Assessing the Accuracy of CME Speed and Trajectory Estimates from STEREO Observations Through a Comparison of Independent Methods

Details Assessing the Accuracy of CME Speed and Trajectory Estimates from STEREO Observations Through a Comparison of Independent Methods Assessing the Accuracy of CME Speed and Trajectory Estimates from STEREO Observations Through a Comparison of Independent Methods

May 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010soph..263..209d&link_type=abstract

Solar Physics, Volume 263, Issue 1-2, pp. 209-222

Physics

11

Coronal Mass Ejection, Stereo, Heliospheric Images

Scientific paper

We have estimated the speed and direction of propagation of a number of Coronal Mass Ejections (CMEs) using single-spacecraft data from the STEREO Heliospheric Imager (HI) wide-field cameras. In general, these values are in good agreement with those predicted by Thernisien, Vourlidas, and Howard in Solar Phys. 256, 111 - 130 (2009) using a forward modelling method to fit CMEs imaged by the STEREO COR2 coronagraphs. The directions of the CMEs predicted by both techniques are in good agreement despite the fact that many of the CMEs under study travel in directions that cause them to fade rapidly in the HI images. The velocities estimated from both techniques are in general agreement although there are some interesting differences that may provide evidence for the influence of the ambient solar wind on the speed of CMEs. The majority of CMEs with a velocity estimated to be below 400 km s-1 in the COR2 field of view have higher estimated velocities in the HI field of view, while, conversely, those with COR2 velocities estimated to be above 400 km s-1 have lower estimated HI velocities. We interpret this as evidence for the deceleration of fast CMEs and the acceleration of slower CMEs by interaction with the ambient solar wind beyond the COR2 field of view. We also show that the uncertainties in our derived parameters are influenced by the range of elongations over which each CME can be tracked. In order to reduce the uncertainty in the predicted arrival time of a CME at 1 Astronomical Unit (AU) to within six hours, the CME needs to be tracked out to at least 30 degrees elongation. This is in good agreement with predictions of the accuracy of our technique based on Monte Carlo simulations. Within the set of studied CMEs, there are two clear events that were predicted from the HI data to travel over another spacecraft; in-situ measurements at these other spacecraft confirm the accuracy of these predictions. The ability of the HI cameras to image Corotating Interaction Region (CIR)-entrained transients as well as CMEs can result in some ambiguity when trying to distinguishing individual signatures.

Affiliated with

Also associated with

No associations

Rating

Assessing the Accuracy of CME Speed and Trajectory Estimates from STEREO Observations Through a Comparison of Independent Methods does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Assessing the Accuracy of CME Speed and Trajectory Estimates from STEREO Observations Through a Comparison of Independent Methods, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Assessing the Accuracy of CME Speed and Trajectory Estimates from STEREO Observations Through a Comparison of Independent Methods will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-799662