[Loops] type II spicule paper

[Doschek, George]

Dear All,

Jim mentions a recent paper of mine as submitted.  It is now published, ApJ, 754, 153 (2012).  This paper deals with the dynamics of active regions as observed by EIS.  I think all of our recent results make a strong case for Solar-C.

I hope everyone is having a good summer.

Regards,

George

________________________________
From: loops-bounces at mithra.physics.montana.edu [mailto:loops-bounces at mithra.physics.montana.edu] On Behalf Of Klimchuk, James A. (GSFC-6710)
Sent: Tuesday, July 31, 2012 9:48 AM
To: (Loops at solar.physics.montana.edu)
Subject: [Loops] type II spicule paper

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<mailto: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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