Mapping solar magnetic fields from the photosphere to the base of the corona

Ishikawa, R.; Bueno, J. Trujillo; Alemán, T. del Pino; Okamoto, Takenori J.; McKenzie, D. E.; Auchère, F.; Kano, Ryouhei; Song, Donguk; Yoshida, Masaki; Rachmeler, Laurel A.; Kobayashi, K.; Hara, Hirohisa; Kubo, Masahito; Narukage, Noriyuki; Sakao, Taro; Shimizu, Toshifumi; Suematsu, Y.; Bethge, Christian; Pontieu, Bart De; Dalda, A. Sainz; Vigil, Genevieve D.; Winebarger, Amy R.; Ballester, Ernest Alsina; Belluzzi, L.; Štěpán, Jiří; Ramos, A. Asensio; Carlsson, Mats; Leenaarts, J.

doi:10.1126/sciadv.abe8406

Cited by 47 publications

(98 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the light of new results of magnetic field measurements above the active corona reported by Ishikawa et al (2021), we re-open an old debate concerning the magnetic and thermal structures that lead to TR emission. There are two camps of thought.…”

Section: The Purpose Of the Present Workmentioning

confidence: 77%

Magnetic connections across the chromosphere-corona transition region

Judge

2021

Preprint

View full text Add to dashboard Cite

The plasma contributing to emission from the Sun between the cool chromosphere (≤ 10 4 K) and hot corona (≥ 10 6 K) has been subjected to many different interpretations. Here we look at the magnetic structure of this transition region (TR) plasma, based upon the implications of CLASP2 data of an active region recently published by Ishikawa et al., and earlier IRIS and SDO data of quiet regions. Ishikawa et al. found that large areas of sunspot plages are magnetically unipolar as measured in the cores of Mg II resonance lines, formed in the lower transition region under low plasma-β conditions. Here we show that IRIS images in the line cores have fibrils which well aligned with the overlying coronal loop segments seen in the 171 Å channel of SDO. When the TR emission in active regions arise from plasma magnetically and thermally connected to the corona, then the line cores can provide the first credible magnetic boundary conditions for force-free calculations extended to the corona. We also re-examine IRIS images of dynamic TR cool loops previously reported as a major contributor to transition region emission from the quiet Sun. Dynamic cool loops contribute only a small fraction of the total TR emission from the quiet Sun.

show abstract

Section: The Purpose Of the Present Workmentioning

confidence: 77%

Magnetic connections across the chromosphere-corona transition region

Judge

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The circular polarisation can also be measured in some UV lines from the upper solar chromosphere. This has been demonstrated by the CLASP-2 suborbital rocket experiment [41]. With a telescope with an aperture of only 27 cm, it could measure the circular polarisation produced by the Zeeman effect in the Mg II h and k resonance lines in a plage region.…”

Section: The Zeeman Effectmentioning

confidence: 96%

“…[79,80]). From the upper chromosphere and transition region into the corona, the two suborbital rocket flights of CLASP obtained and exploited spectropolarimetric data in the Ly-α line at 121 nm [45,109] and Mg II near 280 nm [41]. In permitted (electric dipole) UV lines and in forbidden (magnetic dipole) IR lines, measurements of the polarisation produced by atoms in the solar coronal plasma can probe the magnetism of solar coronal structures, and the solar wind velocity (e.g.…”

Section: Magneto-optical Effects In Strong Resonance Linesmentioning

confidence: 99%

“…Our estimates for the chromospheric telescope are based on the performances of current and near-future facilities that are designed to measure the solar magnetic field at high resolution. The suborbital rocket flights of CLASP [41,45,109] in particular can be regarded as the true pathfinders for this mission (see Fig. 9).…”

