INVESTIGADORES
MANDRINI Cristina Hemilse
artículos
Título:
Three frontside full halo coronal mass ejections with a nontypical geomagnetic response
Autor/es:
RODRIGUEZ, L.; ZHUKOV, A.; CID, C.; CERRATO, Y.; SAIZ, E.; CREMADES, H.; DASSO, S.; MENVIELLE, M.; ARAN, A.; MANDRINI, C.H.; POEDTS, S.; SCHMIEDER, B.
Revista:
Space Weather
Editorial:
American Geophysical Union
Referencias:
Año: 2009 vol. 70 p. 6003 - 6013
ISSN:
1539-4964
Resumen:
We analyze three frontside full halo coronal mass ejections (CMEs) that occurred in the
year 2000 (close to the activity maximum of the solar cycle 23), together with associated
solar and heliospheric phenomena as well as their impact on the Earths magnetosphere.
Even though all three were fast full halos (with plane of the sky speeds higher than 1100
km/s), the geomagnetic response was very different for each case. After analyzing the
source regions of these halo CMEs, it was found that the halo associated with the
strongest geomagnetic disturbance was the one that initiated farther away from disk
center (source region at W66); while the other two CMEs originated closer to the central
meridian but had weaker geomagnetic responses. Therefore, these three events do not fit
into the general statistical trends relating the location of the solar source and the
corresponding geoeffectivity. We investigate possible causes of such a non-typical
behavior. Non-radial direction of eruption, passage through a leg of an interplanetary flux
rope and strong compression at the eastern flank of a propagating ICME during its
interaction with the ambient solar wind are found to be important factors that have a
direct influence on the resulting northsouth interplanetary magnetic field (IMF)
component and thus on the CME geoeffectiveness. We also find indications that
interaction of two CMEs could help in producing long-lasting southward IMF
component. Finally, we are able to explain successfully the geomagnetic response using
plasma and magnetic filed in situ measurements from the L1 point. Our results have
important implications for space weather forecasting.