Simulated prompt acceleration of multi- MeV electrons by the 6-7 - - PowerPoint PPT Presentation

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Simulated prompt acceleration of multi- MeV electrons by the 6-7 - - PowerPoint PPT Presentation

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Simulated prompt acceleration of multi- MeV electrons by the 6-7 September 2017 interplanetary shock Mary K. Hudson, Shri Kanekal, Zhao Li, Maulik Patel, John Wygant Dartmouth, NCAR/HAO, NASA GSFC, UMN Outline IP-shock compressions of

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SLIDE 1

Simulated prompt acceleration of multi- MeV electrons by the 6-7 September 2017 interplanetary shock

Mary K. Hudson, Shri Kanekal, Zhao Li, Maulik Patel, John Wygant Dartmouth, NCAR/HAO, NASA GSFC, UMN

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SLIDE 2

Outline

  • IP-shock compressions of dayside

m’sphere launch fast mode impulse

  • Accelerates electrons azimuthally &

transports radially inward conserving μ

  • Strong events rare, RBSP measurements

see weaker events, pitch angle dispersed drift echoes

  • 17 March 2015; 8 Oct 2013;16 July 2017;

6 Sept 2017;

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SLIDE 3

(Courtesy of J. B. Blake ) July 1990

  • Oct. 1991

CRRES March 91 Electron Injection Event: Not diffusive! Transport >1 Re over drift period

March 24, 1991

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SLIDE 4

Solar Wind Shock Pair 9/6-9/8

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SLIDE 5

Van Allen Probes 6 September 2017

5

23:30 – 00:30 UT Shock arrives 23:45 UT

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SLIDE 6

1.8 MeV 2.1 MeV 2.6 MeV 3.4 MeV 4.2 MeV 5.2 MeV 6.3 MeV 60. 80. 100. 120. 140. Alpha (degrees) 1 05 1 06 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 1 05 1 06 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 2×10 5 4×10 5 6×10 5 8×10 5 10×10 5 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 1 03 1 04 1 05 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 1 02 1 03 1 04 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 2000. 4000. cm

  • 2s
  • 1sr
  • 1MeV
  • 1

23:42 4.047 23:45 4.112 23:48 4.174 23:51 4.239 23:54 4.298 23:57 4.356 2017-09-06 (249) 23:42 to 23:59 L 60. 80. 100. 120. 140. Alpha (degrees) 200. 400. cm

  • 2s
  • 1sr
  • 1MeV
  • 1

REPT A REPT B

6

ULF osc

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SLIDE 7

EFW E-field Measurements

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SLIDE 8

CRRES Data from ~2200 MLT

Li et al., GRL, 1993 Drift echoes

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SLIDE 9

Prompt acceleration of magnetospheric electrons to ultrarelativistic energies by the 17 March 2015 interplanetary shock

Journal of Geophysical Research: Space Physics Volume 121, Issue 8, pages 7622-7635, 15 AUG 2016 DOI: 10.1002/2016JA022596 http://onlinelibrary.wiley.com/doi/10.1002/2016JA022596/full#jgra52812-fig-0002

VAP-A at L ~ 3 Kanekal et al., JGR, 2016

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SLIDE 10

S/C Location at IP Shock Arrival

17 March 2015

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SLIDE 11

Global MHD Simulations of Magnetosphere +Test Particles

  • Observations of the solar

wind parameters made by satellites, operating at the L1 point (OMNI data)

  • The ideal MHD equations are

solved on a grid to simulate the response of the magnetosphere to the dynamic solar wind –

  • Lyon-Fedder-Mobarry model

coupled to ionospheric BC & RC

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SLIDE 12

Simulated Pitch Angles at RBSP-A 17 March 2015 Shock

Hudson et al., JGR, 2017

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SLIDE 13

Simulated RB-A Weighted Flux

L ~ 3

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SLIDE 14

Simulated RB-B Weighted Flux

L ~ 5

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SLIDE 15

Simulated Pitch Angles at RBSP-B

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SLIDE 16

Drift Shell Splitting Effect on PAD Depends on Radial Gradient

Sibeck et al., JGR, 1987

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SLIDE 17

Normalized REPT Flux at RB-B

17 March 2015 IP Shock Injection Event Van Allen Probe – B at L~5 Baker et al, 2016 extended

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SLIDE 18

LFM Ephi Snapshots 17 March 2015 IP Shock

Faraday’s Law: ∂Bz/∂t = - x Ephi

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SLIDE 19

2 MeV electrons – 3D Pitch Angles – Eq Plane Crossing in LFM-RCM Fields 17 March 2015 IP Shock Event

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SLIDE 20
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SLIDE 21

