Carbon Dioxide (CO2) Fluxes Forcing Specifications¶

The carbon dioxide flux pipeline processes monthly gridded anthropogenic surface and aircraft carbon dioxide emissions to produce Unified Model binary ancillary files (.anc) for emission-driven climate experiments in ACCESS-ESM1.6 (experiments EH and ES).

Physical Domain & Scientific Scope¶

Scientific Purpose: In standard concentration-driven simulations (HI, SM), atmospheric CO2 is prescribed via global-mean surface concentrations in &clmchfcg. In contrast, in emission-driven Earth System Model simulations (EH, ES), atmospheric CO2 evolves interactively through coupled carbon-cycle fluxes between the atmosphere, the CABLE land surface model, and the WOMBAT ocean biogeochemistry model, driven by prescribed spatially resolved emissions fluxes.
Target STASH Item: m01s00i251 (SURFACE CO2 EMISSIONS / CO2_FLUXES).
Grid & Interpolation: Conservative area-weighted regridding (AreaWeighted(mdtol=0.5)) from $0.5^\circ$ native grid to global.N96 ($1.875^\circ \times 1.25^\circ$), with polar boundary zeroing (zero_poles).
Source Components Combined: Surface anthropogenic emissions (CO2_em_anthro, sum across economic sectors) plus 3D aircraft emissions collapsed vertically (CO2_em_AIR_anthro).

Provenance & Dataflow Architecture¶

The carbon dioxide flux pipeline follows the W3C PROV framework, collapsing multi-sector surface emissions and vertical aircraft fluxes, regridding conservatively to the N96 grid, and manufacturing binary ancillaries for emission-driven experiments: * Historical Emission-Driven (EH): Sums historical anthropogenic surface and aircraft emissions (1849–2023), regrids conservatively to N96, and packages continuous monthly time-series ancillaries. See Historical Emission-Driven Dataflow Architecture. * ScenarioMIP Emission-Driven (ES): Ingests baseline surface/aircraft projections alongside multi-century extension chunks (*-ext-*), concatenates temporal series to 2150, regrids conservatively to N96, and manufactures future emission ancillaries. See ScenarioMIP Emission-Driven Dataflow Architecture. * Idealised CDR (esm-flat10-cdr): Synthesizes an idealized carbon dioxide removal linear ramp from $+10\,\text{PgC}\,\text{yr}^{-1}$ to $-10\,\text{PgC}\,\text{yr}^{-1}$.

Controlling Suite Switches¶

The execution, experiment inclusion, and temporal extension for interactive CO2 emissions fluxes are governed by parameters in rose-suite.conf:

Master Activation Switch: ANCIL_CREATE_CO2 = true
When set to false, all interactive CO2 flux tasks are excluded from the Cylc task graph.
Experiment Activation: Governed by USE_EXP['EH'] (Historical Emission-Driven) and USE_EXP['ES'] (ScenarioMIP Emission-Driven).
Scenario Extension Controls (EXTEND_SM_CO2):
Controls whether future emission scenarios pass --ext to concatenate 2150 extensions:
- 'h': True (Extended to 2150 via IIASA-IAMC-h-ext-1-1-1, producing ${ESM_ES_EXT_CO2_SAVE_FILENAME['h']})
- 'hl': False (Bounded to 2100, producing ${ESM_ES_CO2_SAVE_FILENAME['hl']})
- 'm': False (Bounded to 2100, producing ${ESM_ES_CO2_SAVE_FILENAME['m']})
- 'vl': True (Extended to 2150 via IIASA-IAMC-vl-ext-1-1-1, producing ${ESM_ES_EXT_CO2_SAVE_FILENAME['vl']})
Reference: See Suite Configuration & Parameters Reference for full object declarations.

