Splinter Group - Chairs: T. Mukai (ISAS), N. Gopalswamy (NASA/GSFC)

Program

9:00-10:30        Plenary Session - H. Petschek, chair

M. Ashour-Abdalla "An MHD View of Magnetotail Reconnection: Causes and Consequences"

    For forty years now researchers have been studying magnetic field
  reconnection in the Earth’s magnetotail.  Our talk will draw on results
  from recent MHD simulations to consider reconnection on a global scale
  and use model results to investigate both the causes and the consequences
  of tail reconnection.  Initially, all MHD reconnection studies employed
  idealized solar wind input to drive the magnetosphere.  This approach is
  particularly valuable in conducting controlled numerical experiments to
  determine how varying a given solar wind parameter affects the magnetospheric
  configuration and reconnection.  Under the auspices of the ISTP program,
  we enhanced this approach by using observed solar wind parameters to simulate
  actual cases.  The fleet of ISTP spacecraft collected the observational data,
  thereby providing not only the solar wind input but also the means to validate
  our modeled magnetosphere. The resulting magnetospheric model is very complex
  and as a result difficult to interpret.  Indeed, researchers commonly resort to
  using the simpler method with idealized solar wind input to interpret the more
  realistic calculations. We will demonstrate this procedure in analyzing the
  magnetotail reconnection that occurred on December 22, 1996.  This event is
  particularly interesting because Geotail and Interball were both located near
  each other within the magnetotail throughout the event and thus were positioned
  to observe the reconnection. In addition, the Polar satellite provided auroral
  images throughout this event.  The interval was characterized by a series of
  azimuthally limited neutral lines. The reconnection was only indirectly related
  to the aurora.  Reconnection altered the magnetospheric convection.  When the
  earthward convecting plasmas from the reconnection reached the near-Earth
  magnetosphere (5-7 RE) they were diverted into the auroral zone.

Jeff Hughes "The Global Consequences of Magnetic Reconnection in the Magnetosphere."

  Much research into magnetic reconnection has necessarily focused on the
  physical mechanisms by which ideal MHD breaks down and the reconnection
  process occurs. However, when looked on from a more global scale, the
  consequences of reconnection are largely independent of the physical
  mechanisms by which it occurs. Of much greater importance on the global
  scale is where does reconnection take place, and is the reconnection rate
  steady or time varying on the short (minutes) time scale. The first of
  these questions implicitly assumes the reconnection is a localized process.
  Most reconnection theory and well as most cartoons on both the local and
  global scales depict reconnection as a two-dimensional process using the
  traditional x-line geometry. These pictures suggest that reconnection can
  be localised; that only a small finite length of the field line or flux
  tube passes through the so-called diffusion region. However Cowley (1973)
  showed that reconnection in a finite three-dimensional geometry is non-
  localized. During the reconnection process an extended length of the flux
  tube stretching along the magnetopause is involved. Some of his conclusions
  are being borne out by modern MHD simulations, that show that reconnection
  can lead to parallel electric fields over extended lengths of flux tubes
  near the magnetopause. This talk will discuss these global aspects of
  reconnection in the context of the earth's magnetosphere.




10:45-17:45       Reconnection Consequences
                    [T. Mukai, N. Gopalswamy, L. Ofman]
                    [Building 26, Room 205]

2-a) Magnetotail								10:45-12:30

S. Machida        "Magnetotail Evolution During Substorms" 
A.A. Petrukovich  "Interball and Geotail Observation of Reconnection 
                    Signatures in the Magnetotail"
T. Terasawa       "Tail Plasma Transport during Northward IMF Periods"
Jim Slavin        "ISTP Observations of the Temporal and Spatial Evolution of 
                    Substorms on July 9, 1997"
Aki Ieda          "The Relationship Between Magnetotail Dynamics and Substorm 
                    Onset Longitudes Determined from Spacecraft Images"

Lunch Break									12:30-1:30

2-b) Magnetopause								1:30-3:30

Tai Phan          "Dual-spacecraft observations of dayside reconnection:
                    Implications for large-scale reconnection"
K. Maezawa        "Evidence for High-Latitude Reconnection during Periods of 
                    Southward as well as Northward IMF"
Terry Onsager     "Magnetic Reconnection under Northward IMF"
S. Fuselier       "Magnetic Field Topology for Northward IMF"
K. Trattner       "Variability of Reconnection at the Magnetopause" 
Nelson Maynard    "The Magnetospheric Sash: Lessons for Model-Data Comparisons"

Coffee break									3:30-3:45

2-c) Solar corona								3:45-4:45

Hugh Hudson       "Flow Fields in Flares"
Russ Dalburg      "Spontaneous Magnetic Reconnection in the Solar Corona"
Judy Karpen       "Dynamic and Energetic Signatures of Reconnecting Solar 
                    Arcades"

2-d) Similarities/dissimilarties in various environments			4:45-5:30

Chris Russell     "Reconnection in Planetary and Interplanetary Environments" 
All               Free Discussions

2-e) Closing remarks & summary							5:30-5:45