Modelling the evolution of the Sun's open and total magnetic flux
| Autor: | Robert H. Cameron, Natalie A. Krivova, Bernhard Hofer, Ilya Usoskin, Chi Ju Wu, Sami K. Solanki |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
Sunspot 010504 meteorology & atmospheric sciences Series (mathematics) Sunspot number FOS: Physical sciences Astronomy and Astrophysics Astrophysics Geophysics 01 natural sciences Power law Magnetic flux Magnetic field Maxima and minima Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science 0103 physical sciences Physics::Space Physics Exponent Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences |
| Popis: | Solar activity in all its varied manifestations is driven by the magnetic field. Two global quantities are particularly important for many purposes, the Sun’s total and open magnetic flux, which can be computed from sunspot number records using models. Such sunspot-driven models, however, do not take into account the presence of magnetic flux during grand minima, such as the Maunder minimum. Here we present a major update of a widely used simple model, which now takes into account the observation that the distribution of all magnetic features on the Sun follows a single power law. The exponent of the power law changes over the solar cycle. This allows for the emergence of small-scale magnetic flux even when no sunspots have been present for multiple decades and leads to non-zero total and open magnetic flux also in the deepest grand minima, such as the Maunder minimum, thus overcoming a major shortcoming of the earlier models. The results of the updated model compare well with the available observations and reconstructions of the solar total and open magnetic flux. This opens up the possibility of improved reconstructions of the sunspot number from time series of the cosmogenic isotope production rate. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|