boundary_impulse_tracer boundary_impulse_tracer::boundary_impulse_tracer_cs integer, parameter integer, parameter boundary_impulse_tracer::ntr_max ntr_max = 1 NTR_MAX is the maximum number of tracers in this module. register_boundary_impulse_tracer logical function, public logical function, public boundary_impulse_tracer::register_boundary_impulse_tracer (HI, GV, param_file, CS, tr_Reg, restart_CS) register_boundary_impulse_tracer HI HI GV GV param_file param_file CS CS tr_Reg tr_Reg restart_CS restart_CS Read in runtime options and add boundary impulse tracer to tracer registry. hi A horizontal index type structure gv The ocean's vertical grid structure param_file A structure to parse for run-time parameters cs The control structure returned by a previous call to register_boundary_impulse_tracer. tr_reg A pointer that is set to point to the control structure for the tracer advection and diffusion module restart_cs A pointer to the restart control structure atmos_ocean_fluxes_mod::aof_set_coupler_flux mom_error_handler::mom_error ntr_max mom_io::query_vardesc mom_tracer_registry::register_tracer mom_io::var_desc subroutine, public subroutine, public boundary_impulse_tracer::initialize_boundary_impulse_tracer (restart, day, G, GV, h, diag, OBC, CS, sponge_CSp, tv) initialize_boundary_impulse_tracer restart restart day day G G GV GV h h diag diag OBC OBC CS CS sponge_CSp sponge_CSp tv tv Initialize tracer from restart or set to 1 at surface to initialize. restart .true. if the fields have already been read from a restart file. day Time of the start of the run. g The ocean's grid structure gv The ocean's vertical grid structure h Layer thicknesses [H ~> m or kg m-2] diag A structure that is used to regulate diagnostic output. obc This open boundary condition type specifies whether, where, and what open boundary conditions are used. cs The control structure returned by a previous call to register_boundary_impulse_tracer. sponge_csp Pointer to the control structure for the sponges. tv A structure pointing to various thermodynamic variables mom_io::query_vardesc subroutine, public subroutine, public boundary_impulse_tracer::boundary_impulse_tracer_column_physics (h_old, h_new, ea, eb, fluxes, dt, G, GV, US, CS, tv, debug, evap_CFL_limit, minimum_forcing_depth) boundary_impulse_tracer_column_physics h_old h_old h_new h_new ea ea eb eb fluxes fluxes dt dt G G GV GV US US CS CS tv tv debug debug evap_CFL_limit evap_CFL_limit minimum_forcing_depth minimum_forcing_depth Apply source or sink at boundary and do vertical diffusion. g The ocean's grid structure gv The ocean's vertical grid structure h_old Layer thickness before entrainment [H ~> m or kg m-2]. h_new Layer thickness after entrainment [H ~> m or kg m-2]. ea an array to which the amount of fluid entrained eb an array to which the amount of fluid entrained fluxes A structure containing pointers to thermodynamic and tracer forcing fields. Unused fields have NULL ptrs. dt The amount of time covered by this call [T ~> s] us A dimensional unit scaling type cs The control structure returned by a previous call to register_boundary_impulse_tracer. tv A structure pointing to various thermodynamic variables debug If true calculate checksums evap_cfl_limit Limit on the fraction of the water that can be fluxed out of the top layer in a timestep [nondim] minimum_forcing_depth The smallest depth over which fluxes can be applied [H ~> m or kg m-2] mom_tracer_diabatic::applytracerboundaryfluxesinout mom_tracer_diabatic::tracer_vertdiff integer function, public integer function, public boundary_impulse_tracer::boundary_impulse_stock (h, stocks, G, GV, CS, names, units, stock_index) boundary_impulse_stock h h stocks stocks G G GV GV CS CS names names units units stock_index stock_index Calculate total inventory of tracer. g The ocean's grid structure gv The ocean's vertical grid structure h Layer thicknesses [H ~> m or kg m-2] stocks the mass-weighted integrated amount of each tracer, in kg times concentration units [kg conc]. cs The control structure returned by a previous call to register_boundary_impulse_tracer. names The names of the stocks calculated. units The units of the stocks calculated. stock_index The coded index of a specific stock being sought. Return value: the number of stocks calculated here. mom_io::query_vardesc subroutine, public subroutine, public boundary_impulse_tracer::boundary_impulse_tracer_surface_state (sfc_state, h, G, CS) boundary_impulse_tracer_surface_state sfc_state sfc_state h h G G CS CS This subroutine extracts the surface fields from this tracer package that are to be shared with the atmosphere in coupled configurations. This particular tracer package does not report anything back to the coupler. g The ocean's grid structure. sfc_state A structure containing fields that describe the surface state of the ocean. h Layer thickness [H ~> m or kg m-2]. cs The control structure returned by a previous call to register_boundary_impulse_tracer. subroutine, public subroutine, public boundary_impulse_tracer::boundary_impulse_tracer_end (CS) boundary_impulse_tracer_end CS CS Performs finalization of boundary impulse tracer. cs The control structure returned by a previous call to register_boundary_impulse_tracer. Implements a boundary impulse response tracer to calculate Green's functions. Transit time distributions (TTD) are the Green's function solution of the passive tracer equation between the oceanic surface and interior. The name derives from the idea that the 'age' (e.g. time since last contact with the atmosphere) of a water parcel is best characterized as a distribution of ages because water parcels leaving the surface arrive at a particular interior point at different times. The more commonly used ideal age tracer is the first moment of the TTD, equivalently referred to as the mean age. A boundary impulse response (BIR) is a passive tracer whose surface boundary condition is a rectangle function with width $\Delta t$. In the case of unsteady flow, multiple BIRs, initiated at different times in the model can be used to infer the transit time distribution or Green's function between the oceanic surface and interior. In the case of steady or cyclostationary flow, a single BIR is sufficient. In the References section, both the theoretical discussion of TTDs and BIRs are listed along with modeling studies which have this used framework in scientific investigations -DO_BOUNDARY_IMPULSE_TRACER: Enables the boundary impulse tracer model -IMPULSE_SOURCE_TIME: Length of time that the surface layer acts as a source of the BIR tracer -Holzer, M., and T.M. Hall, 2000: Transit-time and tracer-age distributions in geophysical flows. J. Atmos. Sci., 57, 3539-3558, doi:10.1175/1520-0469(2000)057<3539:TTATAD>2.0.CO;2. -T.W.N. Haine, H. Zhang, D.W. Waugh, M. Holzer, On transit-time distributions in unsteady circulation models, Ocean Modelling, Volume 21, Issues 1–2, 2008, Pages 35-45, ISSN 1463-5003 http://dx.doi.org/10.1016/j.ocemod.2007.11.004. -Peacock, S., and M. Maltrud (2006), Transit-time distributions in a global ocean model, J. Phys. Oceanogr., 36(3), 474–495, doi:10.1175/JPO2860.1. -Maltrud, M., Bryan, F. & Peacock, Boundary impulse response functions in a century-long eddying global ocean simulation, S. Environ Fluid Mech (2010) 10: 275. doi:10.1007/s10652-009-9154-3