Effect of area divergence and frequency on damping of slow magnetoacoustic waves propagating along umbral fan loops

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Rawat, Ananya, Gupta, Girjesh R.
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866909275032387584
author Rawat, Ananya
Gupta, Girjesh R.
author_facet Rawat, Ananya
Gupta, Girjesh R.
contents Waves play an important role in the heating of solar atmosphere, however, observations of wave propagation and damping from the solar photosphere to corona through chromosphere and transition region are very rare. Recent observations have shown propagation of 3-min slow magnetoacoustic waves (SMAWs) along fan loops from the solar photosphere to corona. In this work, we investigate the role of area divergence and frequencies on the damping of SMAWs propagating from the photosphere to the corona along several fan loops rooted in the sunspot umbra. We study the Fourier power spectra of oscillations along fan loops at each atmospheric height which showed significant enhancements in 1--2 min, 2.3--3.6 min and 4.2--6 min period bands. Amplitude of intensity oscillations in different period bands and heights are extracted after normalizing the filtered light curves with low-frequency background. We find damping of SMAW energy flux propagating along the fan loop 6 with damping lengths ~170 km and ~208 km for 1.5-min and 3-min period bands. We also show the decay of total wave energy content with height after incorporating area divergence effect, and present actual damping of SMAWs from photosphere to corona. Actual damping lengths in this case increases to ~172 km and ~303 km for 1.5-min and 3-min period bands. All the fan loops show such increase in actual damping lengths, and thus highlight the importance of area divergence effect. Results also show some frequency-dependent damping of SMAW energy fluxes with height where high-frequency waves are damped faster than low-frequency waves.
format Preprint
id arxiv_https___arxiv_org_abs_2407_21561
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Effect of area divergence and frequency on damping of slow magnetoacoustic waves propagating along umbral fan loops
Rawat, Ananya
Gupta, Girjesh R.
Solar and Stellar Astrophysics
Waves play an important role in the heating of solar atmosphere, however, observations of wave propagation and damping from the solar photosphere to corona through chromosphere and transition region are very rare. Recent observations have shown propagation of 3-min slow magnetoacoustic waves (SMAWs) along fan loops from the solar photosphere to corona. In this work, we investigate the role of area divergence and frequencies on the damping of SMAWs propagating from the photosphere to the corona along several fan loops rooted in the sunspot umbra. We study the Fourier power spectra of oscillations along fan loops at each atmospheric height which showed significant enhancements in 1--2 min, 2.3--3.6 min and 4.2--6 min period bands. Amplitude of intensity oscillations in different period bands and heights are extracted after normalizing the filtered light curves with low-frequency background. We find damping of SMAW energy flux propagating along the fan loop 6 with damping lengths ~170 km and ~208 km for 1.5-min and 3-min period bands. We also show the decay of total wave energy content with height after incorporating area divergence effect, and present actual damping of SMAWs from photosphere to corona. Actual damping lengths in this case increases to ~172 km and ~303 km for 1.5-min and 3-min period bands. All the fan loops show such increase in actual damping lengths, and thus highlight the importance of area divergence effect. Results also show some frequency-dependent damping of SMAW energy fluxes with height where high-frequency waves are damped faster than low-frequency waves.
title Effect of area divergence and frequency on damping of slow magnetoacoustic waves propagating along umbral fan loops
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2407.21561