Is the Solar Mn I 539.4 nm line variation really explained?

The wavelength coincidence between transition of Mn I and emission peak of Mg II k line is recently used for the explanation of temporal variation of weak resonance line Mn I 539.4 nm anti-correlated with the solar cycle (Doyle et al, 2001). Here we present results of numerical experiments showing that described optical pumping mechanism is not directly responsible for the observed variation. From the other side, it is also shown that the energy transfer between Mn I and Mg II atoms is realistic and strongly dependent on the used model atmosphere. The effect is calculated for seven features on the solar disc described by semi-empirical models. The simple combination of calculated profiles with the average filling factors consistent with used atmospheric models already gives a good estimation of observed effect. Introduction of optical pumping mechanism only involves a correction to this estimation.