Extremely intense ionospheric ion escape during severe ICMEs:

1. Extremely intense ionospheric ion escape during severe ICMEs: M. Yamauchi1, A. Schillings1,2, R. Slapak2, H. Nilsson1, I. Dandouras3 1. IRF, Kiruna, Sweden 2. LTU, Kiruna, Sweden 3. IRAP, U. Toulouse/CNRS, Toulouse, France

2. (1) Slapak et al. (2017): Ion Loss Rate from the Earth for Kp < 7 : Flossµ exp(0.45*Kp)  ∫Floss≈ 1018 kg ≈ atmospheric O2 (2) Yamauchi and Slapak (2017): Extraction of Solar Wind kinetic energy by mass loading : ∆EµFloss·vSW2 (3) Schillings et al. (2017): However, for large Kp ≥ 7+ : Floss (and ∆E)>> prediction by exp(0.45*Kp) Space Weather Events play an important role in O+ escape Key Point

3. Suprathermal H+ & O+ < 70 eV @9000km (Akebono) (1) O+ escape vs. Kp: low-altitudes • Highest flux • = polar region • might mix with • the solar wind (Cully et al., 2003)

4. (1) O+ escape vs. Kp: Cluster/CIS Cluster could distinguish (a) and (b)

5. Cluster/CIS hot O+ obs. of direct escape ??? Kp≥8 1026 1025 ~ 0.7x1025 s-1 1024 Ion Loss Rate : Flossµ exp(0.45*Kp) R Cluster/CIS: 2001 – 2005 (Slapak et al., 2017) ~ 2x1025 s-1 Kp # samples X

6. (2) Feedback from escaping ions VO+ increases while VH+decreases  Mass loading  inelastic momentum conservation  Extraction of kinetic energy O+ escape rate: Flossµ exp(0.45*Kp)

7. (2) Feedback from escaping ions (1) Amount is substantial: nO+/nSW~0.01  rO+/rSW~0.16  extract 7% of kinetic energy  109-10 W to J// through B

8. (2) Feedback from escaping ions Extraction of kinetic energy: ∆E Simple conservation laws:  ∆E µ Floss·vSW2, but nothing else Since Flossµ ionospheric current µ∆E  Positive feedback between ∆E µ Floss·vSW2 & Flossµ exp(0.45*Kp)

9. (2) Feedback from escaping ions Extraction of kinetic energy: ∆E Simple conservation laws:  ∆E µ Floss·vSW2, but nothing else Since F µ ionospheric current µ ∆E  Positive feedback between ∆E µ Floss·vSW2& Flossµ exp(0.45*Kp)  ∆Eµ Kp2 · exp(0.45*Kp) , for Kp<6 We expect nearly linear relation between Kp and log(∆E) But, reality for Kp>7 is….

10. example: Halloween event (2003-10-29) O+ (3) Non-linearity for Kp>7 energy H+ O+ (>0.3 keV) pitch angle O+ (<0.3 keV)

11. example: Halloween event (2003-10-29) entire 2003 (3) Non-linearity for Kp>7 • Flux after scaling to the ionosphere • Reference: 1-year data in the same region 2003-10-29  higher than extrapolation

12. Examined 6 “extreme” events (3) Non-linearity for Kp>7

13. (a) Southern hemisphere Shift of median flux x 47 (3) Non-linearity for Kp>7 x 50 x 10 x 18

14. (b) Northern hemisphere Shift of median flux x 20 x 6 x 9 (3) Non-linearity for Kp>7 x 60 x 83 x 18

15. The O+ outflow during major storms is 1 to 2 orders of magnitude higher than during less disturbed time (3) Non-linearity for Kp>7

16. (1) Slapak et al. (2017): Ion Loss Rate from the Earth for Kp < 7 : Flossµ exp(0.45*Kp)  ∫Floss ≈ 1018 kg ≈ atmospheric O2 (2) Yamauchi and Slapak (2017): Extraction of Solar Wind kinetic energy by mass loading : ∆E µ Floss·vSW2 ∆E µ Kp2·exp(0.45*Kp) , for Kp < 7 (3) Schillings et al. (2017): However, for large Kp ≥ 7+, Floss (and ∆E) >> prediction by exp(0.45*Kp) Space Weather Events play an important role in O+ escape & ∫F >> 1018 kg (atmospheric O2) Space Weather Events play some role in atmospheric evolution Summary and Conclusion

17. Need to understand expansion and escape of neutral atmosphere too.  ESCAPE mission (oral later) Future direction

18. End / extra slides

19. (2) Feedback from escaping ions Extraction of kinetic energy: ∆E Simple conservation laws:  ∆E µ F · vSW2, but nothing else Since F µ ionospheric current µ ∆E  Positive feedback between ∆E µ F · vSW2 & F µ exp(0.45*Kp)  ∆Eµ Kp2 · exp(0.45*Kp) , for Kp<6 & IMF BY effect can be explained

20. (2) Feedback from escaping ions Since F µ ionospheric current µ ∆E  Positive feedback between ∆E µ F · vSW2 & F µ exp(0.45*Kp)  ∆Eµ Kp2 · exp(0.45*Kp) , for Kp<6

21. Method 2nd step: Plot the boxes and look at the plasma beta 29 Oct 2003 Halloween event

22. Method Year 2003 3rd step: Check the plasma beta parameter for the O+ outflow during the year Scaled O+ flux log10 m-2s-1 Number of data points Log10 plasma beta

23. (1) Slapak et al. (2017) Cluster observations in the magnetosheath and plasma mantle show, Ion Loss Rate from the Earth : Fµ exp(0.45*Kp) , for Kp<7  This already gives total escape over past 4 billion years ∫F ≈ 1018 kg ≈ present atmospheric O2 (2) Yamauchi and Slapak (2017) Inelastic mixing of escaping ions with the solar wind (i.e., mass-loading) converts solar wind kinetic energy to electric potential energy, which is consumed in the ionosphere because of direct geomagnetic connection. Conservation laws predicts, Energy extraction (total) : ∆EµF·vSW2 , but nothing else.  Positive feedback between the ion escape and energy extraction transfers the non-linearity (to Kp) from F to ∆E, Ionospheric/Ground current µ∆EµKp2·exp(0.45*Kp) , for Kp<6 (3) Schillings et al. (2017) However, for large Kp, the flux values F is much higher than the prediction by (1), but more than one order of magnitude. ∫F >> 1018 kg ≈ present atmospheric O2  Space Weather Events plays some role in atmospheric evolusion Key Point