The 2.6-3.8 GHz, 4.5-7.5 GHz, 5.2-7.6 GHz and 0.7-1.5 GHz componentspectrometers of Solar Broadband Radio Spectrometer (SBRS) started routine observations,respectively, in late August 1996, August 1999, August 1999, a...The 2.6-3.8 GHz, 4.5-7.5 GHz, 5.2-7.6 GHz and 0.7-1.5 GHz componentspectrometers of Solar Broadband Radio Spectrometer (SBRS) started routine observations,respectively, in late August 1996, August 1999, August 1999, and June 2000. They just managed tocatch the coming 23rd solar active maximum. Consequently, a large amount of microwave burst datawith high temporal and high spectral resolution and high sensitivity were obtained. A variety offine structures (FS) superimposed on microwave bursts have been found. Some of them are known, suchas microwave type Ⅲ bursts, microwave spike emission, but these were observed with more detail;some are new. Reported for the first time here are microwave type U bursts with similar spectralmorphology to those in decimetric and metric wavelengths, and with outstanding characteristics suchas very short durations (tens to hundreds ms), narrow bandwidths, higher frequency drift rates andhigher degrees of polarization. Type N and type M bursts were also observed. Detailed zebra patternand fiber bursts at the high frequency were found. Drifting pulsation structure (DPS) phenomenaclosely associated with CME are considered to manifest the initial phase of the CME, andquasi-periodic pulsation with periods of tens ms have been recorded. Microwave 'patches', unlikethose reported previously, were observed with very short durations (about 300 ms), very high fluxdensities (up to 1000 sfu), very high polarization (about 100% RCP), extremely narrow bandwidths(about 5%), and very high spectral indexes. These cannot be interpreted with the gyrosynchrotronprocess. A superfine structure in the form of microwave FS (ZPS, type U), consisting of microwavemillisecond spike emission (MMS), was also found.展开更多
We investigated 64 pairs of interacting-CME events identified from simultaneous observations by the SOHO and STEREO spacecraft from January 2010 to August 2014, to examine the relationship between large SEP events in ...We investigated 64 pairs of interacting-CME events identified from simultaneous observations by the SOHO and STEREO spacecraft from January 2010 to August 2014, to examine the relationship between large SEP events in the energy range of ～25 to～60 MeV and properties of the interacting CMEs.We found that during CME interactions, the large SEP events in this study were all generated by CMEs with the presence of enhanced type Ⅱ radio bursts, which also have wider longitudinal distributions compared to events without a type Ⅱ radio burst or its enhancement(almost always associated with small SEP events).It seems that the signature of type Ⅱ radio burst enhancement is a good discriminator between large SEP and small or no SEP event producers during CME interactions. The type Ⅱ radio burst enhancement is more likely to be generated by CME interactions, with the main CME having a larger speed(v), angular width(WD), mass(m) and kinetic energy(Ek), and taking over the preceding CMEs. The preceding CMEs in these instances have higher v, WD, m and Ekthan those in CME pairs missing type Ⅱ radio bursts or enhancements. Generally, the values of these properties in the type-Ⅱ-enhanced