Section: Measuring the Magnetic Field In The Chromospherementioning

confidence: 99%

See 1 more Smart Citation

Magnetic imaging of the outer solar atmosphere (MImOSA)

et al. 2021

View full text Add to dashboard Cite

The magnetic activity of the Sun directly impacts the Earth and human life. Likewise, other stars will have an impact on the habitability of planets orbiting these host stars. Although the magnetic field at the surface of the Sun is reasonably well characterised by observations, the information on the magnetic field in the higher atmospheric layers is mainly indirect. This lack of information hampers our progress in understanding solar magnetic activity. Overcoming this limitation would allow us to address four paramount long-standing questions: (1) How does the magnetic field couple the different layers of the atmosphere, and how does it transport energy? (2) How does the magnetic field structure, drive and interact with the plasma in the chromosphere and upper atmosphere? (3) How does the magnetic field destabilise the outer solar atmosphere and thus affect the interplanetary environment? (4) How do magnetic processes accelerate particles to high energies? New ground-breaking observations are needed to address these science questions. We suggest a suite of three instruments that far exceed current capabilities in terms of spatial resolution, light-gathering power, and polarimetric performance: (a) A large-aperture UV-to-IR telescope of the 1-3 m class aimed mainly to measure the magnetic field in the chromosphere by combining high spatial resolution and high sensitivity. (b) An extreme-UV-to-IR coronagraph that is designed to measure the large-scale magnetic field in the corona with an aperture of about 40 cm. (c) An extreme-UV imaging polarimeter based on a 30 cm telescope that combines high throughput in the extreme UV with polarimetry to connect the magnetic measurements of the other two instruments. Placed in a near-Earth orbit, the data downlink would be maximised, while a location at L4 or L5 would provide stereoscopic observations of the Sun in combination with Earth-based observatories. This mission to measure the magnetic field will finally unlock the driver of the dynamics in the outer solar atmosphere and thereby will greatly advance our understanding of the Sun and the heliosphere.

show abstract

“…In the lower atmosphere (1 ≤ r/R ≤ 1.02), although direct observation of the magnetic field is still difficult, flux tubes appear to expand with height in response to an exponential decrease in the ambient gas pressure (Ishikawa et al 2021). Here, we simply assume that the magnetic field expands to keep the plasma beta nearly constant until the field strength reaches the coronal-base value.…”

Section: Background Magnetic Fieldmentioning

confidence: 99%

Testing the Alfvén-wave model of the solar wind with interplanetary scintillation

Shoda,

Iwai,

Shiota

2022

Preprint

View full text Add to dashboard Cite

Understanding the mechanism(s) of the solar wind acceleration is important in astrophysics and geophysics. A promising model of the solar wind acceleration is known as the wave/turbulence-driven (WTD) model, in which Alfvén waves feed energy to the solar wind. In this study, we tested the WTD model with global measurement of wind speed from interplanetary scintillation (IPS) observations. For Carrington rotations in minimal and maximal activity phases, we selected field lines calculated by the potential-field source-surface method in high-and mid-latitudes and compared the simulated and observed wind velocities. The simulation was performed in a self-consistent manner by solving the magnetohydrodynamic equations from the photosphere to the solar wind. In high-latitude regions, the simulated solar wind velocity agrees better with the IPS observation than with the classical Wang-Sheeley empirical estimation, both in maximal and minimal activity phases. In mid-latitude regions, the agreement worsens, possibly because of the inaccuracy of the WTD model and/or the magneticfield extrapolation. Our results indicate that the high-latitude solar wind is likely to be driven by waves and turbulence, and that the physics-based prediction of the solar wind velocity is highly feasible with an improved magnetic-field extrapolation.

show abstract

Mapping solar magnetic fields from the photosphere to the base of the corona

Cited by 47 publications

References 53 publications

Magnetic connections across the chromosphere-corona transition region

Magnetic connections across the chromosphere-corona transition region

Magnetic imaging of the outer solar atmosphere (MImOSA)

Testing the Alfvén-wave model of the solar wind with interplanetary scintillation

Contact Info

Product

Resources

About