What Happens to Coronal Field Models when Fake East-Limb Active Regions are Inserted into Real Synoptic Charts?
Abstract
Global coronal magnetic field models and solar wind models make use of synoptic maps of the photospheric magnetic field as a lower boundary condition. These maps have historically been constructed using observed magnetograms, such that a full-sun map is assembled over the course of a full solar rotation. As a result of this process, a single maps contains observations made at different times over the course of a month, with east-limb longitudes being the most out-of-date. However, there are many instances where significant missing flux located on the east limb of the sun has been shown to affect the configuration of coronal magnetic fields on the Earth-facing side, and in many cases significant downstream effects occur when predicting solar wind speeds and other quantities related to space weather. Here, the same fictitious east-limb active region is inserted into a series of synoptic charts spanning sunspot cycles 23 and 24 as a way to approximate magnetic flux located at east-limb longitudes that would be missing from a synoptic chart. The resulting ensemble of photospheric magnetic maps allows us to evaluate how often and much of an effect such "hidden flux" affects potential-field models of the global coronal field.
- Publication:
-
2018 Triennial Earth-Sun Summit (TESS)
- Pub Date:
- May 2018
- Bibcode:
- 2018tess.conf41603D