Re: interpolate (and extrapolate) SST data over land (fwd)

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Thu, 3 May 2007 20:10:35 -0600 (MDT)

> I have a Hadley center SST which will go through a complex
> interpolation process using CAM3 SST generation package.
>
> My problem is that the CAM3 SST generation package does not
> allow any missing values over land grid points in the original
> Hadley center SST file. So, I need to interpolate (and
> extrapolate) SST data over land and ice regions. I cannot simply
> put any value on land points because CAM3 uses "land fraction"
> concept. In fact, I should be very careful with the
> interpolation because some unrealistic SST can be created
> over the coastal region. I found some discussion about this and
> related topics from ncl-talk, but not enough for me to do it
> myself.
>
> Could you tell me how this can be done in NCL? It will be also
> very helpful to know how this is done in NCAR, and NCDC/NOAA
> (if anybody know)........
====

Under separate email, I indicated how to get the SST
and Sea Ice concentration dataset.

All interpolations over land are bogus :-)

I do not know how NCDC or NOAA interpolate over land.
Possibly, (a) solution of a poisson eqn via relaxation.
              The SSTs over the ocean are held constant.
          (b) I have seen a fortran code called "weaver"
              I was told that had been used. I have never
              seen the code.

The way the SST dataset I pointed you to was created was
what I call a linear iterative approach. I am not
about to explain everything here. I don't think this
is the appropriate forum.

Good luck

 

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Received on Thu May 03 2007 - 20:10:35 MDT

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