Les ceintures de radiation de la Terre, Jupiter et … · 1 Magnétosphères planétaires comparées - 4-6 févr. 2015 Meudon (France) Les ceintures de radiation de la Terre, Jupiter

Magnétosphères planétaires comparées - 4-6 févr. 2015 Meudon (France) 1

Les ceintures de radiation de la Terre, Jupiter et Saturne: similitudes et différences

A. Sicard-Piet, S. Bourdarie, D. Boscher, L. Lorenzato, V. Maget, D. Lazaro, S. Rochel

ONERA/DESP, Toulouse, France


Planet Mercury Earth Jupiter Saturn Uranus NeptuneObliquity to

orbit (o)0.01 23.5 3.1 26.7 97.8 28.3

Magneticmoment(G.Rp3)

0.0033 0.301* 4.28 0.21 0.228 0.142

Dipole tiltto rotation

axis (o)

169 169.5* 9.6 < 1 58.6 46.9

Rp (km) 2439 6371 71398 60330 25600 24765

Introduction

Planetary magnetospheres:

Earth Jupiter

Saturn

( )BvEqF!!!!

∧+=

DriftDrift

Giration

LL αeq

Beq

veq

αeq

Beq

veq

Ωj

Bounce

Bounce

Trapped particletrajectory

Mirror points

Magnetic field line


Radiation belts composition and structure

§  Electrons - Spectrum: 10 keV-10 MeV

- Location: 1-10 Re

- Origin:

§  Protons - Spectrum: 10 keV- 300 MeV

- Location: 1-10 Re

- Origin: + CRAND

§  Heavy ions - Helium:

- Oxygen ?:


- Location: 1-20 Rj

- Origin:

§  Protons - Spectrum: 100 keV- 1 GeV

- Location: 1-20 Rj

- Origin: + CRAND

§  Heavy ions - Helium: + Io

- Oxygen: Io +

- Sulphur: Io


- Location: 1-10 Rs

- Origin:

§  Protons - Spectrum: 10 keV- 100 MeV

- Location: 1-10 Rs

- Origin: + CRAND

§  Heavy ions - Helium: + Enceladus

- Oxygen: + Enceladus


Earth Jupiter

Electron Electron

Proton Proton


Magnétosphères planétaires comparées - 4-6 févr. 2015 Meudon (France)

Main physical processes in the radiation belts

Atmosphere

Rings

Plasmasphere or Neutral cloud or Io torus

Moons

Waves


Radial diffusion

Saturn

2.75 2.87 2.99 61.10 (Rs) 2.331.10 (Rs) 2.33 2.75 2.87 2.99 6

E

Radiale diffusion

Jupiter

6 9,51.10 (Rj) 3,12,6

EuIo

Radial diffusion

Earth6.6

Geo

stat

iona

ry o

rbitHiss Chorus

Interaction of energetic particles with:

5



(cm-2 s-1)

AE8 min Electrons > 500 keV

107

106

105

1 2 3 4 5 6 7

1

0

2

3

-1

-2

-3

(cm-2 s-1) (MeV-1.cm-2 s-1.sr-1)

Salammbô Electron > 21 MeV Salammbô Electron 380 keV Earth Jupiter Saturn

Rings and moons losses Atmospheric losses Wave particle interaction

Radial diffusion from the tail

Electrons


107

106

105

1 2 3 4 5 6 7

1

0

2

3

-1

-2

-3

7 7


(cm-2 s-1)

AP8 min Electrons > 10 MeV (cm-2 s-1) (MeV-1.cm-2 s-1.sr-1)

Salammbô Proton > 30 MeV Salammbô Proton not developed yet Earth Jupiter Saturn

Rings and moons losses CRAND

Radial diffusion from the tail

Protons

Atmospheric losses


8

SmagNgeo

SgeoNmag

15

SmagNgeo

SgeoNmag

Protons Electrons

SAC-C/ICARE Proton 9.65-11.35 MeV SAC-C/ICARE Electron 450-510 keV



Radiation belts dynamics

500

1000

1500

2000

2500

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Particules losses

Atmospheric heating

Magnetic storms

Particles injection

Protons events

Cosmic rays

9


Protons Electrons

Magnetic storm March 1991

Filling of the slot region Enrichment of the inner belt

Temporary second belt

Solar flares


Short time scale dynamics


Injection events seen by Galileo/EPD on November 06, 1996 between Ganymede and Europa


