KokDustDRE2017data

This repository includes data from four climate and atmospheric chemistry transport models used in Kok et al., (Nature Geoscience, 2017), namely CESM, GISS, GEOS-Chem, and WRF-Chem. These data were used to constrain the global direct radiative effect due to mineral dust aerosols.

Below, we describe the data files and the fields included in them for each of the four models. The data fields in all files are monthly averages over the duration of the model simulation.

CESM

The repository includes 4 data files for the CESM simulation of the global dust cycle (CESM_DustDRE_monthly_bin?.nc), one for monthly averaged values for each of the four dust bins. These files contain the following fields:

• FLNS: The difference in the LW flux at the surface between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. LW radiation is defined as positive upward, and units are W/m². Dimensions: [144, 96, 12].
• FLNT: The difference in the LW flux at the top-of-atmosphere between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. LW radiation is defined as positive upward, and units are W/m². Dimensions: [144, 96, 12].
• FSNS: The difference in the SW flux at the surface between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. SW radiation is defined as positive downward, and units are W/m². Dimensions: [144, 96, 12].
• FSNT: The difference in the SW flux at the top-of-atmosphere between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. SW radiation is defined as positive downward, and units are W/m². Dimensions: [144, 96, 12].
• DST0?: The dust mixing ratio of the given bin in kg of dust per kg of air. Dimensions: [144, 96, 56, 12].
• DST0?SF: The dust emission flux of the given bin at the surface in kg/m²/s. Dimensions: [144, 96, 12].
• ODV_DST0?: The optical depth in the visible due to dust in the given bin. Dimensions: [144, 96, 12].
• Transport bin ranges are [0.1 - 1.0 µm, 1.0 – 2.5 µm, 2.5 – 5.0 µm, 5.0 - 10.0 µm]

GEOS-Chem

The file GEOS-Chem_DustDRE_monthly_allbins.nc in the repository includes the data for the GEOS-Chem simulation of the global dust cycle. This file contains the following fields:

• conc_3d: monthly global concentration (µg/m3) of dust in the 4 transport size bins, averaged over 2004 – 2008. Dimensions: [144, 91, 47, 12, 4]
• dustaod: monthly global dust aerosol optical depth at 550 nm in the 7 radiative size bins, averaged over 2004 – 2008. Dimensions: [144, 91, 12, 7]
• dustems: monthly global dust emissions (kg/gridbox/month) in the 4 transport size bins, averaged over 2004 – 2008. Dimensions: [144, 91, 12, 4]
• lwsrf:  Monthly dust direct radiative effect (W/m2) in LW for each radiative size bin at the surface. Dimensions: [144, 91, 12, 7]
• swsrf:  Monthly dust direct radiative effect (W/m2) in SW for each radiative size bin at the surface. Dimensions: [144, 91, 12, 7]
• lwtoa:  Monthly dust direct radiative effect (W/m2) in LW for each radiative size bin at the top of atmosphere. Dimensions: [144, 91, 12, 7]
• swtoa:  Monthly dust direct radiative effect (W/m2) in SW for each radiative size bin at the top of atmosphere. Dimensions: [144, 91, 12, 7]
• Transport bin ranges “tranbins” = [0.1 - 1.0 µm, 1.0 - 1.8 µm, 1.8 - 3.0 µm, 3.0 - 6.0 µm]
• Radiative bin centers “radbins” = [0.15 µm, 0.25 µm, 0.40 µm, 0.80 µm, 1.50 µm, 2.50 µm, 4.00 µm]
• Latitude (“lat”, n=91), longitude (“lon”, n=144) and altitude (“lev”, n=47) levels are also included in the file.

WRF-Chem

The file WRF-Chem_DustDRE_monthly_allbins.nc in the repository includes the data for the WRF-Chem simulation of the global dust cycle. This file contains the following fields:

