Connection between active longitudes and magnetic helicity
  A two-dimensional mean field dynamo model is solved where magnetic helicity conservation is fully included. The model has a negative radial velocity gradient giving rise to equatorward migration of magnetic activity patterns. In addition the model develops longitudinal variability with activity patches travelling in longitude. These patches may be associated with active longitudes. 
A. Brandenburg (Nordita), & P. J. K\"apyl\"a (KIS and Oulu)