Harikrishnan charuvil Asokan, Leibniz Institute of Atmospheric Physics, Kühlungsborn, Germany, Jorge Luis Chau, Leibniz Institute of Atmospheric Physics, Radar Remote Sensing, Kühlungsborn, Germany, Juha Vierinen, Univrsity of Tromsø, Tromso, Norway, Raffaele Marino, CNRS, École Centrale de Lyon, Lyon, France and Victor Avsarkisov, Leibniz Institute for Atmospheric Physics, Kühlungsborn, Germany