Geomagnetically induced currents in Brazil over the solar cycles 23 and 24

International Conference on Astrophysics and Particle Physics

December 08-10, 2016 Dallas, Texas, USA

Cleiton Barbosa, Gelvam A Hartmann, Livia Alves, Ramon Caraballo, Andres R R Papa and Risto J Pirjola

Observat�?�?�?³rio Nacional, Brazil
Augusto Motta University Centre, Brazil
University of Campinas, Brazil
National Institute for Space Research, Brazil
University of the Republic, Uruguay
Finnish Meteorological Institute, Finland
Natural Resources Canada, Canada

Posters & Accepted Abstracts: J Astrophys Aerospace Technol

Abstract :

Geomagnetically induced currents (GIC) are a space weather effect, which affects ground-based technological structures at all latitudes on the Earth�?¢�?�?�?�?s surface. GIC occurrence and amplitudes have been monitored in power grids located at high and middle latitudes since 1970s and 1980s, respectively. This monitoring provides information about the GIC intensity and the frequency of occurrence during geomagnetic storms. In this work, we investigate GIC occurrence in a power network at central Brazilian region during the solar cycles 23 and 24. Calculated and measured GIC data, and are compared for the most intense and moderate geomagnetic storms (i.e., -150 < Dst < -50 nT) of the solar cycle 24. The results obtained from this comparison show a good agreement. The success of the model employed for the calculation of GIC led to the possibility to determine GIC for events during the solar cycle 23 as well. Calculated GIC reached ca. 30 A during the �?¢�?�?�?�?Halloween storm�?¢�?�?�? in 2003 whilst most frequent intensities lie below 10 A. The normalized inverse cumulative frequency for GIC data was calculated for the solar cycle 23 in order to perform a statistical analysis. It was found that a q-exponential Tsallis distribution fits the calculated GIC frequency distribution for more than 99% of the data. This analysis provides an overview of the long term GIC monitoring at low latitudes and suggests new insight into critical phenomena involved in the GIC generation.

Biography :

Email: cleitonferr@hotmail.com