CAMS (regional)

The regional air quality (RAQ) production of the Copernicus Atmosphere Monitoring Service (CAMS) is based on seven state-of-the-art numerical air quality models developed in Europe : CHIMERE from INERIS (France), EMEP from MET Norway (Norway), EURAD-IM from University of Cologne (Germany), LOTOS-EUROS from KNMI and TNO (Netherlands), MATCH from SMHI (Sweden), MOCAGE from METEO-FRANCE (France) and SILAM from FMI (Finland). Common to all models, the meteorological parameters settings (coming from the ECMWF global weather operating sytem), the boundary conditions for chemical species (coming fron the CAMS IFS-MOZART global production), the emissions coming from CAMS emission (for anthropic emissions over Europe and for biomass burning).

Available species

The following species are available from CAMS regional data:

Species Parameter value
CO CO
NH3 NH3
NMVOC NMVOC
NO NO
NO2 NO2
O3 O3
PAN PANS
PM10 PM10
PM2.5 PM25

Configuration

In order to download CAMS regional data, MSS-Chem must be configured as follows:

import os.path

from msschem.models import CAMSRegDriver
from msschem.download import CAMSRegDownload

register_datasources = {
    'CAMSReg_ENSEMBLE': CAMSRegDriver(
        dict(
            dldriver=CAMSRegDownload(
                password='MYTOKEN',
                modelname='ENSEMBLE',
                n_tries=3),
            force=False,
            basepath=os.path.expanduser('~/tmp/mss/data/'),
            name='CAMSReg-ENSEMBLE',
            temppath=None,
            species=['CO', 'NH3', 'NMVOC', 'NO2', 'NO', 'O3', 'PANS', 'PM10',
                     'PM25', 'SO2'],
        )
    ),
}

The modelname value in the CAMSRegDownload constructor must be set to model which shall be downloaded. The following values are supported:

  • CHIMERE
  • EMEP
  • ENSEMBLE
  • EURAD-IM
  • LOTOS-EUROS
  • MATCH
  • MOCAGE
  • SILAM

By default (i.e., if modelname is not specified), the ENSEMBLE will be downloaded.

The password value in the CAMSRegDownload constructor must be set to the access token of the CAMS regional website (see below on how to obtain this token).

The species value is a list of the Parameter values of all species which are to be downloaded (see above for a list of Parameter value s).

Data access

There are two ways of accessing the CAMS Regional forecast: a web service, and a download option. For MSS-Chem, we use the data download option.

When a user clicks on the “Online data” link at http://www.regional.atmosphere.copernicus.eu/ , one can see that the token needed for download is automatically filled into the request URL when one clicks on “Accept license”. So this token is no secret! The options (defined in the CAMSRegDownload class) are:

urlbase = ('http://download.regional.atmosphere.copernicus.eu/services/'
           'CAMS50')
urlparams = {'token': '{token}',
             'grid': '0.1',
             'model': '{model}',
             'package': 'FORECAST_{species}_ALLLEVELS',
             'time': '{fcrange}',
             'referencetime': '{fcinit:%Y-%m-%dT%H:%M:%SZ}',
             'format': 'NETCDF',
             'licence': 'yes'}

Web service access (not used by MSS-Chem)

For the web service, the user has to register. However, the web service only offers downloading 2D fields. In order to get the 4D fields needed by MSS (time, level, longitude, latitude), we would need to loop over both time and altitude. For future reference, these are the parameters for the web service (without implementing the level selection):

urlbase = ('http://geoservices.regional.atmosphere.copernicus.eu/services/CAMS50-{model}-FORECAST-01-EUROPE-WCS')
urlparams = {'service': 'WCS',
             'token': '{token}',
             'request': 'GetCoverage',
             'version': '2.0.1',
             'coverageId': '{species}__SPECIFIC_HEIGHT_LEVEL_ABOVE_GROUND___{fcinit:%Y-%m-%dT%H:%M:%SZ}',
}