Abstracts Details


First Name * : Paul
Last Name * : Bryans
Affiliation * : High Altitude Observatory
Abstract Type * : Poster
Title * : Coronal Hole Variation from Chromosphere to Solar Wind
Author(s) * : Paul Bryans
Abstract Session * : Thermal and magnetic coupling through the atmosphere
Abstract * : Coronal holes (CHs) are most commonly defined as long-lived regions of reduced intensity in EUV images, and known to be the source of the fast solar wind. Recent analysis of the spectral characteristics of CHs, using data from the Interface Region Imaging Spectrograph (IRIS) and the Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode, belies their apparent uniformity in imaging data. Despite the typical assertion that CHs are the source of the fast solar wind, EIS measurements show regions within a CH with indications of slow-wind composition in the corona. The spectral signatures of these regions extend to the chromosphere, as evidenced in the Mg II lines measured by IRIS, with the possibility that differences in the coronal composition could also have signatures in the lower solar atmosphere. In this presentation we will explore what these spectroscopic measurements reveal about the underlying magnetic field and discuss the implications of variations in the chromosphere and corona on the solar wind.