Abstract:
In this paper, we present the evolution and speed expansion of a shock driven by a Coronal Mass Ejection (CME) that
triggered a type II radio. We combine radio analysis with a broad range of observations taken by other ground-based and
space borne observatories to track the evolution of this CME/shock from Sun to 1 AU. The Halo CME studied here occurred on 22 August 2015 at 07:12 UT with a linear speed of 547 km/s derived from white-light observations obtained by
the SoHO/LASCO spacecraft. The CME and its associated flare (M1 Class at 06:39 UT) originated at active region 12403
located at S14E09 on the visible solar disk. Type II radio bursts drift with the shock propagation up from the solar surface
and produce emissions at the fundamental and higher harmonic frequencies which can be seen in radio dynamic spectrograms. The speed of the shock derived from radio observations was consistent with white-light observations. We combined
different models to estimate the evolution of the ambient coronal magnetic field at lower corona. We present evidence that
this halo CME has been detected in interplanetary space near 1 AU as a smooth rotation in the interplanetary magnetic
field suggesting the passage of a magnetic cloud but no shock detected in situ. We compared the CME arrival time with
the arrival time obtained from the Empirical shock arrival model and drag-based model. We discuss the importance of these
findings.
