Tracking Coronal Mass Ejections through the Space Environment

Abstract:

Severe space weather effects at Earth are usually associated with geomagnetic storms, the strongest of which are driven by coronal mass ejections (CMEs). In the last decade or so we have been able to track CMEs in white light near the Sun by coronagraphs and through the inner heliosphere with wide-field viewing heliospheric imagers. Many Earth-directed CMEs have now been observed by solar and HI instruments and in some cases their signatures have been detected in situ at Earth/L1 by ACE or Wind and/or by one or both STEREO spacecraft. STEREO has a Space Weather Group which has used these Sun-to-STEREO/L1 data sets to make near-real time forecasts of CMEs using a variety of techniques. We discuss these results for several selected events. Recently, a new STEREO processing pipeline has been developed that removes background noise to allow improved tracking of CME structures from the Sun to 1 AU. We will discuss the tracking and modeling of CMEs and their internal structures such as magnetic clouds using these new data, and how such techniques can be used to improve space weather prediction.