Ground Based Magnetometry: Friday, June 25, 3:45 - 5:30 PM, Club Room Status and Plans Motivation: Ground based magnetic records have long played a crucial role in understanding the behavior of the magnetosphere and ionosphere. Our understanding of the magnetosphere has reached a stage where we need timing accuracies of 1 second or better and often sub nT precision. Moreover, it is no longer enough to have single sites, or even chains, but rather two dimensional arrays are needed. Fortunately, it is possible to build such precision instruments relatively inexpensively, and many groups have done so. Yet some regions are not adequately covered. In this session we review the status of operating networks, their data availability, their sampling frequency and future plans. We also welcome the discussion of new networks and where our needs are greatest. Speakers: M. Engebretson MACCS J. Waterman Greenland Array R. Clauer Greenland and Antarctic H. Kawano CPMN I. Mann SAMNET M. Moldwin MEASURE V. Angelopoulos IGPP/LANL P. Chi SMALL K. Schwingenschuh CHIMAG J. Cruz Abeyro Mexico A. Green USGS E. Zesta International Magnetometer Flotilla: A proposal All Discussion and Recommendations Inner Magnetosphere/Storms: Wednesday, June 23, 1:30 - 3.20 PM, Club Room Magnetic Pulsation Sounding of the Magnetospheric Density Motivation: Use of dual station measurements of Pc3 pulsations allows the determination of the location of lines resonating at a particular frequency. The resonant frequency depends on the equatorial mass density and, by monitoring this frequency, one can watch the plasmasphere fill as the daylight hours progress. Perhaps surprisingly, storms affect the plasmasphere to very low L-values and the evolution of these depletions and refillings can also be followed by the resonance monitoring technique. This session reviews the principles behind the technique; examines how best to identify the standing waves; and looks at some of the newest results in this field. Speakers: M. Moldwin Using ULF Waves to Sound Magnetospheric Density P. Chi Comparisons with Field Line Resonance Theory C. Russell Techniques to Identify Standing Wave Resonances P. Chi Plasmaspheric Density at L=2 During Storms B. Fraser ULF Wave Plasma Densities - Present and Future I. Mann Remote sensing of the Plasmasphere Density with SAMNET W. Worthington Alaskan studies A. Green Hungarian studies All Discussion and Recommendations Inner Magnetosphere/Storms: Wednesday, June 23, 10:20 - 12:10 AM, Club Room Sudden Impulse Propagation through the Magnetosphere Motivation: The propagation of a simple compression of the magnetopause through the magnetosphere while simple in concept is complicated by the dipolar geometry of the magnetic field, the tensor conductivity of the ionosphere and the multiple MHD modes in which waves travel. Thus we still do not completely understand the signatures that we see in the data, and their relative timing. Sufficient global coverage with high resolution magnetometers now exists that this problem can be addressed. Speakers: C. T. Russell SI Effects on the magnetosphere: Overview of Sept. 24, 1998 Events J. Raeder SI Triggered Oscillations of the Magnetosheath: Sept. 24, 1998 P. Chi SI Arrivals at Low Latitude on Sept. 24, 1998: HM wave or Waveguide mode? G. Lu Global Ionospheric Response to SI on Sept. 24, 1998 T. Moretto SI Propagation at High Latitude R. Mathis Waveguide modes and FLRs driven by the SIs M. Engebretson SI Propagation in the Polar Cap D. H. Lee SI Propagation in MHD Models J. A. Fedder SI/TCV Generation in an MHD Simulation All Summary and Recommendations Tail Substorm: Thursday, June 24, 10:20 - 12:10 AM Club Room Pi2 Propagation Motivation: Understanding the mechanism that initiates substorms requires knowing accurately the relative sequence of events. One of the temporal markers frequently used in substorm research is the generation of Pi2 pulsations, irregular oscillations of the magnetic field with periods of many tens of seconds. The speed of these waves is low with respect to the velocity of many of the particles that are energized in substorms. Thus, unless their propagation can be properly taken into account, they cannot help in distinguishing between mechanisms. In this session we examine what we know about the propagation of Pi2 pulsations and attempt to explain some paradoxical behavior in their arrival times. Speakers: S-I. Ohtani What do we Need to Learn about Pi2 Propagation V. Angelopoulos The Paradox of Low Latitude Pi2 Arrival Times T. Uozumi CPMN Observations of Pi2 Propagation L. Kepko The Effects of Density Gradients on Braking Impulses H. Zhao A Global Pi2 Event D-H. Lee MHD Wave Dynamics Associated with Pi2 Pulsations All Discussion and Recommendations