Improving Salammbô model and coupling it with IMPTAM model

V. Maget1

D. Boscher1, A. Sicard-Piet1, N. Ganushkina2

1. ONERA, Toulouse, FRANCE2. FMI, Helsinki, FINLAND

SPACECAST Final Outreach Meeting, BAS, Cambridge, 07th February, 2014

Bases to better understand Radiation belts modelling

Particles of interest today:• Electrons:

from keV up to a few MeV

• Plots of interest:• L* vs Time representation• Making a satellite fly in the model

• Origin:Sun (through plasmasheet)

• Effects: TiD, surface and deep charging

GEOGPS

POES15 >100keV

RB

SP-A 0.57-1.12 M

eV

• Earth’s radiation belts bases:• 3 quasi-periodic movements due to magnetic

field trapping

• Definition of an adequate coordinate systemL*, Aeq, MLT, Energy

• What a satellite really observes ?

Purpose: the global optimization problem • The model is a complex balance between all active physical processes

• Work done during the SPACECAST project:• Improving the most significant bricks of physics ahead of Salammbô model• Determining the best combination of them by comparing to real data (GEO, Van Allen Probes, …)• Poor physics below about 100 keV due to E-field influence: plug with IMPTAM model

Boundary condition

Radial diffusion

w-p interactions

GPS

GEO

Optimizing the science bricks combination (1/3)

Omnidirectional fluxes @ eq for E = 1,5 MeV -- Kp=2

1,00E+00

1,00E+01

1,00E+02

1,00E+03

1,00E+04

1,00E+05

1,00E+06

1,00E+07

1,00E+08

1,00E+09

0 1 2 3 4 5 6 7 8 9

DLL = Brautigam -- BC = CRRES DLL = Brautigam -- BC = BOSCHERDLL = BOSCHER -- BC = BOSCHER

Omnidirectional fluxes @ eq for E = 1,5 MeV -- Kp=4

1,00E+00

1,00E+01

1,00E+02

1,00E+03

1,00E+04

1,00E+05

1,00E+06

1,00E+07

1,00E+08

1,00E+09

0 1 2 3 4 5 6 7 8 9

DLL = Brautigam -- BC = CRRES DLL = Brautigam -- BC = BOSCHERDLL = BOSCHER -- BC = BOSCHER

High activity1.5 MeV

Low activity1.5 MeV

Omnidirectional fluxes @ eq for E = 1,5 MeV -- Kp=2

1,00E+00

1,00E+01

1,00E+02

1,00E+03

1,00E+04

1,00E+05

1,00E+06

1,00E+07

1,00E+08

1,00E+09

0 1 2 3 4 5 6 7 8 9

DLL = Brautigam -- BC = CRRES DLL = Brautigam -- BC = BOSCHERDLL = BOSCHER -- BC = BOSCHER

• Improved bricks during the SPACECAST project:• Enhanced radial diffusion model based on data• Boundary conditions (THEMIS and NOAA-POES data statistical analysis)• Wave-particle interactions (primarily Chorus waves and plasma densities influence)• Drop-outs modelling (focus on in the following)

• Influence of boundary conditions and radial diffusion modelling:

Flux

in M

eV-1 c

m-2 s

-1 s

r-1

L* L*

109

107

105

103

10

Optimizing the science bricks combination (2/3)

• Cold plasma densities influence wave – particle interaction:

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+10

1.00E+11

1.00E+12

1.00E-02 1.00E-01 1.00E+00 1.00E+01

Flux

(cm

-2.s

-1.M

eV-1

)

Energy (MeV)

t=0 hr

t=6 hrs

t=12 hrs

t=18 hrs

t=24 hrs

10-2 10-1 100 101

Energy (MeV)

Flux

(cm

-2.s

-1.s

r-1)

100

102

104

106

108

1010

1012MLT=0h, L*=6.0, percentile 5%

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+10

1.00E+11

1.00E+12

1.00E-02 1.00E-01 1.00E+00 1.00E+01

Flux

(MeV

-1.c

m-2

.s-1

)

Energy(MeV)

t=0 hr

t=6 hrs

t=12 hrs

t=18 hrs

t= 24hrs

10-2 10-1 100 101

Energy (MeV)

Flux

(cm

-2.s

-1.s

r-1)

100

102

104

106

108

1010

1012MLT=0h, L*=6.0, percentile 95%

• Only few cold plasma models exist

• The density shapes the interaction

• Worst cases can be defined

• Flux energy spectra may be very influenced by this density

Low density

High density

Optimizing the science bricks combination (3/3)• Initial state and wave-particle interactions modelling influence:

• From 27th February, 2013 to 28th March, 2013• Two sets of wave-particle interactions (all type of waves)

RBSP-A 0.57-1.12 MeV

RBSP-A 0.05-0.06 MeV

Salammbô 0.57-1.12 MeV

Salammbô 0.05-0.06 MeV

Kp index

Modelling magnetopause shadowing effect (1/4)• What is magnetopause shadowing effect?

Modelling magnetopause shadowing effect (2/4)

• October 1990 magnetic stormComparison with CRRES data

330 keV 1.17 MeV

CRRES

NO DROPOUTS

DROPOUTS

KP INDEX

Modelling magnetopause shadowing effect (3/4)• 16th – 30th September 2007 drop-outs

GOES 10

GOES 12

> 600 keV

> 2 MeV

> 600 keV

> 2 MeVObservation

Simulation without drop-outs modelling

Simulation with drop-outs modelling

Integrated flux in cm-2 s-1 sr-1

Color code

Modelling magnetopause shadowing effect (4/4)

• Inclusion in the upcoming release

Improving low energy rendering: IMPTAM plug

• Work in progress…• Salammbô 3D physics is poor below about 100

keV thus IMPTAM outputs are considered as always better !

• The coupling is based on a data assimilation pattern: each time IMPTAM outputs are available they are ingested in Salammbô

• Encouraging first results

Kp index

50 – 75 keV

170 – 250 keV

Observation from LANL_97A

Salammbô alone

Salammbô + IMPTAM

Color code

Conclusions

• Conclusions

• Bricks of physics have been improved (radial diffusion, boundary condition, wave-particle interaction)

• Their combination improves SALAMMBO precision (factor of 2 to 10)

• Still a challenge to select the perfect combination valid for any magnetosphere configurations (depend on energies, magnetic activities, initialisation, plasma densities …)

• Drop-outs modeled in Salammbô model: improve the results (will be included in the upcoming release)

• IMPTAM model improves SALAMMBO outputs below 100 keV

• Each step made has been compared to in-flight measurements

Acknowledgements

• The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 262468, and is also supported in part by the UK Natural Environment Research Council