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.

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.