Tsallis’ Analysis of the Horizontal Component of the Earth’s Magnetic Field over India during 2002

A widely used measure of entropy to quantify uncertainity in an open system is the Boltzmann-Gibbs (B-G) entropy. It, however, cannot describe non-equilibrium systems with large variability and multi-fractality. A generalisation of the B - G entropy is the Tsallis’ entropy. The values of the horizontal components of the Earth’s magnetic field, observed at various stations in India in 2002 were used. During the years 2000 – 2002, solar cycle 23 reached its maximum. Data from Ettaiyapuram (ETT, latitude = 90 10’ N, longitude = 780 01’ E, geomagnetic latitude = 0.130 N), Visakhapatnam (VIS, 170 41’ N, 830 19’ E, 8.170 N), Hyderabad (HYD, 170 25’ N, 780 33’ E, 8.170 N), Alibag (ABG, 180 37’ N, 720 52’ E, 10.020 N) and Tirunelveli (TVI, 80 42’ N, 770 48’ E, 0.320 S) were used. Using these values as inputs, we demonstrate that Tsallis’ entropy can be used to detect minor differences in the horizontal components of the geomagnetic field observed between different pairs of stations. The method is a very simple and elegant one to detect minor variations between pairs of similar signals.