events are typically higher than the corresponding non-type-Ⅱ or non-type-Ⅱ-enhanced cases for both the main and preceding CMEs. Our analysis also revealed that the intensities of associated SEP events correlate negatively with the intersection height of the two CMEs. Moreover, the overlap width of two CMEs is typically larger in type-Ⅱ-enhanced events than in non-type-Ⅱ or non-type-Ⅱ-enhanced events. Most type-Ⅱ-enhanced events and SEP events are coincident and are almost always made by the fast and wide main CMEs that sweep fully over relatively slower and narrower preceding CMEs. We suggest that a fast CME with enough energy completely overtaking a relatively narrower preceding CME, especially at low height, can drive a more energetic shock signified by the enhanced type Ⅱ radio bursts. The shock may accelerate ambi展开更多
During non-flaring times,the radio flux of the Sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission,very similar to extremeultraviolet(EUV) radi...During non-flaring times,the radio flux of the Sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission,very similar to extremeultraviolet(EUV) radiation.Owing to such a proximity,it is feasible to investigate the relationship between the EUV emission and radio emission in a quantitative way.In this paper,we reconstruct the radio images of the Sun through the differential emission measure obtained from multi-wavelength EUV images of the Atmospheric Imaging Assembly on board Solar Dynamics Observatory(SDO).Through comparing the synthetic radio images at 6 GHz with those observed by the Siberian Radioheliograph,we find that the predicted radio flux is qualitatively consistent with the observed value,confirming thermal origin of the coronal radio emission during non-flaring times.The results further show that the predicted radio flux is closer to the observations in the case that includes the contribution of plasma with temperatures above 3 MK than in the case of only involving low temperature plasma,as was usually done in the pre-SDO era.We also discuss applications of the method and uncertainties of the results.展开更多
稻城圆环阵太阳射电望远镜(Daocheng Solar Radio Telescope, DSRT)作为子午工程二期太阳-行星际探测子系统的重要部分,工作在150–450 MHz频段,可提供高空间、高时间分辨率的太阳爆发亮温图像.针对DSRT天线的高精度指向测量以及对指向...稻城圆环阵太阳射电望远镜(Daocheng Solar Radio Telescope, DSRT)作为子午工程二期太阳-行星际探测子系统的重要部分,工作在150–450 MHz频段,可提供高空间、高时间分辨率的太阳爆发亮温图像.针对DSRT天线的高精度指向测量以及对指向误差批量标定和校正的需求,首先根据DSRT独有的三轴座架系统,通过四元数旋转变换法建立了天线3参数编码器零点误差模型;然后提出了基于射电源的漂移扫描法获得16个单元天线功率方向图,并根据2维方向图确定波束中心的方法精确测量了DSRT天线指向误差;最后用最小二乘法拟合得到模型参数,并通过天线控制软件重新调整各个轴的零点,后对调整结果进行验证.结果表明指向校正方法可靠有效,校正后16个天线的指向精度为0.5°之内,明显优于校正前3.5°的指向误差,满足误差小于DSRT天线最高工作频率下的1/10波束范围内的要求.展开更多
太阳射电爆发(Solar Radio Burst,SRB)是太阳高能电子与背景等离子体相互作用产生的感应辐射现象,其多样的动力学谱类型及其复杂的精细结构反映了辐射源区磁等离子体结构状态丰富的物理信息,而相关辐射机制则是解读相关物理信息的关键工...太阳射电爆发(Solar Radio Burst,SRB)是太阳高能电子与背景等离子体相互作用产生的感应辐射现象,其多样的动力学谱类型及其复杂的精细结构反映了辐射源区磁等离子体结构状态丰富的物理信息,而相关辐射机制则是解读相关物理信息的关键工具.长期以来,在SRB辐射机制的研究中一直存在着争议不决的两种主要机制,即等离子体辐射机制和电子回旋脉泽(Electron Cyclotron Maser,ECM)辐射机制.近年来,针对传统的ECM辐射机制应用到SRB现象时遇到的一些主要困难,发展了由幂律谱电子低能截止驱动和包含快电子束自生阿尔文波效应的新型ECM驱动模型,并成功应用于解释各类不同SRB动力学谱的形成机制.基于这些新型的ECM辐射模型,系统地总结了ECM辐射机制在各种不同类型SRB现象中的应用,并对它们不同动力学谱结构的形成给出了一致统一的物理解释.展开更多
