1. Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600036, India
2. Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
3. School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907, USA
4. Potsdam Institute for Climate Impact Research, P.O. Box 601203, 14412 Potsdam, Germany
5. Department of Physics, Humboldt University, Newtonstr. 15, 12489 Berlin, Germany