• TAUAER3: the AOD at 600 nm for all aerosols for each model vertical layer (lat x lon x level x month).
• TAUAER3_s1 through TAUAER3_s8: TAUAER3_sx contains monthly-averaged AOD at 600 nm for each model vertical layer for all aerosols *except* for dust bin x. so the DAOD due to dust bin x is obtained from TAUAER3-TAUAER3_sx (lat x lon x level x month).
• SWUPT: The shortwave upwelling flux at TOA, downward positive, with all aerosols present (lat x lon x month).
• SWUPT_S1 through SWUPT_S8: SWUPT_Sx is the flux with all aerosols present *except* dust bin x. So the radiative effect due to dust bin x is SWUPT-SWUPT_Sx (lat x lon x month).
• LWUPT: The longwave upwelling flux at TOA, downward positive, with all aerosols present (lat x lon x month).
• LWUPT_S1 through LWUPT_S8: LWUPT_Sx is the flux with all aerosols present *except* dust bin x. So the radiative effect due to dust bin x is LWUPT-LWUPT_Sx (lat x lon x month).
• SWDNT: The shortwave downwelling flux at TOA, downward positive, with all aerosols present (lat x lon x month).
• SWDNT_S1 through SWDNT_S8: SWDNT_Sx is the flux with all aerosols present *except* dust bin x. So the radiative effect due to dust bin x is SWDNT-SWDNT_Sx (lat x lon x month).
• LWDNT: The longwave downwelling flux at TOA, downward positive, with all aerosols present (lat x lon x month).
• LWDNT_S1 through LWDNT_S8: LWDNT_Sx is the flux with all aerosols present *except* dust bin x. So the radiative effect due to dust bin x is LWDNT-LWDNT_Sx (lat x lon x month).
• E_DUST: dust emission flux for all bins combined in ug/m²/s. This total flux is partitioned into the 8 bins as described in the supplement.
• dust_a01 through dust_a08: Monthly-averaged 3D dust concentrations in ug per kg dry air per particle bin (lat x lon x height x month).
• drydep_dust: Monthly-averaged dry deposition flux per particle bin. Bin 1 here corresponds to transport bins 1-4, bin 2 to transport bins 5 and 6, bin 3 to transport bin 7, and bin 4 to bin 8 (lat x lon x month x bin)
• wetdep_dust: Monthly-averaged wet deposition flux per particle bin. Bin 1 here corresponds to transport bins 1-4, bin 2 to transport bins 5 and 6, bin 3 to transport bin 7, and bin 4 to bin 8 (lat x lon x month x bin).
• Transport bin ranges are [0.039 – 0.078 µm, 0.078  - 0.156 µm, 0.156 – 0.312 µm, 0.312 – 0.625 µm, 0.625 – 1.25 µm, 1.25  – 2.5 µm, 2.5 – 5.0 µm, 5.0 – 10 µm]

GISS

The file GISS_DustDRE_monthly_allbins.nc in the repository includes the monthly averaged data for the GISS simulation of the global dust cycle. Data is included for the 4 bins in the clay size range [0.2 – 0.36, 0.36 – 0.6, 0.6 – 1.2, and 1.2 – 2.0 µm diameter] and 4 bins in the silt size range [2 – 4, 4 – 8, 8 – 16, and 16 – 32 µm diameter]. This file contains the following fields:

• lwf_srf_Clay1 through lwf_srf_Clay4 and lwf_srf_Silt1 through lwf_srf_Silt4: The difference in the LW flux at the surface between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. LW radiation is defined as positive downward, and units are W/m² x 10^-2. Dimensions: [72, 46, 12].
• lwf_toa_Clay1 through lwf_toa_Clay4 and lwf_toa_Silt1 through lwf_toa_Silt4: The difference in the LW flux at the top-of-atmosphere between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. LW radiation is defined as positive downward, and units are W/m² x 10^-2. Dimensions: [72, 46, 12].

• swf_srf_Clay1 through swf_srf_Clay4 and swf_srf_Silt1 through swf_srf_Silt4: The difference in the SW flux at the surface between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. SW radiation is defined as positive downward, and units are W/m² x 10^-2. Dimensions: [72, 46, 12].
• swf_toa_Clay1 through swf_srf_Clay4 and swf_toa_Silt1 through swf_srf_Silt4: The difference in the SW flux at the top-of-atmosphere between the case with all dust present and the case with no dust in this particular dust bin. The values are thus the radiative effect due to dust from the given bin. SW radiation is defined as positive downward, and units are W/m² x 10^-2. Dimensions: [72, 46, 12].
• tau550_Clay1 through tau550_Clay4 and tau550_Silt1 through tau550_ Silt4: The optical depth at 550 nm due to dust in the given bin. Dimensions: [144, 96, 12].
• dust_mass: the dust mass in kg per m² contained in each of the 20 vertical model layers, for each of the 8 particle bins.
• plbdust: the 21 layer edges for the 20 pressure layers.