FG: Metrics and Validation

Co-Chairs: Tim Guild <timothy.b.guild [at] aero.org>, Howard Singer <howard.singer [at] noaa.gov>, and Lutz Rastaetter <lutz.rastaetter [at] nasa.gov>

ULF Wave Modeling Challenge

We're organizing a modeling challenge to investigate the ability of global models to reproduce ULF wave fields in the magnetosphere, and ultimately if those ULF fields can radially diffuse an existing electron population from L~5.5 to L~4.5 in two weeks. To get there, we can split the question into two distinct ones:

1. Can global models of the magnetosphere reproduce the observed persistent, solar wind driven, low mode number ULF wave fields in the magnetosphere? and...

2. Are those waves capable of producing the observed energetic radiation belt population evolution observed during the first two weeks of March 2013 as observed by Van Allen Probes?

The figure above is the REPT flux from http://www.rbsp-ect.lanl.gov/science/LTPlots/RBSP-ECT_LT_Mission_plot.pdf with the interval I mentioned circled in pink. Tick marks in time (x-axis) are one month in duration. The modest electron belt which starts out at L~5.5 seems to diffuse inward a whole L in two weeks. I would think that a key aspect of that question which MHD models could uniquely constrain is the fraction of the diffusion which is accomplished by solar wind driving alone.

The 1st question above may be divided into two basic ULF wave challenges dealing with (Level 0) a idealized continuum of solar wind frequencies [Claudepierre et al., 2010, Paragraph 12] and (Level 1) the real solar wind input from 1-16 March 2013.

Observations

• Remotely sensed ULF wave fields from magnetometers (U. Alberta)
• Space-based ULF wave power from March, 2013 (Sarris/Schiller)
• EMFISIS wave fields from Van Allen Probes (who?)
• ...

Models

• LFM (Claudepierre)
• BATS-R-US (Hartinger)
• OpenGGCM (Raeder)
• Empirical Magnetic field models
• ...

Paragraph 12 of Claudepierre et al., 2010 discusses "continuum" of solar wind frequencies http://onlinelibrary.wiley.com/doi/10.1029/2010JA015399/full#jgra20604-sec-0002

Ozeke & Mann 2008, Paragraph 3 available here: http://onlinelibrary.wiley.com/doi/10.1029/2007JA012468/full#jgra18928-sec-0001