What Determines Solar Flares Producing Interplanetary Type III Radio Bursts?

Kou, Yuankun; Jing, Z. C.; Cheng, Xin; Pan, Wuqi; Liu, Y.; Li, C.; Ding, M. D.

doi:10.3847/2041-8213/aba362

Cited by 8 publications

(8 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ionic charge states within ICMEs are mainly governed by the thermodynamic evolution of the electrons in CMEs up to freeze-in distance of each ion (Owocki, Holzer, and Hundhausen, 1983;Landi et al, 2012a,b;Song et al, 2016). More CMEs are associated with energetic flares around solar maximum (e.g., Kou et al, 2020), indicating higher electron temperatures and then more elevated ionic charge states due to magnetic reconnections (e.g., Lepri and Zurbuchen, 2004;Song et al, 2016). The elevated charge states generated in the current sheets connecting magnetic flux ropes and flare loops can flow into CMEs during eruptions (Song et al, 2016;Wang et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

Solar Cycle Dependence of ICME Composition

Song

Sun

et al. 2021

Sol Phys

View full text Add to dashboard Cite

Coronal mass ejections (CMEs) belong to the most energetic explosions in the solar atmosphere, and their occurrence rates exhibit obvious solar cycle dependence with more events taking place around solar maximum. Composition of interplanetary CMEs (ICMEs), referring to the charge states and elemental abundances of ions, opens an important avenue to investigate CMEs. In this paper, we conduct a statistical study on the charge states of five elements (Mg, Fe, Si, C, and O) and the relative abundances of six elements (Mg/O, Fe/O, Si/O, C/O, Ne/O, and He/O) within ICMEs from 1998 to 2011, and find that all the ICME compositions possess a solar cycle dependence. All of the ionic charge states and most of the relative elemental abundances are positively correlated with sunspot numbers (SSNs), and only the C/O ratios are inversely correlated with the SSNs. The compositions (except the C/O) increase with the SSNs during the ascending phase (1998–2000 and 2009–2011) and remain elevated during solar maximum and descending phase (2000–2005) compared to solar minimum (2007–2009). The charge states of low-FIP (first ionization potential) elements (Mg, Fe, and Si) and their relative abundances are correlated well, while no clear correlation is observed between the C6+/C5+ or C6+/C4+ and C/O. Most interestingly, we find that the Ne/O ratios of ICMEs and slow solar wind have the opposite solar cycle dependence.

show abstract

Section: Discussionmentioning

confidence: 99%

Solar Cycle Dependence of ICME Composition

Song

Sun

et al. 2021

Sol Phys

View full text Add to dashboard Cite

show abstract

“…In general, the formation of type III bursts needs two conditions, one of which is accelerated electrons and the other is open flux. Nevertheless, the energetic electrons are mostly restricted within the close flux of the erupting CME unless the reconnection takes place between the CME flux and the background field so as to release restricted electrons (van Driel-Gesztelyi et al 2008;Masson et al 2013;Kou et al 2020). The released electrons propagate upward and downward and then give rise to the "C-shaped" type III burst (van Driel-Gesztelyi et al 2008;Hillaris et al 2011;Zheng et al 2017).…”

Section: Summary and Discussionmentioning

confidence: 99%

Overexpansion-dominated coronal mass ejection formation and induced radio bursts

Wang

Cheng

Song

et al. 2022

A&A

Self Cite

View full text Add to dashboard Cite

Aims. Coronal mass ejections (CMEs) are the most fascinating explosions in the Solar System. Their formation is still not fully understood, however. Methods. We investigated a well-observed CME on 2021 May 7 that showed a typical three-component structure and was continuously observed from 0 to 3 R ⊙ by a combination of SDO/AIA (0-1.3 R ⊙ ), PROBA2/SWAP (0-1.7 R ⊙ ), and MLSO/K-Cor (1.05-3 R ⊙ ). Furthermore, we compared the morphological discrepancy between the CME white-light bright core and the extreme-UV (EUV) blob. We finally explored the origin of various radio bursts that are closely related to the interaction of the CME overexpansion with a nearby streamer.Results. An interesting finding is that the height increases of the CME leading front and of the bright core are dominated by the overexpansion during the CME formation. The aspect ratios of the CME bubble and bright core, quantifying the overexpansion, are found to decrease as the SO/STIX 4-10 keV and GOES 1-8 Å soft X-ray flux of the associated flare increases near the peaks. This indicates that the flare reconnection plays an important role in the first overexpansion. The CME bubble even undergoes a second overexpansion, although it is relatively weak, which is closely related to the compression with a nearby streamer and likely arises from an ideal magnetohydrodynamics process. Moreover, the CME EUV blob is found to be relatively lower and wider than the CME white-light bright core, which may correspond to the bottom part of the growing CME flux rope. The interaction between the CME and the streamer leads to two type II radio bursts, one that is drifting normally and another that is stationary, which are speculated to be induced by two different sources of the CME-driven shock front. The bidirectional electrons shown in series of C-shaped type III bursts suggest that the interchange reconnection is also involved during the interaction of the CME and streamer.

show abstract

“…As we mentioned above, it is interesting that there is one event accompanied by an IP type III burst at meter-to-kilometer waves. While about half of the flares of class M or above are accompanied by IP type III bursts (Kou et al 2020). Confined flares usually have no radio emission at meter wavelengths or beyond (Gopalswamy et al 2009;Klein et al 2010), because the energetic electrons do not get access to magnetic structures that extend high into the corona.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Energy and spectral analysis of confined solar flares from radio and X-ray observations

Tan,

Klein,

Yan

et al. 2021

Preprint

View full text Add to dashboard Cite

The energy and spectral shape of radio bursts may help us understand the generation mechanism of solar eruptions, including solar flares, CMEs, eruptive filaments, and various scales of jets. The different kinds of flares may have different characteristics of energy and spectral distribution. In this work, we selected 10 mostly confined flare events during October 2014 to investigate their overall spectral behaviour and the energy emitted in microwaves by using radio observations from microwaves to interplanetary radio waves, and X-ray observations of GOES, RHESSI, and Fermi/GBM. We found that: All the confined flare events were associated with a microwave continuum burst extending to frequencies of 9.4 ∼ 15.4 GHz, and the peak frequencies of all confined flare events are higher than 4.995 GHz and lower than or equal to 17 GHz. The median value is around 9 GHz. The microwave burst energy (or fluence) as well as the peak frequency are found to provide useful criteria to estimate the power of solar flares. The observations imply that the magnetic field in confined flares tends to be stronger than that in 412 flares studied by Nita et al. 2004. All 10 events studied did not produce detectable hard X-rays with energies above ∼300 keV indicating the lack of efficient acceleration of electrons to high energies in the confined flares.

show abstract

What Determines Solar Flares Producing Interplanetary Type III Radio Bursts?

Cited by 8 publications

References 35 publications

Solar Cycle Dependence of ICME Composition

Solar Cycle Dependence of ICME Composition

Overexpansion-dominated coronal mass ejection formation and induced radio bursts

Energy and spectral analysis of confined solar flares from radio and X-ray observations

Contact Info

Product

Resources

About