The magnetosphere is an open system that interacts with the solar wind. In this system, solar wind energy continuously permeates different regions of the magnetosphere through electromagnetic processes, which we can well describe in terms of current systems. In fact, our ability to use various methods to study magnetospheric current systems has recently prompted significant progress in our understanding of the phenomenon. Unprecedented coverage of satellite and ground-based observations has advanced global approaches to magnetospheric current systems, whereas advanced measurements of electromagnetic fields and particles have brought new insights about micro?]processes. Increased computer capabilities have enabled us to simulate the dynamics not only of the terrestrial magnetosphere but also the magnetospheres of other planets. Based on such developments, the present volume revisits outstanding issues about magnetospheric current systems.
Dedication
Laurence J. Zanetti ix
Preface
Shin-ichi Ohtani, Ryoichi Fujii, Michael Hesse, and Robert L. Lysak xi
Frameworks for Describing Current Systems
TUTORIAL: Newton, Maxwell, and Magnetospheric Physics
E. N. Parker 1
Paradigm Transitionin Cosmic Plasma Physics, Magnetic Reconnection and the Generation of Field-Aligned Current
Yan Song and Robert L. Lysak 11
FAST Observations of Electromagnetic Stresses Applied to the Polar Ionosphere
R. J. Strangeway, R. C. Elphic, W. J. Peria, and C. W. Carlson 21
Electric Current Approach to Magnetospheric Physics and the Distinction Between Current Disruption and Magnetic Reconnection
A. T. Y. Lui 31
Modeling Magnetospheric Current Systems
Global Geometry of Magnetospheric Currents Inferred From MHD Simulations
G. L. Siscoe, N. U. Crooker, G. M. Erickson, B. U. O. Sonnerup, K. D. Siebert, D. R. Weimer, W. W. White, and N. C. Maynard 41
Field-Aligned-Current Systems in the Numerically Simulated Magnetosphere
T. Tanaka 53
Recent Progress in the Data-Based Modeling of Magnetospheric Currents
N. A. Tsyganenko 61
Field Line Mapping and Birkeland Currents
F. R. Toffoletto and T. W. Hill 71
Magnetotail Currents During the Growth Phase and Local Auroral Breakup
T. I. Pulkkinen, M. V. Kubyshkina, D. N. Baker, L. L. Cogger, S. Kokubun, T. Mukai, H. J. Singer, J. A. Slavin, and L. Zelenyi 81
Magnetosphere-Ionosphere Coupling
TUTORIAL: Magnetosphere-Ionosphere Interactions: A Tutorial Review
S. W. H. Cowley 91
TUTORIAL: Field-Aligned Currents in Geospace: Substance and Significance
Takesi lijima 107
TUTORIAL: Ionospheric Electrodynamics: A Tutorial
A. D. Richmond and J. P Thayer 131
The Role of Alfven Waves in the Formation of Auroral Parallel Electric Fields
Robert L. Lysak and Yan Song 147
A Three-Dimensional Simulation of the Kelvin-Helmholtz Instability
Kristi A. Keller, Robert L. Lysak, and Yan Song 157
The Role of Space-Time Dependent Ionospheric Conductivity in the Evolution of Field Line Resonances: Relation to Auroral Arc
Manju Prakash and Robert Rankin 165
FAST O bservations of Upward A ccelerated E lectron Beams and the Downward Field-Aligned Current Region
R. C. Elphic, J. Bonnell, R .J . Strangeway, C. W. Carlson, M. Temerin, J.P. McFadden, R. E. Ergun, and W. Peria 173
Characteristics of Field-Aligned Currents Near the Auroral Acceleration Region-FAST Observations
W. J. Peria, C. W. Carlson, R. E. Ergun, J. P. McFadden, J. Bonnell, R. C. Elphic, and R. J. Strangeway 181