Van Allen Probes 6 September 2017

21

23:30 – 00:30 UT Shock arrives 23:45 UT

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SLIDE 22

ECT Flux Distribution Prior to Shock for 6 Sept 2017 Storm

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SLIDE 23

L* = 3.9 – 4.6 6 Sept 2017

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SLIDE 24

Pitch Angle Distributions at Probe A ULF osc 6 Sept 2017

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SLIDE 25

1.8 MeV 2.1 MeV 2.6 MeV 3.4 MeV 4.2 MeV 5.2 MeV 6.3 MeV 60. 80. 100. 120. 140. Alpha (degrees) 1 05 1 06 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 1 05 1 06 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 2×10 5 4×10 5 6×10 5 8×10 5 10×10 5 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 1 03 1 04 1 05 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 1 02 1 03 1 04 cm

  • 2s
  • 1sr
  • 1MeV
  • 1

60. 80. 100. 120. 140. Alpha (degrees) 2000. 4000. cm

  • 2s
  • 1sr
  • 1MeV
  • 1

23:42 4.047 23:45 4.112 23:48 4.174 23:51 4.239 23:54 4.298 23:57 4.356 2017-09-06 (249) 23:42 to 23:59 L 60. 80. 100. 120. 140. Alpha (degrees) 200. 400. cm

  • 2s
  • 1sr
  • 1MeV
  • 1

REPT A REPT B

25

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SLIDE 26

L* = 5.22 – 5.11 6 Sept 2017

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SLIDE 27

Pitch Angle Distributions at Probe B 6 Sept 2017

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SLIDE 28

Pitch Angle Distributions at Probe A ULF osc 6 Sept 2017

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SLIDE 29

Conclusions

  • Prompt increase of MeV el flux L = 3-5 on electron drift

time scale due to IP shock launched MHD fast mode

  • Observed for weaker events by VAP than 24 March 1991:

8 Oct 2013; 17 March 2015; 6 Sept 2017; 16 July 2017

  • MHD-test particle simulations reproduce energy, drift echo

& pitch angle distributions & ULF- local flux oscillations

  • Observed commonly for weaker IP shocks
  • Strong events with Ephi ~ 100 mV/m inject el to low L~2.5

and high energy

  • Weaker events with Ephi ~ 10 mV/m transport into L = 3-5,

lost promptly with inward magnetopause motion, drift shell splitting, m’pause shadowing

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SLIDE 30

September 2017 events - REPT

30

2.6 MeV 5.2 MeV 4.2 MeV 3.4 MeV

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SLIDE 31

Backup Slides

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SLIDE 32

Adiabatic trajectories launched from midnight and noon in TS89

Butterfly Pancake Roederer and Lejosne,JGR, 2018 Contours of constant L*

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Backup Add’l REPT Channels 6 Sept 2017 VAP-A

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SLIDE 34

Backup Add’l REPT Channels 6 Sept 2017 VAP-B

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SLIDE 35
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1

1 1 2 2 3 3 4 4 5 5 6 6

  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1

1 1 2 2 3 3 4 4 5 5 6 6 GSE X (RE) GSE X (RE) GSE Y (RE) GSE Y (RE)

2017/09/06 22:30:00 - 2017/09/06 23:30:00 UTC

RBSP-A RBSP-B

  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1

1 1 2 2 3 3 4 4 5 5 6 6

  • 3
  • 3
  • 2
  • 2
  • 1
  • 1

1 1 2 2 3 3 GSE Y (RE) GSE Y (RE) GSE Z (RE) GSE Z (RE)

2017/09/06 22:30:00 - 2017/09/06 23:30:00 UTC

RBSP-A RBSP-B

  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1

1 1 2 2 3 3 4 4 5 5 6 6

  • 3
  • 3
  • 2
  • 2
  • 1
  • 1

1 1 2 2 3 3 GSE X (RE) GSE X (RE) GSE Z (RE) GSE Z (RE)

2017/09/06 22:30:00 - 2017/09/06 23:30:00 UTC

RBSP-A RBSP-B

Van Allen Probes 6 September 2017- Including Pre-Shock

35

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SLIDE 36

REPT-A Lower Energies 6 Sept 2017

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SLIDE 37

REPT-B Lower Energies 6 Sept 2017

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SLIDE 38

September 2017 events - REPT

38

2.6 MeV 5.2 MeV 4.2 MeV 3.4 MeV

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SLIDE 39

Figure 4 7 Oct 2013 IP shock Foster et al., JGR, 2015

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SLIDE 40

ECT Flux Preceding 17 March 2015 IP Shock Arrival

RB-B Location at IP Shock Arrival RB-A Location at IP Shock Arrival

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SLIDE 41

VAP Locations for Second Shock