1. Professor, Dept. of Meteorology and Oceanography, Andhra Univ., Visakhapatnam, Andhra Pradesh 530004, India (corresponding author).
2. Project Assistant II, National Institute of Oceanography, Visakhapatnam, Andhra Pradesh 530017, India.
3. Emeritus Scientist, National Institute of Oceanography, Visakhapatnam, Andhra Pradesh 530017, India.