Temporal Evolution of Oxygen Abundance in Coronal Streamers disrupted by CMEs

VÁSQUEZ, ALBERTO M.; RAYMOND, JOHN C.

Conferencia; 49 Reunión Anual Asociación Argentina de Astronomía; 2006

We present a study of the temporal evolution of the Oxygen abundance within equatorial streamers affected by coronal mass ejections (CMEs). We derive the Oxygen abundance from spectroscopic coronal observations performed by the Ultraviolet Coronagraph Spectrometer (UVCS/SoHO). We analyse UVCS data obtained before and after the CME events. Within the streamer belt core structure the Oxygen abundance usually exhibits a depleted region, presumably due to gravitational settling. The present analysis is an attempt to set observationally derived constraints on the time scale of the abundance depletion mechanism.