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

TL;DR

This study analyzes p-mode wave absorption in a sunspot, revealing increased absorption near the umbral-penumbral boundary linked to stronger transverse magnetic fields, using SOHO/MDI data.

Contribution

It demonstrates a correlation between p-mode absorption enhancement and magnetic field structure at the sunspot boundary, utilizing high-resolution Doppler and magnetogram data.

Findings

Enhanced p-mode absorption near the umbral-penumbral boundary.

Correlation between absorption and transverse magnetic field strength.

Magnetic field structure influences wave absorption patterns.

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.