Estimation of temporal evolution of coronal hole by surface flux transport model and potential field source surface extrapolation method
Abstract
In this study, we will estimate the temporal evolution of coronal holes by the surface flux transport (SFT) model and the potential field source surface (PFSS) extrapolation method. Estimating the temporal evolution of coronal hole, especially low latitude coronal hole, is crucial for space weather study. So far, we have developed the SFT model calculation to predict the next solar cycle activity and construct the forecast scheme. The possible relationship between the polar magnetic fields in the solar minimum and the solar activity in the maximum of the next cycle has been intensively discussed. Iijima et al. (2017) calculated the polar magnetic field at the solar minimum with the SFT model and concluded that the polar magnetic field of the next cycle is weaker than the current solar cycle. This is because polar magnetic fields are well reproduced by the SFT model. On the other hand, it is not clear whether the middle latitude magnetic fields can be well reproduced or not by the SFT model calculation. The middle latitude magnetic fields estimation is crucial for estimating the temporal evolution of coronal hole. With regard to the September 2017 X9.3 flared active region (NOAA12673), we focused on the transport of the magnetic field and the associated time evolutions in the polar coronal holes and open field lines. We compare the temporal evolution of the solar surface magnetic field by the SFT model calculations and observations. Further, we also calculated a three-dimensional coronal magnetic field using the PFSS extrapolation method with the calculated surface magnetic field distribution as a boundary condition and traced the open magnetic field lines derived from the foot point of the coronal hole. Although with the case where coronal holes are generated for the active region that appeared behind the Sun, we estimated whether we can predict coronal holes by comparing the coronal hole temporal evolution estimated by the SFT/PFSS model and AIA observation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH43E3387W
- Keywords:
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- 7524 Magnetic fields;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7529 Photosphere;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7594 Instruments and techniques;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7924 Forecasting;
- SPACE WEATHER