<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br><div><div>On Nov 15, 2012, at 9:25 PM, Wolfgang Bangerth wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On 11/15/2012 03:59 PM, Ian Rose wrote:<br><blockquote type="cite">Problem (probably) solved.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">The lower boundary, having a smaller surface area, requires a thinner<br></blockquote><blockquote type="cite">boundary layer to keep up with the heat flux out of the top boundary.<br></blockquote><blockquote type="cite">If you run at too low a resolution (as I was), then the temperature<br></blockquote><blockquote type="cite">gradient at the bottom is too shallow due to numerical diffusion and you<br></blockquote><blockquote type="cite">significantly underestimate the lower heat flux.<br></blockquote><br>Wow, by a factor of 4? Then, anyway, glad you found what looks like the <br>reason.<br><br>Best<br> W.<br><br>-- <br>------------------------------------------------------------------------<br>Wolfgang Bangerth email: <a href="mailto:bangerth@math.tamu.edu">bangerth@math.tamu.edu</a><br> www: <a href="http://www.math.tamu.edu/~bangerth/">http://www.math.tamu.edu/~bangerth/</a><br><br>_______________________________________________<br>Aspect-devel mailing list<br><a href="mailto:Aspect-devel@geodynamics.org">Aspect-devel@geodynamics.org</a><br>http://geodynamics.org/cgi-bin/mailman/listinfo/aspect-devel<br></div></blockquote></div><br></div></body></html>