Using Nancay Radioheliograph （NRH） imaging observations, combined with SOHO/Michelson Doppler Imager （MDI） magnetogram observations and coronal magnetic field extrapolation, we studied the magnetic nature of metri...Using Nancay Radioheliograph （NRH） imaging observations, combined with SOHO/Michelson Doppler Imager （MDI） magnetogram observations and coronal magnetic field extrapolation, we studied the magnetic nature of metric noise storms that are associated with coronal mass ejections （CMEs）. Four events arc selected： the events of 2000 July 14, 2001 April 26, 2002 August 16 and 2001 March 28. The identified noise storm sources cover or partially cover the active regions （ARs）, but the centers of storm sources are offset from the ARs. Using extrapolated magnetic field lines, we find that the noise storm sources trace the boundary between the open and closed field lines. We demonstrate that the disappearance of noise storm source is followed by the appearance of the burst source. The burst sources spread on the solar disk and their distributions correspond to the extent of the CME in LASCO C2 field of view. All the SOHO/Extreme Ultraviolet Imaging Telescope （EIT） dimmings associated with noise storm sources are located at the periphery of noise storms where the magnetic lines of force were previously closed and low-lying. When the closed field becomes partially or fully open, the basic configurations of noise storm sources are changed, then the noise storm sources are no longer observed. These observations provide the information that the variations of noise storms manifest the restructuring or reconfiguring of the coronal magnetic field.展开更多
Seventy-one occurrences of coronal mass ejections （CMEs） associated with radio bursts, seemingly associated with type III bursts/fine structures （FSs）, in the centimeter-metric frequency range during 2003-2005, we...Seventy-one occurrences of coronal mass ejections （CMEs） associated with radio bursts, seemingly associated with type III bursts/fine structures （FSs）, in the centimeter-metric frequency range during 2003-2005, were obtained with the spectrometers at the National Astronomical Observatories, Chinese Academy of Sciences （NAOC） and the Culgoora radio spectrometer and are presented. The statistical results of 68 out of 71 events associated with the radio type III bursts or FSs during the initiation or early stages of the CMEs indicate that most CMEs contain the emissions of radio type III bursts/FSs near the time of the CME＇s onset, in spite of their fast or slow speeds. Therefore, we propose that type III bursts and FSs are possible precursors of the onset of CMEs. We stress that the radio type III bursts/FSs in the centimetermetric wavelength region and the CME transients possibly occurred in conjunction with the origin of the coronal precursor structures. Thus, the statistical results support the suggestions that type III bursts/FSs are indicators of extra energy input into the corona at the CMEs＇ onset, and that the type III bursts/FSs are produced primarily due to a coronal instability which eventually triggers the CME process. This may signify that the centimeter-metric radio bursts corresponding to or near the CME＇s onset are caused by the disturbed corona （possibly including minor magnetic reconnections）.展开更多
We present a statistical study of decimetric type Ⅲ radio bursts, coronal mass ejections （CMEs）, and Hα flares observed in the period from July 2000 to March 2005. In total, we investigated 395 decimetric type Ⅲ ...We present a statistical study of decimetric type Ⅲ radio bursts, coronal mass ejections （CMEs）, and Hα flares observed in the period from July 2000 to March 2005. In total, we investigated 395 decimetric type Ⅲ radio burst events, 21% of which showed apparent correlation to CMEs that were associated with Hα flares. We noticed that the Hα flares which were strongly associated with CMEs were gradual events, and 82% of them took place before CMEs appeared in the field of view of LASCO C2; that most of the CME-associated radio bursts started in the frequency range around 750 MHz with a frequency drifting rate of several hundred MHz s-1, of which both positive and negative ones were recognized; and that the correlation of type Ⅲ radio bursts to CMEs without associated flares is fairly vague, less than 9%.展开更多
A solar radio burst was observed in a coronal mass ejection/flare event by the Solar Broadband Radio Spectrometer at the Huairou Solar Observing Station on2004 December 1. The data exhibited various patterns of plasma...A solar radio burst was observed in a coronal mass ejection/flare event by the Solar Broadband Radio Spectrometer at the Huairou Solar Observing Station on2004 December 1. The data exhibited various patterns of plasma motions, suggestive of the interaction between sunward moving plasmoids and the flare loop system during the impulsive phase of the event. In addition to the radio data, the associated whitelight, Hα, extreme ultraviolet light, and soft and hard X-rays were also studied.展开更多
对第23太阳周的太阳高能粒子、米波段和DH波段Ⅱ型射电暴的爆发时间和高度进行了统计分析。结果表明:耀斑和日冕物质抛射(coronal mass ejection,CME)产生后,先后爆发米波、DH波Ⅱ型射电暴和高能粒子事件,它们爆发的高度也由低到高。米...对第23太阳周的太阳高能粒子、米波段和DH波段Ⅱ型射电暴的爆发时间和高度进行了统计分析。结果表明:耀斑和日冕物质抛射(coronal mass ejection,CME)产生后,先后爆发米波、DH波Ⅱ型射电暴和高能粒子事件,它们爆发的高度也由低到高。米波、DH波Ⅱ型射电暴的爆发时间和高度同太阳高能粒子事件是否发生并无明显关系,但伴随米波段和DH波段Ⅱ型射电暴的CME有更高的产生太阳高能粒子事件的概率。展开更多
基金Supported by the National Natural Science Foundation of China.
