Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Characterizing the Interaction between Whistler-Mode Chorus and Energetic Electrons via Test Particle Simulations

Characterizing the Interaction between Whistler-Mode Chorus and Energetic Electrons via Test Particle Simulations

Talk presented at 2016 Mini-GEM Meeting, San Francisco, CA, December, 2016

Caitano L. da Silva

December 11, 2016
Tweet

More Decks by Caitano L. da Silva

Other Decks in Science

Transcript

  1. Characterizing the interaction between whistler-mode chorus and energetic electrons via

    test particle simulations Caitano L. da Silva, Richard E. Denton, Mary K. Hudson, Robyn M. Millan Department of Physics & Astronomy Dartmouth College Mini-GEM Workshop December 11, 2016, San Francisco, CA
  2. Waves in the Inner Magnetosphere 3 Motivation: “Understanding acceleration and

    loss mechanisms of radiation belt electrons due to whistler-mode chorus”
  3. Simulation of Whistler-Mode Chorus 4 0.92 0.96 1 1.04 1.08

    0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Curvilinear Coordinates Dawn Noon Pure Dipole Field (b1 =0) Compressed Dipole Field (b1 =1.6B0) (a) (b) (c) Coordinate System da Silva et al. [JGR, In Press, 2016]
  4. 5 0.92 0.96 1 1.04 1.08 0 0.2 0.4 0.6

    0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Curvilinear Coordinates Dawn Noon Pure Dipole Field (b1 =0) Compressed Dipole Field (b1 =1.6B0) (a) (b) (c) Ring Current Electrons da Silva et al. [JGR, In Press, 2016] Simulation of Whistler-Mode Chorus 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1 1.5 2 2.5 3 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 0.01 0. 0.92 0.94 0.96 (a) (b) (c) 0.05 0.06 0.07 0.08 1 1.02 1.04 1.06 1.08 1 1.5 2 2.5 3 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 0° 5° 10° 15° 20° 25° 30° 0.01 0.02 0.03 0.04 0.05 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 (b) (c) Anisotropy
  5. Model Formulation 6 Coupling Particles Fluid References: Hu and Denton

    [JGR, 114, A12217, 2009] Wu et al. [JGR, 120(3), 1908, 2015] da Silva et al. [JGR, In Press, 2016] Hybrid Fluid/Particle Simulation Approach
  6. Wave Development 7 -0.04 -0.02 0 0.02 0.04 0.92 0.94

    0.96 0.98 1 1.02 1.04 1.06 1.08 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 0° 5° 10° 15° 20° 25° 30° -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 (a) 200 (b) 300 (c) 400 0 1 2 3 4 5 6 7 0 - 100 100 - 200 200 - 300 300 - 400 4.5 5 0 1 2 3 4 5 6 7 8 9 7 (a) ( (c) ( Pure Dipole Field (b1 =0) 0 1 2 3 4 5 6 7 0 - 100 100 - 200 200 - 300 300 - 400 0 0.2 0.4 0.6 0.8 1 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 1 2 3 4 5 6 7 8 9 0 0 1 2 3 4 5 6 7 (a) ( (c) ( Pure Dipole Field (b1 =0) -3 -2 -1 0 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 -3 -2 -1 0 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0 20 40 60 80 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0 0.2 0.4 0.6 0.8 0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0 0.2 0.4 0.6 0.8 1 -0.04 -0.02 0 0.02 0.04 (d) (c) (b) (a) Linear Dispersion Analysis: Growth Rate Spectrum Hybrid-Code Simulations
  7. Pitch-Angle Scattering, 100 keV electrons 8 0 100 200 300

    400 0 20 40 60 80 100 120 140 160 180 -3 -2 -1 0 1 2 3 n = -1 n = 0 n = 1 n = 2 n = 3 -1.5 -1 -0.5 0 0.5 1 0 5 10 0 20 40 60 80 100 120 140 160 180 0 100 200 300 400 0 1 2 3 4 Maxwellian Resonance Curves
  8. Energy Changes, 100 keV electrons 9 0 100 200 300

    400 0 20 40 60 80 100 120 140 160 180 -4 -3 -2 -1 0 1 2 3 4 n = -1 n = 0 n = 1 n = 2 n = 3 -1.5 -1 -0.5 0 0.5 1 0 2 4 0 20 40 60 80 100 120 140 160 180 0 100 200 300 400 0 5 10 15
  9. Pitch-Angle Scattering, 1 MeV electrons 10 0 1 2 3

    4 0 20 40 60 80 100 120 140 160 180 -4 -3 -2 -1 0 1 2 3 4 n = -7 n = -5 n = -3 n = -1 n = 0 n = 1 n = 3 n = 5 n = 7 n = 9 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 0 0.5 1 0 20 40 60 80 100 120 140 160 180 0 1 2 3 4 0 0.2 0.4 0.6 0.8 Maxwellian Resonance Curves:
  10. Energy Changes, 1 MeV electrons 11 0 1 2 3

    4 0 20 40 60 80 100 120 140 160 180 -0.015 -0.01 -0.005 0 0.005 0.01 0.015 n = -7 n = -5 n = -3 n = -1 n = 0 n = 1 n = 3 n = 5 n = 7 n = 9 -2 -1.5 -1 -0.5 0 0.5 0 0.1 0.2 0 20 40 60 80 100 120 140 160 180 0 1 2 3 4 0 0.1 0.2 0.3 0.4 0.5
  11. Summary 12 • Predominant energy and pitch-angle changes are easily

    explained by first harmonic resonance (n=1) for counterstreaming electrons and by Landau resonance (n=0) for costreaming electrons. • Significant pitch-angle scattering at high energies does not seem to be compatible with resonant interactions. • Further information: da Silva, C. L., S. Wu, R. E. Denton, M. K. Hudson, R. M. Millan, Hybrid Fluid-Particle Simulation of Whistler-Mode Waves in a Compressed Dipole Magnetic Field: Implications for Dayside High-Latitude Chorus, Accepted for publication in J. Geophys. Res., doi:10.1002/2016JA023446.
  12. Extra Slide E (MeV) 0 1 2 3 4 100

    E (MeV) 0 1 2 3 100 E (MeV) 0 1 2 3 4 Normalized Spectrum 10-4 10-3 10-2 10-1 100 Precipitation Initially trapped E (MeV) 0 1 2 3 Precipitation Probability ×10-3 0 1 2 3 4 5 15 Maxwellian