barot.F

barot

Description

Steps forward solution for depth mean flow and surface elevation using explicit two time step method with updated velocities in elevation equation i.e. fbtcs (forward-backward time, centred space) and grid scale suppression (kgss) scheme.

Subroutine Arguments

None

Local variables

: k,i,j local grid indices
: icg,jcg global grid indices
: nr,ir,is,js river indices
: iub,jub extended indices to include halo region
: nbts barotropic loop counter
: tagur,tagvr,tagzet,tagub,tagvb,tagh,tagu,tagv,tagfu,tagfv integer tagzet2,tagdz,tagh2,tagzet3 integer tags for array exchanges
: akglat,akglon,akgss,delcr,delm,delpl coefficients in Killworth grid scale suppressor
: dz1,dz2,dz3,dz4,dz5,dz6,dz7,dz8 cross terms in Killworth grid scale suppressor
: dubti,dvbti,dzbti temporary time step increments for ub, vb, zb
: f1,f2,f3,f4,rac,rbc temporary flux terms in the continuity equation
: pmean mean atmospheric pressure
: Local arrays
: dub,dvb,dzb time step increments for ub, vb, zet
: fuc,fvc time step increments for flux filter components
: dz time step increments for Killworth cross terms
: imask mask array for kgss filter

Global variables changed

: u, v 3D velocity
: ub(i,j,3), vb(i,j,3) 2D velocity
: zet(i,j,3) elevation
: fs, gs, fb, gb surface and bottom stresses
: fub, fvb depth mean fluxes
: fu, fv fluxes for scalar advection

Logical units

: * standard print output
: ludbg debugger output

Order of Things

sets h across open boundaries
save old h in hold
Update currents ur,vrthrough halo exchange.
Initialise advective fluxes fu,fv
Add the small increments dub, dvb, dzb together to find total increment at end of the mt steps. First set this total to zero.
set imask
Barotropic loop nbts for mt steps.
Within this loop ...
if lzbar true then calculate zbar the equilibrium tide via czbar
update elevation zet through halo exchange and then h
zero open boundary condition variables and call open b.c. subroutines
calculate increments to ub, vb
update currents ub, vb through halo exchange and apply land b.c if needed
calculate increments to zet with Killworth grid scale suppressor
update volume fluxes fub, fvb for scalar advection
adjust sea level to include freshwater inflow at coasts
calculate fluxes due to filter fuc, fvc
apply land b.c. to 3D velocities if needed
update u, v, ub, vb, zet, fu, fv, fb, gb and csq

Calls

: czbar
: expandtoopenbc
: Exch3DS, Exch3DR
: boundaryUVZ_longform
: boundaryUVZ
: tidbnd_longform
: tidbndrp3
: radiationbc
: velocityBC_2D
: velocityBC_3D
: cbfset

Called By

: b3drun

Options - Logical

: lzbar if true calculate equilibrium tide
: rivers if true calculate river flow adjustment to elevation
: no_tide no tidal forcing
: read_zetub read elevation and currents for boundary conditions
: longbcform use old b.c. format around all boundaries
: read_tidecon read tidal constituents for boundary conditions
: bulk_met use bulk formulae to calculate surface fluxes
: point_met use bulk formulae to calculate surface fluxes from data at sinle point
: met_office Met. Office implementation of model
: ucoast coast lies along u-point(case II boundaries
: rivers river fluxes at some coastal points

Options - Compiler

: SCOORD if present, use 'S' not 'sigma' coordinate
: DEBUG, DEBUG_BAROT if present, switch on debug output
: TIMING_BAROT detailed timing of this routine
: MY25CBF if present, use Mellor Yamada 2.5 bottom friction coeff, otherwise use constant value
: UBC apply slip horizontal veloicty boundary conditions
: RIVERFIX adjust elevations due to rivers at baroclinic (not barotropic) time step