Speaker
Description
First, we discuss a model of the solar dynamo that explain its various periodicities on widely different time scales in a self-consistent manner. Starting with Rieger-type periodicities, we show that the two-planet spring tides of Venus, Earth and Jupiter are able to excite magneto-Rossby waves in the solar tachocline with periods between 100 and 300 days and amplitudes of m/s or even more. We show that the quadratic action of these waves contains a beat period of 11.07 years, and argue that its axisymmetric part is strong enough to synchronize the entire solar dynamo via parametric resonance. A secondary beat between the arising 22.14-year Hale cycle and the 19.86-year periodic motion of the Sun around the barycentre of the solar system may explain the longer-term Gleissberg and Suess-de Vries cycles. The spectrum emerging from this double-synchronized dynamo model is in remarkable agreement with climate-related data.
In the second part of the talk, we shortly examine the present status of the DRESDYN precession-driven dynamo experiment. We discuss the combined numerical and experimental efforts to identify dynamo-optimizing precession ratios and nutation angles, and illustrate the recent steps in finalizing and commissioning the machine.