A series of solar radio bursts were observed in AR NOAA 10486 with the SolarBroadband (1.1-7.6 GHz) Radio Spectrometers (SBRS of China). Here we analyze four significant eventsassociated with CME events and strong X-r...A series of solar radio bursts were observed in AR NOAA 10486 with the SolarBroadband (1.1-7.6 GHz) Radio Spectrometers (SBRS of China). Here we analyze four significant eventsassociated with CME events and strong X-ray flares that occurred on 2003 October 22, 26, 27, 29.The Oct. 26 event is a long duration event (LDE) with drift pulsation structure (DPS), narrowbanddm-burst (DCIM), and more than seven types of Fine Structures (FSs); its time of the maximum flux(07:30 UT) is about half an hour later than the X-flare (06:54 UT).展开更多
定标是射电天文观测中基础而重要的工作.定标工作可以得到太阳观测中的一个重要物理量:太阳射电辐射流量,可以扣除射电频谱仪的通道不均匀性,清晰显示射电频谱特征.结合紫金山天文台射电频谱仪的观测数据,详细介绍了定标的基本方法,分...定标是射电天文观测中基础而重要的工作.定标工作可以得到太阳观测中的一个重要物理量:太阳射电辐射流量,可以扣除射电频谱仪的通道不均匀性,清晰显示射电频谱特征.结合紫金山天文台射电频谱仪的观测数据,详细介绍了定标的基本方法,分析了定标常数的变化情况,最后给出了定标结果,并与野边山射电偏振计以及RHESSI(The Reuven Ramaty High Energy Solar Spectroscopic Imager)卫星硬X射线波段的几个太阳耀斑的观测结果进行了比较,结果符合耀斑的光变特征.其中对一个耀斑脉冲相硬X射线流量和微波光变的相关性的分析表明这些观测可以用来研究有关的辐射机制以及相应的能量释放和粒子加速过程.展开更多
We investigate the 2005 August 22 flare event（00：54 UT） exploiting hard X-ray（HXR） observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager（RHESSI） and microwave（MW） observations from the No...We investigate the 2005 August 22 flare event（00：54 UT） exploiting hard X-ray（HXR） observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager（RHESSI） and microwave（MW） observations from the Nobeyama Solar Radio Observatory. The HXR time profile exposes well-damped quasi-periodic pulsations with four sequential peaks, and the MW time profile follows the corresponding peaks.Based on this feature, we derive the time relationship of HXRs and MWs with multifrequency data from the Nobeyama Radio Polarimeter, and the spatially resolvable data from RHESSI and the Nobeyama Radioheliograph. We find that both frequency dependent delays in MWs and energy dependent delays in HXRs are significant.Furthermore, MW emissions from the south source are delayed with respect to those from the north source at both 17 GHz and 34 GHz, but no significant delays are found in HXR emissions from the different sources at the same energies. To better understand all these long time delays, we derive the electron fluxes of different energies by fitting the observed HXR spectra with a single power-law thick-target model, and speculate that these delays might be related to an extended acceleration process. We further compare the time profile of a MW spectral index derived from 17 and 34 GHz fluxes with the flux densities, and find that the spectral index shows a strong anticorrelation with the HXR fluxes.展开更多
F_(10.7)太阳辐射通量作为输入参数被广泛运用于大气经验模型、电离层模型等空间环境模型,其预报精度直接影响航天器轨道预报精度.采用时间序列法统计了太阳辐射通量F_(10.7)指数和太阳黑子数(SSN)的关系,给出了两者之间的线性关系,在...F_(10.7)太阳辐射通量作为输入参数被广泛运用于大气经验模型、电离层模型等空间环境模型,其预报精度直接影响航天器轨道预报精度.采用时间序列法统计了太阳辐射通量F_(10.7)指数和太阳黑子数(SSN)的关系,给出了两者之间的线性关系,在此基础上提出了一种基于长短时记忆神经网络(Long and Short Term Memory,LSTM)的预报方法,方法结合了54 d太阳辐射通量指数和SSN历史数据来对F_(10.7)进行未来7 d短期预报,并与其他预报方法的预报结果进行了比较,结果表明:(1)所建短期预报7 d方法模型的性能优于美国空间天气预报中心(Space Weather Prediction Center,SWPC)的方法,预测值和观测值的相关系数(CC)达到0.96,同时其均方根误差约为11.62个太阳辐射通量单位(sfu),预报结果的均方根误差(RMSE)低于SWPC,下降约11%;(2)对预测的23、24周太阳活动年结果统计表明,太阳活动高年的第7 d F_(10.7)指数预报平均绝对百分比误差(MAPE)最优可达12.9%以内,低年最优可达2.5%以内;(3)联合SSN的LSTM结果和仅使用单变量F_(10.7)的LSTM结果对比显示,新引入的SSN在改进LSTM预测方面是有效的,并且这两个模型的RMSE较SWPC分别低约11%和5%.展开更多
