Observations of sausage modes in magnetic pores

TL;DR

This study provides observational evidence of magneto-hydrodynamic sausage modes in solar magnetic pores, revealing their periods and suggesting a link to global solar oscillations, using advanced wave analysis techniques.

Contribution

First observational detection of MHD sausage modes in solar pores using empirical wave decomposition methods.

Findings

Detected sausage mode oscillations with periods from 30 to 450 seconds.

Identified out-of-phase behavior between pore size and intensity as a signature.

Found periods of 3 and 5 minutes, similar to solar global oscillations.

Abstract

We present here evidence for the observation of the magneto-hydrodynamic (MHD) sausage modes in magnetic pores in the solar photosphere. Further evidence for the omnipresent nature of acoustic global modes is also found. The empirical decomposition method of wave analysis is used to identify the oscillations detected through a 4170 {\AA} 'blue continuum' filter observed with the Rapid Oscillations in the Solar Atmosphere (ROSA) instrument. Out of phase, periodic behavior in pore size and intensity is used as an indicator of the presence of magneto-acoustic sausage oscillations. Multiple signatures of the magneto-acoustic sausage mode are found in a number of pores. The periods range from as short as 30 s up to 450 s. A number of the magneto-acoustic sausage mode oscillations found have periods of 3 and 5 minutes, similar to the acoustic global modes of the solar interior. It is proposed that these global oscillations could be the driver of the sausage type magneto-acoustic MHD wave modes in pores.