%0 Conference Proceedings
%T Comparison between april 1999 and february 2000 solar-terrestrial connection events: interplanetary aspects
%D 2003
%8 2003
%A Echer, Ezequiel,
%A Alves, Maria Virgínia,
%A González-Alarcon, Walter Demétrio,
%A Gonzalez-Alarcon, Alicia Luisa Clua de,
%A Balmaceda, L. A.,
%A Santos, C.,
%A Vieira, Luiz Eduardo Antunes,
%A Dal Lago, Alisson,
%A Guarnieri, Fernando Luís,
%B Latin American Workshop on Plasma Physics, 10; Brazilian Meeting on Plasma Physics, 7 (São Pedro, SP, Brazil, 2003).
%C São Pedro, 2003
%S Anais
%K física básica de plasma, geomagnetic storms.
%X The strong geomagnetic storms on April 17th 1999 (Dst peak = -91 nT) and on February 12th 2000 (Dst peak = -131 nT) were caused by different interplanetary structures. The April 1999 event was caused by a south-north fast magnetic cloud, which drove an interplanetary shock detected at 1 astronomical unit (UA) at 10:30 UT on April 16th 1999. This interplanetary shock had Alfvenic Mach number of about 2.5. The magnetic cloud arrived at UA around 23:00 UT on April 16th and ended around 19:00 UT on April 17th. The southward component of the interplanetary magnetic field remained above -10 nT for 5 hours, with peak value of -14 nT. The February 2000 event was caused by the interaction of two interplanetary remnants of coronal mass ejections. Two interplanetary shocks were detected on February 11th 2000 at 02:00 and at 23:00 UT. These shocks had Alfvenic Mach numbers of about 2.0 and 2.8, respectively, and were driven by interplanetary ejecta. The first interplanetary ejecta arrived at 1 UA around 16:00 UT on February 11th. However, it was engulfed by the second one around 20:00 UT on the same day, creating an intense and highly turbulent southward magnetic field, which remained above -10 nT for 3 hours, with peak value of -16 nT. In this paper the interplanetary aspects of these two solar-terrestrial connection events are analyzed and compared. Plasma and magnetic field data obtained from sensors on board ACE spacecraft orbiting L1 point are used.
%@language en
%3 comparison.pdf