1. Emission-Driven Historical Experiment (EH)¶

Dataflow Architecture¶

The emissions-driven historical workflow aggregates historical gridded surface and aircraft emissions (1849–2023), regrids conservatively to N96, and packages monthly binary ancillaries:

flowchart TD
    %% Custom Styles for W3C PROV Semantics
    classDef inputStyle fill:#e1f5fe,stroke:#0288d1,stroke-width:1.5px,color:#01579b
    classDef activityStyle fill:#e8f5e9,stroke:#2e7d32,stroke-width:1.5px,color:#1b5e20
    classDef outputStyle fill:#fff3e0,stroke:#e65100,stroke-width:1.5px,color:#bf360c
    classDef agentStyle fill:#f3e5f5,stroke:#7b1fa2,stroke-width:1.5px,color:#4a148c
    classDef targetStyle fill:#ede7f6,stroke:#4527a0,stroke-width:2px,color:#311b92

    %% Top Level: Inputs and Agents
    subgraph S_TOP["1. Source Inputs and Agents"]
        direction LR
        subgraph Inputs["Input Entities (prov:Entity)"]
            direction TB
            E_Anthro[("Historical Anthropogenic CO2<br><code>CO2_em_anthro (surface, 1849-2023)</code>")]:::inputStyle
            E_Air[("Historical Aircraft CO2<br><code>CO2_em_AIR_anthro (vertical, 1849-2023)</code>")]:::inputStyle
            E_Mask[("Reference Grid Mask<br><code>qrparm.mask (N96)</code>")]:::inputStyle
        end

        subgraph Agents["Agents (prov:Agent)"]
            direction TB
            AgCylc{{"Cylc 8 Suite Scheduler"}}:::agentStyle
            AgPy{{"esm1p6_ancil.co2 (Iris, Ants, Mule)"}}:::agentStyle
        end
    end

    %% Middle Level: Transformation Pipeline
    subgraph Activities["2. Transformation Pipeline (prov:Activity)"]
        direction TB
        A_Sum["Sector and Aircraft Summation<br><i>collapse surface sectors and merge aircraft flux</i>"]:::activityStyle
        A_Regrid["Conservative Regridding<br><i>AreaWeighted(mdtol=0.5) to N96 and zero_poles</i>"]:::activityStyle
        A_Pack["Mule Ancillary Packaging<br><i>STASH m01s00i251 | calendar=1 | model_version=703</i>"]:::activityStyle

        A_Sum --> A_Regrid --> A_Pack
    end

    %% Lower Level: Output Entities
    subgraph Outputs["3. Output Entities (prov:Entity)"]
        direction TB
        E_EH_Anc[("Historical Emissions Ancillary<br><code>CO2_fluxes_1849_2023_cmip7.anc</code>")]:::outputStyle
    end

    %% Bottom Level: Model Target
    subgraph S_DEPLOY["4. Downstream Deployment"]
        E_Model[["ACCESS-ESM1.6 Configs<br><code>ACCESS-NRI/access-esm1.6-configs (historical)</code>"]]:::targetStyle
    end

    %% Relationships
    E_Anthro & E_Air -->|prov:used| A_Sum
    E_Mask -->|prov:used| A_Regrid
    A_Pack -->|prov:wasGeneratedBy| E_EH_Anc

    E_EH_Anc -->|staged for model execution| E_Model

    %% Agent Associations
    AgPy -.->|prov:wasAssociatedWith| A_Sum
    AgPy -.->|prov:wasAssociatedWith| A_Regrid
    AgPy -.->|prov:wasAssociatedWith| A_Pack
    AgCylc -.->|orchestrates| Activities

`EH_ancil_co2`¶

1. Description & Purpose:
Generates historical gridded CO2 emissions fluxes spanning 1849 to 2023. Ingests anthropogenic surface emissions and aircraft emissions, sums sectors, regrids conservatively to N96, assigns STASH item 251, and saves ${ESM_EH_CO2_SAVE_FILENAME} (CO2_fluxes_1849_2023_cmip7.anc).