利用太阳射电宽带频谱仪(0.7-7.6 GHz)于2001年10月19目观测到的复杂太阳射电大爆发,呈现出许多有趣的特征.结合NoRH(Nobevama Radio Heliograph)的高空间分辨率射电成像观测及TRACE(Transition Region and Coronal Explorer)在远紫外(E...利用太阳射电宽带频谱仪(0.7-7.6 GHz)于2001年10月19目观测到的复杂太阳射电大爆发,呈现出许多有趣的特征.结合NoRH(Nobevama Radio Heliograph)的高空间分辨率射电成像观测及TRACE(Transition Region and Coronal Explorer)在远紫外(EUV)波段的高空间分辨率成像观测资料,分析了该爆发的射电频谱特征和微波射电源的演化以及它们与复杂的EUV日冕环系统的关系.该爆发是一个双带大耀斑的射电表征.前一部分以宽带(从厘米到米波)爆发为主,机制是回旋同步辐射,所对应的是环足源的辐射;后一部分以窄带(分米到米波)分米波爆发为主,机制是等离子体辐射和回旋共振辐射的联合,对应的是环顶源的辐射.展开更多
We present a new sub-class of type Ⅲ solar radio burst at the highfrequencies around 6.0 GHz. In addition to a descending and an ascending branch on the dynamicspectrum, it has an inverted morphology different from t...We present a new sub-class of type Ⅲ solar radio burst at the highfrequencies around 6.0 GHz. In addition to a descending and an ascending branch on the dynamicspectrum, it has an inverted morphology different from the simple type U-burst. We call it 'partialN-burst' because it is interpreted as the known N-burst minus its first branch. The partial N-burstpresented here was detected among a reverse slope type Ⅲ (RS-Ⅲ) burst group prior to the type Ⅴsolar radio continuum and was simultaneously recorded by two spectrometers at the NationalAstronomical Observatories, Chinese Academy of Sciences (NAOC, 5.20-7.60 GHz) and at Purple MountainObservatory (PMO, 4.50-7.50 GHz) on 1999 August 25. After the N-burst and M-burst, the partialN-burst is a third piece of evidence for a magnetic mirror effect in solar radio observation, whenthe same electron is reflected at a pinched foot of a flare loop.展开更多
基金Supported by the National Natural Science Foundation of China
文摘The 2.6-3.8 GHz, 4.5-7.5 GHz, 5.2-7.6 GHz and 0.7-1.5 GHz componentspectrometers of Solar Broadband Radio Spectrometer (SBRS) started routine observations,respectively, in late August 1996, August 1999, August 1999, and June 2000. They just managed tocatch the coming 23rd solar active maximum. Consequently, a large amount of microwave burst datawith high temporal and high spectral resolution and high sensitivity were obtained. A variety offine structures (FS) superimposed on microwave bursts have been found. Some of them are known, suchas microwave type Ⅲ bursts, microwave spike emission, but these were observed with more detail;some are new. Reported for the first time here are microwave type U bursts with similar spectralmorphology to those in decimetric and metric wavelengths, and with outstanding characteristics suchas very short durations (tens to hundreds ms), narrow bandwidths, higher frequency drift rates andhigher degrees of polarization. Type N and type M bursts were also observed. Detailed zebra patternand fiber bursts at the high frequency were found. Drifting pulsation structure (DPS) phenomenaclosely associated with CME are considered to manifest the initial phase of the CME, andquasi-periodic pulsation with periods of tens ms have been recorded. Microwave 'patches', unlikethose reported previously, were observed with very short durations (about 300 ms), very high fluxdensities (up to 1000 sfu), very high polarization (about 100% RCP), extremely narrow bandwidths(about 5%), and very high spectral indexes. These cannot be interpreted with the gyrosynchrotronprocess. A superfine structure in the form of microwave FS (ZPS, type U), consisting of microwavemillisecond spike emission (MMS), was also found.
