the CLEAN method,clean beam width factor(CBWF).We first used SDO/AIA EUV images to compute DEM maps and calculate thermal X-ray maps.Then these realistic sources and several types of simulated sources are used as the ground truth in the imaging simulations for both RHESSI and ASO-S/HXI.The different solutions are evaluated quantitatively by a number of means.The overall results suggest that EM,PIXON,and CLEAN are exceptional methods for sidelobe elimination,producing images with clear source details.Although MEM_GE,MEM_NJIT,VIS_WV and VIS_CS possess fast imaging processes and generate good images,they too possess associated imperfections unique to each method.The two forward fit algorithms,VF and FF,perform differently,and VF appears to be more robust and useful.We also demonstrated the imaging capability of HXI and available HXI algorithms.Furthermore,the effect of CBWF on image quality was investigated,and the optimal settings for both RHESSI and HXI were proposed.展开更多
In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal ...In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal mass ejection(CME),and an extreme-ultraviolet(EUV)wave.Interaction between the wave and a quiescent prominence(QP)leads to a large-amplitude,transverse oscillation of QP.After the transverse oscillation,QP loses equilibrium and rises up.The ascending motion of the prominence is coherently detected and tracked up to∼1.68 R_(⊙)by the Solar UltraViolet Imager onboard the GOES-16 spacecraft and up to∼2.2 R_(⊙)by the Solar Corona Imager(SCI_UV)of the LyαSolar Telescope onboard the ASO-S spacecraft.The velocity increases linearly from 12.3 to 68.5 km s^(−1)at 18:30 UT.The sympathetic eruption of QP drives the second CME with a typical three-part structure.The bright core comes from the eruptive prominence,which could be further observed up to∼3.3 R_(⊙) by the Large Angle Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory mission.The leading edge of the second CME accelerates continuously from∼120 to∼277 km s^(−1).The EUV wave plays an important role in linking the primary eruption with the sympathetic eruption.展开更多
Solar activity plays an important role in influencing space weather,making it important to understand numerous aspects of spatial and temporal variations in the Sun's radiative output.High-performance deep learnin...Solar activity plays an important role in influencing space weather,making it important to understand numerous aspects of spatial and temporal variations in the Sun's radiative output.High-performance deep learning models and long-term observational records of sunspot relative numbers are essential for solar cycle forecasting.Using the multivariate time series of monthly sunspot relative numbers provided by the National Astronomical Observatory of Japan and two Informer-based models,we forecast the amplitude and timing of solar cycles 25 and 26.The main results are as follows:(1)The maximum amplitude of solar cycle 25 is higher than the previous solar cycle 24 and the following solar cycle 26,suggesting that the long-term oscillatory variation of sunspot magnetic fields is related to the roughly centennial Gleissberg cyclicity.(2)Solar cycles 25 and 26 exhibit a pronounced Gnevyshev gap,which might be caused by two non-coincident peaks resulting from solar magnetic flux transported by meridional circulation and mid-latitude diffusion in the convection zone.(3)Hemispheric prediction of sunspot activity reveals a significant northsouth asynchrony,with activity level of the Sun being more intense in the southern hemisphere.These results are consistent with expectations derived from precursor methods and dynamo theories,and further provide evidence for internal changes in solar magnetic field during the decay of the Modern Maximum.展开更多
Solar cycles are fundamental to astrophysics,space exploration,technological infrastructure,and Earth's climate.A better understanding of these cycles and their history can aid in risk mitigation on Earth,while al...Solar cycles are fundamental to astrophysics,space exploration,technological infrastructure,and Earth's climate.A better understanding of these cycles and their history can aid in risk mitigation on Earth,while also deepening our knowledge of stellar physics and solar system dynamics.Determining the solar cycles between 1600 and 1700-especially the post-1645 Maunder Minimum,characterized by significantly reduced solar activity-poses challenges to existing solar activity proxies.This study utilizes a new red equatorial auroral catalog from ancient Korean texts to establish solar cycle patterns from 1623 to 1700.Remarkably,a further reevaluation of the solar cycles between 1610 and 1755 identified a total of 13 cycles,diverging from the widely accepted record of 12 cycles during that time.This research enhances our understanding of historical solar activity,and underscores the importance of integrating diverse historical sources into modern analyses.展开更多
Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commence...Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commencement,high-speed streams,corotating interaction regions,interplanetary shocks and Forbush decreases.We included information on all of the aforementioned solar disturbances for the last six solar cycles,from 1965 to 2023,for this study.Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles.The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions.During even-numbered solar cycles,variations with a period of∼44 days are prominently observed in addition to solar rotation(∼27 days)and extended solar(∼36 days)rotation.However,in addition to solar rotation,prolonged solar rotation,and periods of around 44 days,we also detect a number of intermittent changes with nearly comparable amplitude during the oddnumbered solar cycles.The findings also demonstrate that,in contrast to odd-numbered solar cycles,the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.展开更多
The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind sol...The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind solar eruptions and coronal heating,and to directly measure the coronal magnetic field.The mission will perform in situ measurements of the current sheet between coronal mass ejections and their associated solar flares,and energetic particles produced by either reconnection or fast-mode shocks driven by coronal mass ejections.This will help to resolve the nature of reconnections in current sheets,and energetic particle acceleration regions.To investigate coronal heating,the mission will observe nano-flares on scales smaller than 70 km in the solar corona and regions smaller than 40 km in the photosphere,where magnetohydrodynamic waves originate.To study solar wind acceleration mechanisms,the mission will also track the process of ion charge-state freezing in the solar wind.A key achievement will be the observation of the coronal magnetic field at unprecedented proximity to the solar photosphere.The polar regions will also be observed at close range,and the inner edge of the solar system dust disk may be identified for the first time.This work presents the detailed background,science,and mission concept of SCOPE and discusses how we aim to address the questions mentioned above.展开更多
Solar flares are one of the strongest outbursts of solar activity,posing a serious threat to Earth’s critical infrastructure,such as communications,navigation,power,and aviation.Therefore,it is essential to accuratel...Solar flares are one of the strongest outbursts of solar activity,posing a serious threat to Earth’s critical infrastructure,such as communications,navigation,power,and aviation.Therefore,it is essential to accurately predict solar flares in order to ensure the safety of human activities.Currently,the research focuses on two directions:first,identifying predictors with more physical information and higher prediction accuracy,and second,building flare prediction models that can effectively handle complex observational data.In terms of flare observability and predictability,this paper analyses multiple dimensions of solar flare observability and evaluates the potential of observational parameters in prediction.In flare prediction models,the paper focuses on data-driven models and physical models,with an emphasis on the advantages of deep learning techniques in dealing with complex and high-dimensional data.By reviewing existing traditional machine learning,deep learning,and fusion methods,the key roles of these techniques in improving prediction accuracy and efficiency are revealed.Regarding prevailing challenges,this study discusses the main challenges currently faced in solar flare prediction,such as the complexity of flare samples,the multimodality of observational data,and the interpretability of models.The conclusion summarizes these findings and proposes future research directions and potential technology advancement.展开更多
文摘获得真实的日面观测图像,是用户基于太阳望远镜开展科学和应用研究的基础,而平场定标是科学数据生产过程中的必要步骤之一,因为平场定标可以扣除太阳望远镜在成像过程中产生的不均匀性.“夸父一号”又名先进天基太阳天文台(Advanced Space-based Solar Observatory,ASO-S)卫星的载荷之一,莱曼阿尔法太阳望远镜(Lyman-alpha Solar Telescope,LST),包括3台科学仪器,具体来说是由一个双波段太阳日冕仪(Solar Corona Imager,SCI)以及白光太阳望远镜(White-light Solar Telescope,WST)和莱曼阿尔法全日面太阳成像仪(Solar Disk Imager,SDI)这两个全日面太阳望远镜构成.WST和SDI的探测器是互补金属氧化物半导体(Complementary Metal-Oxide-Semiconductor,CMOS),其平场本身的主要特征是由于激光退火造成的条纹结构,当CMOS探测器在紫外波段使用时会产生一定的衰减与辐射损伤,并且探测器上的水汽凝结和有机物的积累等污染,也会对所得平场产生一定影响.主要展示了ASO-S卫星发射两年多来,载荷LST的两个仪器WST和SDI在轨平场定标时使用的偏摆方案及其优化以及获得的平场图像和其随时间的演化情况等,并简要地介绍了WST和SDI探测器随时间的衰减和辐射损伤情况.
