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Observations of Energetic-particle Population Enhancements along Intermittent Structures near the Sun from the Parker Solar Probe

Bandyopadhyay, Riddhi and Matthaeus, W. H. and Parashar, t. N. and Chhiber, R. and Ruffolo, D. and Goldstein, M. L. and Maruca, B. A. and Chasapis, A. and Qudsi, R. and McComas, D. J. and Christian, E. R. and Szalay, J. R. and Joyce, C. J. and Giacalone, J. and Schwadron, N. A. and Mitchell, D. G. and Hill, M. E. and Wiedenbeck, M. E. and McNutt, R. L., Jr. and Desai, M. I. and Bale, Stuart D. and Bonnell, J. W. and Dudok de Wit, T. and Goetz, Keith and Harvey, Peter R. and MacDowall, Robert J. and Malaspina, David M. and Pulupa, Mark and Velli, M. and Kasper, J. C. and Korreck, K. E. and Stevens, M. and Case, A. W. and Raouafi, N. (2020) Observations of Energetic-particle Population Enhancements along Intermittent Structures near the Sun from the Parker Solar Probe. Astrophysical Journal Supplement Series, 246 (2). Art. No. 61. ISSN 1538-4365. doi:10.3847/1538-4365/ab6220.

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Observations at 1 au have confirmed that enhancements in measured energetic-particle (EP) fluxes are statistically associated with "rough" magnetic fields, i.e., fields with atypically large spatial derivatives or increments, as measured by the Partial Variance of Increments (PVI) method. One way to interpret this observation is as an association of the EPs with trapping or channeling within magnetic flux tubes, possibly near their boundaries. However, it remains unclear whether this association is a transport or local effect; i.e., the particles might have been energized at a distant location, perhaps by shocks or reconnection, or they might experience local energization or re-acceleration. The Parker Solar Probe (PSP), even in its first two orbits, offers a unique opportunity to study this statistical correlation closer to the corona. As a first step, we analyze the separate correlation properties of the EPs measured by the Integrated Science Investigation of the Sun (IS⊙IS) instruments during the first solar encounter. The distribution of time intervals between a specific type of event, i.e., the waiting time, can indicate the nature of the underlying process. We find that the IS⊙IS observations show a power-law distribution of waiting times, indicating a correlated (non-Poisson) distribution. Analysis of low-energy (~15 – 200 keV/nuc) IS⊙IS data suggests that the results are consistent with the 1 au studies, although we find hints of some unexpected behavior. A more complete understanding of these statistical distributions will provide valuable insights into the origin and propagation of solar EPs, a picture that should become clear with future PSP orbits.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper ItemIS⊙IS data and visualization tools ItemNASA Space Physics Data Facility
Bandyopadhyay, Riddhi0000-0002-6962-0959
Matthaeus, W. H.0000-0001-7224-6024
Parashar, t. N.0000-0003-0602-8381
Chhiber, R.0000-0002-7174-6948
Ruffolo, D.0000-0003-3414-9666
Goldstein, M. L.0000-0002-5317-988X
Maruca, B. A.0000-0002-2229-5618
Chasapis, A.0000-0001-8478-5797
Qudsi, R.0000-0001-8358-0482
McComas, D. J.0000-0001-6160-1158
Christian, E. R.0000-0003-2134-3937
Szalay, J. R.0000-0003-2685-9801
Joyce, C. J.0000-0002-3841-5020
Schwadron, N. A.0000-0002-3737-9283
Mitchell, D. G.0000-0003-1960-2119
Hill, M. E.0000-0002-5674-4936
Wiedenbeck, M. E.0000-0002-2825-3128
McNutt, R. L., Jr.0000-0002-4722-9166
Desai, M. I.0000-0002-7318-6008
Bale, Stuart D.0000-0002-1989-3596
Dudok de Wit, T.0000-0002-4401-0943
Goetz, Keith0000-0003-0420-3633
MacDowall, Robert J.0000-0003-3112-4201
Malaspina, David M.0000-0003-1191-1558
Pulupa, Mark0000-0002-1573-7457
Velli, M.0000-0002-2381-3106
Kasper, J. C.0000-0002-7077-930X
Korreck, K. E.0000-0001-6095-2490
Stevens, M.0000-0002-7728-0085
Case, A. W.0000-0002-3520-4041
Raouafi, N.0000-0003-2409-3742
Additional Information:© 2020. The American Astronomical Society. Received 2019 September 14; revised 2019 November 29; accepted 2019 December 16; published 2020 February 3. Early Results from Parker Solar Probe: Ushering a New Frontier in Space Exploration Parker Solar Probe was designed, built, and is now operated by the Johns Hopkins Applied Physics Laboratory as part of NASA's Living with a Star (LWS) program (contract NNN06AA01C). Support from the LWS management and technical team has played a critical role in the success of the Parker Solar Probe mission. We are deeply indebted to everyone who helped make the PSP mission possible. In particular, we thank all of the outstanding scientists, engineers, technicians, and administrative support people across all of the IS⊙IS institutions that produced and supported the IS⊙IS instrument suite and support its operations and the scientific analysis of its data. We also thank the FIELDS and SWEAP teams for cooperation. The IS⊙IS data and visualization tools are available to the community at:; data are also available via the NASA Space Physics Data Facility ( This research was partially supported by the Parker Solar Probe Plus project through Princeton/IS⊙IS subcontract SUB0000165, and in part by NSF-SHINE AGS-1460130, NASA Heliospheric Guest Investigator grant No. 80NSSC19K0284, and grant RTA6280002 from Thailand Science Research and Innovation. S.D.B. acknowledges the support of the Leverhulme Trust Visiting Professorship program.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Ministry of Higher Education, Science, Research and Innovation (Thailand)RTA6280002
Leverhulme TrustUNSPECIFIED
Subject Keywords:Solar energetic particles ; Interplanetary turbulence ; Interplanetary physics ; Interplanetary magnetic fields ; Solar wind ; Slow solar wind
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Solar energetic particles (1491); Interplanetary turbulence (830); Interplanetary physics (827); Interplanetary magnetic fields (824); Solar wind (1534); Slow solar wind (1873)
Record Number:CaltechAUTHORS:20200203-092722125
Persistent URL:
Official Citation:Riddhi Bandyopadhyay et al 2020 ApJS 246 61
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:101066
Deposited By: George Porter
Deposited On:03 Feb 2020 23:34
Last Modified:11 Nov 2022 17:26

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