The Sun's Reversing Flows and Heat Spike as Caused by g -Modes
| Autor: | Hans G. Mayr, Charles L. Wolff |
|---|---|
| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal. 606:L163-L166 |
| ISSN: | 1538-4357 0004-637X |
| DOI: | 10.1086/421327 |
| Popis: | The reversing east-west flows centered near 0.675 R☉ have not been explained by gravity waves from the convection zone because suitable wavelengths do not penetrate deeply enough to drive the observed flow. An alternative is explored using g-modes, many of whose rotation rates have already been detected. Simple formulas for the radial drift of the flow and for angular momentum transfer from asymptotic g-modes are expressed in terms of local oscillation amplitudes and dissipation rates. The main loss mechanism is horizontal turbulence caused by the flow. It exceeds that due to gravity waves for which Schatzman estimated a diffusivity ~108 m2 s-1. Our proposed flow has a peak zonal speed of 50 m s-1, consistent with the observations at current resolving power. An array of g-modes with amplitudes near the detectable limit at the solar surface can cause the flow to replace itself about every 1.3 yr, as observed, if there are ~103 high harmonic modes. Since the flow occupies the same thin layer where the sound speed is anomalous, heat dissipated in driving the flow acts to reduce that solar modeling error. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|