ISSI meeting 31 Mars-04 April Critical questions and tasks

Organization Identified question. Possible answers using experimental data: Constraints list Expertise available Definition of tasks and task coordinator Selection of events Data sets available

Almost perpendicular Crucial issues: The data of observations clearly show the presence of the short scales as small as several c / ω pe. Authors interpretation: Hada-Lembege, that means the dependence upon “the NUMBER OF REFLECTED IONS”.

Almost perpendicular – testable features Scale independent model: final solution does not contain other scale but ion Larmor radius Strongly dependent upon ion temperature: nonstationarity does not exist for ion beta larger than 0.3, electron dynamics has no any importance Critical question: potential should become larger than the energy of almost ALL upstream flowing particles

Almost perpendicular case – gradient catastrophe scenario Testable features: the steepening of the fronts grows, in terms of experimental data analysis it will be “scales decrease” the localized potential electric field increase, the gradients become larger than some limit, the overturning occurs electron dynamics is important: adiabatic-non-adiabatic heating

Testable features Electric field versus magnetic field scales Small scale electrostatic structures that can supply up to 20 % - 30 % of the whole potential jump Electric field scales analysis is crucial The remark to be addressed to the simulations: the results will be very sensitive to the grid size.

Wave activity (common for QPerp and AP) Definition of wave modes and their characteristics (omega – k dependence), Shock front generated waves versus generated by instabilities Pointing vector determination (where possible) Events selection

Instabilities associated mechanisms Waves identification Energy fluxes (Pointing vector) Necessary to have long foot and close to Perp

Almost Perp event for the simulations

QuasiPerp Why not to complet 24 of January by electric field scales, potential, density and wave energy Pointing vector having our version of QPerp There exists already electric field statistics for some quasi-perpendicular

Biscamp mechanism Wave properties determination

Ripples An important issue about almost tangential crossings where the « remote features » can appear

Simulations Two shocks : 24 January 2001 case 2D –Bertrand, 400 mass ratio, and Omega_p/ omega_c (2) Manfred 1D realistic mass ratio (1000) omega_p/omega_c (10) David long system hybrid Second shock: small beta, angle close to 90° The simulations: two codes (not 2D)