Large and small scale solar eruptions might all be triggered by a single process, according to new research that leads to better understanding of the Sun's activity. Researchers at Durham University and NASA's Goddard Space Flight Center, USA, used 3D computer simulations to show a theoretical link between large and small scale eruptions that were previously thought to be driven by different processes. They looked at the mechanism behind coronal jets - relatively small bursts of plasma (hot gas) from the Sun - and much larger-scale coronal mass ejections (CMEs), where giant clouds of plasma and magnetic field are blown into space at high speed. Read more
SOHO and Hinode Offer New Insight Into Solar Eruptions
The sun is home to the largest explosions in the solar system. For example, it regularly produces huge eruptions known as coronal mass ejections when billions of tons of solar material erupt off the sun, spewing into space and racing toward the very edges of the solar system. Scientists know that these ejections, called CMEs, are caused by magnetic energy building up on the sun, which suddenly releases. But the details of what causes the build up and triggers the release are not precisely understood. Read more
Title: A New Class of Complex Ejecta Resulting From the Interaction of Two Coronal Mass Ejections With Different Orientations and Its Expected Geo-Effectiveness Author: N. Lugaz, C. J. Farrugia
A significant portion of transients measured by spacecraft at 1 AU does not show the well-defined properties of magnetic clouds (MCs). Here, we propose a new class of complex, non-MC ejecta resulting from the interaction of two CMEs with different orientation, which differ from the previously studied multiple-MC event. At 1 AU, they are associated with a smooth rotation of the magnetic field vector over an extended duration and do not show clear signs of interaction. We determine the characteristics of such events based on a numerical simulation and identify and analyze a potential case in the long-duration CME measured in situ in 2001 March 19-22. Such events may result in intense, long-duration geo-magnetic storms, with sawtooth events, and may sometimes be misidentified as isolated CMEs.