7. Input Datasets

Input datasets are required to run the model and differ depending on the configuration used. Here we described data sets that are required for some or all of the CESM2 configurations.

All atmospheric configuration require to include emissions, lower boundary condition dataset, soil erodibility files for dust emissions, topography files, and solar input files. In addition, meteorological data are required to run the model in specified dynamics mode. Furthermore, CAM and WACCM SC (specified chemistry), and simulations with prescribed stratospheric aerosols require prescribed input dataset that are derived from full chemistry simulations. Additional dataset include sea-surface temperatures, and prescribed land data.

7.1. Emissions

All CAM, CAM-chem and WACCM configurations require surface emissions and, in most cases, external forcings (vertically distributed emissions). In the standard compsets all biomass burning emissions are at the surface. Anthropogenic emissions are mostly released at the surface, but some sectors of sulfate emissions are injected vertically. Aircraft and volcanic emissions are distributed with altitude. The standard emission files are provided separately for each sector: anthropogenic (anthro), biomass burning (bb), biogenic (bg), volcanic source and others (soil, ocean etc.), for convenience and clarity. CESM will read multiple emissions files for each compound (specified in the namelist) and sum them in the model. There are no restrictions on the filenames or the variable names within the files.

7.1.1. List of available emissions datasets

The default emissions for CESM2 are based on the CMIP6 inventories for anthropogenic and biomass burning emissions, provided by the Community Emissions Data System (CEDS, http://www.globalchange.umd.edu/ceds/ceds-cmip6-data/), original files are available at: https://esgf-node.llnl.gov/search/input4mips/. Additional emissions (soil, ocean) are from the POET inventory (http://eccad.aeris-data.fr/). Continuous volcanic out‐gassing emissions of SO2, with 2.5% emitted as sulfate aerosols, are from the GEIA inventory (Andres & Kasgnoc, https://doi.org/10.1029/98JD02091, 1998). SO2 from eruptive volcanoes is specified as well, based on the database of Volcanic Emissions for Earth System Models, version 3.11 (VolcanEESM; Neely & Schmidt, https://doi.org/10.5285/76ebdc0b-0eed-4f70-b89e-55e606bcd568, 2016). It is straightforward to use different emissions inventories in CAM, CAM-chem or WACCM simulations by specifying different files (in the proper format) in the namelist. A list of emissions inventories that have been used in CESM2 are at: https://wiki.ucar.edu/display/camchem/Emission+Inventories.

7.1.2. List of species with emissions (CAM)

Surface (anthro, bb): bc_a4 , pom_a4 , num_a4 (for bc_a4 and pom_a4), SO2

Surface (anthro, bb, biogenic): SOAG

Vertical (extfrc): SO2 (aircraft, contvolcano), so4_a1 (anthro-ene, contvolcano), so4_a2 (contvolcano), bc_a4 (aircraft), num_a1, num_a2, num_a4

7.1.3. List of species with dry and wet deposition (CAM)

Dry and wet deposition:

Aerosols: bc_a1, bc_a4, dst_a1, dst_a2, dst_a3, ncl_a1, ncl_a2, ncl_a3, num_a1, num_a2, num_a3, num_a4, pom_a1, pom_a4, so4_a1, so4_a2, so4_a3, soa_a1, soa_a2

Gas-phase: H2O2, H2SO4, SO2

7.1.4. List of species with emissions (CAMchem/WACCM)

Surface (anthro, bb, other): NO, NH3, CO, C2H4, C2H6, C3H6, C3H8

Surface (anthro, bb): bc_a4, pom_a4, num_a4, SO2, C2H2, BIGALK, BIGENE, BENZENE, TOLUENE, XYLENES, CH3OH, C2H5OH, CH2O, CH3CHO, CH3COCH3, MEK, HCOOH, CH3COOH, HCN, CH3CN, IVOC, SVOC

Vertical: NO2 (aircraft), SO2 (aircraft, contvolcano, erupting volcanoes), so4_a1 (anthro-ene, contvolcano), so4_a2 (contvolcano), bc_a4 (aircraft), num_a1, num_a2, num_a4

7.1.5. List of species with dry and wet deposition (CAMChem/WACCM)

Species with dry deposition:

Aerosols: bc_a1, bc_a4, dst_a1, dst_a2, dst_a3, ncl_a1, ncl_a2, ncl_a3, num_a1, num_a2, num_a3, num_a4, pom_a1, pom_a4, so4_a1, so4_a2, so4_a3, soa1_a1, soa1_a2, soa2_a1, soa2_a2, soa3_a1, soa3_a2, soa4_a1, soa4_a2, soa5_a1, soa5_a2

