1. S. Bourdarie, V. Maget, A. Brunet, A. Sicard
Data assimilation technic applied to radiation belts and re-analysis data base
S. Bourdarie, V. Maget, A. Brunet, A. Sicard

2. Outline
Introduction Data assimilation with model uncertainties Re-analysis data bases Conclusions
Activity funded by:
R&T CNES
European Union – FP-7 MAARBLE project

3. Count rate data assimilation
𝐹𝑙𝑢𝑥(𝐸)=2𝜋 0 𝜋 𝑃𝑆𝐷× 𝑝 2 ×𝑠𝑖𝑛𝛼 𝑑𝛼
𝐶𝑜𝑢𝑛𝑡 𝑟𝑎𝑡𝑒= 0 ∞ 𝐹𝑙𝑢𝑥(𝐸)×𝑅𝑒𝑠𝑝𝑓𝑢𝑛𝑐 𝐸 𝑑𝐸

4. Model uncertainties: boundary conditions
Boundary condition at L*=8

5. Model uncertainties: wave-particle interactions
Median of Bw
Standard Deviation of Bw

6. Model uncertainties: radial diffusion
@GEO
Number of points Kp
DLL (day-1)

7. Re-analysis database Re-analysis database: EnKF Electrons 0.3-5 MeV
Mean + Standard deviation psd(E, y, L*)
10 mn time resolution
2012/09/25 – 2015/07/13
GOES13 and RBSP → for assimilation
INTEGRAL → for validation

8. Re-analysis database Re-analysis database used to produce the:
Direct data insertion
Electrons MeV
Mean psd(E, y, L*)
10 mn time resolution
1990/01/01 – 2005/01/01
Re-analysis database used to produce the:
OZONE model (2009)
GREEN-e (4<L<8)
Assimilation de données appliquée aux ceintures de radiation électrons

9. Re-analysis database Re-analysis database used to produce the:
1MeV
Re-analysis database:
Direct data insertion (GOES)
Proton 50 keV MeV
Mean psd(E, y, L*)
12 hours time resolution
1989/01/01 – 2017/12/31
POES
Salammbo
(Equatorial)
8,5-35MeV
Re-analysis database used to produce the:
GREEN-p (1<L<6)
HEO3
Salammbo
(Equatorial)
Assimilation de données appliquée aux ceintures de radiation électrons

10. Conclusions
Physics based models or even better data assimilation tools are ideal to create long term consistent databases
Re-analysis databases for trapped electrons and protons have been produced and used to develop the GREEN-e and –p models
Future plans to improve the core of the assimilation tool:
Implement a bias detection and correction procedure (bias blind assimilation tool)
Implement a data assimilation tool not only sequential, like the EnKF, but which also consider the time history of the radiation belts (Smooth ensemble Kalman filter or 4Dvar)
Produce a re-analysis database at the solar cycle time scale is also foreseen from EnKFto get uncertainties as well.
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