文摘Using Nancay Radioheliograph （NRH） imaging observations, combined with SOHO/Michelson Doppler Imager （MDI） magnetogram observations and coronal magnetic field extrapolation, we studied the magnetic nature of metric noise storms that are associated with coronal mass ejections （CMEs）. Four events arc selected： the events of 2000 July 14, 2001 April 26, 2002 August 16 and 2001 March 28. The identified noise storm sources cover or partially cover the active regions （ARs）, but the centers of storm sources are offset from the ARs. Using extrapolated magnetic field lines, we find that the noise storm sources trace the boundary between the open and closed field lines. We demonstrate that the disappearance of noise storm source is followed by the appearance of the burst source. The burst sources spread on the solar disk and their distributions correspond to the extent of the CME in LASCO C2 field of view. All the SOHO/Extreme Ultraviolet Imaging Telescope （EIT） dimmings associated with noise storm sources are located at the periphery of noise storms where the magnetic lines of force were previously closed and low-lying. When the closed field becomes partially or fully open, the basic configurations of noise storm sources are changed, then the noise storm sources are no longer observed. These observations provide the information that the variations of noise storms manifest the restructuring or reconfiguring of the coronal magnetic field.
基金Supported by the National Natural Science Foundation of Chinasupported by the National Basic Research Program of the MOST (Grant No.2011CB811403)the CAS-NSFC Key Project (Grant No. 10978006)
文摘Seventy-one occurrences of coronal mass ejections （CMEs） associated with radio bursts, seemingly associated with type III bursts/fine structures （FSs）, in the centimeter-metric frequency range during 2003-2005, were obtained with the spectrometers at the National Astronomical Observatories, Chinese Academy of Sciences （NAOC） and the Culgoora radio spectrometer and are presented. The statistical results of 68 out of 71 events associated with the radio type III bursts or FSs during the initiation or early stages of the CMEs indicate that most CMEs contain the emissions of radio type III bursts/FSs near the time of the CME＇s onset, in spite of their fast or slow speeds. Therefore, we propose that type III bursts and FSs are possible precursors of the onset of CMEs. We stress that the radio type III bursts/FSs in the centimetermetric wavelength region and the CME transients possibly occurred in conjunction with the origin of the coronal precursor structures. Thus, the statistical results support the suggestions that type III bursts/FSs are indicators of extra energy input into the corona at the CMEs＇ onset, and that the type III bursts/FSs are produced primarily due to a coronal instability which eventually triggers the CME process. This may signify that the centimeter-metric radio bursts corresponding to or near the CME＇s onset are caused by the disturbed corona （possibly including minor magnetic reconnections）.
基金Supported by the National Natural Science Foundation of Chinasupported by the Ministry of Science and Technology of China under the 973 Program grants 2006CB806301+3 种基金supported by the Ministry of Science and Technology of China under the 973 Program grants 2006CB806303by the National Natural Science Foundation of China (Grant Nos. 10473020, 10333030 and 10873030)by the Chinese Academy of Sciences under the grant KJCX2-YW-T04 to YNAONASA grant NNX07AL72G for supporting his visit to CfA
文摘We present a statistical study of decimetric type Ⅲ radio bursts, coronal mass ejections （CMEs）, and Hα flares observed in the period from July 2000 to March 2005. In total, we investigated 395 decimetric type Ⅲ radio burst events, 21% of which showed apparent correlation to CMEs that were associated with Hα flares. We noticed that the Hα flares which were strongly associated with CMEs were gradual events, and 82% of them took place before CMEs appeared in the field of view of LASCO C2; that most of the CME-associated radio bursts started in the frequency range around 750 MHz with a frequency drifting rate of several hundred MHz s-1, of which both positive and negative ones were recognized; and that the correlation of type Ⅲ radio bursts to CMEs without associated flares is fairly vague, less than 9%.
基金Supported by the National Natural Science Foundation of China
文摘A solar radio burst was observed in a coronal mass ejection/flare event by the Solar Broadband Radio Spectrometer at the Huairou Solar Observing Station on2004 December 1. The data exhibited various patterns of plasma motions, suggestive of the interaction between sunward moving plasmoids and the flare loop system during the impulsive phase of the event. In addition to the radio data, the associated whitelight, Hα, extreme ultraviolet light, and soft and hard X-rays were also studied.
文摘对第23太阳周的太阳高能粒子、米波段和DH波段Ⅱ型射电暴的爆发时间和高度进行了统计分析。结果表明:耀斑和日冕物质抛射(coronal mass ejection,CME)产生后,先后爆发米波、DH波Ⅱ型射电暴和高能粒子事件,它们爆发的高度也由低到高。米波、DH波Ⅱ型射电暴的爆发时间和高度同太阳高能粒子事件是否发生并无明显关系,但伴随米波段和DH波段Ⅱ型射电暴的CME有更高的产生太阳高能粒子事件的概率。