文摘针对低空经济发展涉及的安全管理问题,在总结低空经济相关技术路线原理及落地方案的运行经验,分析低空安防普适性的4个建设方案:雷达与通感一体技术融合方案、广播式自动相关监视技术方案、远程识别技术方案和基于TDOA(time difference of arrival)无线电技术的多源融合方案的基础上,构建无人飞行器探测技术评价指标体系,并建立了一种基于决策试验评估实验室(decision-making trial and evaluation laboratory, DEMATEL)和优劣解距离法(technique for order preference by similarity to an ideal solution, TOPSIS)的多属性评价方法。结果发现,以TDOA为基础的多源融合方案是构建城市低空安防体系的有效路径和普适性方案。研究表明,低空安防体系的建设是一个系统性工程,需要政府、企业和社会各方的共同努力,在技术、数据、运营等多个层面进行整合,以适应未来低空经济的发展需求。
文摘Using the new soft X-ray data from the Macao Science Satellite-1,we studied a solar flare that occurred on 22 June 2023.We found that the centroids of the Ca(around 3.9 keV)and Fe(around 6.7 keV)line features exhibit a rapid shift toward higher energy channels during the flare's rising phase,followed by a gradual decrease during the decay phase.Through precise energy calibration,the centroids are determined with high accuracy.Temperature and velocity are then self-consistently derived by comparing the centroids with those calculated from the synthesized line features using the latest CHIANTI atomic database(ver.10.1).The calculated maximum velocity reaches up to 710±60 km s-1,which significantly exceeds the previously reported values.Our results suggest that the entire shift of soft X-ray lines may occur during the process of chromospheric evaporation.
基金supported by the National Natural Science Foundation of China(NSFC)12333010the National Key R&D Program of China 2022YFF0503002+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(grant No.XDB0560000)the NSFC 11921003supported by the Prominent Postdoctoral Project of Jiangsu Province(2023ZB304)supported by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences,grant No.XDA15320000.
文摘Indirect X-ray modulation imaging has been adopted in a number of solar missions and provided reconstructed X-ray images of solar flares that are of great scientific importance.However,the assessment of the image quality of the reconstruction is still difficult,which is particularly useful for scheme design of X-ray imaging systems,testing and improvement of imaging algorithms,and scientific research of X-ray sources.Currently,there is no specified method to quantitatively evaluate the quality of X-ray image reconstruction and the point-spread function(PSF)of an X-ray imager.In this paper,we propose percentage proximity degree(PPD)by considering the imaging characteristics of X-ray image reconstruction and in particular,sidelobes and their effects on imaging quality.After testing a variety of imaging quality assessments in six aspects,we utilized the technique for order preference by similarity to ideal solution to the indices that meet the requirements.Then we develop the final quality index for X-ray image reconstruction,QuIX,which consists of the selected indices and the new PPD.QuIX performs well in a series of tests,including assessment of instrument PSF and simulation tests under different grid configurations,as well as imaging tests with RHESSI data.It is also a useful tool for testing of imaging algorithms,and determination of imaging parameters for both RHESSI and ASO-S/Hard X-ray Imager,such as field of view,beam width factor,and detector selection.
基金supported by the National Key R&D Program of China 2022YFF0503002the National Natural Science Foundation of China(NSFC,Grant Nos.12333010 and 12233012)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(grant No.XDB0560000)supported by the Prominent Postdoctoral Project of Jiangsu Province(2023ZB304)supported by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences,grant No.XDA15320000.
