Calculation of local components of the Earth's magnetic field in Honduras, using the model of Tsyganenko and Sitnov 2005

Abstract

The National Autonomous University of Honduras is installing the First Magnetic Observatory of Honduras, in order to capture the natural sources of the local magnetic field vector. We propose a methodology to analize its data, comparing with near observatories data, with the International Geomagnetic Reference Field, with the Earth’s magnetospheric semi-empirical model of Tsyganenko and Sitnov 2005. The local horizontal geomagnetic component (H−) is computed for the Suyapa Central American Astronomical Observatory, Tegucigalpa, Honduras coordinates (TEG-HTSY ), in the temporal interval 2010 – 2013, using the models. For the same time interval, the local H− component of Chiripa Observatory, Costa Rica (CRP−H), and its quiet daily variation (Sq−H) obtained from the international quiet days are extrated from data. Pearson correlation coefficients are computed between TEG-HTSY and CRP−H . Better correlations are obtained in days with planetary index Kp < 4, when Sq and diurnal variation are removed from CRP−H and TEG-HTSY , respectively. A model (NOCSq) is computed from the Chripa Sq−H, using empirical orthogonal functions (EOFs). When Tegucigalpa’s magnetospheric currents quietest days matrices are projected into EOFs, they represent EOF’s significative percentages in the 12,00 – 24,00 local time interval.