Shukurov, A.Sokoloff, DmitrySubramanian, Kandaswamy2012-03-052012-03-052006-01-19http://hdl.handle.net/11007/483Nonlinear behaviour of galactic dynamos is studied, allowing for magnetic helicity removal by the galactic fountain flow. Methods. A suitable advection speed is estimated, and a one-dimensional mean-field dynamo model with dynamic α-effect is explored. Results. It is shown that the galactic fountain flow is efficient in removing magnetic helicity from galactic discs. This alleviates the constraint on the galactic mean-field dynamo resulting from magnetic helicity conservation and thereby allows the mean magnetic field to saturate at a strength comparable to equipartition with the turbulent kinetic energy.enMagnetic fieldsTurbulenceGalaxiesISMArticle