2. CLI Arguments Passed:

python -m esm1p6_ancil.co2.cmip7_EH_CO2_interpolate \
    --ancil-target-dirname "${VAR.ANCIL_TARGET_PATH}" \
    # Current: "/g/data/${PROJECT}/${USER}/CMIP7/esm1p6_ancil/$(isodatetime -f CCYY.MM.DD)"
    --cmip7-source-data-dirname "${VAR.CMIP7_SOURCE_PATH}" \
    # Current: "/g/data/qv56/replicas/input4MIPs/CMIP7"
    --esm15-inputs-dirname "${VAR.ESM15_INPUTS_PATH}" \
    # Current: "/g/data/vk83/configurations/inputs/access-esm1p5"
    --esm-grid-rel-dirname "${ESM_GRID_DIRNAME}" \
    # Current: "global.N96"
    --esm15-grid-version "${ESM15_GRID_VERSION}" \
    # Current: "2020.05.19"
    --dataset-version "${CMIP7_AEROSOL_ANTHRO_VERSION}" \
    # Current: "CEDS-CMIP-2025-04-18"
    --dataset-vdate "${CMIP7_AEROSOL_ANTHRO_VDATE}" \
    # Current: "v20250421"
    --dataset-date-range-list "${CMIP7_HI_AEROSOL_ANTHRO_DATE_RANGE_LIST}" \
    # Current: "['180001-184912','185001-189912','190001-194912','195001-199912','200001-202312']"
    --save-filename "${ESM_EH_CO2_SAVE_FILENAME}"
    # Current: "CO2_fluxes_1849_2023_cmip7.anc"

3. Input4MIPs Versions & Temporal Metadata:
- Dataset Version: ${CMIP7_AEROSOL_ANTHRO_VERSION} (CEDS-CMIP-2025-04-18)
- Version Date (vdate): ${CMIP7_AEROSOL_ANTHRO_VDATE} (v20250421)
- Input Date Range List: ${CMIP7_HI_AEROSOL_ANTHRO_DATE_RANGE_LIST} (['180001-184912', ..., '200001-202312'])
- Processed Model Timeline: 184901-202312 (2100 monthly slices)
4. Input4MIPs Directory Path & Filenames:
- Surface Path: ${VAR.CMIP7_SOURCE_PATH}/CMIP/CEDS/${CMIP7_AEROSOL_ANTHRO_VERSION}/atmos/mon/CO2_em_anthro/gn/${CMIP7_AEROSOL_ANTHRO_VDATE}/
  (Evaluated: /g/data/qv56/replicas/input4MIPs/CMIP7/CMIP/CEDS/CEDS-CMIP-2025-04-18/atmos/mon/CO2_em_anthro/gn/v20250421/)
- Aircraft Path: ${VAR.CMIP7_SOURCE_PATH}/CMIP/CEDS/${CMIP7_AEROSOL_ANTHRO_VERSION}/atmos/mon/CO2_em_AIR_anthro/gn/${CMIP7_AEROSOL_ANTHRO_VDATE}/
  (Evaluated: /g/data/qv56/replicas/input4MIPs/CMIP7/CMIP/CEDS/CEDS-CMIP-2025-04-18/atmos/mon/CO2_em_AIR_anthro/gn/v20250421/)
5. Python Scripts & Functions:
- Main Script / Entrypoint: esm1p6_ancil.co2.cmip7_EH_CO2_interpolate
- Key Functions Called: cmip7_eh_co2_anthro_interpolate, load_cmip7_hi_aerosol_anthro, load_cmip7_hi_aerosol_air_anthro, esm_grid_mask_cube, zero_poles, save_ancil
- Shared Libraries: iris, mule, ants, numpy
6. Function-Level Cube Transformations & Constraints:
- Input Cubes & Coordinates: Surface emissions cube (time, sector, lat, lon) and aircraft emissions cube (time, altitude, lat, lon).
- Constraints Applied: Date range constraint cmip7_date_constraint_from_years(1849, 2023) using cftime.DatetimeNoLeap.
- Coordinate Bounds & Manipulation:
  - Surface sector coordinate collapsed via cube.collapsed(["sector"], iris.analysis.SUM) and removed via remove_coord("sector").
  - Aircraft altitude coordinate collapsed via cube_air.collapsed(["altitude"], iris.analysis.SUM) and removed.
  - Combined total flux: cube_tot = cube + cube_air.
  - Regridded conservatively to target N96 grid using AreaWeighted(mdtol=0.5). Missing values zeroed (data.filled(0.0)).
  - Polar singularity zeroed via zero_poles(esm_cube).
  - Assigned STASH item m01s00i251.
- Created / Output Cubes: Formats final 3D cube (time: 2100, lat: 144, lon: 192) passed to save_ancil.
7. Produced File Versions & Date Ranges:
- Temporal Coverage: 184901-202312 (2100 monthly slices, including 1849 model spin-up padding)
- Calendar: 365-day (NoLeap) calendar alignment
- STASH Code: m01s00i251
8. Produced File Directory Paths & Filenames:
- Output Directory: ${VAR.ANCIL_TARGET_PATH}/modern/historical-emissions/atmosphere/forcing/${ESM_GRID_DIRNAME}/<ANCIL_TODAY>/
- Output Filename: ${ESM_EH_CO2_SAVE_FILENAME} (CO2_fluxes_1849_2023_cmip7.anc)
9. Namelist File & Variable Updates:
None (Generates binary ancillary .anc file).

