What about just flipping the sign of the vertical coordinate in the display command? If you do that, do the vectors match up?<div><br></div><div>Jeff<br><br><div class="gmail_quote">On Wed, Sep 5, 2012 at 3:31 PM, Jason Furtado <span dir="ltr"><<a href="mailto:jfurtado@aer.com" target="_blank">jfurtado@aer.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">All -<br>
<br>
I am running into an issue with plotting EP flux vectors on the<br>
latitude-by-pressure plane in GrADS. I did the calculations in another<br>
language and wrote out relevant data (EPy, EPz, and the divergence of<br>
the flux) to a binary file to load and plot in GrADS. I have checked<br>
my plot against a plot that I can generate on the NCEP website and the<br>
vertical direction of the arrows is reversed (they point down in the<br>
GrADS plot but should point up according to the NCEP plot).<br>
<br>
Having checked the values plotted in GrADS (using gxout grid), many of<br>
the values of EPz are negative. According to the Edmon et al. (1980)<br>
paper, in pressure coordinates, positive (negative) EPz should point<br>
toward higher (lower) pressure. Is this an issue with GrADs? Anyone<br>
else run into this issue? My (abbreviated) script is below.<br>
<br>
reinit<br>
set background 1<br>
<br>
open epfluxes_epdiv_2009_2010_obs.ctl<br>
<br>
set t 390 390<br>
set lat 10 90<br>
set vpage 0 11 0 6<br>
set annot 0<br>
<br>
set gxout vector<br>
set zlog on<br>
set z 1 17<br>
set xaxis 10 90 10<br>
set xlabs 10N|20N|30N|40N|50N|60N|70N|80N|90N|<br>
set ylevs 10 50 100 300 500 1000<br>
set grads off<br>
set grid off<br>
set font 1<br>
set ylopts 0 4 0.2<br>
set xlopts 0 4 0.2<br>
<br>
set arrscl 1 200<br>
set ccolor 2<br>
set cthick 6<br>
set arrowhead -0.25<br>
set arrlab on<br>
set grid off<br>
d skip(epy,2,1);skip(epz,2,1)<br>
<br>
Thanks!<br>
<span class="HOEnZb"><font color="#888888">- Jason<br>
--<br>
Jason C. Furtado, Ph.D.<br>
Staff Scientist<br>
Atmospheric and Environmental Research (AER), a Verisk Analytics company<br>
131 Hartwell Ave.<br>
Lexington, MA 02421<br>
<br>
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</font></span></blockquote></div><br><br clear="all"><div><br></div>-- <br>Jeff Duda<br>Graduate research assistant<br>University of Oklahoma School of Meteorology<br>Center for Analysis and Prediction of Storms<br><br>
</div>