1. Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens (NOA), 15236 Athens, Greece
2. Department of Applied and Environmental Physics, Aristotle University of Thessaloniki (AUTH), 54124 Thessaloniki, Greece
3. Royal Netherlands Meteorological Institute (KNMI), 3731 GA De Bilt, The Netherlands
4. Research Centre for Atmospheric Physics and Climatology, Academy of Athens (AoA), 10679 Athens, Greece
5. Leibniz Institute for Tropospheric Research (TROPOS), 04318 Leipzig, Germany
6. Department of Geography, Harokopion University of Athens (HUA), 17676 Athens, Greece
7. Department of Meteorology and Climatology, Aristotle University of Thessaloniki (AUTH), 54124 Thessaloniki, Greece
8. European Centre for Medium-Range Weather Forecasts (ECMWF), Shinfield Park, Reading RG2 9AX, UK
9. European Space Agency, 00044 Frascati, Italy