Coronal Mass Ejection-Associated Coronal Dimmings

Abstract

We report on a statistical analysis of 96 CME-associated EUV coronal dimmings between 1998 and 2000. We investigate the size and location of the events and characterize how these events evolve with time. The durations typically range from 3 to 12 hr. The dimmings appear most frequently within the belt of active regions (20°-50° latitude). Dimming events are generally symmetric in latitude and longitude with some tendency to be broader in latitude. The temporal profiles of most events are characterized by a sharp rise and a gradual recovery. Although the majority of cases are well fit by a single recovery slope, a large minority of events have a two-part decay with an initial decaying slope that is similar in magnitude to the rising slope and a secondary, flatter, decay lasting several hours.