Source Files

Parallel array fill helpers for stdpar (GPU/multicore).

This file contains the cute banner we will print when a simulation is run

Barotropic ↔ multilayer coupling kernels for the split-explicit ocean driver — the bt↔ml bridges run around each barotropic-substep call: derive_bt_from_layers (layers → bt state, depth-averaged), sum_slow_tendencies_into_F_slow (per-kernel scratch → composite F_slow), face_depth_mean_u/_v (3D slow tendency → 2D face forcing), apply_bt_correction (bt time-mean → per-layer correction + h rescale).

Barotropic (depth-integrated) solution state on an Arakawa C-grid.

Barotropic-substep kernels for the split-explicit ocean driver.

Barotropic working-state slot for the split-explicit ocean driver.

Bathymetry loading from NetCDF files

Flux-bounded barotropic continuity helpers: piecewise-cubic mass-transport closures that bound face transport as velocity grows, plus their derivatives and inverses. Operate on the per-face coefficient packs on barotropic_workstate_t. Hallberg & Adcroft (2009).

Communication environment — the ONLY backend.

Runtime configuration via Fortran namelists

Central Roundabout namelist schema (strict validation + parameter dumps).

Regime-agnostic MOM6-style console statistics formatter.

Physical constants and working precision for the tidal solver

Continuity-PPM kernel state + barotropic step.

PV-conserving Coriolis-advection kernel state + barotropic step.

Domain decomposition for MPI: splits a global structured grid across ranks.

Driver: full compute-rank lifecycle for the Roundabout solver.

Extended-Fixed-Point (EFP) order-invariant reduction primitives.

Ocean equation-of-state state + kernel.

Ring buffer of specific error messages for the ocean solver-creation path (Python runtime API plan, P2, docs/ocean_python_api_plan.md).

Structured grid metadata

Halo exchange for domain decomposition — the ONLY backend. See rdb_comm_env.F90 for why there is no longer a _stub twin.

Opaque handle type for the ocean C ABI (Python runtime API plan, P1).

v1 slab-atmosphere restoring filler for the ice atmospheric-forcing seam (SIS2 port, PR 3c; PR 26 adds the fourth field, atm_fprec).

Ocean -> ice basal heat flux fb from above-freezing surface heat (PR 3c).

Single-column Winton NkIce-layer ice thermodynamics (SIS2 port, PR 3a).

Sea-ice enthalpy library (SIS2 port, PR 2).

C-grid elastic-viscous-plastic (EVP) sea-ice rheology (SIS2 port, PR 5).

Ocean-side frazil accumulator (SIS2 port, PR 1).

Frazil-heat-bank spend: new-ice formation from the ocean-side supercooling bank (SIS2 port, PR 3b).

Sea-ice initial-condition path (PR 24 — analytic v1).

Ice-thickness-distribution (ITD) restore: adjust_ice_categories (PR 4a).

Sea-ice column mass bookkeeping (SIS2 port, PR 3a).

Ice -> ocean brine-rejection coupling: refresh the surface salt-flux field from the sea-ice slot’s last uptake (SIS2 port, PR 3b).

Sea-ice shortwave optics (SIS2 port, PR 3a).

Ice-free share of the snowfall source term, delivered to the ocean (SIS2 port, PR 26).

Sea-ice slot scaffold (SIS2 port, PR 0/1/3a).

Driver-facing ice thermodynamics: run the column step, reduce the per-(cell,cat) exchange into the ocean-coupling seam diags (PR 3c).

Category ice/snow transport + compress_ice (SIS2 port, PR 4b).

Thin wrapper around netcdf-fortran (nf90_*) with error checking

Massless-layer merge column helper (ocean dyn-core, D4).

Setup-time memory-budget reporting for the device-mapped state.

3D hydrostatic multilayer state on an Arakawa C-grid.

Strict, schema-driven namelist validation engine.

Ocean C ABI — lifecycle (P1) + accessors and the error ring (P2).

Pre-create bathymetry ARRAY injection (Python runtime API plan, P2.5).

