[Met_help] soil verification in point_stat

[John Halley Gotway]

Jonathan,

As a short answer I'd say, yes, you could probably use Point-Stat to verify soil moisture and temperature observations from WRF.

...BUT... I don't think you'll be able to do any vertical interpolation without some code changes.  Right now, Point-Stat is only set up to do vertical interpolation for pressure levels... and that's
done linear in the log of pressure.

Here's what I'd recommend...

(1) Take a look at the soil moisture and temperature fields you have from WRF.  Depending on which "surface scheme" (I think that's right) you're using, the soil moisture fields may be at a single
levels or a layer of levels.  If it's in layers, you probably wouldn't want to interpolate in the vertical.  You'd just like to match the observation to the forecast value for the layer in which the
observation falls.  If it's single levels, you may want to consider interpolating.

(2) Take a look at the observation levels.  Are they all at some set of "standard" depths or do the depths vary greatly?

Here's one approach that may be pretty easy:
- Assuming that your forecasts are in single levels.
- Assuming that your observations are at some set of "standard" depths.
- When you pre-process the observations to prepare them for ASCII2NC, just round the level value for the observation to the nearest depth you have in your model output.
- Then run Point-Stat to verify at each of your model depths (i.e. no vertical interpolation).
- You could even dump out the matched pair (MPR) line type for all of the levels and use the Stat-Analysis tool to aggregate across levels

I've never done this before, but you could *probably* do that approach with no code changes.  However, if you'd like to do more sophisticated vertical interpolation, I may be able to point you in the
right direction as for what code to modify.

Hope that helps.

John


Case, Jonathan (MSFC-VP61)[Other] wrote:
> Thank you John!
> 
> I have another question for you regarding point_stat.  
> 
> I would like to use observations from SCAN (Soil Climate Analysis Network) to verify soil moisture and temperature observations in the WRF model.  Is there a way we could use point_stat for processing/interpolating data for soil verification?  I don't have the exact specs yet on the observations, but it would probably require a vertical interpolation or nearest-neighbor assignment of a soil layer to the sensor obs depth.  I figure that if could use ascii2nc to pre-process the data into a netcdf file with the same variable naming convention as the WRF GRIB output, then I might be able to pull it off.
> 
> Thanks in advance,
> Jonathan
> 
>> -----Original Message-----
>> From: John Halley Gotway [mailto:johnhg at rap.ucar.edu]
>> Sent: Friday, May 08, 2009 8:47 AM
>> To: Case, Jonathan (MSFC-VP61)[Other]; met_help
>> Subject: Re: formatted output in mode_analysis
>>
>> Jonathan,
>>
>> Take a look in METv2.0/lib/vx_analysis_util/mode_job.cc.  In lines 458
>> to 485, change all instances of "%.2f" to "%.3f".  That should increase
>> your precision by 1.
>>
>> Thanks,
>> John
>>
>> Case, Jonathan (MSFC-VP61)[Other] wrote:
>>> John,
>>>
>>> I would like to output an addition decimal place in the mode_analysis
>> -summary output to have 3 decimal places.
>>> What line(s)/file(s) should I modify in order to get 1 more decimal
>> point precision?
>>> Thanks much!
>>> Jonathan
>>>
>>> ***********************************************************
>>> Jonathan Case, ENSCO, Inc.
>>> Aerospace Sciences & Engineering Division
>>> Short-term Prediction Research and Transition Center
>>> 320 Sparkman Drive, Room 3062
>>> Huntsville, AL 35805-1912
>>> Voice: (256) 961-7504   Fax: (256) 961-7788
>>> Emails: Jonathan.Case-1 at nasa.gov
>>>              case.jonathan at ensco.com
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>>>