Statistical analysis of coronal shock dynamics implied by radio and white-light observations

For 19 solar eruptive events we present a statistical comparison of the sho ck dynamics derived from the measured frequency drift rates of metric and d ecametric-hectometric (D-H) type II radio bursts with the dynamics of the a ssociated coronal mass ejection (CME). We find that the shock speed paramet ers derived from the D-H type II radio emissions generated in the high coro na (similar to2-4 R-circle dot; R-circle dot = 696,000 km) are well correla ted with the corresponding CME plane-of-the-sky speeds (correlation coeffic ient = 0.71). On the other hand, we find no obvious correlation between the shock speed parameters derived from the metric type II radio bursts, gener ated in the middle corona (1.4-2 R-circle dot), and the corresponding CME s peeds (correlation coefficient = -0.07). In general, we also find no clear correlation between the shock speed parameters derived from the metric type II bursts and the D-H radio emissions (correlation coefficient = 0.3). How ever, the metric type II radio bursts sometimes include a second component that is possibly related to the DH radio emissions. These statistical compa risons of the shock dynamics, implied by the observed metric and D-H type I I frequency drift rates, provide further evidence for two distinct coronal shocks. Our statistical analyses are preceded by two specific examples that illustrate the methodology used in this study.