BAGNULO: I would like to ask Mathys and Moss to comment about the possible detection of the radial gradients of the magnetic .elds in Ap stars. What would be the consequence of such a feature on the stellar atmosphere? I refer in particular to that the length scale for horizontal variability of the field is not less than 105 km, whereas the depth of the photosphere may be 100 times less.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html