  Characteristics of the depression contribution functions are studied for the
Stokes line profiles formed in a magnetic field. The form of the depression
functions depends mainly on the strength of splitting and the Zeeman component
intensity, and is of a complicated character with a distinctly pronounces
asymmetry. The depths of formation of magnetically sensitive lines are found by
means of these contribution functions. The calculations reveal that the steep
section of the line profile is formed higher than the profile center when a
strong longitudinal magnetic field is present. The Stokes profiles that
describe the polarization characteristics are formed only several kilometers
higher than the Stokes profile that specifies the general depression of the
unpolarized and polarized radiation. The averaged depth of formation of the
whole line profile is practically independent of the magnetic field strength.
The depths of formation of 17 photospheric lines usually used in
magnetospectroscopic observations are calculated for the models of the quiet
photosphere, a flux tube, and the sunspot umbra.
