<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]--><o:SmartTagType
namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PostalCode"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="State"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="PlaceType"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="PlaceName"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="country-region"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="City"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="place"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="PersonName"/>
<!--[if !mso]>
<style>
st1\:*{behavior:url(#default#ieooui) }
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
        {font-family:Helvetica;
        panose-1:2 11 6 4 2 2 2 2 2 4;}
@font-face
        {font-family:"MS Mincho";
        panose-1:2 2 6 9 4 2 5 8 3 4;}
@font-face
        {font-family:Tahoma;
        panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
        {font-family:"\@MS Mincho";
        panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
        {margin:0in;
        margin-bottom:.0001pt;
        font-size:12.0pt;
        font-family:"Times New Roman";}
a:link, span.MsoHyperlink
        {color:blue;
        text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
        {color:blue;
        text-decoration:underline;}
span.EmailStyle19
        {mso-style-type:personal-reply;
        font-family:Arial;
        color:navy;}
@page Section1
        {size:8.5in 11.0in;
        margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
        {page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=blue style='word-wrap: break-word;-webkit-nbsp-mode: space;
-webkit-line-break: after-white-space'>
<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>To clarify, I was referring to the
transition region layer in a (likely sub-resolution) flux tube. This will
be ultra thin, but the layers will occur at different heights in different flux
tubes, so the transition region plasma will span a wide range of heights in a
typical observation.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Jim<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=3 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> loops-bounces@solar.physics.montana.edu
[mailto:loops-bounces@solar.physics.montana.edu] <b><span style='font-weight:
bold'>On Behalf Of </span></b>Markus J. Aschwanden<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, March 05, 2009
5:20 PM<br>
<b><span style='font-weight:bold'>To:</span></b> A mailing list for scientists
involved in the observation and modeling ofsolar loop structures<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Loops] summaries on
nanoflare debates in "coronal loopworkshops"</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Jim Klimchuk wrote:<o:p></o:p></span></font></p>
</div>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt' type=cite><span
style='orphans: 2;text-align:auto;widows: 2;-webkit-border-horizontal-spacing: 0px;
-webkit-border-vertical-spacing: 0px;-webkit-text-decorations-in-effect: none;
-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0;word-spacing:0px'><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PostalCode"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="State"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place">
<div link=blue vlink=blue style='word-wrap: break-word;-webkit-nbsp-mode: space;
-webkit-line-break: after-white-space'>
<div>
<div>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>2. However, the transition region is
an extremely thin layer that moves up and down flux tubes in response to
changes in the coronal pressure resulting from heating and cooling. It is
very difficult for me to see why the magnetic energy dissipation that gives
rise to heating should always follow this layer. Dissipation in the
thicker chromosphere is much easier to swallow.<u1:p></u1:p></span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><u1:p> </u1:p></span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
</div>
</div>
</div>
</blockquote>
</div>
</span></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype></u1:smarttagtype>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Dear Jim,<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Well, the transition region was only an extremely thin layer in old
hydrostatic models, which nobody<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>believes anymore. The current observations from TRACE, <st1:place
w:st="on">SoHO</st1:place>, and Hinode clearly show a highly<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>dynamic transition region, which shows all kind of variabilities
(including the ominous spicules and<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>macrospicules) in a height range of h=2000-8000 km. Since the granular
magneto-convection<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>stirs up the magnetic field on horizontal scales of w~1000-2000 km,
this is exactly the height range where<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>you have most of the braiding, stressing, and reconnection, which is
another plausibility argument<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>for the most likely place of plasma heating that fills up the overlying
corona. Of course, dissipation<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>in the upper chromosphere is included, which provides all the mass for
coronal filling with heated<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>plasma.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Cheers,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Markus<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>P.S. What <st1:PersonName w:st="on">Marco Velli</st1:PersonName>
alluded to, is most relevant for open-field regions such as coronal holes<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><span class=apple-tab-span><font size=3
face="Times New Roman"><span style='font-size:12.0pt'> </span></font></span>I
gather. So we are talking about two different heating mechanisms for AR and
solar wind.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<span style='orphans: 2;text-align:auto;widows: 2;-webkit-border-horizontal-spacing: 0px;
-webkit-border-vertical-spacing: 0px;-webkit-text-decorations-in-effect: none;
-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0;word-spacing:0px'><span
style='-webkit-border-horizontal-spacing: 0px;-webkit-border-vertical-spacing: 0px;
-webkit-text-decorations-in-effect: none;-webkit-text-size-adjust: auto;
orphans: 2;widows: 2;word-spacing:0px'><span style='-webkit-border-horizontal-spacing: 0px;
-webkit-border-vertical-spacing: 0px;-webkit-text-decorations-in-effect: none;
-webkit-text-size-adjust: auto;orphans: 2;widows: 2;word-spacing:0px'><span
style='-webkit-border-horizontal-spacing: 0px;-webkit-border-vertical-spacing: 0px;
-webkit-text-decorations-in-effect: none;-webkit-text-size-adjust: auto;
orphans: 2;widows: 2;word-spacing:0px'>
<div apple-content-edited=true>
<div style='word-wrap: break-word;-webkit-nbsp-mode: space;-webkit-line-break: after-white-space'>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>____________________________________________<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>Dr. Markus J.
Aschwanden<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>Solar &
Astrophysics Laboratory<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>Lockheed Martin
Advanced <st1:place w:st="on"><st1:PlaceName w:st="on">Techology</st1:PlaceName>
<st1:PlaceType w:st="on">Center</st1:PlaceType></st1:place><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>Org. ADBS, Bldg. 252<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><st1:place w:st="on"><font size=1 color=black
face=Helvetica><span style='font-size:6.0pt;font-family:Helvetica;color:black'>3251
Hanover St., <st1:City w:st="on">Palo Alto</st1:City>, <st1:State w:st="on">CA</st1:State>
<st1:PostalCode w:st="on">94304</st1:PostalCode>, <st1:country-region w:st="on">USA</st1:country-region></span></font></st1:place><font
size=1 color=black face=Helvetica><span style='font-size:6.0pt;font-family:
Helvetica;color:black'><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>Phone: 650-424-4001,
FAX: 650-424-3994<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>URL: <a
href="http://www.lmsal.com/~aschwand/">http://www.lmsal.com/~aschwand/</a><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>e-mail: <a
href="mailto:aschwanden@lmsal.com">aschwanden@lmsal.com</a><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'>_______________________________________<o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=1 color=black face=Helvetica><span
style='font-size:6.0pt;font-family:Helvetica;color:black'><br>
<br>
</span></font><font size=1 color=black face=Helvetica><span style='font-size:
7.0pt;font-family:Helvetica;color:black'></span><o:p></o:p></span></font></p>
</div>
</span></span>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'></span><o:p> </o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
</div>
</div>
</body>
</html>