First SDO AIA Observations of a Global Coronal EUV 'Wave': Multiple Components and 'Ripples'

摘要: We present the first Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA) observations of a global coronal EUV disturbance (so-called "EIT wave") revealed in unprecedented detail. The observed on 2010 April 8 exhibits two components: one diffuse pulse superimposed, which are multiple sharp fronts that have slow and fast components. originates front erupting loops some undergo accelerations, both effects implying is driven by mass ejection. pulse, propagating at uniform velocity 204-238 km s–1 with very little angular dependence within its extent south, maintains coherence stable profile for ~30 minutes. Its arrival increasing distances coincides onsets loop expansions front. overtakes front, producing "ripples" steepening local propagate independently afterward. This behavior resembles nature real waves. Unexpectedly, amplitude FWHM decrease linearly distance. A hybrid model, combining wave non-wave components, can explain many, but not all, observations. Discoveries two-component ripples were made possible time thanks to AIA's high cadences (≤20 s) signal-to-noise ratio.