README.md

download_CAMS_daily

This tool is designed to download daily CAMS near-real-time forecast products from ECMWF. Otherwise, the graphical interface provided by ECMWF is available here: http://apps.ecmwf.int/datasets/data/macc-nrealtime/levtype=sfc/

Configuration

  • Create a ECMWF account: https://apps.ecmwf.int/registration/

  • The folder ecmwfapi/ and the file setup.py must be in the working directory.

  • Get your API key at: https://api.ecmwf.int/v1/key/

  • Create the file '.ecmwfapirc' in your home and type:

    {
    "url" : "https://api.ecmwf.int/v1",
    "key" : "your_key",
    "email" : "your_email_address"
    }
    

Example

python download_CAMS_daily.py -d 20180101 -f 20180102 -t 12 -w /path/to/my/CAMSfolder

Parameters

The user can choose the following parameters with the command line:

  • w: where CAMS files will be stored

  • d,f: min/max range of dates to download

  • t: analysis time, i.e. when MODIS (and PMAP?) data were last assimilated

Other parameters could be accessed within the code :

  • step: forecast step in hours (default 3, ony value available so far)

  • type of file to download: surface, pressure or model (default all)

  • name of output files

  • grid: spatial resolution of downloaded files

  • format: grib or netcdf

Info on downloaded files

  • Surface files: Aerosol Optical Thickness (AOT) at 550 nm for the five aerosol models (BlackCarbon, Dust, Sulfate, SeaSalt and OrganicMatter).

    Variable name     Description
    suaod550      Sulphate Aerosol Optical Depth at 550nm
    bcaod550      BlackCarbon Aerosol Optical Depth at 550nm
    ssaod550      SeaSalt Aerosol Optical Depth at 550nm
    duaod550      Dust Aerosol Optical Depth at 550nm
    omaod550      OrganicMatter Aerosol Optical Depth at 550nm
    
  • Model files: mass Mixing Ratios (MR: expressed in kg of aerosol per kg of dry air [kg/kg]) of the aerosol models at 60 different altitude levels (model levels).

    Variable name     Description
    aermr01       Sea Salt Aerosol (0.03 - 0.5 um) Mixing Ratio
    aermr02       Sea Salt Aerosol (0.5 - 5 um) Mixing Ratio
    aermr03       Sea Salt Aerosol (5 - 20 um) Mixing Ratio
    aermr04       Dust Aerosol (0.03 - 0.55 um) Mixing Ratio
    aermr05       Dust Aerosol (0.55 - 0.9 um) Mixing Ratio
    aermr06       Dust Aerosol (0.9 - 20 um) Mixing Ratio
    aermr07       Hydrophobic Organic Matter Aerosol Mixing Ratio
    aermr08       Hydrophilic Organic Matter Aerosol Mixing Ratio
    aermr09       Hydrophobic Black Carbon Aerosol Mixing Ratio
    aermr10       Hydrophilic Black Carbon Aerosol Mixing Ratio
    aermr11       Sulphate Aerosol Mixing Ratio
    
  • Pressure files: Relative Humidity (RH: expressed in %) at 22 different altitude levels (pressure levels).

    Variable name     Description
    r         Relative Humidity
    

Information about these variables can also be found at http://atmosphere.copernicus.eu/ftp-access-global-data under the “Forecast surface parameters” and “Forecast model level parameters” sections, or at http://apps.ecmwf.int/codes/grib/param-db/