Open AccessSolar Wind Streams and Stream Interaction Regions Observed by the Parker Solar Probe with Corresponding Observations at 1 au
Author(s) -
R. C. Allen,
D. Lario,
D. Odstrčil,
G. C. Ho,
L. K. Jian,
C. M. S. Cohen,
S. T. Badman,
S. I. Jones,
C. N. Arge,
M. L. Mays,
G. M. Mason,
S. D. Bale,
J. W. Bonnell,
A. W. Case,
E. R. Christian,
T. Dudok de Wit,
K. Goetz,
P. Harvey,
C. J. Henney,
M. E. Hill,
J. C. Kasper,
K. E. Korreck,
D. E. Larson,
R. Livi,
R. J. MacDowall,
D. Malaspina,
D. J. McComas,
R. L. McNutt,
D. G. Mitchell,
M. Pulupa,
N. E. Raouafi,
N. A. Schwadron,
Michael L. Stevens,
P. L. Whittlesey,
M. E. Wiedenbeck
Publication year - 2020
Publication title -
the astrophysical journal. supplement series/astrophysical journal. supplement series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.546
H-Index - 277
eISSN - 1538-4365
pISSN - 0067-0049
DOI - 10.3847/1538-4365/ab578f
Subject(s) - physics , heliosphere , solar wind , streams , population , astrophysics , orbit (dynamics) , observatory , astronomy , plasma , aerospace engineering , nuclear physics , computer network , demography , sociology , computer science , engineering
Several fast solar wind streams and stream interaction regions (SIRs) were observed by the Parker Solar Probe ( PSP ) during its first orbit (2018 September–2019 January). During this time, several recurring SIRs were also seen at 1 au at both L1 ( Advanced Composition Explorer ( ACE ) and Wind ) and the location of the Solar Terrestrial Relations Observatory-Ahead ( STEREO-A ). In this paper, we compare four fast streams observed by PSP at different radial distances during its first orbit. For three of these fast stream events, measurements from L1 ( ACE and Wind ) and STEREO-A indicated that the fast streams were observed by both PSP and at least one of the 1 au monitors. Our associations are supported by simulations made by the ENLIL model driven by GONG-(ADAPT-)WSA, which allows us to contextualize the inner heliospheric conditions during the first orbit of PSP . Additionally, we determine which of these fast streams are associated with an SIR and characterize the SIR properties for these events. From these comparisons, we find that the compression region associated with the fast-speed streams overtaking the preceding solar wind can form at various radial distances from the Sun in the inner heliosphere inside 0.5 au, with the suprathermal ion population (energies between 30 and 586 keV) observed as isolated enhancements suggesting localized acceleration near the SIR stream interface at ∼0.3 au, which is unlike those seen at 1 au, where the suprathermal enhancements extend throughout and behind the SIR. This suprathermal enhancement extends further into the fast stream with increasing distance from the Sun.