Interaction of solar p-modes with a sunspot. I. Observations

Journal Article · Mon Dec 01 04:00:00 EST 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/164838· OSTI ID:6541945

Abdelatif, T E; Lites, B W; Thomas, J H

Time series of velocity maps of two isolated sunspots and their surroundings were recorded in the Fe I line and the umbral line Ti I. Both 3 and 5 min umbral oscillations were detected at photospheric heights. The 5 min oscillations have reduced amplitude in the umbra, which appears to act as a filter in transmitting selected frequencies in the power spectrum of 5 min p-mode oscillations of the surrounding convection zone. The k-omicron power spectrum of the umbral oscillations shows this selective transmission and also shows a shift of power to longer horizontal wavelengths. This behavior is exhibited by a simple theoretical model of the interaction of p-modes with a sunspot. The 3 min umbral oscillations are concentrated in the dark central part of the umbra. In both sunspots, the kinetic energy density of the 3 min umbral oscillation in the photosphere is much greater than the corresponding kinetic energy density at chromospheric heights measured in other sunspots. 26 references.

• Research Organization: Rochester Univ., NY; High Altitude Observatory, Boulder, CO; C. E. Kenneth Mees Observatory, Rochester, NY
• OSTI ID: 6541945
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 311; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ATMOSPHERIC CIRCULATION
ENERGY
KINETIC ENERGY
MATHEMATICS
OSCILLATIONS
PHOTOSPHERE
SEISMIC P WAVES
SEISMIC WAVES
SOLAR ACTIVITY
SOLAR ATMOSPHERE
STARSPOTS
STELLAR ACTIVITY
SUNSPOTS
TIME-SERIES ANALYSIS
VELOCITY