[Loops] loops and thermal nonequilibrium

[golub at cfa.harvard.edu]

Harry,

The work relied on asymmetric heating which gave rise the flow. The heating input was a generic exponential, adjust to fit the observed intensity in one TRACE channel and the result then also reproduced the other channel without further adjustment. 

Leon
Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: Harry Warren <harry.warren at nrl.navy.mil>
Date: Mon, 07 Dec 2009 08:19:04 
To: A mailing list for scientists involved in the observation and modeling ofsolar loop structures<loops at mithra.physics.montana.edu>
Subject: Re: [Loops] loops and thermal nonequilibrium


Leon,

As I recall, your paper with Amy relied on footpoint heating, which does
lead to higher apex densities and flatter temperature ratios. The observed
densities near 1 MK are so high, however, that the loops become
thermodynamically unstable. Also, the high speed EIS flows are typically
seen in faint regions and are not associated with the types of loops that
Jim is attempting to model.

Harry


On 12/5/09 3:16 PM, "Leon Golub" <golub at cfa.harvard.edu> wrote:

> Jim,
> 
> Amy and I addressed the issues of excess density, flat temperature
> profiles and large scale height about 10 years ago. Having flows of
> 30-40 km/sec, as is observed in TRACE and now verified by EIS, solves
> these problems quite nicely. So there is a viable mechanism other than
> nanoflares.
> 
> Leon
> 
> 
> Klimchuk, James A. (GSFC-6710) wrote:
>> Dear Loops Friends,
>> 
>>  
>> 
>>     If you are interested, the attached paper shows that coronal loops
>> cannot be explained by thermal nonequilibrium.  The results appear to
>> rule out the widespread existence of coronal heating that is both highly
>> concentrated low in the corona and steady or quasi-steady (slowly
>> varying or impulsive with a rapid cadence).  Comments are welcomed.
>> 
>>  
>> 
>> Best wishes,
>> 
>> Jim
>> 
>>  
>> 
>> *****************************************************************************
>> ***
>> 
>> James A. Klimchuk
>> 
>> NASA Goddard Space Flight Center
>> 
>> Solar Physics Lab, Code 671
>> 
>> Bldg. 21, Rm. 158
>> 
>> Greenbelt, MD  20771
>> 
>> USA
>> 
>>  
>> 
>> Phone:  1-301-286-9060
>> 
>> Fax:      1-301-286-7194
>> 
>> E-mail:  James.A.Klimchuk at nasa.gov <mailto:James.A.Klimchuk at nasa.gov>
>> 
>> Home page:  http://hsd.gsfc.nasa.gov/staff/bios/cs/James_Klimchuk.html
>> 
>>  
>> 
>> *****************************************************************************
>> ***
>> 
>>  
>> 
>> 
>> ------------------------------------------------------------------------
>> 
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-- 
// ---------------------------------------------------------------------
// Harry P. Warren             phone : 202-404-1453
// Naval Research Laboratory   fax   : 202-404-7997
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