Long-period eigenoscillations of the solar interior: 1-3 yr, 20-40 yr, and 1500-20000 year modes
Abstract
Waves with periods much larger than the rotation period become trapped in the solar radiative interior. The modelling considers compressible, nonadiabatic, Rossby- like modes (ɛ-mechanism and radiative losses are taken into account) for a very small latitudinal gradient of rotation, without an arbitrary choice of other free parameters. We found global vorticity modes in 3 separate period ranges of ≈1-3 yr, 20-40 yr, and 1500-20000 yr which are maximum unstable. The discovered resonant cavity modes (called R-modes) are different from the known r-modes. We discuss some prospects to develop the theory of R-modes as a driver of the dynamics in the convective zone which could explain e.g., observed short-term fluctuations of rotation, a control of the solar magnetic cycle, and abrupt changes of terrestrial climate in the past (Dansgaard-Oeschger events).
- Publication:
-
Solspa 2001, Proceedings of the Second Solar Cycle and Space Weather Euroconference
- Pub Date:
- March 2002
- Bibcode:
- 2002ESASP.477..167S
- Keywords:
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- Hydrodynamics;
- Sun: Oscillations;
- Sun: Interior;
- Sun: Rotation