<div dir="ltr">Good Evening,<div><br></div><div>I am attempting to calculate both the u and v components of the geostrophic winds in the WRF. </div><div><br></div><div>The function z2geouv (which calculates both components using the geopotential height, as well as the latitude and longitude of gridded data) must utilize the geopotential height on a constant pressure surface. WRF data however, is on constant eta levels/terrain following coordinates, and as such, this function applied to WRF data could only work if data is converted to a constant pressure surface from its original eta coordinate system.</div>
<div><br></div><div>Attached is the WRF code with issues. I have attempted to calculate the geostrophic wind components (ug and vg) by using the z2geouv with a height variable that has been interpolated on to a constant pressure coordinate (z_const_p). I first attempted to interpolate z_const_p with a geopotential height variable that was not terrain following (z_model). When I do this, I get realistic values for the geostrophic wind components, but I obviously would not get the lower levels (below 1000 generally) to be interpolated. I also interpolated z_const_p with an original terrain following geostrophic height or geostrophic height above ground level (AGLheight_model), but then unrealistic answers followed. </div>
<div><br></div><div>I have also taken a similar approach by calculating the ug and vg components separately without using z2geouv, but I am still getting unrealistic answers. </div><div><br></div><div>
I wish to implement this routine in order to plot the geostrophic winds on maps of constant height (above ground level) hence the ug/vg interpolations thereafter to constant height levels</div><div><br></div><div style>For reference, I sent the used RUC and WRF output to the ncl-talk FTP account given their large size. I did get the message "451 Failure writing to local file" so I am not sure if they made it over there successfully. The wrf file is rather large (approximately 9 GB) so maybe the account could not hold it?</div>
<div><br></div><div>I was wondering if someone could guide me to improve this code to get geostrophic winds interpolated on constant height fields from an original terrain following (eta) coordinate system (i.e. 200-2000 m at 100 m intervals), or if someone could assist by making a recommendation for an alternate approach? I have also attached my RUC code for plotting RUC Analysis geostrophic winds along with some sample images of what I believe the WRF profile should look generally like (as the RUC data is already on constant pressure surface).</div>
<div><br></div><div>Any suggestions would be greatly appreciated!<br></div><div><br></div><div>Brian Squitieri</div><div>Graduate Research Assistant</div><div>Iowa State University</div>
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