Aerosol Forcing Specifications

The aerosol forcing suite processes CMIP7 monthly anthropogenic, aircraft, and biomass burning emissions alongside climatological marine dimethyl sulfide (DMS) emissions to manufacture binary Unified Model (UM) ancillary files (.anc) for the classic aerosol and sulfur cycle schemes in ACCESS-ESM1.6.

Physical Domain & Scientific Scope

Species & Output Ancillaries:
- Black Carbon (BC): Surface anthropogenic and aircraft black carbon emissions. Target STASH item: m01s00i057. Filename: BC_<range>_cmip7.anc.
- Organic Carbon (OC): Fossil fuel and anthropogenic organic carbon emissions. Target STASH item: m01s00i059. Filename: OCFF_<range>_cmip7.anc.
- Biomass Burning (Bio): Total particulate emissions from wildland fires, agricultural burning, and deforestation. Target STASH item: m01s00i086. Filename: Bio_<range>_cmip7.anc.
- Sulfur Cycle (SO2 / scycl): Multi-level sulfur dioxide emissions partitioned into low-level surface emissions (STASH item 58), high-level industrial/stack emissions (STASH item 126), and marine dimethyl sulfide (DMS). Filename: scycl_<range>_cmip7.anc.
Spatial Regridding & Masking: All species are regridded from native CMIP7 resolution ($0.5^\circ \times 0.5^\circ$) to the target atmospheric grid (global.N96, $1.875^\circ \times 1.25^\circ$) using conservative area-weighted regridding: $$\text{INTERPOLATION\_SCHEME} = \text{iris.analysis.AreaWeighted}(\text{mdtol}=0.5)$$ against the UM land-sea mask cube generated by esm_grid_mask_cube(args).
Polar Boundary Treatment: Due to the mathematical singularity at the poles on the regular latitude-longitude grid, zero_poles(cube) forces the outermost polar rows to 0.0 to prevent numerical instabilities.

Controlling Suite Switches

The execution and temporal extent of aerosol tasks are governed by parameters in rose-suite.conf:

Master Activation Switch: ANCIL_CREATE_AEROSOL = true
When set to false, all aerosol processing tasks across all experiments are excluded from the execution graph.
Experiment Activation: Governed by USE_EXP['PI'], USE_EXP['HI'], and USE_EXP['SM'].
Scenario Extension Controls (EXTEND_SM_AEROSOL):
Controls whether future pathways are generated through 2100 or extended to 2150 with --ext:
- 'h': True (Extended to 2150 via IIASA-IAMC-h-ext-1-1-1)
- 'hl': False (Bounded to 2100)
- 'm': False (Bounded to 2100)
- 'vl': True (Extended to 2150 via IIASA-IAMC-vl-ext-1-1-1)
Reference: See Suite Configuration & Parameters Reference for full object declarations.

1. Pre-Industrial Experiment (PI)

The pre-industrial aerosol suite generates cyclic 1850-representative annual ancillaries (12 monthly slices) for Black Carbon, Biomass Burning, Organic Carbon, and Sulfur Cycle emissions.

`PI_ancil_aerosol_BC`

1. Description & Purpose: Interpolates CMIP7 1850 anthropogenic surface Black Carbon emissions to the N96 grid, assigns STASH item 57, and saves BC_1850_cmip7.anc.

2. CLI Arguments:

python -m esm1p6_ancil.aerosol.cmip7_PI_BC_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 "${CMIP7_PI_AEROSOL_ANTHRO_DATE_RANGE}" \
    # Current: "185001-189912"
    --save-filename "${ESM_PI_AEROSOL_SAVE_FILENAME['BC']}"
    # Current: "BC_1850_cmip7.anc"

