Enhanced p-Mode Absorption seen near the Sunspot Umbral-Penumbral Boundary

Abstract

We investigate p-mode absorption in a sunspot using SOHO/MDI high-resolution Doppler images. The Doppler power computed from a three and a half hour data set is used for studying the absorption in a sunspot. The result shows an enhancement in absorption near the umbral-penumbral boundary of the sunspot. We attempt to relate the observed absorption with the magnetic field structure of the sunspot. The transverse component of the potential field is computed using the observed SOHO/MDI line-of-sight magnetograms. A comparison of the power map and the computed potential field shows enhanced absorption near the umbral-penumbral boundary where the computed transverse field strength is higher.

arXiv comment9 pages, 4 figures, Accepted for publication in Solar Physics

References in corpus (2)

• Radiative transfer effects on Doppler measurements as sources of surface effects in sunspot seismology
• Variation of Acoustic Power with Magnetic Field as seen in Gong+ Data

Cited by in corpus (4)

• On standing sausage waves in photospheric magnetic waveguides
• The detection of upwardly propagating waves channelling energy from the chromosphere to the low corona
• Acoustic Power Absorption and its Relation with Vector Magnetic Field of a Sunspot
• Activity Related Variations of High-Degree p-Mode Amplitude, Width and Energy in Solar Active Regions