oil_tracer module reference

A tracer package to mimic dissolved oil.

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Data Types

oil_tracer_cs

The control structure for the oil tracer package.

Functions/Subroutines

register_oil_tracer()

Register oil tracer fields and subroutines to be used with MOM.

initialize_oil_tracer()

Initialize the oil tracers and set up tracer output.

oil_tracer_column_physics()

Apply sources, sinks, diapycnal mixing and rising motions to the oil tracers.

oil_stock()

Calculate the mass-weighted integral of the oil tracer stocks, returning the number of stocks it has calculated.

oil_tracer_surface_state()

This subroutine extracts the surface fields from this tracer package that are to be shared with the atmosphere in coupled configurations.

oil_tracer_end()

Deallocate memory associated with this tracer package.

Detailed Description

By Alistair Adcroft and Robert Hallberg, 2010 *.

In the midst of the Deepwater Horizon oil spill, it became evident that models were needed to predict the long-term fate of dissolved oil in the open ocean. This tracer packages mimics the transport, dilution and decay of dissolved oil plumes in the ocean.

This tracer package was central to the simulations used by Adcroft et al., GRL 2010, to prove that the Deepwater Horizon spill was an important regional event, with implications for dissolved oxygen levels in the Gulf of Mexico, but not one that would directly impact the East Coast of the U.S.

Type Documentation

type oil_tracer/oil_tracer_cs

The control structure for the oil tracer package.

Type fields:

  • % ntr [integer] :: The number of tracers that are actually used.

  • % coupled_tracers [logical] :: These tracers are not offered to the coupler.

  • % ic_file [character (len=200)] :: The file in which the age-tracer initial values can be found, or an empty string for internal initialization.

  • % z_ic_file [logical] :: If true, the IC_file is in Z-space. The default is false.

  • % oil_source_longitude [real] :: Latitude of source location (geographic) [degrees_N].

  • % oil_source_latitude [real] :: Longitude of source location (geographic) [degrees_E].

  • % oil_source_i [integer] :: Local i of source location (computational index location)

  • % oil_source_j [integer] :: Local j of source location (computational index location)

  • % oil_source_rate [real] :: Rate of oil injection [kg T-1 ~> kg s-1].

  • % oil_start_year [real] :: The time at which the oil source starts [years].

  • % oil_end_year [real] :: The time at which the oil source ends [years].

  • % time [type(time_type),pointer] :: A pointer to the ocean model’s clock.

  • % tr_reg [type( tracer_registry_type ),pointer] :: A pointer to the MOM tracer registry.

  • % tr [real(:,:,:,:),pointer] :: The array of tracers used in this subroutine, [kg m-3].

  • % ic_val [real( ntr_max )] :: The (uniform) initial condition value [kg m-3].

  • % land_val [real( ntr_max )] :: The value of tr used where land is masked out [kg m-3].

  • % oil_decay_rate [real( ntr_max )] :: Decay rate of oil [T-1 ~> s-1] calculated from oil_decay_days.

  • % oil_source_k [integer( ntr_max )] :: Layer of source.

  • % oil_may_reinit [logical] :: If true, oil tracers may be reset by the initialization code if they are not found in the restart files.

  • % ind_tr [integer( ntr_max )] :: Indices returned by atmos_ocn_coupler_flux if it is used and the surface tracer concentrations are to be provided to the coupler.

  • % tr_desc [type( vardesc )( ntr_max )] :: Descriptions and metadata for the tracers.

  • % diag [type( diag_ctrl ),pointer] :: A structure that is used to regulate the timing of diagnostic output.

  • % restart_csp [type( mom_restart_cs ),pointer] :: A pointer to the restart control structure.

Function/Subroutine Documentation

function oil_tracer/register_oil_tracer(HI, GV, US, param_file, CS, tr_Reg, restart_CS) [logical]

Register oil tracer fields and subroutines to be used with MOM.