2. Emission-Driven ScenarioMIP Experiment (ES)¶

Dataflow Architecture¶

The ScenarioMIP emissions-driven workflow combines baseline surface and aircraft emissions (2022–2100) with extension dataset chunks (*-ext-*, 2101–2150 / 2105–2500) when --ext is specified, validating extension files, concatenating continuous time series, regridding to N96, and packaging future emissions ancillaries:

flowchart TD
    %% Custom Styles for W3C PROV Semantics
    classDef inputStyle fill:#e1f5fe,stroke:#0288d1,stroke-width:1.5px,color:#01579b
    classDef activityStyle fill:#e8f5e9,stroke:#2e7d32,stroke-width:1.5px,color:#1b5e20
    classDef outputStyle fill:#fff3e0,stroke:#e65100,stroke-width:1.5px,color:#bf360c
    classDef agentStyle fill:#f3e5f5,stroke:#7b1fa2,stroke-width:1.5px,color:#4a148c
    classDef targetStyle fill:#ede7f6,stroke:#4527a0,stroke-width:2px,color:#311b92

    %% Top Level: Inputs and Agents
    subgraph S_TOP["1. Source Inputs and Agents"]
        direction LR
        subgraph Inputs["Input Entities (prov:Entity)"]
            direction TB
            E_Base_Surf[("Base Surface CO2 NetCDF<br><code>IIASA-IAMC-SCEN-1-1-1 (2022-2100)</code>")]:::inputStyle
            E_Ext_Surf[("Extension Surface CO2 NetCDF<br><code>IIASA-IAMC-SCEN-ext-1-1-1 (2101-2150)</code>")]:::inputStyle
            E_Base_Air[("Base Aircraft CO2 NetCDF<br><code>IIASA-IAMC-SCEN-1-1-2 (2022-2100)</code>")]:::inputStyle
            E_Ext_Air[("Extension Aircraft CO2 NetCDF<br><code>IIASA-IAMC-SCEN-ext-1-1-2 (2105-2500)</code>")]:::inputStyle
            E_Mask[("Reference Grid Mask<br><code>qrparm.mask (N96)</code>")]:::inputStyle
        end

        subgraph Agents["Agents (prov:Agent)"]
            direction TB
            AgCylc{{"Cylc 8 Suite Scheduler"}}:::agentStyle
            AgPy{{"esm1p6_ancil.co2 (Iris, Ants, Mule)"}}:::agentStyle
        end
    end

