Authors: Bernard V. Jackson (UCSD, LaJolla, CA, USA), Matthew Bracamontes (UCSD, LaJolla, CA, USA), Andrew Buffington (UCSD, LaJolla, CA, USA), Jackie A. Davies (UK STFC, RAL Space, UK), Mario M. Bisi (UK STFC, RAL Space, UK), Kazumasa Iwai (ISEE, Nagoya University, Nagoya, Japan)

We now use the University of California, San Diego (UCSD) iterative tomography analyses to provide high-resolution Solar Mass Ejection Imager (SMEI) and STEREO Heliospheric Imager (HI) 3-D reconstructed plasma densities in the inner heliosphere. These analyses also include Earth-based interplanetary scintillation (IPS) instrumentation data from the Institute for Space-Earth Environmental Research (ISEE), Japan, to help provide more refined high-resolution plasma densities and velocities. Here we present reconstructed densities at one-hour cadences, and with latitude and longitude resolutions at Earth of a few degrees, and solar distance resolution of 0.02 AU. These are well within the regime of mesoscale structures that take up to a half a day to pass over an observer near Earth. The analyses show that the larger mesoscale structures that propagate past Earth are often very “corrugated” and “patchy” in our analyses. Shock sheaths at the fronts of the fastest CMEs also include this structured response. These 3-D reconstructions explain some of the differences inherent in multipoint in-situ measurements from spacecraft near Earth and further afield (e.g., at STEREO and at other interplanetary spacecraft). Patchy structures are poorly represented by many current heliospheric modeling techniques that assume smooth structures propagate outward from the solar surface. This simplification also presents difficulties for most forecasting techniques that require a smooth outward-moving front for ICME arrival timing, unlike those revealed by our analyses.