Ross Baker and Keith Aldridge
Graduate Program in Physics and Astronomy
We consider paleomagnetic intensity data obtained from sedimentary cores as a time series related to fluctuations of the fluid velocity in the Earth's core. Although this is a gross oversimplification of the relationship between these two vector fields, some aspects of their possible interaction might be obtained through inversion of paleomagnetic intensity data. In particular, the onset and development of turbulence as seen in laboratory experiments on fluid instabilities may be contained in a paleointensity time series. Just as in laboratory experiments, changes in flow regimes and the effects of irregularitites on the development of bifurcations can be traced using these observations. But this information may be corrupted by several factors including the determination of the intensity itself as well as variations in sedimentation rates. Non-linear inversion of several records from the SINT-800 dataset of paleomagnetic amplitudes will be presented. Growth and decay with time of paleomagnetic amplitudes are modelled as exponential and two harmonics. This simple model accounts for most of the paleomagnetic amplitude signal, thus providing a first step in modelling the dynamical processes producing the magnetic field.