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R. F. Pfaff, C. Steigies, M. Acuña, H. Freudenreich, Goddard Space Flight Center, MD

Combined Sounding Rocket and SuperDarn/EISCAT Radar Observations of Plasma Convection, Shear, Irregularities and other Phenomena in the Cusp and Boundary Layer during IMF Bz Negative and By Negative Conditions. R. F. Pfaff, C. Steigies, M. Acuña, H. Freudenreich, Goddard Space Flight Center, MD

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R. F. Pfaff, C. Steigies, M. Acuña, H. Freudenreich, Goddard Space Flight Center, MD

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  1. Combined Sounding Rocket and SuperDarn/EISCAT Radar Observations of Plasma Convection, Shear, Irregularities and other Phenomena in the Cusp and Boundary Layer during IMF Bz Negativeand By NegativeConditions R. F. Pfaff, C. Steigies, M. Acuña, H. Freudenreich, Goddard Space Flight Center, MD T. Yeoman, S. Milan, M. Lester, Univ. of Leicester, UK P. E. Sandholt, K. Oksavik, J. Moen, Univ. of Oslo, Norway J. Clemmons, P. Slocum, Aerospace Corporation, El Segundo, CA D. Knudsen, J. Burchill, Univ. of Calgary, Calgary, Canada M. Coplan, A. Gross, Univ. of Maryland, College Park, MD H. Deferaudy, L. Rezeau, D. Fontaine, CETP, France J.-L. Pincon, V. Krasnosselskikh, CNRS, Orléans, France G. Delory, Univ. of California, Berkeley, CA S. Basu, AFRL, Hanscom AFB, MA C. Deehr, Univ. of Alaska, Fairbanks D. Lorentzen, UNIS, Spitzbergen American Geophysical Union 12 December 2003

  2. Scientific Motivation The Goddard Cusp rocket/radar mission combined a sounding rocket with a comprehensive fields and particles instrument suite with ground-based observations in order to investigate: • Electrodynamics and convection patterns of the cusp, boundary region, and open/closed magnetic field line interface and their relation to the IMF. • Cusp irregularities and Alfvén waves in the cusp and boundary region ionosphere and their variations with altitude; • Acceleration processes in the cusp.

  3. B Ny Alesund Rocket Trajectory

  4. Bx By Bz Launch (82 min delay) Btotal Density Speed Temp.

  5. Ny Alesund Ny Alesund Longyearbyen Bjorn Longyearbyen Bjorn Launch From 11:09-11:24 UT, Strong anti-sunward flow during prevailing By negative (Svalgaard-Mansurov effect, 1973)

  6. Plasma Density Upleg Downleg Altitude, km m-3 m-3

  7. Data courtesy Santimay Basu, AFRL

  8. Closed Cusp Boundary region?

  9. Summary • The GSFC Cusp sounding rocket was launched directly into the cusp achieving an apogee of 771 km. • The payload encountered a distorted two-cell convection pattern indicative of the By < 0 and Bz < 0 IMF. • DC electric field measurements revealed an evolving cusp convection pattern, with strong eastward flows in the cusp proper, variable flows in the boundary regions, and westward flows in the region of closed field lines equatorward of the cusp. • Radar measurements provide the context for the rocket measurements and reveal an evolving two cell convection pattern. • Detailed rocket measured E x B drifts and CUTLASS radar flows agree in direction and general magnitude except at the start of the flight when the rocket-measured DC electric fields were very large.

  10. Summary (Cont.) • Intense DN and DE irregularities were observed in the cusp and boundary region, that were particularly strong at and below the F-peak near 300 km. • The irregularities were observed through the upleg, varied in accordance with DC electric field variations, and provided a signature that the payload was on open field lines. • The irregularities were the presumed source for intense scintillations observed on the ground by S. Basu (AFRL). • Energetic particle and magnetometer measurements support the cusp/boundary region interpretation and reveal a dynamic electrodynamic structuring throughout the cusp ionosphere. • Wave particle correlations indicate that acceleration processes are plentiful within the cusp and boundary region.

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