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Numerical simulation of effects of reduced excitationof 5-min.solar oscillations in sunspots. Konstantin Parchevsky, Alexander Kosovichev Stanford University, HEPL. Motivation. The amplitude of 5-min. oscillations is significantly smaller in sunspots than in the quiet Sun.
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Numerical simulation of effects of reduced excitationof 5-min.solar oscillations in sunspots Konstantin Parchevsky, Alexander Kosovichev Stanford University, HEPL
Motivation The amplitude of 5-min. oscillations is significantly smaller in sunspots than in the quiet Sun. • Lack of wave sources inside sunspots where convection is suppressed by strong magnetic field. • Interaction of incoming waves with magnetic field and perturbations of pressure and density inside sunspots.
k- diagram observations simulations
Amplitude maps observations simulations MDI continuum 120 120 50 Mm3 = 3.65 ± 0.6 mHz amplitude ratio: 4.0 ± 0.9 4.6 ± 1.0
Conclusion • The suppression of acoustic sources inside sunspots can almost entirely explain the reduced oscillation amplitude observed in sunspots. • Amplitude ratio of acoustic waves inside and outside sunspots depends on sunspots radii. The bigger radius, the bigger suppression.