Understanding Shock Dynamics in the Inner Heliosphere with Modeling and Type II Radio Data: the 2010-04-03 event

H. XIE; D. ODSTRCIL; L. MAYS; O. C. ST. CYR; N. GOPALSWAMY; H. CREMADES

San Francisco, CA

Congreso; American Geophysical Union, Fall Meeting 2010; 2011

American Geophysical Union

The 2010 April 03 solar event was studied using observations from STEREO A and B SECCHI, SOHO LASCO, and kilometric type II data combined with the WSA-Cone-ENLIL model. In particular, we identified the origin of the coronal mass ejection (CME) using STEREO EUVI and SOHO EIT images. A flux-rope model fit to the SECCHI A and B, and LASCO images were used to determine the CME’s direction, size, and actual speed. J-maps from STEREO COR2/HI-1/HI-2 and simulations from the ENLIL model were used to study the formation and evolution of the shock in the inner heliosphere. In addition, we also studied the time-distance profile of the shock propagation from kilometric type II (kmTII) radio burst observations. Here we report on a comparison of two methods of predicting interplanetary shock arrival time: the ENLIL model and the kmTII method; and investigate whether or not using the ENLIL model density improves the kmTII rediction. We found that the ENLIL model predicted the kinematics of shock evolution well. The shock arrival times (SAT) and linear fit shock velocities in the ENLIL model agreed well with those measurements in the J-maps along both the CME leading edge and the Sun-Earth line. The model also reproduced most of the large scale structures of the shock propagation and gave the SAT prediction at Earth with an error of 1.5 hours. The kmTII method predicted the SAT at Earth with an error of 8 hours when using the ENLIL model plasma density at near Earth; but it improved to 3 hours when using the model density near the CME leading edge at 1 AU.