4 Year Inner Magnetosphere/Storms Campaign - 1st Draft Strategy

Key Unanswered

Questions

Needed Knowledge/

Modeling Tools

 

Suggested Strategies

Global Issues

    

How do the highly-structured and temporarlly-varying electric fields in the inner magnetosphere impact ring current development, thermal plasma heating and structuring, radiation belt dynamics and overall magnetic storm development?

  • Need physical models of the electrodynamics of the IM driven by (and tested against) data to explore how the large-scale E field is established.

  • Need parameterized semi-empirical models that have been tested against physical models and data.
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    Data Analysis:

  • Studies using particles as tracers

  • Studies of the temporally-varying potentials derived from ENA maps

  • Studies of patterns derived by mapping of observed ionospheric E fields

  • Studies of CRRES electric field data in the IM

  • Comparison with plasma flow measured at geosynchronous orbit

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    Modelling Studies:

  • Comparison of RCM runs with data

  • Parameterized electric field model development & testing

  • Event studies and test runs of other physical models with all available electric field models & comparison with data
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    What are the key elements that distinguish storms (e.g., solar max versus solar min, CME vs. high-speed-stream driven, severe vs. minor in intensity)? How do preconditioning and initial state (non-linearity effects) figure into this?

  • Improved representations of electric and magnetic fields, the low-altitude portion of the geocorona, composition, density & temperature variations in IM plasma source populations, etc.
    		•

  • Comparison of carefully selected event studies representative of these types of storm events.

  • Statistical studies

  • Parametric modeling studies.
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    What are the details of the global energy balance during storms? What portion of the energy is available to the IM? What is the nature of the coupling between storms and substorms? How does the energy balance vary among storms with different characteristics, different drivers, etc.?

    Better understanding of

    • the physical meaning of the Dst index and local time asymmetries in the disturbance magnetic field
    • how effective are predictive functions based on upstream solar wind conditions at representing the true energy balance?

  • Comparative event studies (same as above)

  • MHD model estimates of the energy input for selected solar wind conditions or events

  • Comparison of outputs of physical models with predictive functions based on upstream solar wind inputs.
    •

    How does the composition of IM source populations and the variability in this composition impact the storm development and recovery?

    How do we define and model in a time-dependent fashion:

  • SW, ionospheric, & plasmaspheric (?) sources for the near-Earth plasmasheet?

  • ionospheric plasma directly injected into the IM?

  • direct effects on the IM of the auroral zone when it moves to low L during storms?
    •

  • Coordinate activities in this area with the Magnetosphere-Ionosphere Coupling Campaign

  • Model the temporal changes in the composition of the inner plasma sheet using a parameterized ionospheric outflow lower BC (based on DE data) as input to a two-fluid (H+ and O+) MHD model. Use as outer BC for IM models

  • Further statistical and event studies of s/c observations (particularly useful would be analysis of low energy ion data from CRRES, POLAR, FREJA, AKEBONO for evidence of ionospheric injections directly into the IM)
    •

    Ring Current Issues

    		    

    What are the important ring current formation and loss processes? How do they vary between storms with different characteristics? What is the contribution of the electron ring current?

    Modeling & investigation

  • non-adiabatic effects on RC particles due to B field distortions

  • wave-particle interactions

  • effects of compressions

  • quantifying & understanding precipitation losses

  • understanding mechanisms that produce variations in the source population

    electric and magnetic field models
    •

  • ENA measurements to follow global decay for selected events.

  • Statistical studies and event analysis of IM precipitation during storms

  • RC model tests of proposed convection field models, convection + induction field models

  • Event studies of WPI where detailed wave and particle distributions are available

  • Statistical studies of wave observations in the IM

  • Observational studies of ion losses at the magnetopause (esp., during compressions)

  • Event and statistical studies investigating the impacts of variations in the source

    population

     

     

     

     

     

     

     

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    Radiation Belt Issues

    		    

    What are the sources, losses, acceleration and energization mechanisms that are responsible for the build-up and decay of the radiation belts? What are the solar wind drivers?

    Need to identify

  • source populations and their origins

  • waves responsible for diffusion

  • temporal variations in the diffusion coefficients (DLL, Daa, DEE, etc.)

  • effects of magnetopause losses

    •

    Need better electric and magnetic field models, thermal plasma models

    Observational tests of specific theories

  • Statistical studies of waves during RB formation

  • Studies of RB pitch angle distributions to test acceleration theories

  • Statistical studies to identify source distributions using space phase density

  • Observational studies of losses at compressed magnetopause (statistical and event)

  • Ion composition/charge state studies to investigate entry of SW or ionospheric ions

  • Event studies involving the measurement and modeling of the plasmapause profile relative to the RB location (possible unappreciated coupling)
    •

    Thermal Plasma Issues

    		    

    How do electrodynamic and energetic processes, operating on the thermal plasma in the IM, produce the observed structuring in temperature and density? ... how does this structuring impact coupling processes to the higher energy plasma? ... how does it impact storm development? ... the non-linearity of storms? ... what is the role of superthermal distributions in redistributing energy?

    Need to understand

    1. erosion,
    2. drainage plumes,
    3. where plasmaspheric plasma goes after encountering the magnetopause,
    4. impact of thermal temperature and structure on wave generation, propagation and damping,
    5. transfer of energy from the RC to the thermal plasma and its variability,
    6. effects of SAIDs,
    7. how superthermal distributions move energy through the system, etc.

  • GPS observations to define the temporal behavior of the thermal plasma for selected events

  • ULF ground observations combined with other data to track the thermal plasma structure (due to erosion, refilling, substorm fields, ionospheric electric fields, etc.) during selected storm events

  • Coordinated campaigns involving multiple s/c & ULF studies of plasmaspheric structure combined with ground-based observations of the ionospheric electric field and models

  • Event studies to examine the coupling between the thermal structure and RC/RB dynamics
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