1. Space Science MO&DA Programs - April 2001 - Page 1 SS Special Section of JGR Space Physics Marks Polar’s 5th Anniversary September 4, 1996 This April special section is first of two Polar special sections to be published in JGR this year Some featured articles: Mozer et al., Origin & geometry of upward parallel electric fields Frank et al., Encounters of the substorm onset region Reeves et al., The storm-substorm relationship Crumley et al., Studies of ion solitary waves Maynard et al., The magnetospheric “sash” and its implications Trattner et al., Origins of cusp energetic particles Fuselier et al., O+ in the cusp, implications for reconnection 26 papers of new accomplishments in particle acceleration, reconnection, substorm onset, ion outflow, auroral power and precipitation, ad energetic particles of the radiation belts.

2. Space Science MO&DA Programs - April 2001 - Page 2 SS Polar’s orbit has precessed so that it samples regions near the dayside equatorial magnetopause (low- latitude boundary layer, turbulent boundary layer, magnetosphere, and magnetosheath) with high-temporal and spatial resolution. Measurements: Polar Recovers TIMAS, Immediately Detects New Terrestrial Ion Signature On March 27, 2001 the Polar spacecraft switched to its backup telemetry module and restored telemetry capture of the TIMAS mid- energy mass spectrometer.

3. Space Science MO&DA Programs - April 2001 - Page 3 SS Observations: Short description... Polar Recovers TIMAS, Immediately Detects New Terrestrial Ion Signatures

4. Space Science MO&DA Programs - April 2001 - Page 4 SS Other Polar Particle Detectors Support TIMAS Observations Observations: TIDE low-energy ion data, from a similar orbit, clearly demonstrate the presence of the terrestrial source ions within the turbulent boundary layer. Within this layer, circularly polarized waves accelerate the plasmaspheric-like ions to 30-40 km/s perpendicular toB.

5. Space Science MO&DA Programs - April 2001 - Page 5 SS Interpretation and Implications: New Polar Dayside LLBL Observations Promise what???