Re: Plotting Correct Wind Direction in Lamont, OK Profiler Data using NCL.

Thank you David! That resource solved the problem.

On Tue, May 7, 2013 at 1:12 PM, David Brown <dbrown@ucar.edu> wrote:

> Hi Brian,
> I suspect you just need to set the boolean resource vcMapDirection to
> False. The default setting, True, is appropriate for maps, but not in
> situations such as vertical profiles where the X and Y axes have very
> different units for there coordinates. We could probably make NCL smart
> enough to recognize the difference and adjust automatically but it has not
> happened yet. Here is a summary of the doc for vcMapDirection:
>
> This resource controls whether the vector direction is mapped into the
> same coordinate space as the
> vector location, or whether it is rendered in a locally uniform cartesian
> coordinate space.
>
> -dave
>
>
> On May 7, 2013, at 10:29 AM, "brianjs @iastate.edu" <brianjs@iastate.edu>
> wrote:
>
> > Good Morning,
> >
> > Most recently, I have attempted to plot Lamont, OK Profiler wind data
> from the ARM site available to the public using NCL. For the most part, the
> plotting seems correct, with the exception that the wind directions seem to
> be offset by approximately 45 degrees or so. I have attached a copy of a
> Lamont profiler dataset (attachment 1) along with a copy of my code
> (attachment 2) and an example of the Lamont data plotted in both my code
> (attachment 3) and in IDL (that is displayed publicly on the ARM site) to
> illustrate this difference (attachment 4). Please note that I am plotting
> the low power setting, so when looking at the ARM plotted example in IDL,
> please only refer to the bottom image of the document.
> >
> > I have already taken steps to filter out bad data and I have commented
> the code in great detail in attempt to explain exactly what it is I am
> doing. I also left all the print and print var summaries in for those who
> want to look at those individual components.
> >
> > To correctly plot the data, I reassigned the time and height arrays to
> the winds instead of them being functions of range-gate, power and the
> offset time (which is only in seconds).
> >
> > Essentially, I am attempting to compare this data with WRF simulated
> vertical profiles and I attached both the code, with an example image as
> well (attachments 5 and 6, respectively) for anyone's curiosity and to show
> why the Lamont data is plotted this way. For the record, the WRF is a 36
> hour forecast that is 3-hourly vs. Lamont data which is plotted hourly at
> only the 24 hour day. In the future, I will concatenate profiler data daily
> sets and reduce them from hourly to 3-hourly to properly account for this.
> >
> > My problem/question is how to address the wind direction problem? The
> data does have a wind speed and direction variable, but NCL must use the u
> and v components to generate a vector (and subsequently the wind barbs). I
> am not understanding though why the u and v components alone are not
> generating what the IDL illustrations show. These components alone should
> account for proper direction, and the wind speeds seem to be correct as
> well.
> >
> > Again, I appreciate any input that can be provided!
> >
> > Brian Squitieri
> > Graduate Research Assistant
> > Iowa State University
> > <sgp915rwpwindconC1.a1.20120502.000022.cdf><data_profiler_plot.ncl><
> lamont_wind_profiler.ps
> ><sgp915rwpwindconC1.a1.20120502.000022.png><WRF_wind_profile.ncl><WRF_forecast_vertical_wind_profile.ps>_______________________________________________
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>
>

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Received on Tue May 7 12:43:29 2013