PMIP4 HadGEM2-A dust data

The simulation of the pre-industrial and LGM climate states with HadGEM2-A are described in more detail by Hopcroft & Valdes (2015), whilst the dust results are described by Hopcroft et al (2015). The dust scheme itself has been documented by Woodward (2011). HadGEM2-ES is documented by Collins et al (2011).

Information and data provided by Peter Hopcroft

• file names = PMIP4_DUST_Hopcroft_<field>_<expt>.nc
  • field = see Variables section below
  • expt = PI or LGM

• nb_time = 12 (12 monthly time steps in each file)
  • Warning! The time steps are ordered from January to December in the files but, due to the time axis units, the time axis values are not monotonically increasing. This can potentially confuse some programs
    • time:units = “days since 2117-12-01 00:00:00”
    • time = 45, 75, 105, 135, 165, 195, 225, 255, 285, 315, 345, 15
• nb_lat, nb_lon = 145, 192
  • latitude_values = [ -90, -88.75, -87.5, … 87.5, 88.75, 90 ]
  • longitude_values = [ 0, 1.875, 3.75, … 354.375, 356.25, 358.125 ]
• size_bin = 6
  • dust size bin edges = 0.0316, 0.1, 0.316, 1.0, 3.16, 10.0 and 31.6 μm (radius)
• nb_wavelength = 6
  • AOD is given on 6 wavelengths. These are 0.38, 0.44, 0.55, 0.67, 0.87 and 1.02 μm (Bellouin et al 2007).
• nb_levels = 38
  • check the PMIP4_DUST_Hopcroft_conc_<expt>.nc files for details about the hybrid coordinates

• emis: emission (lon,lat,size,month) [g/m2/a]
• ddep: dry deposition (lon,lat,size,month) [g/m2/a]
• wdep: wet deposition (lon,lat,size,month) [g/m2/a]
• load: dust loading (lon,lat,size,month) [kg/m2]
• aot: aerosol optical thickness (lon,lat,wavelength,month) [unitless]
• rfss: surface short-wave radiative forcing (lon,lat,month) [W/m2]
• rfsl: surface long-wave radiative forcing (lon,lat,month) [W/m2]
• rfts: TOA short-wave radiative forcing (lon,lat,month) [W/m2]
• rftl: TOA long-wave radiative forcing (lon,lat,month) [W/m2]

• conc: mass mixing ratio (lon,lat,lev,month) [kg/kg] x 6 bins

• Bellouin, N et al., (2007), Improved representation of aerosols for HadGEM2, Hadley Centre Technical Note 73, Met Office Hadley Centre, Exeter, UK:
• Collins, WJ et al (2011), Development and evaluation of an Earth-System model – HadGEM2, Geoscientific Model Development, 4, 1051-1075, doi:10.5194/gmd-4-1051-2011.
• Hopcroft, P.O. and P.J. Valdes (2014), Last Glacial Maximum constraints on the Earth System Model HadGEM2-ES, Climate Dynamics, 45(5), 1657-1672, doi:10.1007/s00382-014-2421-0.
• Hopcroft, P.O., P.J. Valdes, S. Woodward and M. Joshi (2015), Last glacial maximum radiative forcing from mineral dust aerosols in an Earth System model, J Geophysical Research, 120(16), 8186-8205, doi:10.1002/2015JD023742.
• Woodward, S. (2011), Mineral dust in HadGEM2, Hadley Centre Technical Note 87, Met Office Hadley Centre, Exeter, UK.

You will find below a table with all the available data files, and their md5sum checksum (if you want to check that you download was OK, you can just type md5sum file.nc and compare the result to what is displayed in the table).

If you want to download a file, click on the PMIP4 HadGEM2-A dust data download link and then on the file you need.