CEDAR Frontiers: Utilizing Global Models to Better Understand the Ionosphere and Thermosphere Aaron Ridley - University of Michigan - [e-mail]

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CEDAR Frontiers Utilizing Global Models to
Better Understand the Ionosphere and
ThermosphereAaron Ridley - University of
Michigan - ridley_at_umich.edu

• Idealized Events
• Measurements are limited by what the system is
  driven by, where models can be driven by ideal
  conditions - can conduct numerical experiments.
• Impulse - Response functions allow a better
  understanding of how the system responds to
  zeroeth order.
• Idealized events are similar to averaged
  events.

• Event Analysis
• Put data into a global context, can provide
  measurements that were not made.
• Provide validation studies for global models -
  What physics is missing? What dont we understand?

Propose studies that advance Understanding of
the global coupled ionosphere and thermosphere
processes Understanding of the strengths and
limitations of global models. Understanding of
how experimentalist and modellers can work
together to better understand the system.
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Utilizing Global Models to Better Understand the
Ionosphere and Thermosphere
Idealized Events The Sun never produces idealized
conditions at times in which instruments are
placed in optimum locations to observe what
experimentalists want to measure. Also,
researchers have a difficult time measuring all
relevant processes simultaneously to determine
cause and effect. Models offer the ability to
drive the system over and over again with
idealized conditions. Slight variations on those
conditions can be made to systematically test
theories in a highly controlled environment.
Models also offer the ability to change the way
the world works to better determine cause and
effect. Model runs of idealized conditions can
be compared against super-posed epoch average
conditions to determine if the model is behaving
like the true system.
Event Analysis Models help to put experimental
data into a global context - they can specify
conditions far away from the measurements and can
provide quantities that were not measured. The
coupling between models and experimental results
can give a better context for considering
theories than simply models or localized
measurements. Validation studies provide an
opportunity for improving our understanding of
the global system by forcing researchers to
examine the underlying physics of the models.
This typically results in both a better physical
understanding of the thermosphere and ionosphere
and improvements in the simulations.
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• Possible CEDAR Campaign
• Providing a framework for experimentalists to
  better understand modelling and modellers to
  better understand the benefits of measurements.
• Conducting idealized event studies agreed upon by
  modellers and experimentalists to better
  understand outstanding questions in CEDAR science
  areas.
• Supporting the CEDAR community by modelling
  events of high interest in a more uniform
  environment.
• Providing a forum for modellers to compare
  results for a more informed discussion on the
  numerical and physical differences between
  models.
• Stressing the importance of validated models in
  CEDAR.

• Goals
• Increase collaboration between experimentalists
  and modellers.
• Increase our understanding of the differences
  between community models.
• Create more transparency and uniformity in the
  validation of models.
• Provide community support for event studies.

CEDAR Frontiers- Utilizing Global Models to
Better Understand the Ionosphere and Thermosphere