id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
812	Updated River Runoff: Option LuvSrc	arango		"In the ROMS Forum, Julia Levin [https://www.myroms.org/forum/viewtopic.php?f=19&t=5156 proposed] some enhancements to the Point Source algorithm to model river runoff using either the standard input switches '''!LuvSrc''' or '''!LwSrc'''.  The '''!LuvSrc''' option is used to model river runoff transport by modifying the horizontal advection transport fluxes whereas the '''!LwSrc''' option is used as a vertical mass volume inflow.

----

I updated '''inp_decode.F''' to be more robust with the '''gfortran''' compiler during debugging.  Really weird behavior in the '''DO'''-loop counter. It continued looping after the specified range.  No idea where that comes from but this update force a strict looping.  For example, in load_1d_i, we now have:

{{{
!  If not all values are provided for the variable, assume the last value
!  for the rest of the array.
!
      ic=0
      IF (Ninp.le.Nout) THEN
        DO i=1,Ninp
          ic=ic+1
          Vout(i)=INT(Vinp(i))
        END DO
        IF (Nout.gt.Ninp) THEN
          Nstr=Ninp+1
          DO i=Nstr,Nout
            ic=ic+1
            Vout(i)=INT(Vinp(Ninp))
          END DO
        END IF
      ELSE
        DO i=1,Nout
          ic=ic+1
          Vout(i)=INT(Vinp(i))
        END DO
      END IF
      Nval=ic
}}}


----

I only implemented the changes associated with '''!LuvSrc'''.  The suggested changes for '''!LwSrc''' are unstable and blow-up for the '''TS_MPDATA''' advection option.  It requires further work.  The old algorithm implemented the vertical mass inflow by modifying the vertical advection fluxes in the tracer equations and by modifying the omega equation that is associated with the 3D continuity equation.  The proposed change is to introduce a forcing term to the rate of change of tracer.  At the moment, such treatment is problematic and unstable for a simple Euler forward step.  There are other issues to consider like conservation and variance of the tracer.

For the '''!LuvSrc''', we now have in '''pre_step3d.F''':

{{{
!
!  Apply tracers point sources to the horizontal advection terms,
!  if any.
!
          IF (LuvSrc(ng)) THEN
            DO is=1,Nsrc(ng)
              Isrc=SOURCES(ng)%Isrc(is)
              Jsrc=SOURCES(ng)%Jsrc(is)
              IF (((Istr.le.Isrc).and.(Isrc.le.Iend+1)).and.            &
     &            ((Jstr.le.Jsrc).and.(Jsrc.le.Jend+1))) THEN
                IF (INT(SOURCES(ng)%Dsrc(is)).eq.0) THEN
                  IF (LtracerSrc(itrc,ng)) THEN
                    FX(Isrc,Jsrc)=Huon(Isrc,Jsrc,k)*                    &
     &                            SOURCES(ng)%Tsrc(is,k,itrc)
                  ELSE
                    FX(Isrc,Jsrc)=0.0_r8
                  END IF
                ELSE
                  IF (LtracerSrc(itrc,ng)) THEN
                    FE(Isrc,Jsrc)=Hvom(Isrc,Jsrc,k)*                    &
     &                            SOURCES(ng)%Tsrc(is,k,itrc)
                  ELSE
                     FE(Isrc,Jsrc)=0.0_r8
                  END IF
                END IF
              END IF
            END DO
          END IF
}}}

Changes were made to the tangent, representer, and adjoint versions of '''pre_step3d.F''' and '''step3d_t.F'''.

Many thanks to Julia Levin, John Wilkin, and Chuning Wang (Jupiter Intelligence INC) for looking and testing the formulation of Point Sources."	defect	closed	major	Release ROMS/TOMS 3.7	Nonlinear	3.7	Fixed