3. Input4MIPs Metadata: Version ${CMIP7_AEROSOL_ANTHRO_VERSION} (CEDS-CMIP-2025-04-18), date tag ${CMIP7_AEROSOL_ANTHRO_VDATE} (v20250421), range ${CMIP7_PI_AEROSOL_ANTHRO_DATE_RANGE} (185001-189912).
4. Input4MIPs Path: ${VAR.CMIP7_SOURCE_PATH}/CMIP/CEDS/${CMIP7_AEROSOL_ANTHRO_VERSION}/atmos/mon/BC_em_anthro/gn/${CMIP7_AEROSOL_ANTHRO_VDATE}/
(Evaluated: /g/data/qv56/replicas/input4MIPs/CMIP7/CMIP/CEDS/CEDS-CMIP-2025-04-18/atmos/mon/BC_em_anthro/gn/v20250421/)
5. Scripts & Functions: esm1p6_ancil.aerosol.cmip7_PI_BC_interpolate, load_cmip7_pi_aerosol_anthro, cmip7_aerosol_anthro_interpolate, esm_grid_mask_cube, zero_poles, save_ancil.
6. Cube Transformations: Loads 4D (time, sector, lat, lon) cube via load_cmip7_aerosol, collapses sectors (collapsed(["sector"], SUM)), regrids with AreaWeighted(mdtol=0.5), zero poles, assigns STASH m01s00i057.
7. Produced Coverage: 12 monthly slices for year 1850, STASH m01s00i057. Filename: ${ESM_PI_AEROSOL_SAVE_FILENAME['BC']} (BC_1850_cmip7.anc).
8. Output Path: ${VAR.ANCIL_TARGET_PATH}/modern/pre-industrial/atmosphere/aerosol/${ESM_GRID_DIRNAME}/<DATE>/${ESM_PI_AEROSOL_SAVE_FILENAME['BC']}.
9. Namelist Updates: None (Generates binary ancillary .anc file).

`PI_ancil_aerosol_Bio`

Outputs: Bio_1850_cmip7.anc (STASH m01s00i086).
Source Dataset: DRES-CMIP-BB4CMIP7-2-0, v20250227, range 175001-189912.
Script: esm1p6_ancil.aerosol.cmip7_PI_Bio_interpolate.

`PI_ancil_aerosol_OC`

Outputs: OCFF_1850_cmip7.anc (STASH m01s00i059).
Source Dataset: CEDS-CMIP-2025-04-18, v20250421, range 185001-189912.
Script: esm1p6_ancil.aerosol.cmip7_PI_OC_interpolate.

`PI_ancil_aerosol_SO2`

Outputs: scycl_1850_cmip7.anc (contains items 58, 126, and background DMS).
Source Dataset: CEDS-CMIP-2025-04-18 + baseline DMS ancillary dms_1850.anc.
Script: esm1p6_ancil.aerosol.cmip7_PI_SO2_interpolate.
Cube Pipeline: Splits SO2 into high stack and low surface components, regrids both, fixes 360-day calendar bounds on DMS via fix_esm15_pi_ancil_date, and combines 3 cubes into the output file.

2. Historical Experiment (HI)

The historical aerosol suite produces continuous transient monthly ancillary files spanning 1849 to 2023 (including model padding years).

Task Name	Script Entrypoint	Primary Input Dataset	Output Ancillary Filename	STASH Code
`HI_ancil_aerosol_BC`	`aerosol.cmip7_HI_BC_interpolate`	`CEDS-CMIP-2025-04-18`	`BC_1849_2023_cmip7.anc`	57
`HI_ancil_aerosol_Bio`	`aerosol.cmip7_HI_Bio_interpolate`	`DRES-CMIP-BB4CMIP7-2-0`	`Bio_1849_2023_cmip7.anc`	86
`HI_ancil_aerosol_OC`	`aerosol.cmip7_HI_OC_interpolate`	`CEDS-CMIP-2025-04-18`	`OCFF_1849_2023_cmip7.anc`	59
`HI_ancil_aerosol_SO2`	`aerosol.cmip7_HI_SO2_interpolate`	`CEDS-CMIP` + ESM1.5 DMS	`scycl_1849_2023_cmip7.anc`	58, 126, DMS

`HI_ancil_aerosol_SO2` Specification Details

1. Description & Purpose: Generates historical sulfur cycle emissions (1849–2023). Ingests chunked historical files (180001-184912 through 200001-202312), decomposes into low-level and high-level emissions, tiles climatological DMS across 175 years, and writes ${ESM_HI_AEROSOL_SAVE_FILENAME['SO2']} (scycl_1849_2023_cmip7.anc).

