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ISSI meeting 31 Mars-04 April

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.

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ISSI meeting 31 Mars-04 April

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  1. ISSI meeting 31 Mars-04 April Critical questions and tasks

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

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

  4. 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

  5. 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

  6. 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.

  7. 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

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

  9. Almost Perp event for the simulations

  10. 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

  11. Biscamp mechanism • Wave properties determination

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

  13. 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)

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