LUNAR PRECURSOR EFFECTS IN LUNAR PRECURSOR EFFECTS IN THE TERRESTRIAL - - PowerPoint PPT Presentation

LUNAR PRECURSOR EFFECTS IN LUNAR PRECURSOR EFFECTS IN THE TERRESTRIAL MAGNETOSPHERE AND SOLAR WIND

Jasper S. Halekas Space Sciences Laboratory Uni ersit of California Berkele

ARTEMIS Science Working Team Meeting 9/14‐16/2011

University of California, Berkeley

The Lunar Space Plasma Environment: Pre‐ARTEMIS Environment: Pre ARTEMIS

Precursor Effects in the Terrestrial Magnetosphere

All Electrons Upgoing e‐ (0‐15°) Downgoing e‐ (165‐180°) EFI FFT fp fce

EFI Background

EFI FFT SCM FFT B Wavelets fp fce

EFI Background

B Wavelets B Field fci Spin Tone

Free Energy Sources: Reflected Electrons in Magnetosphere

Converging Magnetic Field Lines above Crustal Magnetic Fields

Loss Cone

Beam

Plasma Electrons Follow Magnetic Field Lines Beam + Loss Cone: Field Lines and Reflect from E & B Beam + Loss Cone: Produced By Combined Magnetic & Electrostatic

D d Secondary Electrons Accelerated Upward

g Effects Near Surface

Downward Electric Field E = ‐ U

Δ

Polarization Properties

Narrowband Waves propagating anti‐parallel to field EXB B0 Coherent Right‐Handed E B Parallel‐Propagating Right Handed

• Wave properties all consistent with parallel propagating whistlers coming down
• Wave properties all consistent with parallel‐propagating whistlers coming down

the magnetic field line towards the Moon

Instability Conditions

Streaming instabilities where df/dv|| positive EFI g

|| p

SCW Whistlers correlate with edges of loss cone: i.e. df/dvperp positive Reduced Distribution Function Whistler Mode: ω/k, (ωce‐ω)/k

Ions in the Mix?

• Waves near f i modulate both the electron beam and the whistlers

Waves near fci modulate both the electron beam and the whistlers

• Possible sources: Electron beam, shadowed ion distributions, bi‐ion streaming

ICW ? Electron Beam Modulated ICWs? Loss Cone Modulated Electron Beam Modulated FGM Wavelets Whistlers Modulated

Proton & Helium Cyclotron Frequencies

Precursor Effects in the Solar Wind Solar Wind

Ions Upgoing e‐ (0‐15°) Upgoing e (0 15 ) Downgoing e‐ (165‐180°) EFI FFT SCM FFT B Wavelets B Field SZA of Surface Connection

Free Energy Sources: Reflected Electrons in Solar Wind

Fitzenreiter et al., 1990

Electron Trajectory Magnetic Field Generalized obstacle with magnetic field Convection Electric Field gradient and/or electrostatic potential gradient Adiabatic Reflection in dHT Frame Gives you “Ears” in Solar Wind Frame

Whistler Cyclotron Resonance Conditions Resonance Conditions

EFI SCW Reduced Distribution Function (ωce‐ω)/k : ω, k on whistler branch (

ce

)/ ,

Ion Observations

P2 Ions

Foreshock Ions

P1 Ions P1 Reduced Dist. Funct.

Reflected Protons

P1 Power Spectrum p P1 Propagation

Parallel‐Propagating

P1 Propagation P1 Ellipticity RH, LH P1 Ellipticity

Free Energy Sources: Reflection From Crustal Magnetic Fields

Reflected Proton Fluxes L t l Reflected Protons Follow Pickup Ion Trajectories Lue et al., 2010 j Distribution Near Cycloid “Cusp” IMF SW

Pickup Ion Trajectories

Reconstructed Ion Trajectories

Connected Unconnected

j Surface Crustal Magnetic Field Surface Crustal Magnetic Field

Ion Reflection Source Map

26 Event Periods, June 29 – August 31

Lunar Precursor Effects