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Monitoring the solar activity and the South Atlantic Magnetic Anomaly (SAMA) using a network of very low frequency (VLF) receivers: SAVNET - South America VLF NETwork

Grant number: 06/02979-0
Support type:Regular Research Grants
Duration: September 01, 2006 - August 31, 2009
Field of knowledge:Physical Sciences and Mathematics - Geosciences - Geophysics
Cooperation agreement: CNRS
Principal Investigator:Jean Pierre Raulin
Grantee:Jean Pierre Raulin
Visiting researcher: Nicole Vilmer
Visiting researcher institution: Observatoire de Paris, France
Principal investigator abroad: Michel Parrot
Institution abroad: Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E), France
Home Institution: Escola de Engenharia (EE). Universidade Presbiteriana Mackenzie (UPM). Instituto Presbiteriano Mackenzie. São Paulo , SP, Brazil

Abstract

In this proposal we plan to use the low ionospheric D-region as a huge detector of solar radiation. Our previous and recent results have shown that the response of this region to external ionizing agents was solar cycle phase dependent. In that sense the low ionosphere has a sensitivity which is function of the solar activity conditions. Because of this, the monitoring of the low ionospheric D-region is an important tool to be explored for a better understanding of solar-terrestrial relationships. We propose a network of seven (7) VLF receivers which will provide genuine information on large spatial scales relevant for space sciences and geophysics researches. The new network will allow determining the physical parameters of the low ionosphere during transient events of ionization excesses, from solar origin or not. Of particular interest are the long-term variations of these parameters, which will allow us to determine ionospheric indices able to reproduce solar cycle variations, and specially the temporal variations of the Lyman-alpha radiation which is poorly known despite its importance factor for the physics of the Sun-Earth connection. Moreover the new instrumentation will provide new insights on recently discovered atmospheric phenomena, sometimes linked to Space Weather studies, and which are particularly relevant in the South Atlantic Magnetic Anomaly region. We also plan to have a better knowledge of the behavior of the quiescent ionosphere, which is poorly known. Better defined template ionospheric variations will provide a better and more precise determination of transient perturbations, and may reveal new phenomena in the new network data, or in already existing long duration data base. The SAVNET network, in collaboration with other two South American countries, provides an instrumentation currently not available in this region, with great potential to generate relevant scientific results for a better understanding of solar-terrestrial relationships. (AU)

Matéria(s) publicada(s) na Agência FAPESP sobre o auxílio:
Changes in animal activity could help forecast earthquakes  

Scientific publications (7)
(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)
SAMANES, JORGE; RAULIN, JEAN-PIERRE; CAO, JINBIN; MAGALHAES, ANTONIO. Nighttime lower ionosphere height estimation from the VLF modal interference distance. JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS, v. 167, p. 39-47, JAN 2018. Web of Science Citations: 2.
SAMANES, JORGE E.; RAULIN, JEAN-PIERRE; MACOTELA, EDITH L.; GUEVARA DAY, WALTER R. Estimating the VLF modal interference distance using the South America VLF Network (SAVNET). RADIO SCIENCE, v. 50, n. 2, p. 122-129, FEB 2015. Web of Science Citations: 8.
RAULIN, JEAN-PIERRE; TROTTET, GERARD; GUILLERMO GIMENEZ DE CASTRO, C.; CORREIA, EMILIA; LILIANA MACOTELA, E. Nighttime sensitivity of ionospheric VLF measurements to X-ray bursts from a remote cosmic source. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, v. 119, n. 6, p. 4758-4766, JUN 2014. Web of Science Citations: 8.
PERIN BERTONI, FERNANDO CELSO; RAULIN, JEAN-PIERRE; GAVILAN, HERNAN RIVERO; KAUFMANN, PIERRE; RODRIGUEZ, RODOLFO; CLILVERD, MARK; CARDENAS, JORGE SAMANES; FERNANDEZ, GERMAN. Lower ionosphere monitoring by the South America VLF Network (SAVNET): C region occurrence and atmospheric temperature variability. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, v. 118, n. 10, p. 6686-6693, OCT 2013. Web of Science Citations: 4.
HAYAKAWA, M.; RAULIN, J. P.; KASAHARA, Y.; BERTONI, F. C. P.; HOBARA, Y.; GUEVARA-DAY, W. Ionospheric perturbations in possible association with the 2010 Haiti earthquake, as based on medium-distance subionospheric VLF propagation data. NATURAL HAZARDS AND EARTH SYSTEM SCIENCES, v. 11, n. 2, p. 513-518, 2011. Web of Science Citations: 16.
TANAKA, Y. T.; RAULIN, JEAN-PIERRE; BERTONI, FERNANDO C. P.; FAGUNDES, P. R.; CHAU, J.; SCHUCH, N. J.; HAYAKAWA, M.; HOBARA, Y.; TERASAWA, T.; TAKAHASHI, T. FIRST VERY LOW FREQUENCY DETECTION OF SHORT REPEATED BURSTS FROM MAGNETAR SGR J1550-5418. Astrophysical Journal Letters, v. 721, n. 1, p. L24-L27, SEP 20 2010. Web of Science Citations: 20.
RAULIN, J. P.; DE MATOS DAVID, P. CORREIA; HADANO, R.; SARAIVA, A. C. V.; CORREIA, E.; KAUFMANN, P. The south America VLF NETwork (SAVNET): Development, installation status, first results. GEOFISICA INTERNACIONAL, v. 48, n. 3, p. 253-261, JUL-SEP 2009. Web of Science Citations: 6.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.