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Nitrogen Deposition Forcing Specifications

The Nitrogen deposition pipeline aggregates 4 atmospheric reactive nitrogen deposition flux species from CMIP7, converts units to \(\text{g}\,\text{m}^{-2}\,\text{day}^{-1}\), regrids conservatively to the global.N96 grid, and outputs binary Unified Model ancillary files (.anc) for the CABLE / CASA-CNP terrestrial biogeochemistry scheme in ACCESS-ESM1.6.

Physical Domain & Scientific Scope

  • Species Aggregated (4 fluxes):
  • Dry deposition of reduced nitrogen (drynhx, \(\text{NH}_x\))
  • Dry deposition of oxidized nitrogen (drynoy, \(\text{NO}_y\))
  • Wet deposition of reduced nitrogen (wetnhx, \(\text{NH}_x\))
  • Wet deposition of oxidized nitrogen (wetnoy, \(\text{NO}_y\))
  • Total Deposition Calculation: $\(\text{Flux}_{\text{total}} = \text{drynhx} + \text{drynoy} + \text{wetnhx} + \text{wetnoy}\)$
  • Unit Conversion: Converted from standard CMIP7 flux units (\(\text{kg}\,\text{m}^{-2}\,\text{s}^{-1}\)) to Unified Model land biogeochemistry units (\(\text{g}\,\text{m}^{-2}\,\text{day}^{-1}\)) via: $\(\text{Flux} \left[\text{g}\,\text{m}^{-2}\,\text{day}^{-1}\right] = \text{Flux} \left[\text{kg}\,\text{m}^{-2}\,\text{s}^{-1}\right] \times 1000.0 \times 86400.0\)$
  • Target STASH Item: m01s00i884 (NITROGEN DEPOSITION).
  • Grid & Interpolation: Conservative area-weighted regridding (AreaWeighted(mdtol=0.5)) using esm_grid_mask_cube(args), with missing data filled to 0.0.

Controlling Suite Switches

The execution, experiment inclusion, and temporal extension for reactive nitrogen deposition are controlled by parameters in rose-suite.conf:

  • Master Activation Switch: ANCIL_CREATE_NITROGEN = true
    When set to false, all nitrogen deposition processing tasks 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_NITROGEN):
    Controls whether future projection pathways pass --ext to extend coverage through 2150:
    • 'h': True (Extended to 2150, producing ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['h']})
    • 'hl': True (Extended to 2150, producing ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['hl']})
    • 'm': True (Extended to 2150, producing ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['m']})
    • 'vl': True (Extended to 2150, producing ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['vl']})
  • Reference: See Suite Configuration & Parameters Reference for full object declarations.

1. Pre-Industrial Experiment (PI)

PI_ancil_nitrogen

  • 1. Description & Purpose:
    Generates cyclic 1850 monthly reactive nitrogen deposition ancillaries for the pre-industrial control run (${ESM_PI_NITROGEN_SAVE_FILENAME} / Ndep_1850_cmip7.anc).
  • 2. CLI Arguments Passed:
    python -m esm1p6_ancil.nitrogen.cmip7_PI_nitrogen_generate \
    --ancil-target-dirname "${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_NITROGEN_VERSION}" \
    # Current: "FZJ-CMIP-nitrogen-1-2"
    --dataset-vdate "${CMIP7_NITROGEN_VDATE}" \
    # Current: "v20251025"
    --dataset-date-range "${CMIP7_PI_NITROGEN_DATE_RANGE}" \
    # Current: "185001-185012"
    --save-filename "${ESM_PI_NITROGEN_SAVE_FILENAME}"
    # Current: "Ndep_1850_cmip7.anc"
  • 3. Input4MIPs Versions & Temporal Metadata:
    • Dataset Version: ${CMIP7_NITROGEN_VERSION} (FZJ-CMIP-nitrogen-1-2)
    • Version Date (vdate): ${CMIP7_NITROGEN_VDATE} (v20251025)
    • Input Date Range: ${CMIP7_PI_NITROGEN_DATE_RANGE} (185001-185012, 12 monthly slices)
  • 4. Input4MIPs Directory Path & Filenames:
    • Directory Path: ${VAR.CMIP7_SOURCE_PATH}/CMIP/FZJ/${CMIP7_NITROGEN_VERSION}/atmos/mon/{species}/gn/${CMIP7_NITROGEN_VDATE}/
      (Evaluated: /g/data/qv56/replicas/input4MIPs/CMIP7/CMIP/FZJ/FZJ-CMIP-nitrogen-1-2/atmos/mon/{species}/gn/v20251025/)
    • Filenames (4 species): {species}_input4MIPs_surfaceFluxes_CMIP_${CMIP7_NITROGEN_VERSION}_gn_${CMIP7_PI_NITROGEN_DATE_RANGE}.nc
  • 5. Python Scripts & Functions:
    • Main Script / Entrypoint: esm1p6_ancil.nitrogen.cmip7_PI_nitrogen_generate
    • Key Functions Called: load_cmip7_nitrogen, regrid_cmip7_nitrogen, save_cmip7_nitrogen, fix_coords, esm_grid_mask_cube, save_ancil
    • Shared Libraries: iris, mule, ants, numpy
  • 6. Function-Level Cube Transformations & Constraints:
    • Input Cubes & Coordinates: Four 3D NetCDF cubes loaded into an iris.cube.CubeList representing drynhx, drynoy, wetnhx, and wetnoy on monthly time points.
    • Constraints Applied: Name constraints corresponding to standard CF names for nitrogen fluxes; attributes equalized via equalise_attributes(nitrogen_cubes).
    • Coordinate Bounds & Manipulation:
      • Cubes summed elementwise into a total flux cube.
      • Units converted from kg m-2 s-1 to g m-2 day-1 via cube_tot.convert_units("g m-2 day-1").
      • Coordinates standardized via fix_coords(args, cube).
      • Regridded to global.N96 using AreaWeighted(mdtol=0.5) against esm_grid_mask_cube(args).
      • Missing values masked and zeroed (data.filled(0.0)).
      • STASH attribute assigned: m01s00i884.
    • Created / Output Cubes: Formats final 3D cube (time: 12, lat: 144, lon: 192) passed to save_ancil.
  • 7. Produced File Versions & Date Ranges:
    • Temporal Coverage: 185001-185012 (12 monthly slices)
    • Calendar: 365-day (NoLeap) calendar alignment
    • STASH Code: m01s00i884
  • 8. Produced File Directory Paths & Filenames:
    • Output Directory: ${VAR.ANCIL_TARGET_PATH}/modern/pre-industrial/atmosphere/nitrogen/${ESM_GRID_DIRNAME}/<ANCIL_TODAY>/
    • Output Filename: ${ESM_PI_NITROGEN_SAVE_FILENAME} (Ndep_1850_cmip7.anc)
  • 9. Namelist File & Variable Updates:
    None (Generates binary ancillary .anc file).

