Coronal holes are the regions with largest scale solar magnetic fields, and are major source regions of high speed solar wind streams (HSSS). Their locations and areas are important for tracing the global magneticfields, modelling the heliospheric magnetic fields, andpredicting the HSSS events that may impact the Earth.Accurate identification of the coronal holes is thus important for various studies. The on-disk coronal holes are often identified either as the regions with open magnetic field lines (OMF) or as the regions with low coronal emission and predominantly unipolar magnetic fields (LIRs). The coronal holes identified by the two methods, however, do not always coincide with each other.Our previous study showed that only 12\% of the OMF regions are located within LIRs. The discrepancy comes from the OMF regions with high coronal emission and from the LIR regions with closed magnetic-field line structures. The emission of coronal plasma is the result of energy transport and generation of plasma in a magnetic field environment. Therefore, the inconsistency between OMF and LIR coronal holes is likely due to inaccurate presumptions of the relationship between the coronal emission and magnetic field structure in the two coronal-hole identification methods. The objective of this proposal is to investigate the effects of magnetic field on the coronal emission of coronal holes and to improve the two coronal hole identification methods to reduce the inconsistency between the coronal holes determined by them.
|Effective start/end date||1/08/20 → 31/07/21|
In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This project contributes towards the following SDG(s):