Evaluating Solar Quiet Variation of the Horizontal Geomagnetic Field using Nonlinear Time Series Analysis Techniques

Abstract

In this present paper, the nonlinear time series techniques were used to analyse solar quiet variation in the horizontal component of the geomagnetic field (SqH) data collected from the INTERMAGNET during the year 2012. The complexity of the nonlinear dynamics based on estimated time delay (τ) and embedding dimension (m) are expressed by Lyapunov exponents (LE). The positive values of the Lyapunov exponent for the Addis Abba (AAE), Eskdalemuir (ESK), Hartebeesthoek (HBK), Hermanus (HER), Mbour (MBO), Sodankyla (SOD) and Tamanrasset (TAM) time series are 0.0027, 0.0118, 0.0082, 0.0042, 0.0027, 0.016 and 0.0036 respectively for the year 2012. We observed positive values of Lyapunov exponent which are more significant at high latitudes (ESK and SOD) and mid latitudes (TAM, HBK and HER) which are located outside the electrojet region. The low latitudes (AAE and MBO) have low values of Lyapunov exponent which are located within electrojet region. The internal dynamics and inherent irregularities of ionosphere may be responsible for the occurrence of chaos during the Sq (H) variation, which show evidence of nonlinear properties. The external factors such as counter electrojet (CEJ) and equatorial electrojet (EEJ) might be responsible for inherent dynamics.This may possibly be the reason for the higher and lower values of Lyapunov exponents during SqH.