Abstract
We present a new model for the Sun's global photospheric magnetic field during a deep minimum of activity, in which no active regions emerge. The emergence and subsequent evolution of small-scale magnetic features across the full solar surface is simulated, subject to the influence of a global supergranular flow pattern. Visually, the resulting simulated magnetograms reproduce the typical structure and scale observed in quiet Sun magnetograms. Quantitatively, the simulation quickly reaches a steady state, resulting in a mean field and flux distribution that are in good agreement with those determined from observations. A potential coronal magnetic field is extrapolated from the simulated full Sun magnetograms to consider the implications of such a quiet photospheric magnetic field on the corona and inner heliosphere. The bulk of the coronal magnetic field closes very low down, in short connections between small-scale features in the simulated magnetic network. Just 0.1% of the photospheric magnetic flux is found to be open at 2.5 R⊙, around 10-100 times less than that determined for typical Helioseismic and Magnetic Imager synoptic map observations. If such conditions were to exist on the Sun, this would lead to a significantly weaker interplanetary magnetic field than is currently observed, and hence a much higher cosmic ray flux at Earth.
| Original language | English |
|---|---|
| Article number | 160 |
| Pages (from-to) | 1-13 |
| Number of pages | 13 |
| Journal | Astrophysical Journal |
| Volume | 830 |
| Issue number | 2 |
| Early online date | 19 Oct 2016 |
| DOIs | |
| Publication status | Published - 20 Oct 2016 |
Keywords
- Sun: activity
- Sun: corona
- Sun: magnetic fields
- Sun: photosphere
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science
