Re: How to mask data over ocean

[Mark Verschell <markverschell@xxxxxxxxxxxxxx>]

Jozef,

I can't promise a nifty way, but at least this is a way that will work, 
IF you are working with relatively small parts of the globe...

First, create a subset of the etopo5 data set over the region you're 
interested in (from your example 10S:45S, 110E:155E)

Then, apply corrections to the data set
yes? if rose[y=25S:34S,x=135E:140E] eq 0 then temp=100

and do this for the other regions, shading the mask to make sure you 
make no errors, changing the variable names each time of course

(You can zoom in and really look at it closely to make your region 
selections more carefully, just use explicit regions in the plot command 
rather than using set region otherwise you mess up your new land mask)

Then save this new mask and use that to mask your rainfall data.

Hope this helps,

Mark



On Saturday, September 29, 2001, at 03:41 AM, Jozef SYKTUS wrote:

> Hi,
>     I am using ferret to plot say rainfall from climate models and
> frequently need to mask out data over ocean. I am using go focean 5 
> white
> which uses etopo5 data file to mask out points laying <=0 m, however
> for some strange reason this dataset has values <0m over some parts of
> Arnhemland (top of plot) and also Lake Eyre comes as a large white 
> patch.
>
> Can anybody suggest some nifty solution to get high resolution
> land/sea mask which I can use to mask out ocean points in ferret??
>
> Regards,
>
> Jozef
>
>
> ---------------------------------------------------------------
> Jozef Syktus -- Senior Research Scientist
> Experimental Seasonal Climate Prediction Modelling Project
> Queensland Centre for Climate Applications
> ---
> Climate Impacts and Natural Resource Systems
> Natural Resource Sciences
> Queensland Department of Natural Resources
>
> ---------------------------------------------------------------
> Mail address:
> _______________________________________________________________
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> | also jis@dar.csiro.au at CSIRO Atmospheric Research          I
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