Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-07-17
Astronomy and Astrophysics
Astrophysics
12 pages, 5 figures, accepted to ApJL
Scientific paper
10.1086/521602
Five-minute oscillations on the Sun (acoustic and surface gravity waves) are excited by subsurface turbulent convection. However, in sunspots the excitation is suppressed because strong magnetic field inhibits convection. We use 3D simulations to investigate how the suppression of excitation sources affects the distribution of the oscillation power in sunspot regions. The amplitude of random acoustic sources was reduced in circular-shaped regions to simulate the suppression in sunspots. The simulation results show that the amplitude of the oscillations can be approximately 2-4 times lower in the sunspot regions in comparison to the quiet Sun, just because of the suppressed sources. Using SOHO/MDI data we measured the amplitude ratio for the same frequency bands outside and inside sunspots, and found that this ratio is approximately 3-4. Hence, the absence of excitation sources inside sunspots makes a significant contribution (about 50% or higher) to the observed amplitude ratio and must be taken into account in sunspot seismology.
Kosovichev Aleksandr G.
Parchevsky Konstantin V.
No associations
LandOfFree
Effect of suppressed excitation on the amplitude distribution of 5-min oscillations in sunspots does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Effect of suppressed excitation on the amplitude distribution of 5-min oscillations in sunspots, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Effect of suppressed excitation on the amplitude distribution of 5-min oscillations in sunspots will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-563274