A. Rees

Three‐Dimensional Simulations of Shock Propagation in the Heliosphere and Beyond

Continuous input of solar data to time‐dependent 3D models is necessary for the study of shock propagation in the solar wind. We have performed time‐dependent 3D simulations using two different models, the full MHD based HHMS model and the kinematic HAF model, to study turbulence, particle acceleration and transport, cosmic ray modulation, and other physically significant phenomena. The continuous solar inputs to these models include solar data from source surface maps, Wang‐Sheeley‐Arge parameters, and information on solar events such as coronal mass ejections, flares, etc. Model output options include the time series at any location of specific solar wind and magnetic field parameters, entropy, momentum flux, shock propagation, longitude and latitude distributions of parameters, meridian slices at any orientation for any parameter throughout the 3D heliosphere, flux ropes, interplanetary coronal mass ejections, corotating interaction regions, merged interaction regions, etc. Through comparisons with in‐...

ICME Observations During the Ulysses Fast Latitude Scan

Between November 2000 and October 2001 the Ulysses spacecraft performed a fast traversal of the heliospheric latitudes between 80°S and 80°N, a period close to the activity maximum of the current solar cycle. This paper provides an overview of the Ulysses observations of the transient solar wind structures associated with coronal mass ejections (ICMEs) during this period. Compared to the previous Ulysses fast latitude scan near solar minimum in 1995, many more ICME related signatures were observed in the present data set. Events were encountered spread over the full latitude range between 80°S and 80°N. Those at high northern latitudes, where fast solar wind from a northern polar coronal hole had become re‐established, were of the over‐expanding type first identified in Ulysses data at mid‐latitudes near solar minimum. The signatures of these events and their latitude dependence are discussed and some ongoing and possible future studies with this data set are described.

3D modeling and turbulence: from the Sun to Voyager 1

We compare in‐situ observations at ACE and Ulysses with simulation results obtained from two different 3D models. Specifically, we look at results from the time dependent full 3D MHD HHMS model and also from the quick‐look tool: the 3D HAFv2 kinematic model. These comparisons provide insights into the 3D propagation of interplanetary shocks. We find excellent agreement between results from our 3D models and spacecraft data. Our results also suggest that Voyager 1 and Voyager 2 continue to observe the effects of solar‐induced shocks. The presence of planar magnetic structures is found from ACE to Voyager 1 in association with the Halloween 2003 events. These results are consistent with large‐scale compressions and may have possible consequences for cosmic ray modulation. The results of our models, along with numerous in‐situ observations, illustrate several aspects of interplanetary shock propagation that have implications for future modeling efforts. First, only continuous 3D models can accurately capture...