C2RCC Processor |

### Auxiliary Data Directory

The C2RCC can make use of auxiliary ozone and pressure data. The data can be downloaded from https://oceandata.sci.gsfc.nasa.gov/Ancillary/Meteorological Such data can be specified either specifically for each run of the product vie the TOMSOMI and NCEP source product parameters. As Alternative a directory can be specified via the 'Atmospheric aux data path' parameter. The necessary auxiliary products are taken from this directory or if not found appropriate data is automatically downloaded.

NOTE: Automatic download is currently not working because the download now requires a login. See issue: [SIIITBX-369] Auxillary data is not automatically downloaded anymore in C2RCC

If the source product contains these variables the data from the source product is preferred, e.g. SENTINEL-3 OLCI data. As a fall back value, in case of missing values in the auxdata sources or they have not been specified at all, the parameters Air Pressure and Ozone are used.

When creating the directory by your own, then please note that the directory structure needs to follow the convention:

    {root_ancillary_dir}
        - {year}
          - {doy}
            - {files for this day}

So the path to a file would be would be for example: "H:\c2rcc_ancillary\2020\172\N202017200_O3_AURAOMI_24h.hdf"
As parameter you would specify: "H:\c2rcc_ancillary"