**AAS 196th Meeting, June 2000**

*Session 49. Solar System Objects and The Sun*

Display, Thursday, June 8, 2000, 9:20am-4:00pm, Empire Hall South
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## [49.03] Random Walks of Magnetic Bright Points and Coronal Loop Heating

*J.K. Lawrence, A.C. Cadavid (CSUN), A.A. Ruzmaikin (JPL)*

The random walks of small-scale (~0.2 arcsec) magnetic
bright points (MBPs) in the lanes between photospheric
granules are anomalous. The temporal growth of the q-th
moment of the displacement r(t) is a power law with exponent
q \gamma(q)/2. For normal, Gaussian walks \gamma (q)= 1
for all q. However, for the MBP walks on time scales <
45 minutes we find that \gamma (2)<1 and that \gamma
(q) is a decreasing function of q.

Many viable models for the heating of coronal loops are
based on the additon of energy via twisting and braiding of
magnetic flux lines by the random motions of their
footpoints. If the MBPs are associated with such footpoints,
then the statistics of their motions are directly relevant
to coronal heating. For example, a number of models derive
heating rates based on moments of the displacements and
include the standard assumption that \gamma = 1. However,
this assumption is wrong for MBPs, and the actual value of
\gamma depends on exactly which moment enters the
expression. All such models are therefore subject to
modification.

The result \gamma (2)<1 is a result of pauses in the MBP
walks on all time scales (''fractal time'') up to ~45
min. This implies that the motions of an individual
footpoint are not statistically stationary. This in turn
means that the injection of energy into a given loop will be
strongly variable and intermittent. This can be related to
observations of the details of variability in coronal loop
emissions, giving information on the locations of energy
deposition and on time scales of energy release. We thus
hope to further constrain acceptable heating models.

This work was supported in part by NSF Grant ATM-9628882.

The author(s) of this abstract have provided an email address
for comments about the abstract:
jlawrenc@galileo.csun.edu

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