Quiet-sun connection between the C IV resonance lines and the photospheric magnetic field

The quiet-Sun relation between the C IV resonance line parameters and the photospheric magnetic field is studied with a spatial resolution of 1'' x 1''. The material is ordered into groups according to the magnitude of the magnetic flux density, \B\, and conditional probabilities are calculated. We find that redshifted profiles with either high intensity, large Doppler shift, or large line broadening occupy an increasing fraction of the area when \B\ increases. These results are contrasted by blueshifted profiles which indicate a slight decrease with increasing magnetic flux density. The similarity in the results obtained with magnetograms taken several hours before and after the UV data led us to suggest that the tendency for redshifted profiles to outnumber blueshifted profiles in quiet regions originates in the supergranular network. Suggestions regarding the origin of the redshift phenomenon are briefly confronted with the observations. It appears difficult to explain the observations with models based on continuous gas flows. However, a model containing Alfven wave pulses traveling from the corona toward the transition region promises to be compatible with the observations.