2. Historical Experiment (HI)

HI_ancil_nitrogen

  • 1. Description & Purpose:
    Ingests monthly transient nitrogen deposition fluxes from 1850 to 2022, pads timeline to span 1849–2023 for model spin-up/spin-down boundary compliance, regrids to N96, and produces ${ESM_HI_NITROGEN_SAVE_FILENAME} (Ndep_1849_2023_cmip7.anc).
  • 2. CLI Arguments Passed:
    python -m esm1p6_ancil.nitrogen.cmip7_HI_nitrogen_generate \
    --ancil-target-dirname "${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_NITROGEN_VERSION}" \
    # Current: "FZJ-CMIP-nitrogen-1-2"
    --dataset-vdate "${CMIP7_NITROGEN_VDATE}" \
    # Current: "v20251025"
    --dataset-date-range "${CMIP7_HI_NITROGEN_DATE_RANGE}" \
    # Current: "185001-202212"
    --save-filename "${ESM_HI_NITROGEN_SAVE_FILENAME}"
    # Current: "Ndep_1849_2023_cmip7.anc"
  • 3. Input4MIPs Versions & Temporal Metadata:
    • Dataset Version: ${CMIP7_NITROGEN_VERSION} (FZJ-CMIP-nitrogen-1-2), ${CMIP7_NITROGEN_VDATE} (v20251025), Range: ${CMIP7_HI_NITROGEN_DATE_RANGE} (185001-202212).
    • Processed Model Timeline: 184901-202312 (175 years, 2100 monthly slices).
  • 4. Input4MIPs Directory Path & Filenames:
    • Path: ${VAR.CMIP7_SOURCE_PATH}/CMIP/FZJ/${CMIP7_NITROGEN_VERSION}/atmos/mon/{species}/gn/${CMIP7_NITROGEN_VDATE}/
      (Evaluated: /g/data/qv56/replicas/input4MIPs/CMIP7/CMIP/FZJ/FZJ-CMIP-nitrogen-1-2/atmos/mon/{species}/gn/v20251025/)
    • Filenames: {species}_input4MIPs_surfaceFluxes_CMIP_${CMIP7_NITROGEN_VERSION}_gn_${CMIP7_HI_NITROGEN_DATE_RANGE}.nc
  • 5. Python Scripts & Functions: esm1p6_ancil.nitrogen.cmip7_HI_nitrogen_generate, load_cmip7_nitrogen, regrid_cmip7_nitrogen, extend_years, save_cmip7_nitrogen.
  • 6. Cube Transformations:
    • Aggregates 4 species, converts units to g m-2 day-1.
    • Prepends 1849 (repeating 1850) and appends 2023 (repeating 2022) via extend_years to satisfy UM padding requirements.
    • Regrids to N96 (AreaWeighted(mdtol=0.5)) and sets STASH m01s00i884.
  • 7. Produced File: ${ESM_HI_NITROGEN_SAVE_FILENAME} (Ndep_1849_2023_cmip7.anc, 2100 monthly slices, 1849–2023).
  • 8. Destination Path: ${VAR.ANCIL_TARGET_PATH}/modern/historical/atmosphere/nitrogen/${ESM_GRID_DIRNAME}/<DATE>/${ESM_HI_NITROGEN_SAVE_FILENAME}.
  • 9. Namelist Updates: None (Generates binary ancillary .anc file).

