The NSF GEM Program and the IHY

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The NSF GEM Program and the IHY
R. J. StrangewayIGPP/UCLAGEM Steering
Committee Chair
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Geospace Environment Modeling

• Program supported by the National Science
  Foundation Division of Atmospheric Sciences.
• Now in its 14th Year.
• Overall goal development of a Geospace General
  Circulation Model (GGCM).
• GGCM originally envisaged as being a GEM entity.
  Now GGCMs are more likely to arise out of efforts
  such as the Boston University Center for
  Integrated Space weather modeling (CISM). Other
  examples include the University of Michigan
  MIURI, and efforts supported by the Community
  Coordinated Modeling Center (CCMC).
• GEM is a forum for providing inputs to the GGCM
  concept (modules required, science that needs to
  be addressed to further the GGCM goal).

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An Earlier GGCM Concept
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Current Concept of a GGCM

• Global MHD provides the spine.
• Add-on modules to provide the missing physics.
• Example 1 Knight relationship that relates
  current density to parallel potential. Associated
  energy flux used as input to Robinson
  conductivity to provide enhanced auroral
  conductivities.
• Example 2 Better ionosphere models for lower
  boundary (TING, TGCM).
• Example 3 Pressure gradient and particle drift
  ring current models.
• Future efforts Sub-scale kinetic/hybrid codes,
  Data assimilation, better models of the gap
  between the atmosphere and the inner boundary of
  the MHD code.

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GEM Elements

• Summer workshop is main scientific activity,
  organized around campaigns.
• Student sessions and tutorials important
  component of GEM summer workshop.
• Joint GEM/CEDAR, GEM/SHINE workshops.
• Although modeling is the major thrust of GEM, GEM
  also has a tradition of including ground-based
  observations, reflecting its NSF support, as well
  as the intrinsic importance of such observations.
• Current workshop size 250 participants much
  larger than the number of scientists explicitly
  supported by GEM grants.
• Part of the appeal of GEM is that it still tries
  to adhere to a workshop mode.

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GEM Campaigns

• 1st Campaign Boundary layers (1991 -
  1998)Mainly emphasized processes at the
  magnetopause.
• 2nd Campaign Magnetotail/Substorms (1994 -
  2004)Largely dominated by substorm issues.
• 3rd Campaign Inner Magnetosphere/Storms (1996 -
  ??)Campaign Coordinator M. Liemohn
• WG1 Plasmasphere and Ring Current (D. Gallagher,
  M. Chen)
• WG2 Radiation Belts (R. Friedel, R. Thorne)
• WG3 ULF Waves (B. Fraser, M. Moldwin)

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GGCM Science Steering Committee

• The GGCM functions within GEM though a science
  steering committee.
• The GGCMSSC works with the campaigns (see later)
  to identify topics and speakers for each
  workshop.
• The GGCMSSC also acts a liaison with the external
  computational efforts.
• GGCMSSC chair J. Raeder

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GEM Campaigns - Continued

• 4th Campaign Magnetosphere-Ionosphere Coupling
  (1998 - ??)Campaign Coordinators R. Greenwald,
  J. Hughes
• WG1 Mass Exchange (W. Peterson, R. Winglee)
• WG2 Electrodynamic Coupling (W. Lotko, J.
  Semeter)
• WG3 (new) Global Coupling (M. Freeman, D. Murr)
• 5th Campaign Global Interactions (2004 -
  ??)Campaign Coordinators T. Phan, D. Sibeck
• WG1 Reconnection Dynamics, Cusp, and LLBL (J.
  Berchem, N. Omidi, K.-H. Trattner)
• WG2 Plasma Acceleration and Transport in the
  Magnetosphere (T. Onsager, A. Otto)

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What Does GEM bring to IHY?

• GEM emphasizes the coupled system.
• GEM has international liaison many of these
  individuals strongly committed to ground-based
  observations X. Blanco-Cano  Mexico B. Fraser
  Australia E. Donovan Canada. Also have
  Asian and European liaisons.
• GEM is actively interested in Sun to mud
  research.

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What Does IHY bring to GEM?

• Sponsorship of a joint GEM/SHINE summer workshop
  in 2007?
• Additional ground networks, especially for
  developing nations.
• Universal processes addressed by GEM science TO
  BE DEFINED
• Reconnection
• Stellar wind - magnetosphere - ionosphere -
  atmosphere coupling differential rotation in a
  magneto-plasma.