<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br><div class="gmail_quote">---------- Forwarded message ----------<br>
From: <b class="gmail_sendername">Diego Araneo</b> <span dir="ltr"><<a href="mailto:daraneo@lab.cricyt.edu.ar" target="_blank">daraneo@lab.cricyt.edu.ar</a>></span><br>
Date: Wed, Jul 1, 2009 at 3:38 PM<br>Subject: ADVECTION FUNCTIONS<br>To: <a href="mailto:ddasilva@umd.edu" target="_blank">ddasilva@umd.edu</a><br><br><br>
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<p><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;" lang="EN-US">Hello Arlindo. </span></font></p>
<p><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;" lang="EN-US"> </span></font></p>
<p><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;" lang="EN-US">In <a href="http://opengrads.org/doc/udxt/libbjt/" target="_blank">http://opengrads.org/doc/udxt/libbjt/</a>,
where it says -d(u*EXPR)/dx, it should say -u*d(EXRR)/dx.</span></font></p>
<p><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;" lang="EN-US"> </span></font></p>
<p><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;" lang="EN-US">I hope the last is the real expression the command
function calculates. </span></font></p>
<p><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;" lang="EN-US"> </span></font></p></div></div></div></blockquote></div><br>I am not sure what you are refering to. There are 2 kind of functions under the "Advection Functions" banner. These are actually advection, e.g., u d EXPR/ dx, etc.<br>
<a name="advection_functions"><br></a>
<br><dl><dd>
<p>display <strong>muadv</strong>(<em>U</em>,<em>EXPR</em>) - Changing rate [EXPR/s] due to zonal advection</p>
</dd><dt>
<br></dt><dd>
<p>display <strong>mvadv</strong>(<em>V</em>,<em>EXPR</em>) - Changing rate [EXPR/s] due to meridional advection</p>
</dd><dt>
<br></dt><dd>
<p>display <strong>mwadv</strong>(<em>W</em>,<em>EXPR</em>) - Changing rate [EXPR/s] due to vertical advection</p>
</dd></dl>Now, these are actually components of the flux gradient:<br><br><dl><dd>
<p>display <strong>madvu</strong>(<em>U,EXPR</em>) - Zonal flux gradient: -d(U*EXPR)/dx</p>
</dd><dt>
<br></dt><dd>
<p>display <strong>madvv</strong>(<em>V,EXPR</em>) - Meridional flux gradient: -d(V*EXPR)/dy</p>
</dd><dt>
<br></dt><dd>
<p>display <strong>madvw</strong>(<em>W,EXPR</em>) - Vertical flux gradient: -d(W*EXPR)/dz</p>
</dd></dl>These are useful for budget calculations (say, divergence of moisture flux ~ E - P).<br><br> Arlindo<br clear="all"><br>-- <br>Arlindo da Silva<br><a href="mailto:dasilva@alum.mit.edu">dasilva@alum.mit.edu</a><br>