A Study of the 2012 January 19 Complex Type II Radio Burst Using Wind, SOHO, and STEREO Observations

摘要

We report on a case study of the complex type II radio burst of 2012 January19 and its association with a white light coronal mass ejection (CME). Thecomplexity can be described as the appearance of an additional type II burstcomponent and strong intensity variation. The dynamic spectrum shows a pair oftype II bursts with fundamental harmonic structures, one confined todecameter-hectometric (DH) wavelengths and the other extending to kilometric(km) wavelengths. By comparing the speeds obtained from white-light images withthat speed of the shock inferred from the drift rate, we show that the sourceof the short-lived DH component is near the nose.