Re: Petterssen frontogenesis

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Mon Dec 10 2012 - 08:56:40 MST

There is no builtin Petterssen frontogenesis equation.

However, the GFS is a global grid and the spherical harmonic
functions could be used to accurately calculate some of the
various terms.

gradient terms: du/dx, dv/dx, dy/dy, du/dy
   http://www.ncl.ucar.edu/Document/Functions/Built-in/gradsf.shtml

There is an **unsupported** function in shea_util.ncl

function advect_gradient (u:numeric, v:numeric, x:numeric \
                          ,gridType[1]:integer, con[1]:numeric \
                          ,long_name:string, units:string, iopt[1]:integer)
;
; linear advection of a scalar quantity: UV.GRADIENT(X)
; : U*(dX/dlon) + V*(dX/dlat)
======
The documentation is embedded in the library. You can read vis:

   %> less $NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl

search for 'advect_gradient'

Don't know about the calculation of the angles.

On 12/9/12 3:56 AM, Adrian Antonescu wrote:
> Hi,
>
> Does anyone have a NCL script to calculate Petterssen frontogenesis?
> I am trying to calculate Petterssen frontogenesis using the GFS 0.5 degrees data.
>
> Thank you so much.
>
> Bogdan Antonescu
>
> The University of Manchester
> Simon Building, Oxford Road
> Manchester, M13 9PL, United Kingdom
> Room 3.16, Simon Building
> +44 (0)161 306 3911
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Received on Tue Dec 11 03:18:53 2012

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