Are geomagnetic field reversals controlled by turbulence within the Earth's core?

We consider geomagnetic field reversal sequences from the last 160 Ma, and find the inter‐reversal times to be well fit by a lognormal distribution. Such a distribution could arise from ‘multiplicative noise’ in the underlying geodynamo; and turbulent fluctuations within the core may be expected to provide such noise via the α ‐effect of dynamo theory. We investigate this mechanism by coupling a low order αω ‐type dynamo to a shell model of turbulence. This model reproduces field reversals varying in duration from subchrons to superchrons; these are reasonably fit by a lognormal distribution, consistent with the multiplicative noise mechanism proposed.