Sounding the Ionospheric/ Thermospheric Effects of Storm Enhanced Density Plumes

M.L. Adrian, T.E. Moore, R.F. Pfaff, M.R. Collier, D.E. Rowland, J. Clemmons, 
J.B. Blake, J. Hecht, J.C. Foster, D.N. Baker, G. Garbe, and R. Greenwald


It has been theorized that storm enhanced density (SED) plumes observed in
Global Positioning System maps of total electron content (GPS/TEC) are a thermal
plasma signature of the erosion of the outer plasmasphere by subauroral
polarization streams (SAPS) penetration electric fields.  SAPS are themselves
thought to develop as a result of the redistribution of thermal ionospheric
plasmas uplifted from equatorial latitudes and deposited at lowÐ to
midÐlatitudes.  It has been demonstrated that these GPS/TEC SED signatures map
to the plasmaspheric drainage plumes observed by the Extreme Ultraviolet (EUV)
camera on the IMAGE satellite.  This strongly coupled innerÐ magnetospheric
interaction is thought responsible for numerous plasmaspheric and ring current
dynamics.  Additionally, the SAPS-GPS/TEC-plasmaspheric drainage plume structure
has recently been identified as a possible contributing factor in the
development of the slot region of the electron radiation belt.  While a
large-scale, global picture of the SAPS-driven SED-plasmaspheric drainage plume
dynamics and structure has begun to emerge, little is known of the local,
micro-scale physics of these structures.  A structure that, from the perspective
of GPS/TEC observations, generally forms over the Atlantic off the eastern coast
of the North America and moves westward via corotation, often passing directly
over Wallops Flight Facility (WFF).

Owing to a fortunate nexus of phenomenon and resources, we propose to develop
and launch from WFF a highly focused sounding rocket, named it-PLUMEs, to study
the ionospheric/thermospheric consequences of the development and evolution of a
storm/SAPSÐdriven SED plume.  The it-PLUMEs payload will be instrumented
specifically to make quantitative measurements of the localized SAPS electric
and associated magnetic fields, the thermal/superthermal electron and ion plasma
response to these fields, the composition of the neutral atmosphere and its flow
as a consequence of SAPS-driven ionospheric modification, and precipitating
radiation belt electrons.  Supported by the MIT Millstone Hill and SuperDARN
Wallops Island ground-based incoherent scatter radars (ISRs), the it-PLUMEs
investigation will be uniquely positioned to address the
ionospheric/thermospheric localized consequences of the development and
propagation of storm enhanced density plumes at the origins of these
highly-coupled inner-magnetospheric phenomenon.

Herein, we present the scientific motivation/justification for the development
of the it-PLUMEs sounding rocket and our proposed methodology.

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Global Aspects of Magnetosphere-Ionosphere Coupling, 2006 Yosemite Workshop, 
Yosemite National Park, CA, USA, 7-10 February 2006