    %% Middle Level: Transformation Pipelines
    subgraph S_ACT["2. Transformation Pipelines (prov:Activity)"]
        direction TB
        subgraph S_Ext["Extension Validation and Concatenation"]
            direction TB
            A_Validate["Validate Extension Availability<br><i>check_aerosol_ext_available (--ext)</i>"]:::activityStyle
            A_Concat["Concatenate Time Chunks<br><i>CubeList.concatenate_cube (2022-2150)</i>"]:::activityStyle
            A_Validate --> A_Concat
        end

        subgraph S_Proc["Flux Processing and Regridding"]
            direction TB
            A_Sum["Sector and Aircraft Summation<br><i>collapse surface sectors and merge 3D aircraft</i>"]:::activityStyle
            A_Regrid["Conservative Regridding<br><i>AreaWeighted(mdtol=0.5) to N96 and zero_poles</i>"]:::activityStyle
            A_Pack["Mule Ancillary Packaging<br><i>STASH m01s00i251 | calendar=1</i>"]:::activityStyle
            A_Sum --> A_Regrid --> A_Pack
        end

        A_Concat --> A_Sum
    end

    %% Lower Level: Output Entities
    subgraph Outputs["3. Output Entities (prov:Entity)"]
        direction TB
        E_ES_Anc[("Scenario Emissions Ancillaries<br><code>CO2_fluxes_SCEN_2022_2150_cmip7.anc</code>")]:::outputStyle
    end

    %% Bottom Level: Model Target
    subgraph S_DEPLOY["4. Downstream Deployment"]
        E_Model[["ACCESS-ESM1.6 Configs<br><code>ACCESS-NRI/access-esm1.6-configs (esm-scen7-*)</code>"]]:::targetStyle
    end

    %% Relationships
    E_Base_Surf & E_Ext_Surf & E_Base_Air & E_Ext_Air -->|prov:used| A_Validate
    E_Mask -->|prov:used| A_Regrid
    A_Pack -->|prov:wasGeneratedBy| E_ES_Anc

    E_ES_Anc -->|staged for model execution| E_Model

    %% Agent Associations
    AgPy -.->|prov:wasAssociatedWith| A_Validate
    AgPy -.->|prov:wasAssociatedWith| A_Concat
    AgPy -.->|prov:wasAssociatedWith| A_Sum
    AgPy -.->|prov:wasAssociatedWith| A_Regrid
    AgPy -.->|prov:wasAssociatedWith| A_Pack
    AgCylc -.->|orchestrates| S_ACT

`ES_{h,hl,m,vl}_ancil_co2`¶

Tasks generate future projection CO2 emissions fluxes across scenarios h, hl, m, and vl, with automatic extension to 2150 when --ext is specified.

Scenario h (High)Scenario hl (High-Low)Scenario m (Medium)Scenario vl (Very Low)

1. Description & Purpose: Generates future surface CO2 emissions fluxes for ScenarioMIP scenario h (2022–2150). Combines surface and aircraft emissions, validates extension file availability via check_aerosol_ext_available, regrids conservatively to N96, and produces ${ESM_ES_EXT_CO2_SAVE_FILENAME['h']} (CO2_fluxes_h_2022_2150_cmip7.anc).

