Re: Questions about SkewT plot

The documentation indicates how to not draw the U.S Standard Atmosphere

http://www.ncl.ucar.edu/Applications/skewt.shtml

Set the the following resource to avoid drawing the standard atm.

    DrawStandardAtm = False

I had forgotten the wThin resourse which is also documented.

     dataOpts@Wthin = 1 ; Plot a subset of the winds. Default =1
                                ; =1 means every wind barb
                                ; =5 would mean every 5-th
                                ; wind report would be plotted.

---
I think it would be VERY difficult to extend this plot to higher levels.
It manually specifies where various quantities should be at the corners.
Not shure where you would get that information.
There may be skewT in other languages that go higher than 100hPa.
Check the WWW.
Good luck
On 3/13/14, 3:23 PM, Gökhan Sever wrote:
> Thanks for your comments Dennis. Below are my comments.
>
>
> On Mon, Mar 10, 2014 at 12:30 PM, Dennis Shea <shea@ucar.edu> wrote:
>>
>> Hello,
>>
>> Please read and examine:
>>       http://www.ncl.ucar.edu/Applications/skewt.shtml
>>
>> -------
>>
>>
>>
>> http://www.ncl.ucar.edu/Applications/skewt.shtml
>>
>> [1] As noted in the documentation
>>
>> It is designed to reproduce the "USAF Skew-t, log p diagram (form dod-wpc 9-16-1).
>>
>>      The USAF skew-t only goes to 100mb.
>>
>> You would have to copy the code
>>
>> %> $NCARG_ROOT/lib/ncarg/nclscripts/csm/skewt_func.ncl my.skewt_func.ncl
>>
>> and alter the code.
>
>
> I need to get more familiar with your script. As this seems to require
> more than a simple number change in the code.
>
>
>>
>>
>>
>> [2] See Example 1
>
>
> skewtOpts@DrawColAreaFill   = False   ; color on background plot
>
> setting this option to False did the trick.
>
>>
>>
>> [3] CAPE calculation is somewhat sensitive to where the
>>      ascent is started. There are a number of CAPE codes tested
>>      and none agreed. There are two CAPE calculations: one by
>>      the WRF project and another that is included with NCL but is not
>>      documented.
>
>
> I sent "Skew-T CAPE overestimation" titled e-mail back in Nov 2013.
> There you mentioned of various CAPE calculation routines. I will yet
> to compare these once I make some progress in my current research.
>
>>
>>
>> [4] I think the easiest way to accomplish )say) every 5th wind would be
>>      to do something like
>>
>>        uu = u
>>        vv = v
>>        uu@_Fillvalue = u@_FillValue
>>        uu@_Fillvalue = u@_FillValue
>>        uu(::5) = u(::5)
>>        vv(::5) = v(::5)
>
> This assignment fails with the following message, perhaps because my u
> is a 2D array.
>
> fatal:["Execute.c":7454]:performASSIGN_VAR_VAR_OP: Number of
> subscripts on rhs do not match
>
> Jose Garcia of our department suggested a simpler way, which works perfect:
>
>   dataOpts@Wthin = 5
>
> To answer my original 4th question, it seems the Skew-T code needs to modified.
>
>>
>> [5] Isn't that the adibatic lapse rate!
>>
>>      Again, you would have to modify the code.
>
> Although I couldn't figure out to suppress the gray line, upon closer
> inspection in the code, it looks like the line is the US standard
> atmosphere. So, at least I have an explanation as to what it is.
>
>>
>> [6] When you open the work station
>>
>>      wks  = gsn_open_wks ("png", "skewt")
>
> This simply does it. Thanks again.
>
>>
>> Good luck
>>
>> On 3/9/14, 9:19 AM, Gökhan Sever wrote:
>>>
>>> Hello,
>>>
>>> I have some questions about a Skew-T Log-P plot produced in NCL. Consider
>>> the attached Weisman and Klemp (1982) type sounding as a reference, created
>>> from an idealized WRF simulation output.
>>>
>>> 1) How to set y-axis upper limit to, say 10 mb instead of the default 100
>>> mb?
>>>
>>> 2) How to change the green-white alternating background to white only?
>>>
>>> 3) The input data before calling skewT_PlotData are interpolated (using 100
>>> vertical levels instead of 50) in my case, otherwise CAPE estimation seems
>>> to be off by a couple hundred J/kg. However, as an artifact, there are so
>>> many wind barbs are plotted. Is there a way to plot barbs, say at every 5
>>> points?
>>>
>>> 4) How to move the barb axis or height axis so that the plot looks more
>>> compact? I am only interested in u-wind, so these two axes really can be
>>> combined.
>>>
>>> 5) What is the straight grey line ascending from in between 8-12 g/kg
>>> mixing ratio lines up above? Is there a way to suppress it?
>>>
>>> 6) Is there a way to save SkewT plot directly to png or jpg? It's easy to
>>> save in PDF, however I couldn't figure out a way to directly saving as a
>>> png or jpg.
>>>
>>> Many thanks.
>>>
>>>
>>>
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>
>
>
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