Parameters:

  • hi :: [in] A horizontal index type structure

  • gv :: [in] The ocean’s vertical grid structure

  • us :: [in] A dimensional unit scaling type

  • param_file :: [in] A structure to parse for run-time parameters

  • cs :: A pointer that is set to point to the control structure for this module

  • tr_reg :: A pointer that is set to point to the control structure for the tracer advection and diffusion module

  • restart_cs :: [inout] MOM restart control struct

Call to:

mom_error_handler::mom_error ntr_max mom_io::query_vardesc mom_tracer_registry::register_tracer mom_io::var_desc

subroutine oil_tracer/initialize_oil_tracer(restart, day, G, GV, US, h, diag, OBC, CS, sponge_CSp)

Initialize the oil tracers and set up tracer output.

Parameters:

  • restart :: [in] .true. if the fields have already been read from a restart file.

  • day :: [in] Time of the start of the run.

  • g :: [in] The ocean’s grid structure

  • gv :: [in] The ocean’s vertical grid structure

  • us :: [in] A dimensional unit scaling type

  • h :: [in] Layer thicknesses [H ~> m or kg m-2]

  • diag :: [in] 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_oil_tracer.

  • sponge_csp :: Pointer to the control structure for the sponges.

Call to:

mom_error_handler::mom_error mom_io::query_vardesc mom_tracer_z_init::tracer_z_init

subroutine oil_tracer/oil_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, G, GV, US, CS, tv, evap_CFL_limit, minimum_forcing_depth)

Apply sources, sinks, diapycnal mixing and rising motions to the oil tracers.

Parameters:

  • g :: [in] The ocean’s grid structure

  • gv :: [in] The ocean’s vertical grid structure

  • h_old :: [in] Layer thickness before entrainment [H ~> m or kg m-2].

  • h_new :: [in] Layer thickness after entrainment [H ~> m or kg m-2].

  • ea :: [in] an array to which the amount of fluid entrained

  • eb :: [in] an array to which the amount of fluid entrained

  • fluxes :: [in] A structure containing pointers to thermodynamic and tracer forcing fields. Unused fields have NULL ptrs.

  • dt :: [in] The amount of time covered by this call [T ~> s]

  • us :: [in] A dimensional unit scaling type

  • cs :: The control structure returned by a previous call to register_oil_tracer.

  • tv :: [in] A structure pointing to various thermodynamic variables

  • evap_cfl_limit :: [in] Limit on the fraction of the water that can be fluxed out of the top layer in a timestep [nondim]

  • minimum_forcing_depth :: [in] The smallest depth over which fluxes can be applied [H ~> m or kg m-2]

Call to:

mom_tracer_diabatic::applytracerboundaryfluxesinout mom_tracer_diabatic::tracer_vertdiff

function oil_tracer/oil_stock(h, stocks, G, GV, CS, names, units, stock_index) [integer]

Calculate the mass-weighted integral of the oil tracer stocks, returning the number of stocks it has calculated. If the stock_index is present, only the stock corresponding to that coded index is returned.

Parameters:

  • g :: [in] The ocean’s grid structure

  • gv :: [in] The ocean’s vertical grid structure

  • h :: [in] Layer thicknesses [H ~> m or kg m-2]

  • stocks :: [out] 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_oil_tracer.

  • names :: [out] the names of the stocks calculated.

  • units :: [out] the units of the stocks calculated.

  • stock_index :: [in] the coded index of a specific stock being sought.

Return:

undefined :: The number of stocks calculated here.

Call to:

mom_spatial_means::global_mass_int_efp mom_io::query_vardesc

Called from:

mom_tracer_flow_control::call_tracer_stocks

subroutine oil_tracer/oil_tracer_surface_state(sfc_state, h, G, GV, 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.

Parameters:

  • g :: [in] The ocean’s grid structure.

  • gv :: [in] The ocean’s vertical grid structure

  • sfc_state :: [inout] A structure containing fields that describe the surface state of the ocean.

  • h :: [in] Layer thickness [H ~> m or kg m-2].

  • cs :: The control structure returned by a previous call to register_oil_tracer.

Call to:

mom_coupler_types::set_coupler_type_data

subroutine oil_tracer/oil_tracer_end(CS)

Deallocate memory associated with this tracer package.

Parameters:

cs :: The control structure returned by a previous call to register_oil_tracer.

Called from:

mom_tracer_flow_control::tracer_flow_control_end