LWS05

Effects of Coronal Mass Ejections and Solar Wind Streams on the Earth’s Radiation Belts: 

Effects of Coronal Mass Ejections and Solar Wind Streams on the Earth’s Radiation Belts D.N. Baker, S. Kanekal, X. Li, S. Elkington Laboratory for Atmospheric and Space Physics Department of Astrophysical and Planetary Sciences University of Colorado - Boulder

Adiabatic Invariants: 

Adiabatic Invariants M: perpendicular motion K: parallel motion L: radial distance of eq-crossing in a dipole field Associated with each motion is a corresponding adiabatic invariant: If the fields guiding the particle change slowly compared to the characteristic motion, the corresponding invariant is conserved. Gyro: M=p2/2m0B Bounce: K Drift: L

The Earth’s Radiation Belts: 

The Earth’s Radiation Belts Contours of the omnidirectional flux (particles per square centimeter per second) of protons with energies greater than 10 MeV Contours of the omnidirectional flux of electrons with energies greater than 0.5 MeV

The South Atlantic Anomaly Region: 

TOPEX (1992-1998) and TERRA-MODIS (2001) The South Atlantic Anomaly Region

Slide5: 

Solar Activity Cycle

The Disturbed Solar Wind: Coronal Mass Ejections (CMEs): 

The Disturbed Solar Wind: Coronal Mass Ejections (CMEs) Occur most often near the peak of the Sun’s 11-year activity cycle Propel >109 tons of matter into interplanetary space Can travel at speeds exceeding 2000 km/s Drive interplanetary shocks Can trigger geomagnetic storms when they impact Earth’s magnetosphere

Coronal Mass Ejection - Earth Impact: 

Coronal Mass Ejection - Earth Impact Courtesy of NASA

Impulsive Injection Due to Shock Wave: 

Impulsive Injection Due to Shock Wave [Li et al., 1993]

Outer Belt Electrons: 1992-2002: 

Outer Belt Electrons: 1992-2002

Mapping of the Radiation Belt: 

Mapping of the Radiation Belt SAMPEX: 18 August 1993

Dynamic Radiation Belts: 1993-1995: 

Dynamic Radiation Belts: 1993-1995

Acceleration by Radial Transport: 

Acceleration by Radial Transport Nonrelativistically, and in a dipole, or so transport in L while conserving M will necessarily lead to change in energy, W.

Transport in M, K: Local Heating: 

Transport in M, K: Local Heating

Local Heating Example:Resonant Interactions with VLF Waves: 

Local Heating Example: Resonant Interactions with VLF Waves Whistler mode chorus at dawn combined with EMIC interactions heat and isotropize particles Leads to transport in M, K, and L Summers et al. (JGR 103, 20487, 1998) proposed that resonant interactions with VLF waves could heat particles:

MHD Simulations of ULF Power, 09/24/1998: 

MHD Simulations of ULF Power, 09/24/1998 ULF power in MHD shows expected radial, frequency dependence Azimuthal dependence: frequently see structure in local time

Shear Waves and Particle Acceleration: 

Shear Waves and Particle Acceleration Limited local time: propagating waves dusk and counterpropagating waves dawn still lead to energization

MHD Simulation of a Strong Storm: 

MHD Simulation of a Strong Storm

MHD/Particle Simulations of Energetic Electron Trapping: 

MHD/Particle Simulations of Energetic Electron Trapping 60 keV test electrons, constant M Started 20 RE downtail, 15s intervals Evolves naturally under MHD E and B fields Removed from simulation at magnetopause Color coded by energy

High-Energy Electrons: Deep-Dielectric Charging: 

High-Energy Electrons: Deep-Dielectric Charging 3. Influx of electrons increases to levels higher than the leakage rate 2. Electrons slowly leak out of the insulator 1. Electrons bury themselves in the insulator 4. Electrons build up faster than they leak off 5. Discharge (electrical spark) that damages or destroys the material

Star Tracker Anomalies at GEO: 

Star Tracker Anomalies at GEO Baker et al. (1987)

Anomalies Due to Dielectric Charging: 

Probability of discharges goes up dramatically with increasing electron fluence. Anomalies Due to Dielectric Charging Vampola (1977)

Radiation Belt Content Index: 

Radiation Belt Content Index Gives a single “Radiation Belt Electron content” Index (RBI) Idea introduced in Baker et al. (1999) Integrates over energy spectrum and 2.5 < L < 6.5

RBI-Solar Wind Speed Comparison: 

RBI-Solar Wind Speed Comparison Many operational anomalies in 1994 period Late 1993 and early 1994 were remarkable times for VSW

ANIK Failures: Deep-Dielectric Charging: 

ANIK Failures: Deep-Dielectric Charging ANIK Anomalies ANIK/Intelsat failures in January 1994 occurred during the highest radiation belt content interval of the last decade

The RBI Allows Averaging and Superposition: 

The RBI Allows Averaging and Superposition Builds on idea of radiation belt “coherence” Annual and seasonal averaging is readily done Gives a true global view Baker et al., GRL (1999)

Radiation Belt Content : POLAR/SAMPEX: 

Radiation Belt Content : POLAR/SAMPEX Baker et al., JGR (2001)

October 2003 Events: 

October 2003 Events

The Halloween Storm in the Heliosphere: 

The Halloween Storm in the Heliosphere

Slide32: 

D. N. Baker et al., Nature, 16 Dec 2004

Spacecraft Anomalies: October-November: 

Spacecraft Anomalies: October-November

Day-to-Day Variation of the Radiation Belts: 

Day-to-Day Variation of the Radiation Belts

Selected Days: Outer Belt Properties: 

Selected Days: Outer Belt Properties

Resonant Scattering: 

30.4 nm EUV (Courtesy of J. Goldstein ) Resonant Scattering Plasmasphere He+ 15%

EUV Images of the Plasmasphere: 

EUV Images of the Plasmasphere Plasmasphere He+ 15% plasmasphere Global EUV He+ Image

Extreme Plasmasphere Erosion: 

Extreme Plasmasphere Erosion

Slide41: 

D. N. Baker et al., Nature, 16 Dec 2004

Regions of Wave-Particle Interactions: 

Regions of Wave-Particle Interactions

Largest Flare in Recorded History, Extremely Fast CME - Narrow Miss at Earth: 

X-28 Class Flare SEP Fast CME, 2657 km/s Glancing Blow Largest Flare in Recorded History, Extremely Fast CME - Narrow Miss at Earth