<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hey,<div class=""><br class=""></div><div class="">[1] it’s always preferable to use <span style="color: rgb(51, 51, 51); font-family: verdana, sans-serif; font-size: 13.3333px; font-variant-ligatures: normal; line-height: 16px; orphans: 2; text-indent: -13.3333px; widows: 2; background-color: rgb(255, 255, 255);" class=""> </span><font color="#852d85" face="verdana, sans-serif" size="2" class=""><span style="line-height: 16px; orphans: 2; text-indent: -13.3333px; widows: 2; background-color: rgb(255, 255, 255);" class=""><a href="mailto:wrfhelp@ucar.edu" class="">wrfhelp@ucar.edu</a></span></font> for WRF-related issues with NCL. We generally don’t know so well the WRF functions so that we can not help if something it’s going wrong when interpolating/reading from WRF output files. However it seems that your problem it’s not strictly WRF related so I’ll give you my 2 cents on what is going wrong.</div><div class=""><br class=""></div><div class="">[2] when plotting any model variable @500 hPa you are getting the effect of the orography, especially with high mountains</div><div class=""> peaks like the ones found in the Rockies. In that area you are exactly getting the orography since isobaric levels intersect the mountains so that geopotential height corresponds with geometric height. So, from that point of view, you are getting exactly what you should from a model.</div><div class=""><br class=""></div><div class="">[3] you can mask the data over mountains with missing value so that NCL will automatically try to interpolate with values at lower altitudes. This can be easily achieved with the mask function and using the orography from the model output.</div><div class=""><br class=""></div><div class="">[4] you can smooth the geopotential height field but I doubt that will give you the correct results, since you’ll need to use a really strong filter to mask the effect of the mountains. I personally tried multiple times to use the smoothing functions of NCL and never worked out, so that I cannot give you a lot of advices regarding this option…but you can start from here <a href="http://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_smooth_2d.shtml" class="">http://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_smooth_2d.shtml</a></div><div class=""><br class=""></div><div class="">Regards,</div><div class=""><div class="">
<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><br class="Apple-interchange-newline">Guido Cioni</div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="http://guidocioni.altervista.org" class="">http://guidocioni.altervista.org</a> </div>
</div>
<br class=""><div><blockquote type="cite" class=""><div class="">On 07 Sep 2016, at 05:57, Lijun Diao <<a href="mailto:ljdiao@gmail.com" class="">ljdiao@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
<div dir="ltr" class="">
<div dir="ltr" class="">
<div style="font-size: 12pt; font-family: Calibri;" class="">
<div class="">Hi, everyone:</div>
<div class=""> </div>
<div class="">I am trying to plot 500 hpa geopotential height. I used wrf_user_getvar to
get gh and wrf_user_intrp3d to interpolate to 500 hpa. Please verify I am doing
right. </div>
<div class=""> </div>
<div class="">gh
= wrf_user_getvar(b,"geopotential",-1)</div>
<div class="">gh
= gh / 9.8 / 10.</div>
<div class="">; interpolation</div>
<div class="">gh_plane = wrf_user_intrp3d(gh, p, "h",
500, 0., False)</div>
<div class=""> </div>
<div class="">For the contour lines, I noticed there are a bunch of small circles over
the Rocky Mountain as shown in the attached f1.png. What I want is a smoother
plot as in the black lines in f2.png. Those small gh line circles actually
coincide with the topograph as shown in f3.png. Please let me how I can plot a
smooth gh as in f2. </div>
<div class=""> </div>
<div class="">thanks,</div>
<div style="font-size: 12pt; font-family: Calibri;" class="">-----------------------------------------------------------------------------<br class="">Lijun
Diao<br class=""><a href="mailto:ldiao@uh.edu" class="">ldiao@uh.edu</a><br class="">Research Assistant<br class="">Department of Earth &
Atmospheric Sciences<br class="">University of Houston<br class="">4800 Calhoun RD., Bldg.
S&R1-312<br class="">Houston, TX 77204-5007</div></div></div></div>
<span id="cid:4AD3DC6E-FBDD-4BCD-B3BC-EA6F727AC460@homenet.telecomitalia.it"><f1.png></span><span id="cid:0106BBE0-9F14-482A-8A66-CCCD4EFA1642@homenet.telecomitalia.it"><f2.png></span><span id="cid:85FBF9B8-E9A2-489A-807A-B30385216A60@homenet.telecomitalia.it"><f3.png></span>_______________________________________________<br class="">ncl-talk mailing list<br class=""><a href="mailto:ncl-talk@ucar.edu" class="">ncl-talk@ucar.edu</a><br class="">List instructions, subscriber options, unsubscribe:<br class="">http://mailman.ucar.edu/mailman/listinfo/ncl-talk<br class=""></div></blockquote></div><br class=""></div></body></html>