1. Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research (SIDEER), Blaustein Institutes for Desert Research (BIDR); Ben-Gurion University of the Negev, Sede Boqer Campus; Midreshet Ben-Gurion 8499000 Israel
2. Department of Physics; Ben-Gurion University of the Negev; Be'er Sheva 8410501 Israel