STUDY ON THE GEOMAGNETIC VARIATIONS USING WAVELET TECHNIQUES.

• Grant number: 11/20588-7
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): May 01, 2012
• Effective date (End): November 30, 2014
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal researcher: Odim Mendes Junior
• Grantee: Virginia Klausner de Oliveira
• Home Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovações (Brasil). São José dos Campos , SP, Brazil
• Associated scholarship(s): 13/06029-0 - Wavelet techniques applied to study of space electrodynamic phenomena, BE.EP.PD

Abstract

In this work, magnetic variations from external sources observed in Brazilian region and in other regions around the globe are investigated. Magnetic variations from external sources are generated by ionospheric currents and may reach several orders of magnitude (between tens to hundreds of nanoTeslas).Such magnetic variations can be classified into two kinds: regular and irregular. One kind of regular variation are the so-called diurnal variations which present a fundamental period of 24 hours and also other periodicities (called harmonics) of 12, 8 and 6 hours. On the other hand, are the irregular variations such as the geomagnetic storms which are closely related to the solar activity.Magnetic indices have been used to describe the characteristics of the Earth's magnetosphere electric current system in order to evaluate how the geomagnetic field is disturbed by the solar activity.The Disturbance storm time (Dst) index monitors the geomagnetic activity level, in particular the effects in the geomagnetic field due to the ring current.This work intend to: analyze the geomagnetic variations from external sources; to reformulate the ``quiet days baseline'' which compose the Dst index; and to evaluate and separate from the magnetic records the local, seasonal and related with solar cycle variabilities.As tools for achieving these goals, both wavelet and empirical orthogonal functions techniques are jointly used.Significant results this work will provide to Brazilian science, once it lets Brazil able to effectively participate in Space Weather forecasting as well as in the improvement of the knowledge of the Brazilian region.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

KLAUSNER, VIRGINIA; RODRIGUEZ PAPA, ANDRES REINALDO; NICOLE CANDIDO, CLAUDIA MARIA; DOMINGUES, MARGARETE OLIVEIRA; MENDES, ODIM. An alternative way to identify local geomagnetically quiet days: a case study using wavelet analysis. Annales Geophysicae, v. 34, n. 4, p. 451-462, 2016. (13/06029-0, 11/20588-7)

KLAUSNER, VIRGINIA; KHERANI, ESFHAN A.; MUELLA, MARCIO T. A. H.. Near- and far-field tsunamigenic effects on the Z component of the geomagnetic field during the Japanese event, 2011. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, v. 121, n. 2, p. 1772-1779, FEB 2016. (13/06029-0, 11/21903-3, 11/20588-7)

KLAUSNER, V.; MENDES, ODIM; DOMINGUES, MARGARETE O.; PAPA, ANDRES R. R.; TYLER, ROBERT H.; FRICK, PETER; KHERANI, ESFHAN A.. Advantage of wavelet technique to highlight the observed geomagnetic perturbations linked to the Chilean tsunami (2010). JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, v. 119, n. 4, p. 3077-3093, APR 2014. (13/06029-0, 11/20588-7)

KLAUSNER, VIRGINIA; GONZALEZ, ARIAN OJEDA; DOMINGUES, MARGARETE OLIVEIRA; MENDES, ODIM; RODRIGUEZ PAPA, ANDRES REINALDO. Study of local regularities in solar wind data and ground magnetograms. JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, v. 112, p. 10-19, MAY 2014. (07/07723-7, 11/20588-7)

KLAUSNER, V.; PAPA, A. R. R.; MENDES, O.; DOMINGUES, M. O.; FRICK, P.. Characteristics of solar diurnal variations: A case study based on records from the ground magnetic station at Vassouras, Brazil. JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, v. 92, p. 124-136, JAN 2013. (07/07723-7, 11/20588-7)