Re: vinth2p with CMIP data

From: kelly lombardo <kellyann7319_at_nyahnyahspammersnyahnyah>
Date: Tue Mar 27 2012 - 12:10:06 MDT

I was just interpolating to 850; 700; 500; 300; 200 hPa, nothing below ground level. Could it be that this routine isn't calibrated for GFDL model output, and can only be used with the CESM? I assumed that the A and B coefficients would be alright since it looks like these coefficients in both the GFDL and CESM are used for the middle point in between the model grid levels. Maybe this was an incorrect assumption? ________________________________ From: Dennis Shea <shea_at_ucar.edu> To: kelly lombardo <kellyann7319_at_yahoo.com> Cc: "ncl-talk_at_ucar.edu" <ncl-talk_at_ucar.edu> Sent: Tuesday, March 27, 2012 1:50 PM Subject: Re: vinth2p with CMIP data If you are interpolating, there should be no winds that look "too strong". If you are extrapolating (below ground level) then this could be the case. vinth2p_ecmwf will extrapolate temperature (using the lapse rate) and/or geopotential (lapse rate and hydrostatic formula). *All* other variables are set to the the nearest non-missing value. This could result in "too strong" winds. As noted in the documentation, the vinth2p was taken directly from the old model processor. NCL changed nothing. My suggestions: (1) do not extrapolate [*all* extrapolations not guided by physics are dangerous, even then use with caution] (2) Look at "Grid Fill" examples at     http://www.ncl.ucar.edu/Applications/grid_fill.shtml     In particular the ones using 'poisson_grid_fill' Good Luck On 03/27/2012 11:27 AM, kelly lombardo wrote: > Hey everyone > > I am trying to interpolate CMIP GFDL-ESM2M data (such as U, V, T) which > is stored on hybrid sigma-pressure coordinates to pressure coordinates > using vinth2p. I was able to interpolate the data, but the winds look > too strong. Has anyone encountered a similar problem? Or does anyone > know where I can find the vinth2p code so I can see how the > interpolation is calculated? > > Thanks > kelly > > > _______________________________________________ > ncl-talk mailing list > List instructions, subscriber options, unsubscribe: > http://mailman.ucar.edu/mailman/listinfo/ncl-talk

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Received on Tue Mar 27 12:10:17 2012

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