Analytic TRIPOLAR (Murray 1996) bipolar-cap coordinate map.

Bottom drag for the ocean dynamical core. Applies a momentum sink at the bed-adjacent LIVE layer of each face — ms%k_bot_u/v, the first layer live on both sides counting up from the bed (bed at k=1, surface at k=nz). k_bot ≡ 1 on every coordinate without a static bed filler, so this is the historical k = 1 row there; under z_fixed the layers below it are inert fillers the vdiff solve cuts out of the column, and a drag on k = 1 would never reach water. Two variants supported via a tag:

Abstract ocean boundary data source.

Ocean open-boundary condition types.

Per-region BT-mode energy + per-term power diagnostic probe.

Wide-halo BT march-in state (Phase 3c, D3 v1.1).

Global-integral conservation-budget PRIMITIVES — a verification instrument, not a production reporter.

Ice-shelf basal melt, COUPLED: the slot, the far-field sampler and the once-per-thermo-step driver that turns rdb_ocean_cavity_melt’s scalar three-equation kernel into two surface-flux components the ocean integrates.

Ice-shelf basal-melt interface thermodynamics — the three-equation kernel for an ice-shelf cavity. KERNEL ONLY: nothing in this module is called by the ocean step yet (no namelist group, no state slot, no engine wiring — that is the coupling PR). What ships here is the scalar, pure, !$acc routine seq physics, under unit test against a 17-significant-digit golden oracle.

MOM6-style per-phase field checksums (“DEBUG=True” analogue).

MOM6-style console-line statistics for the ocean dynamical core.

File-backed surface forcing (PR-15) — the first production consumer of the shared PR-14 NetCDF reader.

The shared time-varying NetCDF input reader (PR-14).

Ocean diagnostics manager.

Library of derived ocean diagnostics — static catalog binding a diagnostic name to a fill procedure + CF-1.8 metadata, picked by name from the namelist. Every fill is a pure function of the current ocean_state_t; outputs at cell centres (vgrid LAYER, z-level remap via remap_layer_to_z). Includes the opt-in sea-ice drift diagnostics (ice_speed/ice_u/ice_v) — the canonical ice_conc/ice_thick fills live in rdb_ocean_diag_fills (module- cycle rule: this module USES that one).

Default fill routines for the ocean diagnostics registry.

Region masks for ocean diagnostics.

Serial NetCDF emit hook for the ocean diagnostics registry.

Split-explicit RK2 dynamics state + driver step.

Ocean setup / step / teardown engine (P2.4) — the ONE shared lifecycle path for the ocean dyn-core, called by driver_run_ocean (src/driver/rdb_driver.F90), the C ABI (src/api/rdb_ocean_api.F90) and, where it would not distort the benchmark’s own measurement, benchmarks/bench_ocean.F90.

Ocean-side EOS shim over the C-grid multilayer state.

Energetics-based planetary boundary layer (EPBL) for the ocean core.

Tripolar north-fold seam-exchange helpers for the ocean dyn-core.

State-level tripolar north-fold seam application for the ocean dyn-core.

Distributed tripolar north-fold exchange (px > 1) — MPI backend.

Routing plan for the DISTRIBUTED tripolar north fold (px > 1).

Geothermal bottom heat flux for the ocean core — bed-side analogue of rdb_ocean_surface_flux. Stamps a constant bottom heat flux Q_geo (W/m^2, positive into the ocean from below) into the bottom layer (k=1, ROMS-style k=1 bed / k=nz surface). Heat only.

Ghost-band sentinel-NaN fill for exchange-coverage regression testing.

Gent-McWilliams thickness-diffusion (eddy-induced bolus transport) slot.

Ocean-grid staggered halo-exchange — MPI backend.

Ocean halo-exchange counters — backend-agnostic bookkeeping module.

State-level shim routing ML prognostic ghost exchange through the O1 comm primitives.

One required_halo query folding every scattered minimum-nghost rule (Python runtime API plan, P2.5).

