<html><head><base href="x-msg://162/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Jim,<div><br></div><div>I read your paper with interest. You made a faithful attempt to explain five observed </div><div>loop properties, which I really appreciate. The hydrodynamic simulations indeed show </div><div>some puzzling condensation blobs that remain at stationary locations that seem not</div><div>to correspond to observations. However, I have the impression that this puzzling</div><div>effect, which you use as main argument that cooling loops are not consistent</div><div>with observations, is an artifact of the perfect pressure balance in your model.</div><div>When you watch TRACE movies, you will see that real coronal loops always evolve:</div><div>sway, expand, twist, or shrink on time scales of an hour, which slowly changes the </div><div>pressure balance along the loop and would move condensation blobs to one side.</div><div>Loops are also always asymmetric, have diverging and converging cross-sections,</div><div>which causes siphon flows and drains condensation blobs to one side. So, I think</div><div>that the simulations are too idealized to tell us the long-term evolution. </div><div>It is like balancing a ball on the Eiffeltower - an equilibrium solution is mathematically</div><div>possible - but is impossible in reality, there are always vibrations or wind ...</div><div>Perhaps you can repeat a simulation by superimposing some slowly-varying</div><div>pressure disturbances, use a varying cross-section, and fill it by upflows from</div><div>gentle chromospheric evaporation (more like in flares).</div><div><br></div><div>Cheers,</div><div>Markus</div><div><br></div><div><br></div><div><br><div><div>On Dec 4, 2009, at 2:04 PM, Klimchuk, James A. (GSFC-6710) wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; 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: 0px; "><div lang="EN-US" link="blue" vlink="purple"><div class="Section1"><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; ">Dear Loops Friends,<o:p></o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "> 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.<o:p></o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; ">Best wishes,<o:p></o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; ">Jim<o:p></o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><o:p> </o:p></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">********************************************************************************</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">James A. Klimchuk</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">NASA Goddard Space Flight Center</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">Solar Physics Lab, Code 671</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">Bldg. 21, Rm. 158</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">Greenbelt, MD 20771</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">USA</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "> <o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">Phone: 1-301-286-9060</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">Fax: 1-301-286-7194</span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">E-mail: <a href="mailto:James.A.Klimchuk@nasa.gov" style="color: blue; text-decoration: underline; "><span style="color: blue; ">James.A.Klimchuk@nasa.gov</span></a></span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">Home page: <a href="http://hsd.gsfc.nasa.gov/staff/bios/cs/James_Klimchuk.html" style="color: blue; text-decoration: underline; "><span style="color: blue; ">http://hsd.gsfc.nasa.gov/staff/bios/cs/James_Klimchuk.html</span></a></span><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; "> <o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 10pt; font-family: Arial, sans-serif; ">********************************************************************************<o:p></o:p></span></div><div style="margin-top: 0in; margin-right: 0in; margin-bottom: 0.0001pt; margin-left: 0in; font-size: 11pt; font-family: Calibri, sans-serif; "><span style="font-size: 12pt; font-family: 'Times New Roman', serif; "> </span><o:p></o:p></div></div><span><klimchuk_submitted.pdf></span>_______________________________________________<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></div></span></blockquote></div><br><div>
<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; "><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></span><br class="Apple-interchange-newline">
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