Gas-phase: ALKNIT, ALKOOH, BENZOOH, BZOOH, C2H5OH, C2H5OOH, C3H7OOH, C6H5OOH, CH2O, CH3CHO, CH3CN, CH3COCH3, CH3COCHO, CH3COOH, CH3COOOH, CH3OH, CH3OOH, CO, EOOH, GLYALD, H2O2, H2SO4, HCN, HCOOH, HNO3, HO2NO2, HONITR, HPALD, HYAC, HYDRALD, IEPOX, ISOPNITA, ISOPNITB, ISOPNO3, ISOPNOOH, ISOPOOH, IVOC, MACROOH, MEKOOH, MPAN, NC4CH2OH, NC4CHO, NH3, NH4, NO, NO2, NOA, NTERPOOH, O3, ONITR, PAN, PHENOOH, POOH, ROOH, SO2, SOAG0, SOAG1, SOAG2, SOAG3, SOAG4, SVOC, TERP2OOH, TERPNIT, TERPOOH, TERPROD1, TERPROD2, TOLOOH, XOOH, XYLENOOH, XYLOLOOH

Species with wet deposition:

Aerosols: bc_a1, bc_a4, dst_a1, dst_a2, dst_a3, ncl_a1, ncl_a2, ncl_a3,
num_a1, num_a2, num_a3, num_a4, pom_a1, pom_a4, so4_a1, so4_a2, so4_a3, soa1_a1, soa1_a2, soa2_a1, soa2_a2, soa3_a1, soa3_a2, soa4_a1, soa4_a2, soa5_a1, soa5_a2

Gas-phase: ALKNIT, ALKOOH, BENZOOH, BRONO2, BZOOH, C2H5OH, C2H5OOH, C3H7OOH, C6H5OOH, CH2O, CH3CHO, CH3CN, CH3COCH3, CH3COCHO, CH3COOH, CH3COOOH, CH3OH, CH3OOH, CLONO2, COF2, COFCL, EOOH, GLYALD, H2O2, H2SO4, HBR, HCL, HCN, HCOOH, HF, HNO3, HO2NO2, HOBR, HOCL, HONITR, HPALD, HYAC, HYDRALD, IEPOX, ISOPNITA, ISOPNITB, ISOPNO3, ISOPNOOH, ISOPOOH, IVOC, MACR, MACROOH, MEKOOH, MVK, NC4CH2OH, NC4CHO, NDEP, NH3, NH4, NHDEP, NOA, NTERPOOH, ONITR, PHENOOH, POOH, ROOH, SO2, SOAG0, SOAG1, SOAG2, SOAG3, SOAG4, SVOC, TERP2OOH, TERPNIT, TERPOOH, TERPROD1, TERPROD2, TOLOOH, XOOH, XYLENOOH, XYLOLOOH

7.1.6. List of species with biogenic emissions (CAMChem/WACCM)

Species with MEGAN emissions (CAM-chem (TS1) and WACCM (TSMLT)) are listed in drv_flds_in, and can be modified in user_nl_cam. Note, modifications may be required for other mechanisms), see Running with interactiv / prescribed biogenic emissions

 megan_specifier = 'ISOP = isoprene',
     'MTERP = pinene_a + carene_3 + thujene_a + 2met_styrene + cymene_p + cymene_o + terpinolene + bornene + fenchene_a +
ocimene_al + pinene_b + sabinene + camphene + limonene + phellandrene_a + terpinene_g + terpinene_a + phellandrene_b +
myrcene + ocimene_t_b + ocimene_c_b',
     'BCARY = caryophyllene_b + bergamotene_a + bisabolene_b + farnescene_b + humulene_a',
     'CH3OH = methanol',
     'C2H5OH = ethanol',
     'CH2O = formaldehyde',
     'CH3CHO = acetaldehyde',
     'CH3COOH = acetic_acid',
     'CH3COCH3 = acetone',
     'HCOOH = formic_acid',
     'HCN = hydrogen_cyanide',
     'CO = carbon_monoxide',
     'C2H6 = ethane',
     'C2H4 = ethene',
     'C3H8 = propane',
     'C3H6 = propene',
     'BIGALK = pentane + hexane + heptane + tricyclene',
     'BIGENE = butene',
     'TOLUENE = toluene'

7.1.7. WACCM-X emissions

WACCM-X uses emissions relevant to middle atmosphere (MA) chemistry, consistent with those provided for the REF-C1 experiment of the IGAC/SPARC Chemistry-Climate Model Initiative (CCMI) Community Simulations.

7.2. Lower boundary data sets

In CESM2 a number of very long-lived chemical species have their mixing ratios specified at the surface (e.g., CO2, CH4, CFCs). The standard lower boundary condition file is provided for 1750 to 2015, and is suitable for various horizontal resolutions. This file works for all CESM2 atmospheric configurations. flbc_file = ‘/glade/p/cesmdata/cseg/inputdata/atm/waccm/lb/LBC_17500116-20150116_CMIP6_0p5degLat_c180227.nc’ Additional files are available for the SSP scenarios.

7.3. Soil erodibility files

Soil erodibility maps provide a proxy for the relative ability of the soils in different regions to generate dust. The maps are input as a netcdf file, with no time dependence, and are a unitles factor for each grid box, and are interpolated to the resolution of the model within the model. They are input in the CAM, although the rest of the dust generation itself is included in CLMl. The idea of the soil erodibility map comes from Ginoux et al., 2001, and the specific maps used is the geomorphic map from Zender et al., 2003a and are used in combination with the Dust Entrainment and Deposition scheme from Zender et la., 2003b, as described in Mahowald et al., 2006. The regional distribution of these values are tuned to generate a good distribution as described in Albani et al., 2014.