3. ScenarioMIP Experiment (SM)

SM_{h,hl,m,vl}_ancil_nitrogen

  • 1. Description & Purpose: Generates future projection nitrogen deposition ancillaries for scenario h. When EXTEND_SM_NITROGEN['h'] is active (--ext), extends 2022–2100 data to 2150 by tiling the final year (2100) or applying pathway extensions, saving ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['h']} (Ndep_h_2022_2150_cmip7.anc).
  • 2. CLI Arguments Passed: 
    python -m esm1p6_ancil.nitrogen.cmip7_SM_nitrogen_generate \
    --scenario "${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 "${CMIP7_SM_NITROGEN_VERSION[SCEN]}" \
    # Current: "FZJ-CMIP-nitrogen-h-1-0"
    --dataset-vdate "${CMIP7_SM_NITROGEN_VDATE[SCEN]}" \
    # Current: "v20260409"
    --dataset-date-range "${CMIP7_SM_NITROGEN_DATE_RANGE}" \
    # Current: "202201-210012"
    --ext \
    --save-filename "${ESM_SM_EXT_NITROGEN_SAVE_FILENAME[SCEN]}"
    # Current: "Ndep_h_2022_2150_cmip7.anc"
  • 3. Input4MIPs Versions & Temporal Metadata:
    • Version: ${CMIP7_SM_NITROGEN_VERSION['h']} (FZJ-CMIP-nitrogen-h-1-0), ${CMIP7_SM_NITROGEN_VDATE['h']} (v20260409), Range: ${CMIP7_SM_NITROGEN_DATE_RANGE} (202201-210012).
    • Target Coverage: 2022-2150 (1548 monthly slices).
  • 4. Input4MIPs Directory Path & Filenames:
    • ${VAR.CMIP7_SOURCE_PATH}/ScenarioMIP/FZJ/${CMIP7_SM_NITROGEN_VERSION['h']}/atmos/mon/{species}/gn/${CMIP7_SM_NITROGEN_VDATE['h']}/{species}_input4MIPs_surfaceFluxes_ScenarioMIP_${CMIP7_SM_NITROGEN_VERSION['h']}_gn_${CMIP7_SM_NITROGEN_DATE_RANGE}.nc
  • 5. Scripts & Functions: esm1p6_ancil.nitrogen.cmip7_SM_nitrogen_generate, load_cmip7_sm_nitrogen, regrid_cmip7_nitrogen, extend_years, save_cmip7_nitrogen.
  • 6. Cube Transformations: Aggregates 4 nitrogen species, converts units, extends time axis to 2150 via extend_years, regrids conservatively to N96, and attaches STASH item 884.
  • 7. Produced File: ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['h']} (Ndep_h_2022_2150_cmip7.anc, 1548 monthly slices, 2022–2150).
  • 8. Destination Path: ${VAR.ANCIL_TARGET_PATH}/modern/scen7-h/atmosphere/nitrogen/${ESM_GRID_DIRNAME}/<DATE>/${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['h']}.
  • 9. Namelist Updates: None (Generates binary ancillary .anc file).
  • Dataset: ${CMIP7_SM_NITROGEN_VERSION['hl']} (FZJ-CMIP-nitrogen-hl-1-0), ${CMIP7_SM_NITROGEN_VDATE['hl']} (v20260706), ${CMIP7_SM_NITROGEN_DATE_RANGE} (202201-210012).
  • Produces: ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['hl']} (Ndep_hl_2022_2150_cmip7.anc, STASH 884, extended via EXTEND_SM_NITROGEN['hl'] == True).
  • Dataset: ${CMIP7_SM_NITROGEN_VERSION['m']} (FZJ-CMIP-nitrogen-m-1-0), ${CMIP7_SM_NITROGEN_VDATE['m']} (v20260706), ${CMIP7_SM_NITROGEN_DATE_RANGE} (202201-210012).
  • Produces: ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['m']} (Ndep_m_2022_2150_cmip7.anc, STASH 884, extended via EXTEND_SM_NITROGEN['m'] == True).
  • Dataset: ${CMIP7_SM_NITROGEN_VERSION['vl']} (FZJ-CMIP-nitrogen-vl-1-0), ${CMIP7_SM_NITROGEN_VDATE['vl']} (v20260409), ${CMIP7_SM_NITROGEN_DATE_RANGE} (202201-210012).
  • Produces: ${ESM_SM_EXT_NITROGEN_SAVE_FILENAME['vl']} (Ndep_vl_2022_2150_cmip7.anc, STASH 884, extended via EXTEND_SM_NITROGEN['vl'] == True).