Computer Science – Sound
Scientific paper
May 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007aas...210.2206b&link_type=abstract
American Astronomical Society Meeting 210, #22.06; Bulletin of the American Astronomical Society, Vol. 39, p.125
Computer Science
Sound
Scientific paper
The discovery that sunspots absorb acoustic waves was first announced twenty years ago at a previous SPD meeting in Honolulu. A considerable effort has been made to understand the physics of the interaction between acoustic waves and sunspots. However, the implications of this two-decade old discovery are still being explored in helioseismology. An ongoing controversy involves the role of surface effects, including absorption, in modeling the subsurface structure of sunspots. Braun and Birch recently suggested that observed frequency variations, at fixed phase speeds, of acoustic travel-time perturbations through sunspots offers evidence for a strong contribution to travel times from structures with vertical scales smaller than about one Mm near the solar surface. We test this suggestion with the numerical simulations of acoustic-wave propagation hrough specified sound-speed perturbations of a background solar model. An important finding is that travel times measured using helioseismic holography from simulations employing sound-speed perturbations typical of recent time-distance inversions do not predict the strong frequency variations observed in with solar data. We are in the process of evaluating whether shallow sound-speed perturbations, such as that proposed by Fan, Braun and Chou to explain the acoustic scattering propertis of sunspots observed with Hankel analysis, can reproduce the frequency variations observed in sunspots.
This work is supported by contracts NAS5-02139, NNH05CC76C and NNH04CC05C from NASA, and grant AST-0406225 from the NSF.
Birch Aaron C.
Braun Douglas
Hanasoge Shravan M.
No associations
LandOfFree
Sunspot Seismology: Testing Surface Effects with Numerical Simulations 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 Sunspot Seismology: Testing Surface Effects with Numerical Simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sunspot Seismology: Testing Surface Effects with Numerical Simulations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1029093