The file used: soil_erod_file = ‘/glade/p/cesmdata/cseg/inputdata/atm/cam/dst/dst_source2x2tunedcam6-2x2-04062017.nc’

7.4. Topography files

Topography files are generated with the NCAR Global Model Topography Generation Software for Unstructured Grids:

https://github.com/NCAR/Topo/tree/TopoCESM2

7.5. Meteorological data sets

For specified dynamics model simulations, meteorolocial analysis from the Goddard Earth Observing System Model, Version 5 (GEOS5) and the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA2) data have been prepared to run CESM and WRF simulations and are available in 3 resolutions, and are availbe on the Research Data Archive:

GEOS5 2005-present (currently only 1.9x2.5 degree horizontal resolution): https://rda.ucar.edu/datasets/ds313.0/

and

MERRA2 1980-close to present (1.9x2.5, 0.9x1.25, and 0.5x0.63 degrees horizontal resolution): https://rda.ucar.edu/datasets/ds313.3/

These datasets and additional resolutions for GEOS5, MERRA, and MERRA2 can be found on repository, and on HSI.

7.6. Solar input files

7.6.1. Solar irradiance

CESM2 uses solar input files provided by CMIP6: All versions of CESM2 use the solar_irrad_data_file, which provides the reconstructed spectral solar irradiance at 1 AU as the variable ssi, with units of mW m -2 nm -1.

piControl:

solar_irrad_data_file = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6piControl_c160921.nc'

Historical:

solar_irrad_data_file = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6_18491230-22991231_c171031.nc'

7.6.2. WACCM solar inputs

WACCM uses 2 additional solar input files for upper-atmosphere processes:

solar_parms_data_file: geomagnetic parameters, including daily planetary Ap and Kp indices, and F10.7 solar radio flux

epp_all_filepath: Provides epp_ion_rates variable with ion pair production rate from energetic particle precipitation, including solar protons, cosmic rays, and medium energy electrons.

The data for all three solar inputs have been combined into a single file for each time period, so that WACCM points to the same file for each.

piControl:

solar_irrad_data_file = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6piControl_c160921.nc'

solar_parms_data_file = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6piControl_c160921.nc'

epp_all_filepath      = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6piControl_c160921.nc'

Historical

solar_irrad_data_file = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6_18491230-22991231_c171031.nc'

solar_parms_data_file = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6_18491230-22991231_c171031.nc'

epp_all_filepath      = '$DIN_LOC_ROOT/atm/cam/solar/SolarForcingCMIP6_18491230-22991231_c171031.nc'

7.6.3. WACCM-X solar inputs

WACCM-X uses the Naval Research Laboratory (NRL) Version 1 reconstruction for solar irradiance (Lean, ref), rather than CMIP6. Instead of the epp_all_filepath, WACCM-X uses the epp_spe_filepath, which provides ion pair production rates just for solar proton events (neglecting cosmic rays and MEE). For historical simulations, WACCM-X uses a solar_parms_data_file with 3-hour time resolution, spanning the dates April 10, 1947 to July 23, 2016.

Historical

solar_irrad_data_file = '$DIN_LOC_ROOT/atm/cam/solar/spectral_irradiance_Lean_1950-2014_daily_GOME-Mg_Leap_c150623.nc'

epp_spe_filepath      = '$DIN_LOC_ROOT/atm/waccm/solar/spes_1963-2014_c150717.nc'

solar_parms_data_file = '$DIN_LOC_ROOT/atm/waccm/solar/waxsolar_3hr_c170504.nc'

Constant year 2000

solar_irrad_data_file = '$DIN_LOC_ROOT/atm/cam/solar/spectral_irradiance_Lean_1950-2014_daily_GOME-Mg_Leap_c150623.nc'

epp_spe_filepath      = '$DIN_LOC_ROOT/atm/waccm/solar/spes_1963-2014_c150717.nc'

solar_parms_data_file = '$DIN_LOC_ROOT/atm/waccm/phot/wa_avg_c20170519.nc'

7.7. Additional inputs for WACCM and WACCM-X

7.7.1. Geomagnetic coefficients

igrf_geomag_coefs_file = ‘$DIN_LOC_ROOT/atm/waccm/geomag/igrf_ceofs_c160412.nc’

7.7.2. Ion drag

efield_hflux_file = ‘$DIN_LOC_ROOT/atm/waccm/efld/coeff_hflux.dat’

efield_lflux_file = ‘$DIN_LOC_ROOT/atm/waccm/efld/coeff_lflux.dat’

efield_wei96_file = ‘$DIN_LOC_ROOT/atm/waccm/efld/wei96.cofcnts’

7.7.3. Electrons

electron_file = ‘$DIN_LOC_ROOT/inputdata/atm/waccm/phot/electron_121129.dat’

7.7.4. Upper boundary condition

snoe_ubc_file = ‘$DIN_LOC_ROOT/inputdata/atm/waccm/ub/snoe_eof.nc’