Time‐independent and time‐dependent behaviour of high‐latitude flux bundles at the core‐mantle boundary

Using a numerical dynamo model, we examine whether quasi‐stationary high latitude flux bundles which are observed in the geomagnetic field over the last 300 years, and possibly over much longer time periods, result from thermal core‐mantle interactions. We do so by imposing lateral heat flux variations at the core‐mantle boundary based upon the dominant pattern of seismic heterogeneity in the lowermost mantle. We find that the time‐averaged field then has a similar arrangement of flux bundles to that observed during the last few hundred years. However, the field is time‐dependent, and this arrangement of flux bundles is not a feature of the field at all times.