Radiation Belt Electron Transport & Energization

innerbelt

outerbelt

Slotregion

Mary K. Hudson,

Magnetospheric Thrust Participants

Coupled Modeling Scheme

Solar Cycle of SAMPEX Solar Cycle of SAMPEX 2-6 MeV Electrons 2-6 MeV Electrons

Li et al., GRL, 2006

Response to Solar Wind ForcingResponse to Solar Wind Forcing

2-3 day lag at Geo2-3 day lag at Geo Paulikas & Blake, 1979Paulikas & Blake, 1979

Prompt peak L ~3Prompt peak L ~3 Vassiliadis et al., 2003Vassiliadis et al., 2003

SAMPEX/Vsw correlation

2-6 MeV fluxes

ULF Wave-Relativistic Electron ULF Wave-Relativistic Electron CorrelationCorrelation

Rostoker et al., GRL, 1998

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

Kepko & Spence, JGR, 2003

Or Convective Growth Or Convective Growth Magnetopause K-H Magnetopause K-H Waves Waves Miura, JGR, 1992; Claudepierre et al., JGR, 2008 LFM time series analysis

Halloween ’03 2-6 and >10 MeV ElectronsHalloween ’03 2-6 and >10 MeV Electrons

See filling of slot regionon storm timescale (days)at 2-6 MeV (Baker et al., 2004)

SAMPEX observes > 2 monthdelay in high > 10 MeV fluxesat low altitude (longer loss time)

Halloween ’03 Shock Injection Halloween ’03 Shock Injection

W ~ 5 MeV W ~ 5 MeV 15 MeV 15 MeV

R ~ 6 RE R ~ 6 RE 2.5 RE 2.5 RE

Kress et al., JGR, 07

LFM-test particle simulation

E = - B/t : Bz/t E

Halloween ’03 Shock Injection of >10 Halloween ’03 Shock Injection of >10 MeV (W0=1-7 MeV) ElectronsMeV (W0=1-7 MeV) Electrons

Kress et al., 2006

Low altitude SAMPEX Low altitude SAMPEX observations at > 10 observations at > 10 MeV electrons, MeV electrons, injected 10/29/03 injected 10/29/03 Looper Looper et al., ‘06et al., ‘06

Simulated pitch angle distribution-> Kress et al., 2006

MHD Fields Inject RadBelt MHD Fields Inject RadBelt ElectronsElectrons

Elkington et al., JASTP, 2004

Plasmasheetel injection

MHD Fields Injection of RadBelt MHD Fields Injection of RadBelt ElectronsElectrons

Elkington et al., JASTP, 2004

PSD calculations for other storms…PSD calculations for other storms…

January 1995September 1998 (final)

•The (big) September 1998 storm shows a significant change in trapped PSD as a result of coupling to the plasmasheet.•The more moderate storm of January 1995 showed almost no coupling with the plasmasheet.

Elkington et al., 2008

Diffusion Rates vs. L Diffusion Rates vs. L

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

D_LL ~ D_LL ~ LLNN

Perry et al., JGR, 05, includes Perry et al., JGR, 05, includes δEφ, δBr, δB//, freq and L-δEφ, δBr, δB//, freq and L-dependent powerdependent power

Braughtigam & Albert, 2000, N = 10; Perry et al., 2006

Radial diffusion rates Radial diffusion rates in in model ULF wave fieldsmodel ULF wave fieldsDDLLLL ~ ~ DD00LLNN

Tau(L,E) Summers 04;Tau = days/Kp Shprits 05

##

ULF wave DLL studies:Elkington et al., 2003;Ukhorskiy et al., 2005;Fei et al., 2006

Radial Diffusion forNov 04 Storm

↑

Baker et al., GRL, 07

F. Chu et al., AGU, F 07

τf

L

fLD

LL

dt

dfll −⎥⎦

⎤⎢⎣⎡

∂

∂

∂

∂= ∗

−∗∗

∗ 22

= 1000 MeV/G

July & Nov 04 Differ by SSCJuly & Nov 04 Differ by SSC

Plasmapause Control of Electron Plasmapause Control of Electron Flux Peak and Slot RegionFlux Peak and Slot Region

Shprits et al., JASTP 2008Local accel and pitchangle scatteringdue to VLF/ELF waves (Whistler, EMIC)

Magnetospheric SEP Simulations

SEP Cutoffs: Brian Kress poster

SEP Cutoff rigidities calculated in a CISM SEP Cutoff rigidities calculated in a CISM

CMIT simulation of 14 May 1997 stormCMIT simulation of 14 May 1997 storm

IGRF field embedded within MHD inner boundary

Handoff to Forecast TransitionHandoff to Forecast Transition Radial diffusion model with DRadial diffusion model with DLLLLdetermined by determined by LTR ULF wave power tabulated by vLTR ULF wave power tabulated by vswsw or Kp or Kp switchswitch

SEP cutoffs in solar-wind parametrized MHD SEP cutoffs in solar-wind parametrized MHD field snapshotsfield snapshots

Neither involve pushing millions of particles Neither involve pushing millions of particles in time-dependent MHD fields in real time in time-dependent MHD fields in real time using appropriate input spectra; using appropriate input spectra;

Given input spectra, e.g. SEPs from Given input spectra, e.g. SEPs from COHREL+parametrized shock model COHREL+parametrized shock model SEP cutoffsSEP cutoffs

Given continuously available geo fluxesGiven continuously available geo fluxes radbelt f at peak flux, typically L~3-4 at 2-radbelt f at peak flux, typically L~3-4 at 2-6 MeV, determined from radial diffusion code 6 MeV, determined from radial diffusion code includingincluding

time-dependent plasmapause loss term time-dependent plasmapause loss term