Correlation of Coronal Loop Evolution with
Photospheric Magnetic Fields
Werner Neupert
Proposal: We propose to study the evolution of active
region coronal loops as it may relate to changes in the
underlying photospheric magnetic field. These comparisons
will be made by comparing a sequence of EIT sub-field
(probably 7x7 arc min) images with a corresponding sequence
of the photospheric B field obtained by the MDI instrument.
Such a comparison is intended to investigate whether the
appearance of coronal loops and their subsequent development
over time, such as evolution of density and temperature
and the degree of shear relative to the photospheric
neutral line, can be related to the evolution of the
underlying photospheric field and, specifically,to motions
of the photospheric footpoints of the coronal features. In
addition to direct comparison of data sets, the MDI data can
also be used to calculate potential or force-free coronal
fields, with the results being compared with EIT images.
Results of this study will be important in evaluating
Parker's theory that the twisting together of coronal loops
due to footpoint motions can lead to nanoflares and
subsequent coronal heating. The observational program will
require intermittent tracking of several active regions over
a period of days, with concurrent MDI data, so that the
evolution of the corona in response to field changes can be
documented.
Complete text of proposal.