From: Dibyendu Nandi [mailto:nandi@mithra.physics.montana.edu]
Sent: Wednesday, November 26, 2003 5:16 PM
To: Richard Canfield
Subject: REU Projects

Determining the role of twists (local alpha) and its evolution in flaring
activity of solar active regions.
   
Aim 

A study of what characteristics distinguish active regions that tend
to evolve according to Taylor's hypothesis from other ARs that do not
follow Taylor's hypothesis. Taking a closer look at evolution of local
alpha maps over solar active regions and co-spatial flaring activity, to
see if localized gradients in alpha initiate flaring acitivity over and
across these regions and determine whether those gradients are smoothed
out after the flaring activity.

Plan of Study

Go back to the Hahn database and construct two subset of flare productive
ARS, one that showed a decrease in their variance over the flaring period,
and a second that did not show a decrease in variance.

a) Study the state of flux emergence in these two different datasets to
see whether these two subsets can be distinguished by their flux
evolution. That is whether the flux was increasing during the duration
over which the HSP twist evolution study was done, or was the flux
decreasing, or was it at a same level. Flux evolution data can be obtained
from either the GOES database or from any Magnetogram.
 
b) Study if the above ARs were evolving in isolation during the period of
HSP twist observations, or were they interacting with nearby ARs via
overlying loops making the flux systems deviate from a closed flux system 
(which would make Taylor's hypothesis invalid in these systems). 
 
Select a few candidate ARs from the subset which showed a decrease in
their overall variance during the flaring activity. The selection
criterion for these candidate ARs should be such that; 1) there was at
least one stand alone major flare durig the period of the HSP twist
evolution study; 2) HSP magnetograms exist as close as possible before and
after the flare (this would be a day at best, i am not sure whether thats
good enough???). 3) Signatures of that flare (brightening or surges etc)
was observed by an instrument that has similar resolution and similar
field of view as the HSP instrument (MCCD or any other instrument???) 
   
Construct contour maps of local alpha on the heliographic coordinate
system for the before and after magnetograms. Superimpose the flare image
on both the before and after HSP local alpha contours. Repeat this
procedure for all the candidate ARs that were selected using the earlier
criterion building many such alpha maps with superimposed flare images. 
Study if the flaring is cospatial with regions of large gradients in the
alpha maps and whether these gradients got smoothed out at the particular
places at which the flaring occurred. This will tell us if there is
evidence that gradients in alpha drives flaring activity and how the
latter reorganizes the former.