[NARCCAP-discuss] Clipping a sub-domain from NARCCAP data based on lat/lon

[Seth McGinnis]

Hi Darrin,

It sounds like you want ncap2's "where" statement.  I've never used it, but the
example in section 4.1.13 of the NCO documentation matches almost exactly what
you're trying to do.

Cheers,

--Seth

P.S.: If you get it working, share your technique with the list, would you?

On Thu, 22 Mar 2012 17:55:53 -0600
 Darrin Sharp <dsharp at coas.oregonstate.edu> wrote:
>Is there an easy way using netcdf operators (nco) to clip a subdomain  
>from the NARCCAP North American coverage?
>
>For example, I want to look at the subdomain defined by  
>(41.5N<=lat<=49.5N) and (236E<=lon<=249E). This is the Pacific  
>Northwest (i.e. OR, WA, part of ID).
>
>I'm familiar with using nco to clip based on dimensions, where in a  
>case like this lat and lon would be dimensions. In that case I'd do  
>something like:
>
>ncks -h -O -d lat,41.5,49.5 -d lon,236,249  
>tas_CRCM_cgcm3_1968010103.nc out.nc
>
>But since the dimensions in NARCCAP are xc and yc (in meters) and not  
>lat/lon (in degrees) that doesn't work.
>
>I've been trying to use ncap2 with a script to mask the lat and lon  
>variables, but am not having much luck. For example:
>
>ncap2 -s 'mask_var=(lat>=41.5 && lat <= 49.5) && (lon>=236 &&  
>lon<=249);' tas_CRCM_cgcm3_1968010103.nc out.nc
>
>This ncap2 command works (i.e. produces a valid out.nc file), but I'm  
>not sure what to do with it then.
>
>Am I making this too hard? Is there an easier way?
>
>-Darrin
>
>======================================
>Darrin Sharp
>Faculty Research Assistant
>Oregon Climate Change Research Inst. (OCCRI)
>dsharp at coas.oregonstate.edu
>970-219-6713
>
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