Modify paths in Makefile and execute make in a terminal window. This will create the executable file 'dssf'
Libraries HDF5, SZIP and ZLIB are necessary to run MDSSFTD. Working versions at CNRM are: hdf5-1.8.19, szip-2.1, and zlib zlib-1.2.8.
After compilation and generation of the executable file, please type the following command in a terminal window: ./dssf config/AlgorithmConfigurationFile config/ProductConfigurationFile
These following files will be automatically created in ./output
The outputs in HDF5 format include total shortwave radiation incident at surface (DSSF_TOT), diffuse fraction (FRACTION_DIFFUSE), quality-flag (Q_FLAG), equivalent aerosol optical depth (AOD), and the opacity of the atmosphere (OPACITY_INDEX).
ASCII extractions for ground stations¶
Several ASCII files are also generated to provide a fast access to the inputs and outputs for some ground stations belonging to radiation networks.
The inputs detailed below are necessary to run MDSSFTD. All inputs must available on the native spatial grid of SEVIRI and at the corresponding 15-minute frequency. The only exception is surface albedo which must be available with a daily frequency.
- Aerosol Inputs: information on aerosol particles is derived from CAMS aerosol products. Aerosol optical depth is needed for five aerosol types, namely Black Carbon (BC), Organic Carbon (OC), Dust (DU), Sea Salt (SS), and Sulfate (SU), in order to describe the aerosol mixture.
- Gas Inputs: information on gases comes from ECMWF, which provides the total column content for O3 and water vapor.
- Cloud mask : information on the presence of clouds to switch between the cloudy sky method and the clear sky approach.
- SEVIRI radiances: calibrated radiances for channels VIS06, VIS08, and IR016.
- SEVIRI angles: solar zenith angle, solar azimuth angle, view zenith angle, and view azimuth angle.
- Surface albedo: MDAL product from the LSA SAF project containing surface albedo derived from SEVIRI/MSG.
These files must be copied in ./inputs.
- Topography: two Digital Elevation Models (DEM) are needed for the height correction of AOD. The DEM needs to be available at the resolution of the CAMS aerosol data and at the resolution of the native SEVIRI grid.
- Aerosol LUT: the code relies on several LUTs containing pre-computed transmittances for gases and aerosols for aerosol components. The algorithm combines this information with the data from CAMS to calculate the radiative properties of the aerosol mixture.
These files are in ./inputs/static and must not be erased.
Test data set¶
A set of inputs and outputs of reference are provided with this release. The user may want to cross check the obtained outputs with the existing ones.
- This code considers total aerosol optical depth up to 4. For heavier aerosol loads, the quality of the retrievals is considered to be compromised and therefore the quality flag is set accordingly.
- The determination of cloud properties may be uncertain some times due to the limitation of the used parameterization. This behavior is reflected in the quality flag.
- The MDSSFTD code is open source and free to use. The code is released under the CeCILL-C licence. Please read the attached files below for moire information on the usage of MDSSFTD
- We ask the users to acknowledge this code sharing by including the following text in their works using MDSSF: The MDSSFTD code (Carrer et al. 2020) was made available to the community by CNRM/Météo-France thanks to the support of EUMETSAT
- The MDSSF code includes some interpolation routines developed by John Burkardt and distributed under the GNU LGPL license.
- Some routines to read and write HDF5 files in Fortran were initially developed by the IPMA institute. We acknowledge IPMA for sharing these routines and for their support in the activities related to MDSSFTD in the framework of the LSA SAF.