Stratification and Fatal Error

Question

1. Got model running
2. Lake not stratifying
3.  Assumed it was because no inflows and outflows
4.  Got inflows and outflows working
5. No stratification.
6.  Fatal error about 30 days into the model run:
 
 ***** FATAL ERROR **** FATAL ERROR **** FATAL ERROR *****
 * in module     
 * in subroutine sl_momentum_hi_cfl
 * ELM method stopped before complete
 *  Cell:        39633
 *  ijk:          103          11           3
 *  uvw:  -7.2691278E-03  2.5686305E-03 -3.1779928E-03
 *********************************************************

Answer 1

Hi,

This error message means that your timestep is probably too large.  The model does some internal sub-time-stepping in the momentum solution (and also in the scalar transport) to try and ensure the CFL condition is not violated but if the sub-time-stepping is too severe you will see this error.

Try reducing your time-step.   The general rule we use is 1 second for each metre of your horizontal grid size.  So if your minimum dx or dy is 50m use a 50s time step.

Chris