C.P. Escoubet - Böcker

Cluster was one of the two missions - the other being the Solar and Heliospheric Observatory (SOHO) - constituting the Solar Terrestrial Science Programme (STSP), the first "cornerstone" of ESA's Horizon 2000 Programme. After the catastrophic Ariane-5 accident on 4 June 1996 which destroyed the four Cluster spacecraft, the European Space Agency Science Programme Committee gave approval for the refurbishment of the spare Cluster spacecraft and its preparation for flight. This new spacecraft, considered to be the first of a new fleet, is called Phoenix. In the meantime various options for repeating the Cluster four-point measurements are being studied. Since Phoenix, as the fifth Cluster spacecraft, will be equipped with the spare Cluster experiments, the instrumentation articles in this book are still appropriate to the new mission. Furthermore, the objectives of the recovery mission, the ground systems, the ground observation programme and the theory and modelling efforts all remain unchanged.

8. 8 Boundary Layer Structure and Detached Plasma 305 8. 8. 1 Background 305 8. 8. 2 Structure inside the boundary layer 306 8. 8. 3 Observation of detached plasma 308 8. 8. 4 Summary 309 8. 9 Summary and Conclusions 310 References 312 9. CLUSTER AT THE MAGNETOSPHERIC CUSPS 321 9. 1 Introduction 321 9. 1. 1 Previous work 323 9. 1. 2 How Cluster investigates the cusp 325 9. 2 The High-Altitude Cusp 326 9. 2. 1 March 17, 2001 328 9. 2. 2 February 4, 2001 332 9. 2. 3 February 13, 2001 337 9. 2. 4 Statistical survey 340 9. 2. 5 Waves and turbulence 343 9. 3 The Mid-Altitude Cusp 352 9. 3. 1 Structure: Case study 352 9. 3. 2 Structure: Statistical survey 354 9. 3. 3 Ionospheric ions 354 9. 3. 4 Mid-altitude signatures of the LLBL 357 9. 4 Discussion 359 References 360 10. MAGNETOPAUSE PROCESSES 367 10. 1 Magnetopause Reconnection 368 10. 1. 1 Intermittent vs. quasi-steady reconnection 368 10. 1. 2 Component vs. anti-parallel reconnection 382 10. 1. 3 Tailward-of-the-cusp reconnection 385 10. 1. 4 Quantitative tests of reconnection occurrence 388 10. 1. 5 Summary 391 10. 2 Kelvin-Helmholtz Instability at the Flank Magnetopause 391 10. 3 Microphysics of Magnetopause Processes 396 10. 3. 1 Collisionless generalised Ohm’s law 397 10. 3. 2 Ion di?usion region observations 398 10. 3. 3 High-frequency waves 402 10. 3. 4 Lower-hybrid waves 405 10. 3.

8. 8 Boundary Layer Structure and Detached Plasma 305 8. 8. 1 Background 305 8. 8. 2 Structure inside the boundary layer 306 8. 8. 3 Observation of detached plasma 308 8. 8. 4 Summary 309 8. 9 Summary and Conclusions 310 References 312 9. CLUSTER AT THE MAGNETOSPHERIC CUSPS 321 9. 1 Introduction 321 9. 1. 1 Previous work 323 9. 1. 2 How Cluster investigates the cusp 325 9. 2 The High-Altitude Cusp 326 9. 2. 1 March 17, 2001 328 9. 2. 2 February 4, 2001 332 9. 2. 3 February 13, 2001 337 9. 2. 4 Statistical survey 340 9. 2. 5 Waves and turbulence 343 9. 3 The Mid-Altitude Cusp 352 9. 3. 1 Structure: Case study 352 9. 3. 2 Structure: Statistical survey 354 9. 3. 3 Ionospheric ions 354 9. 3. 4 Mid-altitude signatures of the LLBL 357 9. 4 Discussion 359 References 360 10. MAGNETOPAUSE PROCESSES 367 10. 1 Magnetopause Reconnection 368 10. 1. 1 Intermittent vs. quasi-steady reconnection 368 10. 1. 2 Component vs. anti-parallel reconnection 382 10. 1. 3 Tailward-of-the-cusp reconnection 385 10. 1. 4 Quantitative tests of reconnection occurrence 388 10. 1. 5 Summary 391 10. 2 Kelvin-Helmholtz Instability at the Flank Magnetopause 391 10. 3 Microphysics of Magnetopause Processes 396 10. 3. 1 Collisionless generalised Ohm’s law 397 10. 3. 2 Ion di?usion region observations 398 10. 3. 3 High-frequency waves 402 10. 3. 4 Lower-hybrid waves 405 10. 3.