1. Faculty of Science, Beirut Arab University, P.O. Box 11-5020, Riad El Solh, Beirut 1107 2809, Lebanon
2. Department of Physics, Khalifa University, P.O. Box 127788, Abu Dhabi 51133, United Arab Emirates
3. Space and Planetary Science Center, Khalifa University, Abu Dhabi 51133, United Arab Emirates