changes this in a way which has never been quantitatively estimated.
which have numerical simulation confirmation.
@ARTICLE{2008ApJ...677.1348R, author = {{Rappazzo}, A.~F. and {Velli},
M. and {Einaudi}, G. and {Dahlburg}, R.~B. }, title = "{Nonlinear
Markus et al.,
It is unambiguous that there is a lot of dynamic activity going on
in the
transition region. However:
. . . a significant fraction of the Sun's magnetic flux closes at low
heights (several Mm), so it is unclear how much of this activity is
related
to what we see in the corona.
. . . my impression of SOT magnetic field measurements is that
active region
plage (where many active region loops are rooted) is unipolar. It is
hard to
see how small-scale reconnection in the transition region could be
important
here. I could be wrong about this! I'm sure that an SOT person could
provide
a more definitive answer.
Best wishes,
Harry
//
---------------------------------------------------------------------
// Harry P. Warren phone : 202-404-1453
// Naval Research Laboratory fax : 202-404-7997
//
---------------------------------------------------------------------
Markus J.
Aschwanden
Sent: Thursday, March 05, 2009 10:16 AM
To: Hugh Hudson; A mailing list for scientists involved in the
observation
and modeling of solar loop structures
Subject: [Loops] summaries on nanoflare debates in "coronal loop
workshops"
Dear Hugh,
Jim Klimchuk sent a great summary of the current status of a
nanoflare model
around,
so it deals with all the PROs. An outside reader who wants to hear
both
sides might be
interested to hear also the CONs, which you could find in the ApJ
Letter
entitled
"An observational test that disproves coronal nanoflare heating
models"
(Aschwanden
2008, ApJ 672, L135). The arguments made therein do not dismiss
nanoflares
altogether, but come to the conclusion that they occur in the
transition
region,
rather than in the corona (as Parker originally suggested).
Cheers,
Markus
On Mar 3, 2009, at 7:32 AM, Klimchuk, James A. (GSFC-6710) wrote:
Dear loops friends,
Here is a paper I wrote for the Hinode II conference
proceedings. In
it, I try to do three things: (1) review the arguments leading to the
conclusion that warm EUV loops must by bundles of strands heated by
storms
of nanoflares (the flow chart some of you have asked about); (2)
reconcile
the isothermal/multi-thermal debate in terms of the duration of the
nanoflare storm; and (3) address the possibility that loops can be
explained
by thermal nonequilibrium. Comments are welcomed.
Thanks,
James A. Klimchuk
____________________________________________
Dr. Markus J. Aschwanden
Solar & Astrophysics Laboratory
Lockheed Martin Advanced Techology Center
Org. ADBS, Bldg. 252
3251 Hanover St., Palo Alto, CA 94304, USA
Phone: 650-424-4001, FAX: 650-424-3994
_______________________________________
____________________________________
_______________________________________________
Loops mailing list