radiation belt electron transport & energization inner belt outer belt slot region mary k....
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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
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