Heliophysics Science Division
Sciences and Exploration Directorate - NASA's Goddard Space Flight Center

March 4, 2011, 12:00 pm - 1:00 pm

March 4, 2011, 12:00 pm - 1:00 pm

SDO/AIA observations and models of Kelvin-Helmholtz instability associated with CME's



Dr. Leon Ofman, NASA GSFC/Catholic University of America

The Kelvin-Helmholtz (KH) instability was first described in fluid flows in the 19th century. It is commonly observed in nature on Earth, on other planets, and in laboratory fluids. The magnetic counterpart of KH instability was studied extensively as well, and was identified in planetary magnetospheres. The KH instability is believed to play an important role in the transition to turbulence an in the cascade of large scale fluctuations energy to small (dissipation) scales. In the solar corona the KH instability was associated theoretically and in MHD models with plasma flows, reconnection jets, waves, and with coronal heating. However, only recently direct observations of KH instability related features were obtained in solar coronal magnetized plasma in EUV with SDO/AIA. The features or wave-trains of vortices are associated with erupting CMEs, and appear on the boundary between the erupting and non-erupting regions. The observation of these vortices is now possible in multiple EUV wavelengths thanks to the high cadence and high resolution of SDO/AIA. An overview of KH instability, and the results of recent SDO/AIA observations of KH instability as well as MHD models in the solar corona will be presented. The relation of KH instability to the cascade of energy in the solar coronal plasma will be discussed.