文摘Imaging observations of solar X-ray bursts can reveal details of the energy release process and particle acceleration in flares.Most hard X-ray imagers make use of the modulation-based Fourier transform imaging method,an indirect imaging technique that requires algorithms to reconstruct and optimize images.During the last decade,a variety of algorithms have been developed and improved.However,it is difficult to quantitatively evaluate the image quality of different solutions without a true,reference image of observation.How to choose the values of imaging parameters for these algorithms to get the best performance is also an open question.In this study,we present a detailed test of the characteristics of these algorithms,imaging dynamic range and a crucial parameter for the CLEAN method,clean beam width factor(CBWF).We first used SDO/AIA EUV images to compute DEM maps and calculate thermal X-ray maps.Then these realistic sources and several types of simulated sources are used as the ground truth in the imaging simulations for both RHESSI and ASO-S/HXI.The different solutions are evaluated quantitatively by a number of means.The overall results suggest that EM,PIXON,and CLEAN are exceptional methods for sidelobe elimination,producing images with clear source details.Although MEM_GE,MEM_NJIT,VIS_WV and VIS_CS possess fast imaging processes and generate good images,they too possess associated imperfections unique to each method.The two forward fit algorithms,VF and FF,perform differently,and VF appears to be more robust and useful.We also demonstrated the imaging capability of HXI and available HXI algorithms.Furthermore,the effect of CBWF on image quality was investigated,and the optimal settings for both RHESSI and HXI were proposed.
基金supported by the Strategic Priority Research Program on Space Science,Chinese Academy of Sciencessupported by the National Key R&D Program of China 2022YFF0503003(2022YFF0503000),2021YFA1600500 (2021YFA1600502)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences,grant No.XDB0560000the National Natural Science Foundation of China (NSFC,grant Nos.12373065,12203102,12403064,and 12403068)Natural Science Foundation of Jiangsu Province (BK20231510,BK20241707)Supported by the Specialized Research Fund for State Key Laboratories,and Yunnan Key Laboratory of Solar Physics and Space Science under the grant No.YNSPCC202206
文摘In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal mass ejection(CME),and an extreme-ultraviolet(EUV)wave.Interaction between the wave and a quiescent prominence(QP)leads to a large-amplitude,transverse oscillation of QP.After the transverse oscillation,QP loses equilibrium and rises up.The ascending motion of the prominence is coherently detected and tracked up to∼1.68 R_(⊙)by the Solar UltraViolet Imager onboard the GOES-16 spacecraft and up to∼2.2 R_(⊙)by the Solar Corona Imager(SCI_UV)of the LyαSolar Telescope onboard the ASO-S spacecraft.The velocity increases linearly from 12.3 to 68.5 km s^(−1)at 18:30 UT.The sympathetic eruption of QP drives the second CME with a typical three-part structure.The bright core comes from the eruptive prominence,which could be further observed up to∼3.3 R_(⊙) by the Large Angle Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory mission.The leading edge of the second CME accelerates continuously from∼120 to∼277 km s^(−1).The EUV wave plays an important role in linking the primary eruption with the sympathetic eruption.
基金supported by the National Nature Science Foundation of China(12463009)the Yunnan Fundamental Research Projects(202301AV070007,202401AU070026)+2 种基金the"Yunnan Revitalization Talent Support Program"Innovation Team Project(202405AS350012)the Scientific Research Foundation Project of Yunnan Education Department(2023J0624,2024Y469)the GHfund A(202407016295)。
文摘Solar activity plays an important role in influencing space weather,making it important to understand numerous aspects of spatial and temporal variations in the Sun's radiative output.High-performance deep learning models and long-term observational records of sunspot relative numbers are essential for solar cycle forecasting.Using the multivariate time series of monthly sunspot relative numbers provided by the National Astronomical Observatory of Japan and two Informer-based models,we forecast the amplitude and timing of solar cycles 25 and 26.The main results are as follows:(1)The maximum amplitude of solar cycle 25 is higher than the previous solar cycle 24 and the following solar cycle 26,suggesting that the long-term oscillatory variation of sunspot magnetic fields is related to the roughly centennial Gleissberg cyclicity.(2)Solar cycles 25 and 26 exhibit a pronounced Gnevyshev gap,which might be caused by two non-coincident peaks resulting from solar magnetic flux transported by meridional circulation and mid-latitude diffusion in the convection zone.(3)Hemispheric prediction of sunspot activity reveals a significant northsouth asynchrony,with activity level of the Sun being more intense in the southern hemisphere.These results are consistent with expectations derived from precursor methods and dynamo theories,and further provide evidence for internal changes in solar magnetic field during the decay of the Modern Maximum.
基金supported by the National Natural Science Foundation of China (42388101)the CAS Youth Interdisciplinary Team (JCTD-2021-05)funded by the Youth Innovation Promotion Association, Chinese Academy of Sciences.
