[RegCNET] (no subject)

[Graziano Giuliani]

On 07/31/2012 12:08 PM, Kishore Babu wrote:
> Dear RegCM users,
>
> I am trying to run RegCM with unsupported global data. While running
> RegCM-4.1.1, it gives the following error. Could you please anyone tell me
> where the problem is? Do you think that there is a problem with global data
> or with parameter settings of RegCM? Your explanation is highly helpful...
[...]
>   CFL violation detected, so model STOP
[...]

First check in mind would be an in deep look at the ICBC files fields: are you 
sure the fields in there are physically consistent? The ICBC program does not 
have in deep checks, it just interpolates, so you may end up with non physical 
input to the model, and get numerical problems soon after start.

If anyway the model runs for at least couple of months, I would go for a check 
in the terrain elevation to identify steep gradients, and either smooth them or 
decrease the dt in the input namelist file.

Another hint would be to check for smooth continuity of the input datasets: it 
may occur to feed the model with boundary conditions with strong discontinuity 
(say wrong month in a series), and this may get you to numerical instabilities.

-- 
Graziano Giuliani - Earth System Physics Section
The Abdus Salam International Centre for Theoretical Physics
Strada Costiera, 11 - I - 34151 Trieste Italy