Re: Area average

Hi Kim,
I think the following code will do what you want:
z2 = z(:,{30:40},{60:72}) ; select specific region
delete(z)
printVarSummary(z2)
z2Area = wgt_areaave_Wrap(z2,1.0,1.0,0) ; create area-avg. timeseries
printVarSummary(z2Area)
z2_za = dim_avg_Wrap(z2) ; create time x lat array
z2_ma = dim_avg_Wrap(z2(time|:,lon|:,lat|:) ; create time x lon array
printVarSummary(z2_za)
printVarSummary(z2_ma)

printVarSummary is a wonderful tool that you can use to view the details
of an array. printVarSummary will show the metadata associated with an
array, as well as the range of the coordinate variables (if there are
any).

As you are area-averging, you should account for the difference in sizes
of the grid boxes as the meridians converge at the poles. You can do this
by applying gaussian or cosine weights in the area-averaging process. See
example 1 here:
http://www.ncl.ucar.edu/Document/Functions/Built-in/wgt_areaave.shtml

If you haven't done so already, I suggest you take a look at the NCL
Mini-Language Manual available here:
http://www.ncl.ucar.edu/Document/Manuals/

Good luck,
Adam

> Dear NCL users,
> I want to calculate only the map area averaged and remove the area outside
> the map (sample Fig.attached). I don’t know how to calculate the
> required map area and remove the outside area?
> Furthermore, how does calculate time vs lon and time series plot of only
> map area?
> Is it correct if I use this function?
> zArea = wgt_areaave_Wrap(z(:,{30:40},{60:72}),1.0,1.0,0)
> but how I confirm it is only map area averaged(as indicated in Fig)?
> Kindly, your guidance regarding this will be appreciated.
> Thanks in advance,
> kim
>  
>
>
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Received on Mon Mar 1 09:45:56 2010