文摘Solar cycles are fundamental to astrophysics,space exploration,technological infrastructure,and Earth's climate.A better understanding of these cycles and their history can aid in risk mitigation on Earth,while also deepening our knowledge of stellar physics and solar system dynamics.Determining the solar cycles between 1600 and 1700-especially the post-1645 Maunder Minimum,characterized by significantly reduced solar activity-poses challenges to existing solar activity proxies.This study utilizes a new red equatorial auroral catalog from ancient Korean texts to establish solar cycle patterns from 1623 to 1700.Remarkably,a further reevaluation of the solar cycles between 1610 and 1755 identified a total of 13 cycles,diverging from the widely accepted record of 12 cycles during that time.This research enhances our understanding of historical solar activity,and underscores the importance of integrating diverse historical sources into modern analyses.
文摘Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commencement,high-speed streams,corotating interaction regions,interplanetary shocks and Forbush decreases.We included information on all of the aforementioned solar disturbances for the last six solar cycles,from 1965 to 2023,for this study.Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles.The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions.During even-numbered solar cycles,variations with a period of∼44 days are prominently observed in addition to solar rotation(∼27 days)and extended solar(∼36 days)rotation.However,in addition to solar rotation,prolonged solar rotation,and periods of around 44 days,we also detect a number of intermittent changes with nearly comparable amplitude during the oddnumbered solar cycles.The findings also demonstrate that,in contrast to odd-numbered solar cycles,the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.
基金supported by the National Key R&D Program of China (2022YFF0503800)National Natural Science Foundation of China grants (12073073, 11933009, 12273107 and U2031141)+6 种基金grants associated with the Yunnan Revitalization Talent Support Programthe Foundation of the Chinese Academy of Sciences (Light of West China Program)the Yunling Scholar Project of Yunnan Provincethe Yunnan Province Scientist Workshop of Solar Physicsthe Applied Basic Research of Yunnan Province grants (202101AT070018 and 2019FB005)supported by the National Natural Science Foundation of China grants (12273107 and U2031141)the Yunnan Key Laboratory of Solar Physics and Space Science (202205AG070009)
文摘The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind solar eruptions and coronal heating,and to directly measure the coronal magnetic field.The mission will perform in situ measurements of the current sheet between coronal mass ejections and their associated solar flares,and energetic particles produced by either reconnection or fast-mode shocks driven by coronal mass ejections.This will help to resolve the nature of reconnections in current sheets,and energetic particle acceleration regions.To investigate coronal heating,the mission will observe nano-flares on scales smaller than 70 km in the solar corona and regions smaller than 40 km in the photosphere,where magnetohydrodynamic waves originate.To study solar wind acceleration mechanisms,the mission will also track the process of ion charge-state freezing in the solar wind.A key achievement will be the observation of the coronal magnetic field at unprecedented proximity to the solar photosphere.The polar regions will also be observed at close range,and the inner edge of the solar system dust disk may be identified for the first time.This work presents the detailed background,science,and mission concept of SCOPE and discusses how we aim to address the questions mentioned above.
基金supported by the National Key Research and Development Program of China(grant No.2022YFF0503600)the National Natural Science Foundation of China(NSFC,grant No.42130202).
文摘Solar flares are one of the strongest outbursts of solar activity,posing a serious threat to Earth’s critical infrastructure,such as communications,navigation,power,and aviation.Therefore,it is essential to accurately predict solar flares in order to ensure the safety of human activities.Currently,the research focuses on two directions:first,identifying predictors with more physical information and higher prediction accuracy,and second,building flare prediction models that can effectively handle complex observational data.In terms of flare observability and predictability,this paper analyses multiple dimensions of solar flare observability and evaluates the potential of observational parameters in prediction.In flare prediction models,the paper focuses on data-driven models and physical models,with an emphasis on the advantages of deep learning techniques in dealing with complex and high-dimensional data.By reviewing existing traditional machine learning,deep learning,and fusion methods,the key roles of these techniques in improving prediction accuracy and efficiency are revealed.Regarding prevailing challenges,this study discusses the main challenges currently faced in solar flare prediction,such as the complexity of flare samples,the multimodality of observational data,and the interpretability of models.The conclusion summarizes these findings and proposes future research directions and potential technology advancement.