2. CLI Arguments:

python -m esm1p6_ancil.aerosol.cmip7_HI_SO2_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 "${CMIP7_HI_AEROSOL_ANTHRO_DATE_RANGE_LIST}" \
    # Current: "['180001-184912','185001-189912','190001-194912','195001-199912','200001-202312']"
    --esm15-aerosol-version "${ESM15_AEROSOL_VERSION['HI']}" \
    # Current: "2021.06.22"
    --save-filename "${ESM_HI_AEROSOL_SAVE_FILENAME['SO2']}"
    # Current: "scycl_1849_2023_cmip7.anc"

6. Cube Transformations:
- Uses netCDF4.Dataset to extract sector indices for Energy and Industrial.
- Computes high-level emissions: cmip7_so2[:, Energy] + 0.5 * cmip7_so2[:, Industrial].
- Computes low-level emissions: cmip7_so2.collapsed(["sector"], SUM) - cmip7_so2_high.
- Scales by 0.5 to convert molecular SO2 to mass of elemental Sulfur ($S$).
- Regrids via AreaWeighted(mdtol=0.5) to N96 grid, fills missing values with 0.0, and zeroes poles.
- Climatological DMS is read from dms_1850.anc, date-converted from 360-day to Gregorian calendar via fix_esm15_pi_ancil_date, tiled across 175 years using tile_yearly_data, and packaged into a matching 3D Cube.
7. Produced Coverage: 1849–2023 (2100 monthly slices). STASH items 58, 126, and DMS. Output file: ${ESM_HI_AEROSOL_SAVE_FILENAME['SO2']} (scycl_1849_2023_cmip7.anc).
8. Destination Path: ${VAR.ANCIL_TARGET_PATH}/modern/historical/atmosphere/aerosol/${ESM_GRID_DIRNAME}/<DATE>/${ESM_HI_AEROSOL_SAVE_FILENAME['SO2']}.

3. ScenarioMIP Experiment (SM)

The ScenarioMIP aerosol suite manufactures future projection ancillaries across scenarios h, hl, m, and vl. When extension is active (EXTEND_SM_AEROSOL[SCEN] == True, passing --ext), datasets concatenate extension files to span the full timeline to 2150.

`SM_{h,hl,m,vl}_ancil_aerosol_SO2`

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

1. Description & Purpose: Generates sulfur cycle emissions ancillaries for ScenarioMIP scenario h. Combines anthropogenic surface emissions, aircraft emissions, and biomass burning emissions from CMIP7 with background dimethyl sulfide (DMS) emissions from CMIP6/ESM1.5 inputs. Interpolates monthly fields, handles extension to 2150 with constant padding if EXTEND_SM_AEROSOL['h'] is active (--ext), zeroes the poles, assigns STASH code 89, and saves the .anc file.

2. CLI Arguments:

python -m esm1p6_ancil.aerosol.cmip7_SM_SO2_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"
    --esm15-aerosol-version "${ESM15_AEROSOL_VERSION['PI']}" \
    # Current: "2020.05.19"
    --ext \
    --dataset-ext-version "${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"
    --save-filename "${ESM_SM_EXT_AEROSOL_SAVE_FILENAME[SCEN]['SO2']}"
    # Current: "scycl_h_2022_2150_cmip7.anc"

