Photospheric Observations of Surface and Body Modes in Solar Magnetic
Pores.
Abstract
MHD wave phenomena have been readily observed in recent years in various
magnetic elements found within the solar atmosphere. They are often
touted as a possible mechanism in channeling energy to the outer layers
of the solar atmosphere. Recent advances in both observational
techniques and instrumentation has gradually bridged the gap between
observations and theory of these phenomena, as various wave modes have
been identified and their properties studied across a wide range of
structures. For example, numerous contemporary studies have identified
and studied the properties associated with compressible sausage modes in
different bandpasses, often employing magnetic pores as a test bed.
However, the spatial structuring of the mode within the flux tube, that
is, the surface and body characteristics, has thus far been ignored in
observational studies. We employed high spatial and temporal resolution
observations from a combination of both ground- (ROSA) and space-based
(SDO) instrumentation to study several pore datasets, which were
observed to support sausage modes. Using a range of techniques, we
observed and were able to classify, for the first time, the surface and
body characteristics for the wave modes observed within the pores. The
most frequently occurring oscillation period in our observations was
found to be ~300s, which is consistent with the p-mode
spectrum. We find surface modes more frequently in the data. We find
frequencies in the range of ~2–12 mHz, with body modes
as high as 11 mHz, but we do not find surface modes above 10 mHz.
Estimates made for the energetics of these wave modes will also be
discussed within the context of our results.