基金supported at NUIST by the National Natural Science Foundation of China (NSFC) (Grant Nos. U1731105 and 41304150)the Natural Science Foundation of Jiangsu Province of China (No. BK20171456)+3 种基金sponsored also by the Qing Lan Project of Jiangsu Province for L.G. Ding (2016)supported by NSFC (Grant Nos.11522328, 11473070 and 11427803)the Youth Innovation Promotion Associationthe specialized research fund from the State Key Laboratory of Space Weather for financial support
文摘We investigated 64 pairs of interacting-CME events identified from simultaneous observations by the SOHO and STEREO spacecraft from January 2010 to August 2014, to examine the relationship between large SEP events in the energy range of ～25 to～60 MeV and properties of the interacting CMEs.We found that during CME interactions, the large SEP events in this study were all generated by CMEs with the presence of enhanced type Ⅱ radio bursts, which also have wider longitudinal distributions compared to events without a type Ⅱ radio burst or its enhancement(almost always associated with small SEP events).It seems that the signature of type Ⅱ radio burst enhancement is a good discriminator between large SEP and small or no SEP event producers during CME interactions. The type Ⅱ radio burst enhancement is more likely to be generated by CME interactions, with the main CME having a larger speed(v), angular width(WD), mass(m) and kinetic energy(Ek), and taking over the preceding CMEs. The preceding CMEs in these instances have higher v, WD, m and Ekthan those in CME pairs missing type Ⅱ radio bursts or enhancements. Generally, the values of these properties in the type-Ⅱ-enhanced events are typically higher than the corresponding non-type-Ⅱ or non-type-Ⅱ-enhanced cases for both the main and preceding CMEs. Our analysis also revealed that the intensities of associated SEP events correlate negatively with the intersection height of the two CMEs. Moreover, the overlap width of two CMEs is typically larger in type-Ⅱ-enhanced events than in non-type-Ⅱ or non-type-Ⅱ-enhanced events. Most type-Ⅱ-enhanced events and SEP events are coincident and are almost always made by the fast and wide main CMEs that sweep fully over relatively slower and narrower preceding CMEs. We suggest that a fast CME with enough energy completely overtaking a relatively narrower preceding CME, especially at low height, can drive a more energetic shock signified by the enhanced type Ⅱ radio bursts. The shock may accelerate ambi
基金supported by the National Natural Science Foundation of China(Grant Nos.11722325,11733003,11790303 and 11790300)the Jiangsu Natural Science Foundation(BK20170011)supported by the “Dengfeng B” program of Nanjing University
文摘During non-flaring times,the radio flux of the Sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission,very similar to extremeultraviolet(EUV) radiation.Owing to such a proximity,it is feasible to investigate the relationship between the EUV emission and radio emission in a quantitative way.In this paper,we reconstruct the radio images of the Sun through the differential emission measure obtained from multi-wavelength EUV images of the Atmospheric Imaging Assembly on board Solar Dynamics Observatory(SDO).Through comparing the synthetic radio images at 6 GHz with those observed by the Siberian Radioheliograph,we find that the predicted radio flux is qualitatively consistent with the observed value,confirming thermal origin of the coronal radio emission during non-flaring times.The results further show that the predicted radio flux is closer to the observations in the case that includes the contribution of plasma with temperatures above 3 MK than in the case of only involving low temperature plasma,as was usually done in the pre-SDO era.We also discuss applications of the method and uncertainties of the results.
