[Loops] type II spicule paper

[Robertus von Fay-Siebenburgen]

jim,

interesting paper:),
robertus

On 31 Jul 2012, at 14:47, Klimchuk, James A. (GSFC-6710) wrote:

> Dear friends,
>  
>       You might be interested in my recent paper on “The Role of Type II Spicules in the Upper Solar Atmosphere,”  which can be downloaded at   http://arxiv.org/abs/1207.7048
>  
> Cheers,
> Jim
>  
> ABSTRACT:
> We examine the suggestion that most of the hot plasma in the Sun's
> corona comes from type II spicule material that is heated as it is
> ejected from the chromosphere.  This contrasts with the traditional
> view that the corona is filled via chromospheric evaporation that
> results from coronal heating.  We explore the observational
> consequences of a hypothetical spicule dominated corona and conclude
> from the large discrepancy between predicted and actual observations
> that only a small fraction of the hot plasma can be supplied by
> spicules (<2% in active regions and <5% in the quiet Sun).  The
> red-blue asymmetries of EUV spectral lines and the ratio of lower
> transition region (LTR; T<0.1 MK) to coronal emission measures
> are both predicted to be 2 orders of magnitude larger than observed.
> Furthermore, hot spicule material would cool dramatically by
> adiabatic expansion as it rises into the corona, so coronal heating
> would be required to maintain the high temperatures that are seen at
> all altitudes.  The necessity of coronal heating is inescapable.
> Traditional coronal heating models predict far too little emission
> from the LTR, and we suggest that this emission comes primarily from
> the bulk of the spicule material that is heated to <0.1 MK and
> is visible in He II (304 A) as it falls back to the surface.
>  
> ********************************************************************************
> 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
> Homepage:  https://sedupdate.gsfc.nasa.gov/sed/index.cfm?fuseAction=people.jumpBio&&iPhonebookId=15844
> No endorsement by NASA is implied for any correspondence related to my role as an officer of professional organizations (American Geophysical Union, International Astronomical Union, American Astronomical Society).
>  
> ********************************************************************************
>  
>  
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