PHYSICS AND ENGINEERING PHYSICS

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PHYSICS AND ENGINEERING PHYSICS
Early PolarDARN results J.-P. St.-Maurice, G.J.
Sofko, J. Wiid, D. Andre, A.V. Koustov, K.A.
McWilliams, R. K. Choudhary, R. Drayton, and G.C.
Hussey ISAS, University of Saskatchewan,
Saskatoon, SK, Canada R. A. Greenwald Johns
Hopkins University APL, Laurel, MD, USA
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History

• Construction was funded by CFI with matching from
  Saskatchewan and the CSA
• Radar was built in 2005
• First echoes on May 11, 2006
• Uninterrupted echoes since May 15

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Technical details

• Located at Rankin Inlet, 73.2 deg mag lat
• Boresight 5.7 deg E of N
• Resolute Bay in beam 5
• Wire antenna design doing very well. Minimal
  backlobes thanks to high quality reflector

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Typical echoes

• 6UT is local midnight
• Beam 5 over Resolute Bay and beam team looking
  more to the east
• Antisunward flow clearly seen
• Pos Doppler shift at local midnight and negative
  near local noon.

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July 12, 2006
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In spite of its small magnitude, the IMF affects
the convection, notably around 1720 UT, when
there is a jump in the IMB By
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Average convection over 24 hrs from Rankin alone
the fluctuations are hidden, but the trends remain
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40 min shift applied due to 600 km/s solar wind
speed
July 5, 2006
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• Echoes from the cusp, on the other side of the
  cap IMF related?
• Sustained sunward at other side from 745 to 759
  UT

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Conclusion on individual days

• Echoes are abundant, with many instances from
  clear across the polar cap (particularly when
  looking from the night sector).
• Even modest changes in IMF appear to trigger a
  convection response, as seen by PolarDARN
• Average convection pattern as expected, with the
  potential to study fluctuations in detail

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STATISTICAL PROPERTIES
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Statistics for June and July
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Statistics for Aug15-Sept 15
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Conclusions regarding statistics

• We definitely see farther inside the polar cap
  with Rankin Inlet
• Complements lower latitude data very well
• Antisunward convection over the PC stands out
• Narrow echoes at high latitudes on the nightside
• No evidence for seasonal variation just yet.

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Some examples of upcoming studies with AMISR

• Convection Rankin will provide good mesoscale
  coverage right along the LLBL and magnetotail
  boundary layers.
• Open-close field line boundaries PC events have
  been observed with Rankin as far as Resolute Bay
• Multiscale studies AMISR will provide much finer
  details of the convection in space, but PolarDARN
  radars will convey a wider field of view and a
  different context, particularly when coupled with
  other SuperDARN radars
• Gravity waves propagating towards the pole do
  they lose their coherence and will they produce
  TIDs in AMISR?
• When ion density plumes from midlatitudes pass
  over the AMISR field of view, will they trigger
  instabilities seen in PolarDARN?