Short time scale dynamics

Plasma injection events seen by CASSINI/CAPS/ELS on October 30, 2005 at L=7

Tao X. et al., J. Geophys. Res., VOL. 115, A12204,doi:10.1029/2010JA015598, 2010



Long time scale dynamics

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1976 1981 1986 1991 1996 2001

année

flux

(keV

-1cm

-2s-

1sr-

1)

61.2488.74125.5183.71266.22396.86612.37908.31284.52

50-75 keV75-105 keV105-150 keV150-225 keV225-315 keV315-500 keV500-750 keV750-1100 keV1100-1500 keVFl

ux (k

eV-1

cm

-2 s

-1 s

r-1)

Year



Long time scale dynamics

D. Santos-Costa, S. J. Bolton, R. M. Thorne, Y. Miyoshi, and S. M. Levin, « Investigating the origins of the Jovian decimetric emission’s variability », Journal of Geophysical Research: Space Physics, vol. 113, no A1, 2008


Radiation belts observations

GEO

HEO GTO

MEO

LEO PEO

GPS (20000 km - 55o)

Geostationnary(35500 - 0o)

SPOT(800 km - 98o)

CONSTELLATION(1400 km - 52o)

GPS (20000 km - 55o)

Geostationnary(35500 - 0o)

SPOT(800 km - 98o)

CONSTELLATION(1400 km - 52o)

(cm-2s -1)

(cm-2s -1)

(cm-2s -1)

(cm-2s -1)

Many different orbits and many observations of the Earth radiation belts



Pioneer 10 and 11

Voyager 1 and 2

Galileo Orbiter

101 2 3 4 5 6 7 8 9

2

3

4

-2

-3

-4

X (Rj)

Ligne de champ

0

1

-1

Z (R

j)

Pioneer 10

Pioneer 11

Voyager 1

Galileo Orbiter

Galileo Probe

101 2 3 4 5 6 7 8 9

2

3

4

-2

-3

-4

X (Rj)

Ligne de champ

0

1

-1

Z (R

j)

Pioneer 10

Pioneer 11

Voyager 1

Galileo Orbiter

Galileo Probe

Ulysses

Few observations: in-situ measurements by interplanetary missions and synchrotron measurements on the ground

Galileo Probe

103

104

105

106

107

108

02:4703DEC74

04:1003DEC74

05:3303DEC74

06:5603DEC74

Flux

(cm

-2.s-1

)

Ec >21 MeV

+++ Pioneer 11Salammbô (Khurana)Divine & Garett

2

-2

0

4 2 0 -2 -4 0

500

1000

Radius (Rj)

Rad

ius (

Rj)

Tb

(Kel

vin)

VLA Observation (max = 1269 K)

-2

0

4 2 0 -2 -40

500

1000

Tb (K

elvi

n)

Salammbô Simulation (max = 1264 K)2

1424 MHz λIII(CML)=20°

Magnetic field line



Even few observations: in-situ measurements by interplanetary missions

Pioneer(s)

Voyager(s)

Cassini

Comparaison with Salammbo

Pioneer 11 e- : >40 keV

Cassini e- : 175-300 keV


Specification models

[cm-2 s -1]

[cm-2 s -1]

AP8 >10 MeV AE8 >1MeV

-  AE8/AP8 (NASA) -  AE9/AP9 (Aerospace)

Local models

Global models

-  IGE-2006 at GEO (ONERA) -  MEO-V2 at MEO (ONERA) -  Slot model (ONERA) -  OPAL protons at LEO (ONERA)

JOSE Elec >10 MeV JOSE Prot >1MeV

-  D&G 1983 (JPL) -  GIRE (JPL) -  JOSE (ONERA)

Global models

-  SATRAD(JPL)

Global model


Perspectives

•  Improvement of the understanding and modeling of the physical processes in the radiation belts

•  Study of the link between solar wind parameters and radiation belts dynamics (space weather)

•  Development of a global model for Earth radiation belts

•  Comparison of synchrotron mapping derived from Salammbô results and LOFAR observations

•  Study of the dynamics of the Jovian radiation belts (link with solar wind)

•  Modeling of protons radiation belts •  Modeling of Uranus radiation belts

Documents

Les ceintures de radiation de la Terre, Jupiter et … · 1 Magnétosphères planétaires comparées - 4-6 févr. 2015 Meudon (France) Les ceintures de radiation de la Terre, Jupiter