Periodicities in an active region correlated with Type III radio bursts observed by Parker Solar Probe

Cattell, C. A.; Glesener, Lindsay; Leiran, Benjamin; Dombeck, J.; Goetz, K.; Oliveros, J. C. Martinez; Badman, S. T.; Pulupa, M.; Bale, S. D.

doi:10.1051/0004-6361/202039510

Cited by 17 publications

(19 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Krupar et al (2020) used radio triangulation of a single strong radio burst on 3 April and show its location to be consistent with a Parker spiral emerging from AR 12738, indicating it was responsible for at least some of the radio activity observed at this time. In addition, Cattell et al (2021), find some evidence of correlating periodicities in AR 12738 and in radio at PSP, although the interval they investigated is well after the time period studied in this paper, once AR 12738 had rotated on disc and AR 12737 had rotated off disc.…”

Section: Introductionmentioning

confidence: 61%

The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2

Harra

Brooks

Bale

et al. 2021

A&A

View full text Add to dashboard Cite

Context. We investigated the source of a type III radio burst storm during encounter 2 of NASA’s Parker Solar Probe (PSP) mission. Aims. It was observed that in encounter 2 of NASA’s PSP mission there was a large amount of radio activity and, in particular, a noise storm of frequent, small type III bursts from 31 March to 6 April 2019. Our aim is to investigate the source of these small and frequent bursts. Methods. In order to do this, we analysed data from the Hinode EUV Imaging Spectrometer, PSP FIELDS, and the Solar Dynamics Observatory Atmospheric Imaging Assembly. We studied the behaviour of active region 12737, whose emergence and evolution coincides with the timing of the radio noise storm and determined the possible origins of the electron beams within the active region. To do this, we probed the dynamics, Doppler velocity, non-thermal velocity, FIP bias, and densities, and carried out magnetic modelling. Results. We demonstrate that although the active region on the disc produces no significant flares, its evolution indicates it is a source of the electron beams causing the radio storm. They most likely originate from the area at the edge of the active region that shows strong blue-shifted plasma. We demonstrate that as the active region grows and expands, the area of the blue-shifted region at the edge increases, which is also consistent with the increasing area where large-scale or expanding magnetic field lines from our modelling are anchored. This expansion is most significant between 1 and 4 April 2019, coinciding with the onset of the type III storm and the decrease of the individual burst’s peak frequency, indicating that the height at which the peak radiation is emitted increases as the active region evolves.

show abstract

Section: Introductionmentioning

confidence: 61%

The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2

Harra

Brooks

Bale

et al. 2021

A&A

View full text Add to dashboard Cite

show abstract

“…The importance of far side evolution is particularly emphasized by PSP encounter 2 (middle column, Figure 6), where step changes in metric scores are observed (around 2019 March 20 and 2019 April 8). For this specific encounter, there was significant solar activity (Pulupa et al 2020) that evolved and changed the global coronal field while out of view from Earth-based magnetograms, mostly concentrated in two key active regions (AR 12737 and AR12378; Cattell et al 2021;Harra et al 2021). This meant a strong photospheric field concentration rotated on disk twice during this time interval and at this time produced sudden and significant changes in magnetograms.…”

Section: Discussionmentioning

confidence: 97%

Constraining Global Coronal Models with Multiple Independent Observables

Badman

Brooks

Poirier

et al. 2022

ApJ

Self Cite

View full text Add to dashboard Cite

Global coronal models seek to produce an accurate physical representation of the Sun’s atmosphere that can be used, for example, to drive space-weather models. Assessing their accuracy is a complex task, and there are multiple observational pathways to provide constraints and tune model parameters. Here, we combine several such independent constraints, defining a model-agnostic framework for standardized comparison. We require models to predict the distribution of coronal holes at the photosphere, and neutral line topology at the model’s outer boundary. We compare these predictions to extreme-ultraviolet (EUV) observations of coronal hole locations, white-light Carrington maps of the streamer belt, and the magnetic sector structure measured in situ by Parker Solar Probe and 1 au spacecraft. We study these metrics for potential field source surface (PFSS) models as a function of source surface height and magnetogram choice, as well as comparing to the more physical Wang–Sheeley–Arge (WSA) and the Magnetohydrodynamic Algorithm outside a Sphere (MAS) models. We find that simultaneous optimization of PFSS models to all three metrics is not currently possible, implying a trade-off between the quality of representation of coronal holes and streamer belt topology. WSA and MAS results show the additional physics that they include address this by flattening the streamer belt while maintaining coronal hole sizes, with MAS also improving coronal hole representation relative to WSA. We conclude that this framework is highly useful for inter- and intra-model comparisons. Integral to the framework is the standardization of observables required of each model, evaluating different model aspects.

show abstract

“…4h), and is commonly seen in strahl dropout events in the solar wind (e.g., Crooker et al 2003;Pagel et al 2005;Halekas et al 2021). Wave scattering is a possible source of the electron isotropization in these weak magnetic field, high β regions (e.g., Crooker et al 2003;Pagel et al 2005;Cattell et al 2021Cattell et al , 2020.…”

Section: Long Duration Partial Hcs Crossings and Magnetic Disconnectionmentioning

confidence: 99%

Prevalence of magnetic reconnection in the near-Sun heliospheric current sheet

Phan

Lavraud

Halekas

et al. 2021

A&A

View full text Add to dashboard Cite

During three of its first five orbits around the Sun, Parker Solar Probe (PSP) crossed the large-scale heliospheric current sheet (HCS) multiple times and provided unprecedented detailed plasma and field observations of the near-Sun HCS. We report the common detections by PSP of reconnection exhaust signatures in the HCS at heliocentric distances of 29.5–107 solar radii during encounters 1, 4, and 5. Both sunward and antisunward-directed reconnection exhausts were observed. In the sunward reconnection exhausts, PSP detected counterstreaming strahl electrons, indicating that HCS reconnection resulted in the formation of closed magnetic field lines with both ends connected to the Sun. In the antisunward exhausts, PSP observed dropouts of strahl electrons, consistent with the reconnected HCS field lines being disconnected from the Sun. The common detection of reconnection in the HCS suggests that reconnection is almost always active in the HCS near the Sun. Furthermore, the occurrence of multiple long-duration partial crossings of the HCS suggests that HCS reconnection could produce chains of large bulges with spatial dimensions of up to several solar radii. The finding of the prevalence of reconnection in the HCS is somewhat surprising since PSP has revealed that the HCS is much thicker than the kinetic scales required for reconnection onset. The observations are also in stark contrast with the apparent absence of reconnection in most of the small-scale and much more intense current sheets encountered near perihelia, many of which are associated with “switchbacks”. Thus, the PSP findings suggest that large-scale dynamics, either locally in the solar wind or within the coronal source of the HCS (at the tip of helmet streamers), plays a critical role in triggering reconnection onset.

show abstract

Periodicities in an active region correlated with Type III radio bursts observed by Parker Solar Probe

Cited by 17 publications

References 77 publications

The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2

The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2

Constraining Global Coronal Models with Multiple Independent Observables

Prevalence of magnetic reconnection in the near-Sun heliospheric current sheet

Contact Info

Product

Resources

About