Constraints on Scale Lengths of Equatorial Electrojet and Counter Electrojet Phenomena From the Indian Sector

R. K. Archana, N. Phani Chandrasekhar, Kusumita Arora, and Nandini Nagarajan

Concurrent observations of magnetic variations from three longitudes in the electrojet region of the Indian sector for the year 2015, reveal increasing EEJ amplitudes from west to east and a new observation of increasing CEJ amplitudes from east to west. From these longitudinal trends, we confirm that EEJ strengths are controlled by the large-scale DE3 nonmigrating tide. A marked difference in CEJ amplitude between MNC and VEN suggests that scale lengths of CEJ and EEJ are different, and we infer that CEJ are primarily generated by short-scale length variations in the middle atmosphere caused by localized interactions of planetary and gravity waves and are also influenced by the DE3 nonmigrating tide. 

Citation: Archana, R. K., Phani Chandrasekhar, N., Arora, K., & Nagarajan, N. (2018). Constraints on scale lengths of equatorial electrojet and counter electrojet phenomena from the Indian sector. Journal of Geophysical Research: Space Physics, 123. 10.1029/2018JA025213

Figure: Contour plot of daytime hourly values of EEJ strength for all days of (top row) May, (middle row) September, and (bottom row) December from 2015 at (left column) MNC, (middle column) VEN, and (right column) CBY to highlight the difference in the EEJ strength between the sites. Note the different scale of color ranges for each month. EEJ = equatorial electrojet; MNC = Minicoy; VEN = Vencode; CBY = Campbell Bay.