Auroral Surge Currents and Electrodynamics With FAST and VIS
S. A. Cummer, R. R. Vondrak, R. F. Pfaff, J. W. Gjerloev, C. W. Carlson, R. E. Ergun, W. J. Peria, R. C. Elphic, R. J . Strangeway, J. B. Sigwarth, and L. A. Frank 191
A Synthetic View of the Magnetospheric-Ionospheric Current System Associated With Substorms
Gang Lu 199
The Harang Discontinuity in Auroral Substorms
J. W. Gjerloev, E. Friis-Christensen, R. A. Hoffman, and S. A. Cummer 209
The Effect of the January 10, 1997, Pressure Pulse on the Magnetosphere-Ionosphere Current System
E. Zesta, H. J. Singer, D. Lummerzheim, C. T. Russell, L. R. Lyons, and M. J. Brittnacher 217
Ionospheric Shear Flow Situations Observed by the MIRACLE Network, and the Concept of Harang Discontinuity
0. Amm, P. Janhunen, H. J. Opgenoorth, T. I. Pulkkinen, and A. Viljanen 227
Statistical Characteristics of Field-Aligned Currents in the Earth's Inner Magnetosphere
Francis K. Chun and Christopher T. Russell 237
Independencoy of the Dayside Field-Aligned Current System: A Restriction to Cusp Models
M. Yamauchi, R. Lundin, L . Eliasson, S. Ohtani, P -A. Lindqvist, and R. P. Lepping 245
Disappearance of Large-Scale Field-Aligned Current Systems: Implications for the Solar Wind-Magnetosphere Coupling
S. Ohtani, T. Higuchi, T. Sotirelis, and P.T . Newell 253
Storm-Time Energetic Particle Penetration Into the Inner Magnetospheres and the Electromotive Force in the Subauroral Ion Drift Current Circuit
J. De Keyser 261
Magnetospheric Electrodynamics
Structured Currents Associated With Tail Bursty Flows During Turbulent Plasma Sheet Conditions
L. R. Lyons, T. Nagai, J. C. Samson, E. Zesta, T. Yamamoto, T. Mukai, A. Nishida, and S. Kokubun 267
Substorm Associated Tail Current Changes Inferred From Lobe Magnetic Field Observations
Christian Jacquey 275
The Current Disruption Myth
Joachim Birn and Michael Hesse 285
Near- and Mid-tail Current Flow During Substorms: Small-and Large-Scale Aspects of Current Disruption
Michael Hesse and Joachim Birn 295
Intrinsic Variability in the Quiet-Time Magnetotail
Vahe Peroomian, Maha Ashour-Abdalla, and Lev M . Zelenyi 305
Self-Consistent Model of 1D Current Sheet: The Role of Drift, Magnetization and Diamagnetic Currents
Helmi V. Malova, Mikhail I. Sitnov, Lev M. Zelenyi, and Surja Sharma 313
Pressure Anisotropy and By in the Magnetotail Current Sheet
Richard L. Kaufmann, Bryan M. Ball, W. R. Paterson, and L. A. Frank 323
Formation of the Storm-Time Ring Current and the Dst Field: Some Recent Topics
T. lyemori 331
Current Systems in Other Magnetospheres
TUTORIAL: Currents and Flows in Distant Magnetospheres
Margaret Galland Kivelson 339
Rotational Current Systems and the Offset lo Plasma Torus
Duane H. Pontius Jr. 353
MHD Simulations of Current Systems in Planetary Magnetospheres: Mercury and Saturn
Tamas I. Gombosi, Darren L. DeZeeuw, Clinton PT. Groth, Kenneth C. Hansen, Konstantin Kabin, Kenneth G. Powell 363
Currents in Mercury's Magnetosphere
Karl-Heinz Glassmeier 371
New Analysis Techniques
A New Technique for the Mapping of Ionospheric Field-Aligned Currents From Satellite Magnetometer Data
Daniel R. Weimer 381
Automatic Identification of Large-Scale Field-Aligned Current Structures and its Application to Night-Side Current Systems
T. Higuchi and S. Ohtani 389
Symmetry Breaking and Nonlinear Wave-Wave Interaction in Current Disruption: Possible Evidence for a Phase Transition
Giuseppe Consolini and Anthony T. Y. Lui 395