3D Reconstruction of Density Enhancements Behind Interplanetary Shocks from Solar Mass Ejection Imager White-Light Observations

The Solar Mass Ejection Imager (SMEI) observes the increased brightness from the density enhancements behind interplanetary shocks that are also observed in situ near the Earth. We use the University of California, San Diego (UCSD) time‐dependent three‐dimensional (3D) reconstruction technique to map the extents of these density enhancements. Here, we examine shock‐density enhancements associated with several well‐known interplanetary coronal mass ejections (ICMEs) including those on 30 May 2003 and on 21 January 2005. We compare these densities with reconstructed velocities from the Solar‐Terrestrial Environment Laboratory (STELab) interplanetary scintillation (IPS) observations for the 30 May 2003 ICME, and show the shock is present at the front edge of the reconstructed high speed solar wind. The SMEI analyses certify that the brightness enhancements observed behind shocks identified and measured in situ near Earth are a direct response to the plasma density enhancements that follow the shocked plasma.