<div dir="ltr"><div><div>(Very) small values are reasonable for divergence: -/+ 1e-5 or 1e-6 (1/sec).<br></div><div> d = (du/dx)+(dv/dy)<br><br></div>Basic meteorology. Small differences in the numerator eg: [u(j,i-1)-u(j,i+1)] divided by<br></div><div>large numbers: spatial distance (meters) between (i+1) and (i-1). Same for v.<br><br></div><div>The ud and vd are divergent wind components 14.8m/s, vd=-2.7 m/s. Very reasonable!<br><br>Did you look at this site like I requested.<br> <a href="http://www.ncl.ucar.edu/Applications/wind.shtml" target="_blank">http://www.ncl.ucar.edu/Applications/wind.shtml</a><br></div><div>If not, please do so.<br><br></div><div>The divergence field here was arbitrarily scaled by 1e+6 for nicer numbers.<br></div><div><br>Really, this is basic .... <br></div><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Dec 19, 2014 at 2:03 PM, Abdoulaye SY <span dir="ltr"><<a href="mailto:sy.abdoulaye3@ugb.edu.sn" target="_blank">sy.abdoulaye3@ugb.edu.sn</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div>Thank you Dennis<br><br></div>My problem is when calculate divergence with <b><b> div =</b>uv2dvF_Wrap(qu,qv)<br> <br></b>I have result<b> div </b>is an array of small values like 1.427085e-05 <br><br></div>when i calculate the components with <b>dv2uvf (div, ud, vd) </b>i get ud=14.63604<br><br></div>vd=-2.875391<br><br><span lang="en"><span>Why</span> <span>this difference?</span></span> <br></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">2014-12-19 17:59 GMT+00:00 Abdoulaye SY <span dir="ltr"><<a href="mailto:sy.abdoulaye3@ugb.edu.sn" target="_blank">sy.abdoulaye3@ugb.edu.sn</a>></span>:<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div>Hi<br><br></div>I want to calculate divergence of the water vapor flux with ncl.<br><br></div>I use <b> div = uv2dvF_Wrap(qu,qv) <br> </b><br><b> </b>and<b> dv2uvf (div, ud, vd)<br> </b>where qu and qv are water vapor flux zonal and meridional respectively.<br><br></div>I want to understand the<span lang="en"><span> Principles</span> <span>of</span> <span>operation</span></span> of these functions. I have read the documentation but it is not clear.<br><br></div>thanks</div>
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