1. Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15784 Athens, Greece
2. Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens (IAASARS/NOA), 15236 Athens, Greece
3. Physics and Meteorology Observatory of Davos, World Radiation Center (PMOD/WRC), 7260 Davos, Switzerland
4. Institute of Environmental Research and Sustainable Development, National Observatory of Athens, 15236 Athens, Greece
5. Research Centre for Atmospheric Physics and Climatology, Academy of Athens, 10679 Athens, Greece
6. Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece