Measurements of Flow Speeds in the Corona Between 2 and 30<i>R</i><sub>☉</sub>

Sheeley, N. R.; Wang, Y.-M.; Hawley, Scott H.; Brueckner, G. E.; Dere, K. P.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Paswaters, S. E.; Socker, D. G.; Cyr, O. C. St.; Wang, D.; Lamy, P. L.; Llebaria, A.; Schwenn, R.; Simnett, G. M.; Plunkett, S. P.; Biesecker, D. A.

doi:10.1086/304338

Cited by 538 publications

(487 citation statements)

References 8 publications

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“…Observations made by the LASCO and later SECCHI coronagraphs suggest that the slow wind may indeed be produced in a non-steady fashion. Plasmoids are seen to disconnect from the tips of helmet streamers and propagate away from the Sun (Sheeley et al 1997). Flattened remnants of these plasmoids can be seen at great distances by the HI instruments on STEREO (Sheeley et al 2009).…”

Section: Sources Of the Solar Windmentioning

confidence: 99%

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

et al. 2015

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The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on SolarProbe Plus is a four sensor instrument suite that provides complete measurements of the electrons and ionized helium and hydrogen that constitute the bulk of solar wind and coronal plasma. SWEAP consists of the Solar Probe Cup (SPC) and the Solar Probe Analyzers (SPAN). SPC is a Faraday Cup that looks directly at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic analyzer (ESA) on the ram side of SPP (SPAN-A) and an electron ESA on the anti-ram side (SPAN-B). The SPAN-A ion ESA has a time of flight section that enables it to sort particles by their mass/charge ratio, permitting differentiation of ion species. SPAN-A and -B are rotated relative to one another so their broad fields of view combine like the seams on a baseball to view the entire sky except for the region obscured by the heat shield and covered by SPC. Observations by SPC and SPAN produce the combined field of view and measurement capabilities required to fulfill the science objectives of SWEAP and Solar Probe Plus. SWEAP measurements, in concert with magnetic and electric fields, energetic particles, and white light contextual imaging will enable discovery and understanding of solar wind acceleration and formation, coronal and solar wind heating, and particle acceleration in the inner heliosphere of the solar system. SPC and SPAN are managed by the SWEAP Electronics Module (SWEM), which distributes power, formats onboard data products, and serves as a single electrical interface to the spacecraft. SWEAP data products include ion and electron velocity distribution functions with high energy and angular resolution. Full resolution data are stored within the SWEM, enabling high resolution observations of structures such as shocks, reconnection events, and other transient structures to be selected for download after the fact. This paper describes the implementation of the SWEAP Investigation, the driving requirements for the suite, expected performance of the instruments, and planned data products, as of mission preliminary design review.

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Section: Sources Of the Solar Windmentioning

confidence: 99%

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

et al. 2015

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“…Antiochos et al (2007), on the other hand, suggest that the slow solar wind may be accelerated by continuous small-scale reconnection events, which occur between closed and open magnetic fields at the boundaries of coronal holes. WISPR will look for signatures of these mechanisms by Sheeley et al 1997) observing and characterizing structures, which are ejected into the solar wind from streamer current sheets.…”

Section: Science Question 2: 'How Do the Observed Structures In The Cmentioning

confidence: 99%

“…White-light imaging with the LASCO coronagraphs has revealed a variety of such dynamical phenomena within the HPS in the outer corona, including plasma blobs that are ejected continually from the cusps of streamers (Sheeley et al 1997;Wang et al 1999b;Wang and Sheeley 2006), ray-like structures pervading the streamer belt (Thernisien and Howard 2006), and swarms of small-scale inflows (Wang et al 1999a;Sheeley and Wang 2001) that occur during times of high solar activity (Fig. 4) : Crooker et al 2004;Zurbuchen et al 2002), between closed magnetic fields lines (generating helical fields) and between open field lines of opposite polarities (Einaudi et al 1999;Wang et al 2007;Linton et al 2009) have all been invoked as the different mechanisms which could trigger the formation and release of such streamer blobs.…”

Section: Science Question 2: 'How Do the Observed Structures In The Cmentioning

confidence: 99%

The Wide-Field Imager for Solar Probe Plus (WISPR)

et al. 2015

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mission designed to orbit as close as 7 million km (9.86 solar radii) from Sun center. WISPR employs a 95 • radial by 58 • transverse field of view to image the fine-scale structure of the solar corona, derive the 3D structure of the large-scale corona, and determine whether a dust-free zone exists near the Sun. WISPR is the smallest heliospheric imager to date yet it comprises two nested wide-field telescopes with large-format (2 K × 2 K) APS CMOS detectors to optimize the performance for their respective fields of view and to minimize the risk of dust damage, which may be considerable close to the Sun. The WISPR electronics are very flexible allowing the collection of individual images at cadences up to 1 second at perihelion or the summing of multiple images to increase the signal-to-noise when the spacecraft is further from the Sun. The dependency of the Thomson scattering emission of the corona on the imaging geometry dictates that WISPR will be very sensitive to the emission from plasma close to the spacecraft in contrast to the situation for imaging from Earth orbit. WISPR will be the first 'local' imager providing a crucial link between the large-scale corona and the in-situ measurements.

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“…As described previously [Sheeley et al, 1997], one can use differencing techniques to study the proper motion of faint coronal features. Differences between consecutive white-light coronal images, obtained with the LASCO coronagraph, indicate proper motions by black-and-white areas whose white portions lead the black in the direction of motion.…”

Section: Techniquementioning

confidence: 99%

Continuous tracking of coronal outflows: Two kinds of coronal mass ejections

Sheeley¹,

Walters²,

Wang³

et al. 1999

J. Geophys. Res.

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530

501

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The statistics improved during the 1980s as the SOLWIND (1979)(1980)(1981)(1982)(1983)(1984)(1985) and SMM (1980,(1984)(1985)(1986)(1987)(1988)(1989) However, there were relatively few systematic studies of acceleration. Despite its large 2.5-10 Rs field of view, the SOLWIND coronagraph had a low spatial resolution (-1.25 arc min) and revealed unambiguous accelerations for only a small number of particularly well observed events [Howard et 24,739

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Measurements of Flow Speeds in the Corona Between 2 and 30R_☉

Cited by 538 publications

References 8 publications

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

The Wide-Field Imager for Solar Probe Plus (WISPR)

Continuous tracking of coronal outflows: Two kinds of coronal mass ejections

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Measurements of Flow Speeds in the Corona Between 2 and 30R☉

Cited by 538 publications

References 8 publications

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus

The Wide-Field Imager for Solar Probe Plus (WISPR)

Continuous tracking of coronal outflows: Two kinds of coronal mass ejections

Contact Info

Product

Resources

About

Measurements of Flow Speeds in the Corona Between 2 and 30R_☉