3. Input4MIPs Versions & Temporal Metadata:
- Surface Anthro: ${CMIP7_SM_AEROSOL_VERSION['h']} (IIASA-IAMC-h-1-1-1), ${CMIP7_SM_AEROSOL_VDATE['h']} (v20260409), ${CMIP7_SM_AEROSOL_DATE_RANGE} (202201-210012)
- Aircraft Anthro: ${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)
- Extension Anthro: ${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)
- Baseline DMS: ${ESM15_AEROSOL_VERSION['PI']} (2020.05.19, dms_1850.anc)
4. Input4MIPs Directory Path & Filenames:
- Surface: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_AEROSOL_VERSION['h']}/atmos/mon/SO2_em_anthro/gn/${CMIP7_SM_AEROSOL_VDATE['h']}/SO2-em-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_AEROSOL_VERSION['h']}_gn_${CMIP7_SM_AEROSOL_DATE_RANGE}.nc
- Aircraft: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_AEROSOL_AIR_VERSION['h']}/atmos/mon/SO2_em_AIR_anthro/gn/${CMIP7_SM_AEROSOL_AIR_VDATE['h']}/SO2-em-AIR-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_AEROSOL_AIR_VERSION['h']}_gn_${CMIP7_SM_AEROSOL_DATE_RANGE}.nc
- Extension: ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/IIASA-IAMC/${CMIP7_SM_EXT_AEROSOL_VERSION['h']}/atmos/mon/SO2_em_anthro/gn/${CMIP7_SM_EXT_AEROSOL_VDATE['h']}/SO2-em-anthro_input4MIPs_emissions_ScenarioMIP_${CMIP7_SM_EXT_AEROSOL_VERSION['h']}_gn_${CMIP7_SM_EXT_AEROSOL_DATE_RANGE}.nc
5. Scripts & Functions: esm1p6_ancil.aerosol.cmip7_SM_SO2_interpolate, load_cmip7_sm_so2_aerosol_anthro, load_cmip7_sm_aerosol_anthro, load_sm_dms, load_dms, save_cmip7_so2_aerosol_anthro, tile_yearly_data, zero_poles, esm_grid_mask_cube, save_ancil.
6. Cube Transformations:
- Base cube (2022–2100) constrained by cmip7_date_constraint_from_years(2022, 2100).
- Extension cube (2101–2150) constrained by cmip7_date_constraint_from_years(2101, 2150).
- Concatenated via CubeList.concatenate_cube() after attribute equalization.
- High and low components separated via sector indices, scaled by 0.5, regridded to N96, and zeroed at poles.
- DMS cube constructed by tiling 12-month climatology across 129 years.
7. Produced File: ${ESM_SM_EXT_AEROSOL_SAVE_FILENAME['h']['SO2']} (scycl_h_2022_2150_cmip7.anc, 1548 monthly slices, 2022–2150).
8. Destination Path: ${VAR.ANCIL_TARGET_PATH}/modern/scen7-h/atmosphere/aerosol/${ESM_GRID_DIRNAME}/<DATE>/${ESM_SM_EXT_AEROSOL_SAVE_FILENAME['h']['SO2']}.
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: BC_hl_2022_2150_cmip7.anc, Bio_hl_2022_2150_cmip7.anc, OCFF_hl_2022_2150_cmip7.anc, scycl_hl_2022_2150_cmip7.anc.

Dataset Versions: Base IIASA-IAMC-m-1-1-1 (v20260327), Extension IIASA-IAMC-m-ext-1-1-1 (v20260327).
Produces: BC_m_2022_2150_cmip7.anc, Bio_m_2022_2150_cmip7.anc, OCFF_m_2022_2150_cmip7.anc, scycl_m_2022_2150_cmip7.anc.

Dataset Versions: Base IIASA-IAMC-vl-1-1-1 (v20260409), Extension IIASA-IAMC-vl-ext-1-1-1 (v20260409).
Produces: BC_vl_2022_2150_cmip7.anc, Bio_vl_2022_2150_cmip7.anc, OCFF_vl_2022_2150_cmip7.anc, scycl_vl_2022_2150_cmip7.anc.

Aerosol Forcing Specifications

Physical Domain & Scientific Scope

Controlling Suite Switches

1. Pre-Industrial Experiment (PI)

PI_ancil_aerosol_BC

PI_ancil_aerosol_Bio

PI_ancil_aerosol_OC

PI_ancil_aerosol_SO2

2. Historical Experiment (HI)

HI_ancil_aerosol_SO2 Specification Details

3. ScenarioMIP Experiment (SM)

SM_{h,hl,m,vl}_ancil_aerosol_SO2

`PI_ancil_aerosol_BC`

`PI_ancil_aerosol_Bio`

`PI_ancil_aerosol_OC`

`PI_ancil_aerosol_SO2`

`HI_ancil_aerosol_SO2` Specification Details

`SM_{h,hl,m,vl}_ancil_aerosol_SO2`