define the grid error in roms ocean model

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himanshu
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Joined: Wed Jun 03, 2015 4:06 pm
Location: ALLAHABAD UNIVERSITY

define the grid error in roms ocean model

#1 Unread post by himanshu »

REspected Sir/Mam,
I want to know the meaning of PGE and CFL error in the Grid Stiffness Ratios (below Grid Generation Examples with pyroms) in the RegCM-ROMS tutorial Introduction to ROMS ocean model pdf Grid Generation (5/7).
KIndly, provide me this information as soon as possible
THanking You
Himanshu Gandhi
ROMS user

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kate
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Joined: Wed Jul 02, 2003 5:29 pm
Location: CFOS/UAF, USA

Re: define the grid error in roms ocean model

#2 Unread post by kate »

I don't know the document you refer to, but the PGE stands for pressure gradient error while CFL refers to the names of three people who describe an advective timestep limit. The term CFL generally refers to the timestep limit on any numerical method, meaning that all non-implicit schemes require a short enough timestep for stability.

For the PGE, there will be errors in the horizontal pressure gradient associated with our non-flat coordinate system (unless your bottom is flat). The exact magnitude of these errors depends on which pressure gradient scheme you use, the degree to which your bottom depth changes from one grid point to its neighbors, the vertical stratification, and so on.

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