International ISSI Team on ''Heliosheath Processes and Structure of the Heliopause: Modeling Energetic Particles, Cosmic Rays, and Magnetic Fields''


Motivation and Goals

The Voyager 1 and 2 (V1 and V2) spacecraft are the most distant spacecraft which, after 35 years of historic discoveries are exploring the boundaries of the heliosphere. Launched in October 2008, the Interstellar Boundary Explorer (IBEX) has also started exploring the outermost reaches of the heliosphere, but from an orbit at 1 Astronomical Unit using the measurements of energetic neutral atoms (ENAs) created in the boundary regions separating the heliosphere from the local interstellar medium. Numerical modeling of ions, neutral atoms, and magnetic fields critically benefits from data obtained by these spacecraft. To perform such numerical analysis, we have developed a new generation of physical models that can adequately describe the distributions of energetic particles, as well as the thermal plasma, in the inner and outer heliosheath. From the newly emerging scenarios arises a deeper understanding of the physics of this interface region. This requires close international cooperation of theorists, observers, and modelers. To trigger such cooperation, we will bring together a group of experts who cover all required fields and who have first-hand access to the most recent measurements. Our group has developed a number of sophisticated modeling tools, which offer quantitative explanations for such surprising observations as negative solar wind velocities at V1 and the IBEX ribbon. We have recently demonstrated the possibility of a dramatic decrease in the anomalous cosmic ray (ACR) flux at V1 being due to solar cycle effects similar to those resulting in the solar wind sunward flow. We anticipate producing new results which will be of importance for heliospheric physics (observation-based plasma model with pickup ions treated kinetically, particle acceleration, cosmic ray transport, magnetic reconnection, turbulence, heliopause instabilities, etc.) and physics of the local interstellar medium. Our numerical codes will be used to perform multi-component MHD simulations, kinetic modeling based on the Boltzmann and Fokker-Planck equations, and particle-in-cell (PIC) computations. Modeling results will be compared with the spacecraft measurements and used for the predictions of what Voyagers may expect when they cross the heliopause. Our efforts will complement the mission of ISSI as an international organization aimed to provide a multi- and interdisciplinary setting to reach out for new scientific horizons.

Team Members

(from left to right:)
Marius Potgieter, North-West University, Campus Potchefstroom, South Africa
Andrzej Czechowski, Space Research Centre, Warsaw, Poland
Roelf Du Toit Strauss, North-West University, Campus Potchefstroom, South Africa
Ming Zhang, Florida Institute of Technology, Melbourne, USA
Nick Pogorelov, University of Alabama, Huntsville, USA (Team Leader)
Bertrand Lembege, Labor. Atmosphères, Milieux, Observ. Spatiales, Paris, France
Jakobus le Roux, University of Alabama, Huntsville, USA
Klaus Scherer, Ruhr-Universität Bochum, Germany
Gary Zank, University of Alabama, Huntsville, USA
Horst Fichtner, Ruhr-Universität Bochum, Germany (Co-Leader)
Not on photo:
Alex Lazarian, University of Wisconsin at Madison, USA
Ed Stone, California Institute of Technology, Pasadena, USA
Tobias Wiengarten, Ruhr-Universität Bochum, Germany
Peter Wurz, Universität Bern, Switzerland

Publications resulting from/related to the ISSI Team                   Final Report

First Meeting, 13-16 January 2014:    Programme    Talks (internal link)

Second Meeting, 17-20 November 2014:    Programme    Talks (internal link)