Constant-coefficient horizontal tracer diffusion for the ocean multilayer C-grid. Conservative curvilinear flux-form Laplacian on T = hTr/h (design §2, mirrors continuity):

Constant-coefficient Laplacian horizontal viscosity on the ocean C-grid. Baseline closure for the dynamical core — gives a flat nu_h momentum diffusion that damps grid-scale gravity-wave noise and keeps the unsplit driver bounded. Phase 5a / 5b will plug Leith and Smagorinsky scaled nu_h fields into the same compute kernel — the apply step is the same forward-Euler accumulation regardless of closure.

Ideal-age tracer kernels for the ocean path.

Isopycnal (neutral) slope diagnostics for the ocean dynamical core.

Shear-driven interior turbulence (kappa-shear) for the ocean core.

Per-segment layer-KE attribution probe (“kediag” rebuilt).

Ocean lateral mixing parameterisation state.

Mesoscale eddy kinetic energy (MEKE) prognostic slot.

Orthogonal curvilinear horizontal metrics for the ocean dyn-core.

Ocean mixed-layer-eddy (Fox-Kemper) restratification slot.

Ocean open-boundary nesting state.

Baroclinic open-boundary kernels for the ocean dyn-core.

Ocean atmospheric surface-pressure loading state (inverse barometer).

Periodic-boundary ghost-wrap helpers for the ocean dyn-core.

Generic 5-point Boole density integrals for the FV pressure-gradient force.

Porous barriers — subgrid sill/strait blocking of C-grid face widths.

Ocean pressure-force kernel state + the layered hydrostatic PGF variants.

Pseudo-salt verification tracer for the ocean path.

ALE remap orchestrator for the ocean dynamical core (centre-cell pass).

Ocean restart / checkpoint manager + per-slot field registry.

NetCDF read/write of the ocean restart registry.

Ocean slot configuration from a parsed namelist config.

Sponge relaxation kernel.

Configure-time numerical-stability audit for the ocean dyn-core.

Top-level ocean-regime state.

Named status codes for the ocean solver-creation path’s optional ierr out-arguments (P0 of the Python runtime API plan, docs/ocean_python_api_plan.md).

Surface heat + salt fluxes for the ocean dynamical core. Sister module to rdb_ocean_surface_stress — same 2D-field shape, applies a tracer flux at the surface layer (k = nz under the ROMS-style k=1-bed convention).

Surface momentum stress for the ocean dynamical core. Carries a 2D wind-stress field tau_x, tau_y (N/m^2) and applies it as a momentum source at the surface-most layer (k = nz under the ROMS-style k=1-bed convention).

Internal-tide-driven interior diapycnal mixing (St-Laurent/Simmons) for the ocean core.

Equilibrium-tide astronomy generator (mean longitudes, equilibrium arguments, nodal corrections, constituent catalog).

Ocean tidal forcing state.

Ice-shelf TOP drag: the momentum sink at the ocean’s upper boundary where an ice shelf sits on it. The mirror image of rdb_ocean_bottom_drag about the middle of the column — under the ROMS-style bottom-up convention this codebase uses everywhere, the bed is k = 1 and the ice base is k = nz.

Spatially-varying GM/Redi lateral-diffusivity coefficients (VarMix).

Ocean vertical-coordinate + ALE remap state.

Backward-Euler vertical diffusion solver for the ocean multilayer C-grid. Two public entry points:

Vertical tracer advection on the ocean multilayer C-grid.

Ocean vertical mixing parameterisation state.

First-baroclinic gravity-wave speed + Rossby deformation radius.

Z-level T/S initial-condition overlay (capability A2).

Named profiling regions with wall-clock timers and optional NVTX ranges. -DUSE_NVTX enables NVTX (else no-op); -DDISABLE_PROFILER disables everything.

WENO tracer face-reconstruction ladder for the layered tracer transport.

Conservative vertical remapping for ALE coordinates

Reproducibility-safe wrappers around transcendentals and ** — a finished library with no production consumer today.

Reusable 3D scratch-buffer type.

Shared tracer-registry defaults for the ocean dyn-core.

Multilayer tracer descriptor

Vertical coordinate type for hybrid z-sigma and ALE support