1. Department of Physics, Bankura University, Bankura 722 155, West Bengal, India
2. Chaos and Complex Systems Research Laboratory, Department of Physics, University of Burdwan, Burdwan 713 104, West Bengal, India
3. Potsdam Institute for Climate Impact Research, Telegraphenberg, D-14415 Potsdam, Germany
4. Institute of Physics, Humboldt University Berlin, D-12489 Berlin, Germany