<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Jim,<div><br></div><div>Ok, we agree we need heating of chromospheric material to fill coronal loops (i.e. the well-established</div><div>chromospheric evaporation scenario for flares), which is a kind of a secondary step. What we are not</div><div>sure is where is the primary energy release that leads up to the chromospheric heating: </div><div><br></div><div>(1) Is it in coronal reconnection sites that produces precipitating particles/donward conduction like in flares? </div><div>(2) Is it coronal nanoflares that could also produce precipitating particles and/or downward conduction?</div><div>(3) Is it reconnection events in the chromosphere/transition region</div><div><br></div><div>Since I see a continous transition from high-lying reconnection regions in large flares to low-lying</div><div>reconnection regions in microflares or EUV nanoflares, it appears natural to me that there is a</div><div>continuouity from (1) to (3). But do we need case (2), which was postulated by Parker ?</div><div>As long we do not have any observational measurements for case (2), it remains a</div><div>theoretical construct. So, what observational diagnostics can people come up to test case (2) ?</div><div><br></div><div>Markus</div><div><br></div><div><br></div><div><br><div><div>On Mar 6, 2009, at 11:11 AM, Klimchuk, James A. (GSFC-6710) wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -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; "><div lang="EN-US" link="blue" vlink="blue" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><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="City"><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="place"><div class="Section1"><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy; ">Markus, you are definitely right that all coronal material originates in the chromosphere. If the energy release (heating) occurs in the corona, a downward thermal conduction flux (and possibly also a downward flux of nonthermal particles) causes material to evaporate into the corona. That is the traditional view. What other people (including you?) are proposing is that the energy release occurs directly in the chromosphere or transition region, and this process both heats the cool plasma and injects it upward.<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy; "><o:p> </o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy; ">Jim<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy; "><o:p> </o:p></span></font></div><div style="border-top-style: none; border-right-style: none; border-bottom-style: none; border-width: initial; border-color: initial; border-left-style: solid; border-left-color: blue; border-left-width: 1.5pt; padding-top: 0in; padding-right: 0in; padding-bottom: 0in; padding-left: 4pt; "><div><div class="MsoNormal" align="center" style="text-align: center; margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><hr size="3" width="100%" align="center" tabindex="-1"></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><b><font size="2" face="Tahoma"><span style="font-size: 10pt; font-family: Tahoma; font-weight: bold; ">From:</span></font></b><font size="2" face="Tahoma"><span style="font-size: 10pt; font-family: Tahoma; "><span class="Apple-converted-space"> </span><a href="mailto:loops-bounces@solar.physics.montana.edu" style="color: blue; text-decoration: underline; ">loops-bounces@solar.physics.montana.edu</a><span class="Apple-converted-space"> </span>[<a href="mailto:loops-bounces@solar.physics.montana.edu" style="color: blue; text-decoration: underline; ">mailto:loops-bounces@solar.physics.montana.edu</a>]<span class="Apple-converted-space"> </span><b><span style="font-weight: bold; ">On Behalf Of<span class="Apple-converted-space"> </span></span></b>Markus J. Aschwanden<br><b><span style="font-weight: bold; ">Sent:</span></b><span class="Apple-converted-space"> </span>Friday, March 06, 2009 11:52 AM<br><b><span style="font-weight: bold; ">To:</span></b><span class="Apple-converted-space"> </span>A mailing list for scientists involved in the observation and modeling ofsolar loop structures<br><b><span style="font-weight: bold; ">Subject:</span></b><span class="Apple-converted-space"> </span>Re: [Loops] summaries on nanoflare debates in "coronalloopworkshops"</span></font><o:p></o:p></div></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div><div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">On Mar 6, 2009, at 8:44 AM, Klimchuk, James A. (GSFC-6710) wrote:<o:p></o:p></span></font></div></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><br><br><o:p></o:p></span></font></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><br>By the way, I do NOT believe that observations necessarily point to low<br>altitude heating. My view is that observations are consistent with both<br>low altitude and high altitude heating. Perhaps this should be a topic<br>for Loops IV.<br><br>Jim<o:p></o:p></span></font></div></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">There is no way around to heat up first chromospheric material to fill coronal<o:p></o:p></span></font></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">loops to produce the enhanced soft X-ray and EUV emission we see from<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">coronal loops (like in flares). Any heating mechanism that heats directly<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">in the corona, does not increase the local density, so we would not see<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">any loops.<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; ">Markus<o:p></o:p></span></font></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div><span style="orphans: 2; 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: 0px; 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><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">____________________________________________<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">Dr. Markus J. Aschwanden<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">Solar & Astrophysics Laboratory<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">Lockheed Martin Advanced<span class="Apple-converted-space"> </span><st1:place w:st="on"><st1:placename w:st="on">Techology</st1:placename><span class="Apple-converted-space"> </span><st1:placetype w:st="on">Center</st1:placetype></st1:place><o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">Org. ADBS, Bldg. 252<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><st1:place w:st="on"><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">3251 Hanover St.,<span class="Apple-converted-space"> </span><st1:city w:st="on">Palo Alto</st1:city>,<span class="Apple-converted-space"> </span><st1:state w:st="on">CA</st1:state><span class="Apple-converted-space"> </span><st1:postalcode w:st="on">94304</st1:postalcode>,<span class="Apple-converted-space"> </span><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: 6pt; font-family: Helvetica; color: black; "><o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">Phone: 650-424-4001, FAX: 650-424-3994<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">URL:<span class="Apple-converted-space"> </span><a href="http://www.lmsal.com/~aschwand/" style="color: blue; text-decoration: underline; ">http://www.lmsal.com/~aschwand/</a><o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">e-mail:<span class="Apple-converted-space"> </span><a href="mailto:aschwanden@lmsal.com" style="color: blue; text-decoration: underline; ">aschwanden@lmsal.com</a><o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">_______________________________________<o:p></o:p></span></font></div></div><div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; ">____________________________________<o:p></o:p></span></font></div></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="1" color="black" face="Helvetica"><span style="font-size: 6pt; font-family: Helvetica; color: black; "><br><br></span></font><font size="1" color="black" face="Helvetica"><span style="font-size: 7pt; font-family: Helvetica; color: black; "></span><o:p></o:p></font></div></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "></span><o:p> </o:p></font></div></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="3" face="Times New Roman"><span style="font-size: 12pt; "><o:p> </o:p></span></font></div></span></span></span></span></div></div></div></div>_______________________________________________<br>Loops mailing list<br><a href="mailto:Loops@solar.physics.montana.edu" style="color: blue; text-decoration: underline; ">Loops@solar.physics.montana.edu</a><br><a href="https://mithra.physics.montana.edu/mailman/listinfo/loops" style="color: blue; text-decoration: underline; ">https://mithra.physics.montana.edu/mailman/listinfo/loops</a><br></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></div></span></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -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; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>____________________________________________</div><div>Dr. Markus J. Aschwanden</div><div>Solar & Astrophysics Laboratory</div><div>Lockheed Martin Advanced Techology Center</div><div>Org. ADBS, Bldg. 252</div><div>3251 Hanover St., Palo Alto, CA 94304, USA</div><div>Phone: 650-424-4001, FAX: 650-424-3994</div><div>URL: <a href="http://www.lmsal.com/~aschwand/">http://www.lmsal.com/~aschwand/</a></div><div>e-mail: <a href="mailto:aschwanden@lmsal.com">aschwanden@lmsal.com</a></div><div>_______________________________________</div><div>____________________________________</div><br class="Apple-interchange-newline"></span></span></span></div></span><br class="Apple-interchange-newline"> </div><br></div></body></html>