The richly structured linearly polarized spectrum that is produced by coherent scattering in the Sun's atmosphere contains a number of spectral features for which no explanation has been found within the standard scattering theory. According to this …
The remarkable polarization structure of the Na I D_1 and D_2 lines that is due to coherent scattering has remained an enigma, since it has not yet been possible to find an explanation that is consistent with both current understanding of quantum …
Observations of Ti I lines at 2.2 micrometer show that the Evershed flow takes place in cool, almost horizontal channels with a low magnetic field strength (~500-900 G) that does not appear to change significantly across the penumbra. This property …
The first systematic observations of sunspot umbrae using the lines of the Ti Ii multiplet at 2.2 mu m are presented. Their diagnostic capabilities are investigated, developed and used to investigate the magnetic and velocity structure of a sunspot. …
Synoptic Optical Long-term Investigations of the Sun (SOLIS) is a synoptic facility for solar observations over a long time frame that is funded by the NSF and designed and built by the National Solar Observatory.
High-resolution observations of the full Stokes vector in FeI spectral lines around 5250 Angstroms obtained at the Swedish Vacuum Solar Telescope on La Palma with the ZIMPOL I Stokes polarimeter in a complex active region reveal the presence of …
While diagnostic techniques based on the ordinary Zeeman effect (e.g. magnetograms) are almost ``blind'' to a turbulent magnetic field with mixed magnetic polarities within the spatial resolution element, the Hanle effect is sensitive to this domain …
SOLIS (Synoptic Optical Long-term Investigations of the Sun) is a proposed suite of instruments that will modernize and greatly improve synoptic solar observations carried out by the National Solar Observatory. The primary scientific goal is to …