Re: Height as vertical coordinate for data on eta levels

From: <shea_at_nyahnyahspammersnyahnyah>
Date: Wed Jun 20 2012 - 12:54:25 MDT

Hi Karl,

I am forwarding this to ncl-talk@ucar and wrfhelp@ucar.edu.

Plotting against model levels allows the constant model levels
to be used. The issue with height is that at (say) level 10,
the heights vary at each grid point. I think you will have to
interpolate in the vertical to constant height levels.
Perhaps, multiple calls to:

http://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_interp_3d_z.shtml

Regards

> Hello Dennis -
>
> No I do not believe so.
>
> perhaps my subject line is incorrect
>
> What I am trying to do is do a time height plot on height levels.
> There is code around that does times (on x-axis) vs. model levels (on
> y-axis). Model levels are not simple to interpret physically. I would
> like to have the y-axis in meters (0-10,000) not in model-levels
> (0-49). Somewhat like attached image. Pressure would work okay, too.
>
> Conceptually I need to go from (fc, level, lat, lon) $var -> (fc,
> height, lat, lon) $var. I know the data needs interpolation to
> height(s), I just don't see how to do it for a bunch of i-j points
> over a 48 hour period. It seems like there should be a way to make a
> coordinate pair between model level and z for each hour of the 3D
> variables. Since we know u and v on level 1 and we know z of level 1
> we should be able to plot U at height of model level 1.
>
>
>
> On Jun 19, 2012, at 2:30 PM, Dennis Shea wrote:
>
>> Is this what you want
>>
>> eta = f->ZNW(0,:)
>> eta!0 = "eta
>>
>> w!0 = "eta"
>> w&eta = eta
>>
>> printVarSummary(w)
>>
>> On 6/19/12 4:22 PM, Karl Volz wrote:
>>> Hello-
>>>
>>>
>>> I have the same question but I do not understand the response. If I
>>> have
>>> a wrfout file that has z as level,time,lat,lon ordered values, how
>>> do I
>>> access the values , assign them to "z", and then associate them to
>>> the
>>> eta levels as the vertical coordinate?
>>>
>>>
>>> I believe this:
>>>
>>>
>>> z = wrf_user_get_var(f,"z",-1)
>>>
>>> w!0="z"
>>>
>>> w&z =z
>>>
>>>
>>> yields this:
>>>
>>>
>>> *fatal:Coordinate variables must have one dimension only*
>>>
>>>
>>> -
>>>
>>> Karl
>>>
>>>
>>> From: Mary Haley <haley_at_nyahnyahspammersnyahnyah
>>> <mailto:haley_at_nyahnyahspammersnyahnyah?Subject=Re:%20Fwd:%20change%20y%20axis%20from%20eta%20height%20to%20z%20(km)%20from%20wrf%20output
>>> >>
>>>
>>> Date: Thu Jan 12 2012 - 10:15:44 MST
>>>
>>> Mark,
>>>
>>> It is a simple matter to change the coordinate array of a variable to
>>> something else, especially if it is the same type (float, double,
>>> etc).
>>>
>>> So, yes, if the current coordinate array is called "w&znw" and you
>>> want
>>> to replace these values with the variable "z":
>>>
>>> (I'm assuming eta height is the leftmost dimension of w):
>>>
>>> w!0 = "z"
>>> w&z = z
>>>
>>> --Mary
>>>
>>> On Jan 11, 2012, at 2:43 PM, mark vogel wrote:
>>>
>>> /> Dear All /
>>> /> I would like to change the y axis to be the level Height (z)
>>> values
>>> instead of eta height. /
>>> /> Anyone know how can I do that. Do I need to use get wrf var (z)
>>> and
>>> then specific w&znw = z. /
>>> /> How can I specify the y axis? /
>>> /> Thanks /
>>> /> Mark /
>>>
>>>
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> List instructions, subscriber options, unsubscribe:
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>
>

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Received on Wed Jun 20 12:54:35 2012

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