ULF Wave Modelling With A ULF Wave Modelling With A Motive: Effects on Energetic Motive: Effects on Energetic

ParitclesParitcles

Mary Hudson, Scot Elkington, Brian Kress, Kara Perry, John Lyon, Mike Wiltberger

ULF Wave-Relativistic Electron ULF Wave-Relativistic Electron CorrelationCorrelation

Rostoker et al., GRL, 1998

Toroidal and Polodial ModesToroidal and Polodial Modes

Hughes, Solar Wind Sources of Magnetospheric ULF Waves, AGU, 1994

CRRES Poloidal and Toriodal ULF Wave B Components

Hudson et al., Annales. Geophys., 2004

CRRES 18 degree inclination, 6.3 RE apogee, July 90 – Oct 91

CRRES Occurrence Rates of CRRES Occurrence Rates of Poloidal and Toroidal ULF WavesPoloidal and Toroidal ULF Waves

Hudson et al., Annales Geophys., 2004

AMPTE CCE Occurrence Rates Of AMPTE CCE Occurrence Rates Of Toroidal Mode Toroidal Mode

9 RE apogeeTakahashi et al., JGR, 2002

AMPTE IRM Occurrence Rates Of AMPTE IRM Occurrence Rates Of Poloidal/Compressional ModePoloidal/Compressional Mode

Anderson et al., JGR 1990

Mathie & Mann JGR 2000

Mathie & Mann 2000 JGR

Groundbased Magnetometer ULF Wave Studies

Pc5 Correlation with Solar Wind Pc5 Correlation with Solar Wind Speed and Relativistic Electrons Speed and Relativistic Electrons

Mann et al., JASTP, 2004

Convective Growth of Convective Growth of Magnetopause K-H WavesMagnetopause K-H Waves

Miura, JGR, 1992

Direct Coupling of Solar Wind ULF WavesDirect Coupling of Solar Wind ULF Waves

Kepko et al., GRL, 2002

Transmitting ULF Wave Power Into Transmitting ULF Wave Power Into Magnetosphere via Fast ModeMagnetosphere via Fast Mode

Structure of Externally Driven FLRsStructure of Externally Driven FLRs

Linear dipoleMHD simulation

Proehl et al., JGR 2002

δv ~ δE/B_0

Parallel Mode StructureParallel Mode Structure

Poloidal mL=1/3

Global LFM-MHD Simulations Global LFM-MHD Simulations of Magnetosphereof Magnetosphere

Solar wind Solar wind measurements made measurements made by satellite at L1, or by satellite at L1, or CME-solar wind CME-solar wind coupled MHD codes coupled MHD codes

Ideal MHD equations are Ideal MHD equations are solved on a solved on a computational grid to computational grid to simulate the response simulate the response of the magnetosphereof the magnetosphere

Goodrich et al. ‘98

L dependence of Ephi powerL dependence of Ephi power

Elkington, S. R., M. Wiltberger, A. A. Chan, and D. N. Baker, J. Atmos. Solar Terr. Phys., 66, 1371, 2004.

0.558-15 mHz

Azimuthal Distribution of P(Ephi)Azimuthal Distribution of P(Ephi)

Azimuthal Distribution of P(Ephi)Azimuthal Distribution of P(Ephi)

Azimuthal Mode Number from MHD Azimuthal Mode Number from MHD Simulations and Ground MagnetometersSimulations and Ground Magnetometers

Mathie & Mann, JGR, 2000

Sept 98 storm MHD (Ephi) wave power in 0.14-15 mHz, low m modes

Frequency DependenceFrequency Dependence

Bloom, R. M. and H. J. Singer, JGR, 100, 14943, 1995.

Convective Growth of Convective Growth of Magnetopause K-H WavesMagnetopause K-H Waves

K-H Shear-Driven InstabilityK-H Shear-Driven Instability

Direct Coupling of Solar Wind ULF WavesDirect Coupling of Solar Wind ULF Waves

Kepko et al., GRL, 2002

3 MHz Solar Wind Pulsations3 MHz Solar Wind Pulsations

SW Density Driven PulsationsSW Density Driven Pulsations

Test Particle Simulations of Test Particle Simulations of Radiation BeltsRadiation Belts

2D: Drift motion of electrons 2D: Drift motion of electrons and ions in the equatorial and ions in the equatorial plane is followed using time-plane is followed using time-varying electric and magnetic varying electric and magnetic fields from global MHD fields from global MHD simulationsimulation

3D: Bounce and drift motion 3D: Bounce and drift motion of guiding center electrons in of guiding center electrons in MHD fields; gyro, bounce and MHD fields; gyro, bounce and drift motion of Solar Energetic drift motion of Solar Energetic Particles (el, protons, Fe)Particles (el, protons, Fe)

