1. Energetic Particles: From Sun to Heliosphere – and vice versa
Robert Wimmer-Schweingruber1, Javier Rodriguez-Pacheco2, Sebastian Boden1, Stephan Böttcher1, Ignacio Cernuda2, Nina Dresing1, Christian Drews1, Wolfgang Dröge4, Francisco Espinosa Lara2, Raul Gomez-Herrero2, Bernd Heber1, George Ho3, Andreas Klassen1, Shrinivasrao Kulkarni1, Gottfried Mann5, Cesar Martin1, Glenn Mason3, Lauri Panitzsch1, Manuel Prieto2, Sebastian Sanchez2, Jan Steinhagen1, Jan Tammen1, Christoph Terasa1, Jia Yu1, Rami Vainio6
1Christian-Albrechts University Kiel, Germany, 2University of Alcala, Spain, 3Applied Physics Laboratory, MD, USA, 4University of Würzburg, Germany, 5Astrophysical Institute Potsdam, Germany, 6University of Turku, Finland
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2. Red: Ulysses (see above)
Blue: 1AU
Red: Ulysses (see above)
How does the Sun fill the heliosphere with energetic particles?
Note how the decay phases are all very similar.
This indicates that a large 'reservoir' of energetic particles that fills the heliosphere is being depleted at the same rate everywhere.
How is it filled?
Why does it empty in lockstep?
Measurements close to Sun!
(McKibben et al., 2003)
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3. Radiation Transport in the Heliosphere
Electrically charged
ions and electrons
IP Magnetic field
controls propagation
For a 1 MeV proton,
rc is nearly 30,000 km at 1 AU
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4. Charged energetic particles are tied to magnetic field...
Large-scale interplanetary magnetic field organized along Parker spiral
SOHO
Charged energetic particles are tied to magnetic field...
SOHO, STEREO, Messenger widely separated M
STA
STB
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5. Connection Sun-Heliosphere for November 2011
Active region & flare
Add PFSS model here
STEREO B
footpoint Nov. 3, 2011
SOHO
footpoint Nov. 3, 2011
STEREO A
footpoint Nov. 3, 2011
Messenger
footpoint Nov. 3, 2011
(Gomez-Herrero et al., 2015)
You don't really expect all spacecraft to see the event, do you?
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6. How does the Sun connect to the heliosphere?
We need to better understand the connection!
SOHO
Wide spread events seen in
- ions,
- electrons,
- and 3He
This is sobering...
(can we connect S-H?)
… but also at 1 AU!
STEREO B
STEREO A
Messenger
(Gomez-Herrero et al., 2015)
(Richardson et al., 2014)
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7. The Problem From the Solar Orbiter Red Book:
How do solar eruptions produce energetic particle radiation that fills the heliosphere?
1) How and where are energetic particles accelerated at the Sun?
2) How are energetic particles released from their sources and distributed in space and time?
3) What are the seed populations for energetic particles?
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8. To be an energetic particle, you need to be: - injected
- accelerated
- transported
From the Solar Orbiter Red Book:
How do solar eruptions produce energetic particle radiation that fills the heliosphere?
3) What are the seed populations for energetic particles?
1) How and where are energetic particles accelerated at the Sun?
2) How are energetic particles released from their sources and distributed in space and time?
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9. To be an energetic particle, you need to be: - injected
- accelerated
- transported
Suprathermal seed particles
Origin not understood
Flares, shocks, and compression
Increasing role of turbulence
Charged particles tied to B
Perpendicular diffusion not understood
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10. Have you seen this lately?
Why does IMP8 at 1 AU only see such a smeared-out event?
Can we infer solar onset times from particle data?
(Kallenrode & Wibberenz, 1991)
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11. How does the Sun connect to the heliosphere?
Injection, Acceleration, and Transport
Scatter-free transport in initial (onset) phase of event
Outward moving particles
Inward moving mirrored particles
(Roelof, 2008)
Agueda & Lario (2016) performed careful analysis of the Helios events and determined using this method.
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12. Inversion method (not discussed)
(previous slide)
Inversion method (not discussed)
(Kallenrode & Wibberenz, 1991)
Reconstruction works remarkably well!
(Agueda & Lario, 2016)
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13. 1) Different magnetic connection?
Model predictions for IMP 8 assuming: a) same temporal release profile, b) same transport parameters from Helios to IMP 8
(Agueda & Lario, 2016)
(Kallenrode & Wibberenz, 1991)
1) Different magnetic connection?
2) Different spatio-temporal evolution?
3) Transport effects?
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14. STA/PLASTIC H+ measurements at SIRs
Only little change
Substantial flux
downstream
But also upstream
(Yu et al, in prep.)
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15. Power law like spectrum upstream
(Yu et al, in prep.)
Power law spectrum
downstream
Power law like spectrum upstream
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16. Upstream VDFs are not always power laws
(Yu et al, in prep.)
??? law
??? law
Power law
Should look for wave activity in these regions!
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17. He+ at 1AU CIRs: Messengers from Elsewhere
ACE/SWICS
SOHO/CELIAS/
STOF
(Yu et al., 2016)
As observer moves away from reverse shock, magnetic connection moves farther out into heliosphere.
If there is more He+ „out there“, we don‘t see it here.
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18. Jovian Electrons
(Pyle & Simpson, 1977)
Jupiter‘s magnetosphere can be considered a point source at scale of heliosphere.
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19. Jovian Electrons
(Chenette et al., 1977)
Measurements at 1 AU show 13-month periodicity (at quiet times) which is due to magnetic connection between Earth and Jupiter.
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20. Jovian Electrons Access only by perp. diffusion
(Kühl et al., 2013)
Access only by perp. diffusion
Measurements at 1 AU have potential to determine the efficiency of perpendicular diffusion.
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21. Jovian Electrons „are all over the place“
Jupiter is a point source for relativistic and highly relativistic electrons
Strong radial dependence from source (length along Parker spiral)
Jovian electrons seen by Mariner 10 at 0.5 AU
Jovian electrons also seen at up to 16° heliographic latitude and likely up to 84.5°.
Inner heliosphere (r<1AU): Solar Orbiter and PSP
„High“ latitudes: Solar Orbiter
Can Solar Orbiter/EPD/HET and PSP/EPI-High measure Jovian electrons?
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22. EPD/STEP
EPD/SIS
EPD/EPT-HET1
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23. Summary & Conclusions EPD suite of 4 sensors part of Solar Orbiter
Injection: suprathermal particles
(STEP, EPT, SIS, SWA/HIS/PAS/EAS)
Acceleration: plasma properties & turbulence
(EPD, MAG, SWA, RPW, METIS, SPICE)
Transport: plasma properties & turbulence, source
(EPD, MAG, SWA, RPW, STIX, EUI)
Connectivity: anisotropy, dispersion, source
(EPD, MAG, RPW, SWA, STIX, EUI, SPICE, etc.)
Combination with other instruments is crucial. Payload is meant to be used together, as a suite.
Combination with PSP, Earth, & other assets.
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