2. CLI Arguments Passed:

python -m esm1p6_ancil.co2.cmip7_ES_CO2_interpolate \
    --scenario "${SCEN}" \
    # Current: "h"
    --ancil-target-dirname "${VAR.ANCIL_TARGET_PATH}" \
    # Current: "/g/data/${PROJECT}/${USER}/CMIP7/esm1p6_ancil/$(isodatetime -f CCYY.MM.DD)"
    --cmip7-source-data-dirname "${VAR.CMIP7_SOURCE_PATH}" \
    # Current: "/g/data/qv56/replicas/input4MIPs/CMIP7"
    --esm15-inputs-dirname "${VAR.ESM15_INPUTS_PATH}" \
    # Current: "/g/data/vk83/configurations/inputs/access-esm1p5"
    --esm-grid-rel-dirname "${ESM_GRID_DIRNAME}" \
    # Current: "global.N96"
    --esm15-grid-version "${ESM15_GRID_VERSION}" \
    # Current: "2020.05.19"
    --dataset-version "${CMIP7_SM_AEROSOL_VERSION[SCEN]}" \
    # Current: "IIASA-IAMC-h-1-1-1"
    --dataset-vdate "${CMIP7_SM_AEROSOL_VDATE[SCEN]}" \
    # Current: "v20260409"
    --dataset-date-range "${CMIP7_SM_AEROSOL_DATE_RANGE}" \
    # Current: "202201-210012"
    --dataset-air-version "${CMIP7_SM_AEROSOL_AIR_VERSION[SCEN]}" \
    # Current: "IIASA-IAMC-h-1-1-2"
    --dataset-air-vdate "${CMIP7_SM_AEROSOL_AIR_VDATE[SCEN]}" \
    # Current: "v20260624"
    --ext \
    --dataset-ext-version "${CMIP7_SM_EXT_AEROSOL_VERSION[SCEN]}" \
    # Current: "IIASA-IAMC-h-ext-1-1-1"
    --dataset-ext-vdate "${CMIP7_SM_EXT_AEROSOL_VDATE[SCEN]}" \
    # Current: "v20260409"
    --dataset-ext-date-range "${CMIP7_SM_EXT_AEROSOL_DATE_RANGE}" \
    # Current: "210101-215012"
    --dataset-air-ext-version "${CMIP7_SM_EXT_AEROSOL_AIR_VERSION[SCEN]}" \
    # Current: "IIASA-IAMC-h-ext-1-1-2"
    --dataset-air-ext-vdate "${CMIP7_SM_EXT_AEROSOL_AIR_VDATE[SCEN]}" \
    # Current: "v20260804"
    --dataset-air-ext-date-range "${CMIP7_SM_EXT_AEROSOL_AIR_DATE_RANGE}" \
    # Current: "210501-250012"
    --save-filename "${ESM_ES_EXT_CO2_SAVE_FILENAME[SCEN]}"
    # Current: "CO2_fluxes_h_2022_2150_cmip7.anc"