Solar Energetic Particle (SEP) cutoffs calculated using MHD fields

MHD Fields Injection of RadBelt MHD Fields Injection of RadBelt ElectronsElectrons

Radiation Belt Electron Energization Radiation Belt Electron Energization Processes Conserving First InvariantProcesses Conserving First Invariant

Particles can be Particles can be energized by: energized by:

1)1)ConvectionConvection: steady, : steady, or substorm and or substorm and storm-enhancedstorm-enhanced

2)2)Diffusion*Diffusion*: : convection E convection E fluctuations, ULF wave fluctuations, ULF wave δE and δBδE and δB δE δE enhance diffusionenhance diffusion

3) 3) Drift time scale Drift time scale injection injection (Mar 91)(Mar 91)

a)Falthammar, JGR, 1965;b)Elkington et al., JGR, 2003

*

Diffusion Rates vs. L Diffusion Rates vs. L

Radial diffusion Radial diffusion rates in model rates in model ULF wave fieldsULF wave fields

D_LL ~ D_LL ~ LLNN

Falthammar, 1965 N=6, 10Falthammar, 1965 N=6, 10 Elkington et al., 2003Elkington et al., 2003 N=11N=11

Selesnick et al., 97, 2000 N=12Selesnick et al., 97, 2000 N=12

Perry et al., JGR, 2005, N=6, 18Perry et al., JGR, 2005, N=6, 18

Perry includes δEφ, δBr, δB//, freq Perry includes δEφ, δBr, δB//, freq and L-dependent Powerand L-dependent Power

Braughtigam & Albert, 2000, N=6, 10

MHD-Driven Phase Space DensityMHD-Driven Phase Space Density

AE8 Max-Initialized, Sept 98 Storm Fei et al., 2005

Drift Time Scale Injection from SSC’sDrift Time Scale Injection from SSC’s

Blake et al., 2005

EE in equatorial plane from MHD simulation of March 24, 1991 in equatorial plane from MHD simulation of March 24, 1991

CME-interplanetary shock compression of magnetopause.CME-interplanetary shock compression of magnetopause.

E x B transport of ring of radiation belt electrons inward E x B transport of ring of radiation belt electrons inward

by inductive by inductive EE due to magnetopause compression dBz/dt. due to magnetopause compression dBz/dt.

MHD-Guiding Center SimulationMHD-Guiding Center Simulation

Elkington et al., JASTP, 2002; 2004

Equatorial Plane Proton MHD Guiding Center Simulation

Hudson et al., JGR, 1997March 24, 91 event

Average Count Rate of 10-20 MeV Average Count Rate of 10-20 MeV Electrons Mirroring at SAMPEXElectrons Mirroring at SAMPEX

Solar Proton Trapping Nov 01Solar Proton Trapping Nov 01

New belt example: 24 Nov 2001New belt example: 24 Nov 2001

Clear trapping of solar particles - no other source of heavy ions possible

Mazur et al., SHINE mtg, 2004

Solar Energetic Particle AccessSolar Energetic Particle Access

Summary of ‘ULF Wave’ Effects on Summary of ‘ULF Wave’ Effects on Energetic ParticlesEnergetic Particles

Electrons interact diffusively with ULF Electrons interact diffusively with ULF waves with f ~ electron drift period while waves with f ~ electron drift period while conserving first invariantconserving first invariant

Large amplitude distortion of Large amplitude distortion of magnetopause launches magnetosonic magnetopause launches magnetosonic impulse outside range of linear ULF wave impulse outside range of linear ULF wave models, drift time scale injection of MeV models, drift time scale injection of MeV electrons and protons (electrons unusual)electrons and protons (electrons unusual)

Solar energetic particles trapped on drift Solar energetic particles trapped on drift time scale, stay trapped as long as 1time scale, stay trapped as long as 1stst invariant conserved (Young et al., 2002)invariant conserved (Young et al., 2002)

Higher Frequency Wave Mode Higher Frequency Wave Mode EffectsEffects

Other, 1Other, 1stst invariant invariant violating processes violating processes responsible for responsible for energy/momentum energy/momentum diffusion and pitch diffusion and pitch angle diffusion at angle diffusion at fixed L (VLF/ELF)fixed L (VLF/ELF)

Summers and Ma, JGR, 2000

Externally and Internally Excited Pc5 (mHz) ULF Waves: low and high m

Field Line ResonanceField Line Resonance

Dawn-Dusk Assymmetry in Dawn-Dusk Assymmetry in Toroidal Mode ULF Wave PowerToroidal Mode ULF Wave Power

Duskside B-compression affects K-H instability threshold velocity shear (Lee et al., JGR, 1981)

Sharper dawn-side radial gradient affects ionospheric screening (Glassmeir & Stellmacher, JGR, 2000)

Compressed (solid) vs. dipole (dashed) diffusion coefficients

Perry et al., JGR, 2005