Custom Query (964 matches)

There is a bug in inp_par.F for sediment runs with no cohesive sediment classes, in other words, with only non-cohesive classes.

When the sediment input file is being read, NEWLAYER_THICK and BEDLOAD_COEF should be independent of the type of sediment (mud or sand). But they are currently being read into a temporary variable called "Rmud" which, of course, it dimensioned to be 0 when there are no mud classes.

My fix was to introduce a class-independent temporary variable called "Rbed" that is a function of NG only. See my change at:

​https://www.myroms.org/projects/cstm/changeset/1152/branches/rps_branch/cstm_trunk/ROMS/Utility/inp_par.F

-Rich

Following the discussion in the ​forum, I'd like to report a bug triggered by the PERFECT_RESTART option and related to vertical diffusion processes for the Generic Length Scale formulation.

The variables tke and gls, together with diffusion coefficients are initialized to their background values (see subroutine initialize_mixing), but subsequently they are read from the restart NetCDF and the values on land areas (matching _FillValue in NetCDF) are set to 0 (see subroutine nf_fread4d).

The tke and gls values enter as denominators for calculations inside subroutine gls_corstep and the 0 values generate a floating point exception.

The resulting NaN are propagated in particular (but not only) to the vertical diffusion coefficient for tracers (Akt) and this causes a model blow-up in subsequent calculations.

I suggest to set the flag SetFillValue to .FALSE. (in: subroutine def_rst and subroutine wrt_rst) for variables tke and gls, in order to preserve the background values over land points. Maybe the same should be applied to the other variables added to the restart file when PERFECT_RESTART is active (Akp, Akk and Lscale) but they don't seem to be involved in potential floating point exceptions.

Please see ​post in the ROMS Bugs forum for a bit more detailed description of the issue. Thank you, Alex

In Modules/mod_boundary.F line 1100

      IF (tl_LBC(isouth,isUbar,ng)%acquire) THEN
        allocate ( BOUNDARY(ng) % tl_ubar_north(LBi:UBi) )
      END IF

we need to have instead

     IF (tl_LBC(inorth,isUbar,ng)%acquire) THEN
        allocate ( BOUNDARY(ng) % tl_ubar_north(LBi:UBi) )
      END IF