3. Input4MIPs Versions & Temporal Metadata:
- Surface Base: ${CMIP7_SM_AEROSOL_VERSION['h']} (IIASA-IAMC-h-1-1-1), ${CMIP7_SM_AEROSOL_VDATE['h']} (v20260409), ${CMIP7_SM_AEROSOL_DATE_RANGE} (202201-210012)
- Surface Ext: ${CMIP7_SM_EXT_AEROSOL_VERSION['h']} (IIASA-IAMC-h-ext-1-1-1), ${CMIP7_SM_EXT_AEROSOL_VDATE['h']} (v20260409), ${CMIP7_SM_EXT_AEROSOL_DATE_RANGE} (210101-215012)
- Aircraft Base: ${CMIP7_SM_AEROSOL_AIR_VERSION['h']} (IIASA-IAMC-h-1-1-2), ${CMIP7_SM_AEROSOL_AIR_VDATE['h']} (v20260624), ${CMIP7_SM_AEROSOL_DATE_RANGE} (202201-210012)
- Aircraft Ext: ${CMIP7_SM_EXT_AEROSOL_AIR_VERSION['h']} (IIASA-IAMC-h-ext-1-1-2), ${CMIP7_SM_EXT_AEROSOL_AIR_VDATE['h']} (v20260804), ${CMIP7_SM_EXT_AEROSOL_AIR_DATE_RANGE} (210501-250012)
4. Input4MIPs Directory Path & Filenames:
- Surface Base: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_AEROSOL_VERSION['h']}/atmos/mon/CO2_em_anthro/gn/${CMIP7_SM_AEROSOL_VDATE['h']}/CO2-em-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_AEROSOL_VERSION['h']}_gn_${CMIP7_SM_AEROSOL_DATE_RANGE}.nc
- Surface Ext: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_EXT_AEROSOL_VERSION['h']}/atmos/mon/CO2_em_anthro/gn/${CMIP7_SM_EXT_AEROSOL_VDATE['h']}/CO2-em-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_EXT_AEROSOL_VERSION['h']}_gn_${CMIP7_SM_EXT_AEROSOL_DATE_RANGE}.nc
- Aircraft Base: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_AEROSOL_AIR_VERSION['h']}/atmos/mon/CO2_em_AIR_anthro/gn/${CMIP7_SM_AEROSOL_AIR_VDATE['h']}/CO2-em-AIR-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_AEROSOL_AIR_VERSION['h']}_gn_${CMIP7_SM_AEROSOL_DATE_RANGE}.nc
- Aircraft Ext: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_EXT_AEROSOL_AIR_VERSION['h']}/atmos/mon/CO2_em_AIR_anthro/gn/${CMIP7_SM_EXT_AEROSOL_AIR_VDATE['h']}/CO2-em-AIR-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_EXT_AEROSOL_AIR_VERSION['h']}_gn_${CMIP7_SM_EXT_AEROSOL_AIR_DATE_RANGE}.nc
5. Scripts & Functions: esm1p6_ancil.co2.cmip7_ES_CO2_interpolate, cmip7_es_co2_anthro_interpolate, load_cmip7_sm_aerosol_anthro, load_cmip7_sm_aerosol_air_anthro, check_aerosol_ext_available, esm_grid_mask_cube, zero_poles, save_ancil.
6. Cube Transformations:
- Validates completeness of extension chunks via check_aerosol_ext_available.
- Loads surface and aircraft cubes, collapses sectors and altitude coordinates.
- Concatenates baseline (2022–2100) and extension (2101–2150) cubes.
- Conservative regridding to N96 (AreaWeighted(mdtol=0.5)), zeroing polar edges, and assigning STASH m01s00i251.
7. Produced File: ${ESM_ES_EXT_CO2_SAVE_FILENAME['h']} (CO2_fluxes_h_2022_2150_cmip7.anc, 1548 monthly slices, 2022–2150).
8. Destination Path: ${VAR.ANCIL_TARGET_PATH}/modern/esm-scen7-h/atmosphere/forcing/${ESM_GRID_DIRNAME}/<ANCIL_TODAY>/${ESM_ES_EXT_CO2_SAVE_FILENAME['h']}.
9. Namelist Updates: None (Generates binary ancillary .anc file).

Dataset Versions: Base IIASA-IAMC-hl-1-1-1 (v20260327), Extension IIASA-IAMC-hl-ext-1-1-1 (v20260327).
Produces: ${ESM_ES_CO2_SAVE_FILENAME['hl']} (CO2_fluxes_hl_2022_2100_cmip7.anc, STASH 251, bounded to 2100 as EXTEND_SM_CO2['hl'] == False).

Dataset Versions: Base IIASA-IAMC-m-1-1-1 (v20260327), Extension IIASA-IAMC-m-ext-1-1-1 (v20260327).
Produces: ${ESM_ES_CO2_SAVE_FILENAME['m']} (CO2_fluxes_m_2022_2100_cmip7.anc, STASH 251, bounded to 2100 as EXTEND_SM_CO2['m'] == False).

Dataset Versions: Base IIASA-IAMC-vl-1-1-1 (v20260409), Extension IIASA-IAMC-vl-ext-1-1-1 (v20260409).
Produces: ${ESM_ES_EXT_CO2_SAVE_FILENAME['vl']} (CO2_fluxes_vl_2022_2150_cmip7.anc, STASH 251, extended to 2150 as EXTEND_SM_CO2['vl'] == True).

Carbon Dioxide (CO2) Fluxes Forcing Specifications¶

Physical Domain & Scientific Scope¶

Provenance & Dataflow Architecture¶

Controlling Suite Switches¶

1. Emission-Driven Historical Experiment (EH)¶

Dataflow Architecture¶

EH_ancil_co2¶

2. Emission-Driven ScenarioMIP Experiment (ES)¶

Dataflow Architecture¶

ES_{h,hl,m,vl}_ancil_co2¶

`EH_ancil_co2`¶

`ES_{h,hl,m,vl}_ancil_co2`¶