文摘稻城圆环阵太阳射电望远镜(Daocheng Solar Radio Telescope, DSRT)作为子午工程二期太阳-行星际探测子系统的重要部分,工作在150–450 MHz频段,可提供高空间、高时间分辨率的太阳爆发亮温图像.针对DSRT天线的高精度指向测量以及对指向误差批量标定和校正的需求,首先根据DSRT独有的三轴座架系统,通过四元数旋转变换法建立了天线3参数编码器零点误差模型;然后提出了基于射电源的漂移扫描法获得16个单元天线功率方向图,并根据2维方向图确定波束中心的方法精确测量了DSRT天线指向误差;最后用最小二乘法拟合得到模型参数,并通过天线控制软件重新调整各个轴的零点,后对调整结果进行验证.结果表明指向校正方法可靠有效,校正后16个天线的指向精度为0.5°之内,明显优于校正前3.5°的指向误差,满足误差小于DSRT天线最高工作频率下的1/10波束范围内的要求.
文摘太阳射电爆发(Solar Radio Burst,SRB)是太阳高能电子与背景等离子体相互作用产生的感应辐射现象,其多样的动力学谱类型及其复杂的精细结构反映了辐射源区磁等离子体结构状态丰富的物理信息,而相关辐射机制则是解读相关物理信息的关键工具.长期以来,在SRB辐射机制的研究中一直存在着争议不决的两种主要机制,即等离子体辐射机制和电子回旋脉泽(Electron Cyclotron Maser,ECM)辐射机制.近年来,针对传统的ECM辐射机制应用到SRB现象时遇到的一些主要困难,发展了由幂律谱电子低能截止驱动和包含快电子束自生阿尔文波效应的新型ECM驱动模型,并成功应用于解释各类不同SRB动力学谱的形成机制.基于这些新型的ECM辐射模型,系统地总结了ECM辐射机制在各种不同类型SRB现象中的应用,并对它们不同动力学谱结构的形成给出了一致统一的物理解释.
基金Supported by the National Natural Science Foundation of China
文摘A series of solar radio bursts were observed in AR NOAA 10486 with the SolarBroadband (1.1-7.6 GHz) Radio Spectrometers (SBRS of China). Here we analyze four significant eventsassociated with CME events and strong X-ray flares that occurred on 2003 October 22, 26, 27, 29.The Oct. 26 event is a long duration event (LDE) with drift pulsation structure (DPS), narrowbanddm-burst (DCIM), and more than seven types of Fine Structures (FSs); its time of the maximum flux(07:30 UT) is about half an hour later than the X-flare (06:54 UT).
文摘定标是射电天文观测中基础而重要的工作.定标工作可以得到太阳观测中的一个重要物理量:太阳射电辐射流量,可以扣除射电频谱仪的通道不均匀性,清晰显示射电频谱特征.结合紫金山天文台射电频谱仪的观测数据,详细介绍了定标的基本方法,分析了定标常数的变化情况,最后给出了定标结果,并与野边山射电偏振计以及RHESSI(The Reuven Ramaty High Energy Solar Spectroscopic Imager)卫星硬X射线波段的几个太阳耀斑的观测结果进行了比较,结果符合耀斑的光变特征.其中对一个耀斑脉冲相硬X射线流量和微波光变的相关性的分析表明这些观测可以用来研究有关的辐射机制以及相应的能量释放和粒子加速过程.
