[Loops] summaries on nanoflare debates in "coronalloopworkshops"

[Leon Golub]

OK, I have to jump in, since there seems to be some confusion about 
this. Yes, the increase in coronal density comes up from the 
chromosphere. This has been known for decades and has been well-modeled, 
especially by the Palermo group. But it is entirely possible for the 
energy to be deposited in the corona, then travel down (relying on the 
ambient density) to be deposited and cause evaporation. The pattern of 
brightness variations that you see does, in fact, change depending on 
where in the loop the energy is deposited, and can be used to determine 
where it happened. By seeing how the loop brightens, you can tell where 
the energy deposition took place. See:

> 
> 	A Brightening Coronal Loop Observed by TRACE. II. Loop Modeling and Constraints on Heating
> 	Reale, F.; Peres, G.; Serio, S.; Betta, R. M.; DeLuca, E. E.; Golub, L.
> 	Astrophysical Journal, Volume 535, Issue 1, pp. 423-437, 05/2000.

Leon


Markus J. Aschwanden wrote:
> 
> On Mar 6, 2009, at 8:44 AM, Klimchuk, James A. (GSFC-6710) wrote:
> 
>>
>> By the way, I do NOT believe that observations necessarily point to low
>> altitude heating.  My view is that observations are consistent with both
>> low altitude and high altitude heating.  Perhaps this should be a topic
>> for Loops IV.
>>
>> Jim
> 
> There is no way around to heat up first chromospheric material to fill 
> coronal
> loops to produce the enhanced soft X-ray and EUV emission we see from
> coronal loops (like in flares). Any heating mechanism that heats directly
> in the corona, does not increase the local density, so we would not see
> any loops.
> 
> Markus
> 
> 
> 
> ____________________________________________
> 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
> URL: http://www.lmsal.com/~aschwand/
> e-mail: aschwanden at lmsal.com <mailto:aschwanden at lmsal.com>
> _______________________________________
> ____________________________________
> 
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Loops mailing list
> Loops at solar.physics.montana.edu
> https://mithra.physics.montana.edu/mailman/listinfo/loops