Different temporal regimes of core flow variability

Wednesday, 17 December 2014
Ingo Wardinski and Vincent Lesur, Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany
Recently, our attempts to describe future geomagnetic secular
variation by a kinematic dynamo prediction scheme has shown that
sufficiently accurate forecasts cannot be obtained for longer periods
than a decade. The reason for this might be the insufficient knowledge
of the short term core flow variation, but not the differently resolved
spatial flow complexity. In order to characterize the short term flow
variability, and to inspect possible distinct behaviors on different
time scales (rather regular behavior on long term and chaotic
behavior on short time scale), we derived joint field and core surface
flow models (e.g. Lesur et al., 2010) for the last 120 years.

We plan to present results that may provide indications for typical
time scales and the partition of the core flow temporal behavior.