基金Supported by the National Natural Science Foundation of China
文摘We investigate the 2005 August 22 flare event（00：54 UT） exploiting hard X-ray（HXR） observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager（RHESSI） and microwave（MW） observations from the Nobeyama Solar Radio Observatory. The HXR time profile exposes well-damped quasi-periodic pulsations with four sequential peaks, and the MW time profile follows the corresponding peaks.Based on this feature, we derive the time relationship of HXRs and MWs with multifrequency data from the Nobeyama Radio Polarimeter, and the spatially resolvable data from RHESSI and the Nobeyama Radioheliograph. We find that both frequency dependent delays in MWs and energy dependent delays in HXRs are significant.Furthermore, MW emissions from the south source are delayed with respect to those from the north source at both 17 GHz and 34 GHz, but no significant delays are found in HXR emissions from the different sources at the same energies. To better understand all these long time delays, we derive the electron fluxes of different energies by fitting the observed HXR spectra with a single power-law thick-target model, and speculate that these delays might be related to an extended acceleration process. We further compare the time profile of a MW spectral index derived from 17 and 34 GHz fluxes with the flux densities, and find that the spectral index shows a strong anticorrelation with the HXR fluxes.
文摘F_(10.7)太阳辐射通量作为输入参数被广泛运用于大气经验模型、电离层模型等空间环境模型,其预报精度直接影响航天器轨道预报精度.采用时间序列法统计了太阳辐射通量F_(10.7)指数和太阳黑子数(SSN)的关系,给出了两者之间的线性关系,在此基础上提出了一种基于长短时记忆神经网络(Long and Short Term Memory,LSTM)的预报方法,方法结合了54 d太阳辐射通量指数和SSN历史数据来对F_(10.7)进行未来7 d短期预报,并与其他预报方法的预报结果进行了比较,结果表明:(1)所建短期预报7 d方法模型的性能优于美国空间天气预报中心(Space Weather Prediction Center,SWPC)的方法,预测值和观测值的相关系数(CC)达到0.96,同时其均方根误差约为11.62个太阳辐射通量单位(sfu),预报结果的均方根误差(RMSE)低于SWPC,下降约11%;(2)对预测的23、24周太阳活动年结果统计表明,太阳活动高年的第7 d F_(10.7)指数预报平均绝对百分比误差(MAPE)最优可达12.9%以内,低年最优可达2.5%以内;(3)联合SSN的LSTM结果和仅使用单变量F_(10.7)的LSTM结果对比显示,新引入的SSN在改进LSTM预测方面是有效的,并且这两个模型的RMSE较SWPC分别低约11%和5%.
文摘利用太阳射电宽带频谱仪(0.7-7.6 GHz)于2001年10月19目观测到的复杂太阳射电大爆发,呈现出许多有趣的特征.结合NoRH(Nobevama Radio Heliograph)的高空间分辨率射电成像观测及TRACE(Transition Region and Coronal Explorer)在远紫外(EUV)波段的高空间分辨率成像观测资料,分析了该爆发的射电频谱特征和微波射电源的演化以及它们与复杂的EUV日冕环系统的关系.该爆发是一个双带大耀斑的射电表征.前一部分以宽带(从厘米到米波)爆发为主,机制是回旋同步辐射,所对应的是环足源的辐射;后一部分以窄带(分米到米波)分米波爆发为主,机制是等离子体辐射和回旋共振辐射的联合,对应的是环顶源的辐射.
文摘We present a new sub-class of type Ⅲ solar radio burst at the highfrequencies around 6.0 GHz. In addition to a descending and an ascending branch on the dynamicspectrum, it has an inverted morphology different from the simple type U-burst. We call it 'partialN-burst' because it is interpreted as the known N-burst minus its first branch. The partial N-burstpresented here was detected among a reverse slope type Ⅲ (RS-Ⅲ) burst group prior to the type Ⅴsolar radio continuum and was simultaneously recorded by two spectrometers at the NationalAstronomical Observatories, Chinese Academy of Sciences (NAOC, 5.20-7.60 GHz) and at Purple MountainObservatory (PMO, 4.50-7.50 GHz) on 1999 August 25. After the N-burst and M-burst, the partialN-burst is a third piece of evidence for a magnetic mirror effect in solar radio observation, whenthe same electron is reflected at a pinched foot of a flare loop.
