Modelling complex magnetic fields in stars with radiative envelopes

Magnetic chemically peculiar A and B type stars (Ap/Bp) exhibit strong globally organised magnetic fields, this is combined with strong chemical abundance non-uniformities within the atmosphere. The presence of the magnetic field influences energy and mass transport within the atmosphere of a star, this is thought to cause these observed chemical non-uniformities. These stars offer the ideal laboratory for understanding the interplay between magnetic field structure, atmospheric transport processes and other stellar parameters. With the recent increase in the availability of spectropolarimetric data and by using magnetic Doppler imaging (MDI) techniques, the number of detailed maps of the magnetic structure of Ap/Bp stars is growing. It is now possible to begin to investigate correlations between the magnetic field structure, chemical abundance structures in the photospheres of Ap/Bp stars and other stellar parameters, the first steps in understanding the evolution of such magnetic fields.