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Linking Interplanetary Coronal Mass Ejections (ICMEs) observed in-situ to their CME origin at the Sun
SHINE Student Day tutorial
July 29th 2018
Yeimy Rivera
University of Michigan
Overview
• Tutorial: CMEs – Remote sensing
observation of CMEs
– Dynamics and Evolution
– In-situ signatures
• Research: Compositional signatures to derive the thermal history
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 2
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 3
• CMEs are large eruptions at the Sun that propel massive amounts of ionized material into the Interplanetary Medium
• Three-part structure of CMEs – Leading edge and cavity: n=107-8 cm-3 and T > 106 K
– Prominence (Core): n = 109 -11 cm-3 and T =104-5 K (Occurring 70% of the time)
LASCO/SOHO C2 white light image, FOV 1.5-6 Rs
Coronal Mass Ejections
SDO/AIA 171Å band (log T = 5.8), 193Å band (log T = 6.1) taken from Parenti et al. (2012)
CME Dynamics
• Acceleration/Deceleration – MHD form of 'aerodynamic' drag
imposed by solar wind is significant factor to CME propagation and transit time (Vršnak and Žic 2007, Gopalswamy et al. 2001)
• Expansion – More radial in the inner corona and
self-similar out in the Heliosphere (Chen 2011)
• Heating – Prominence material is observed to
transition from absorption to emission in EUV images (Landi et al. 2010)
– Heating source is still an open question
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 4
LASCO/SOHO C3 white light image, FOV 4 -30 Rs
Series of images for a CME in STEREO-A EUVI-A 284Å line (Fe XV formation temperature of 2x106 K)
taken from Landi et al. (2010)
• Freeze-in process undergone by ions (Hundhausen et al. 1968)
– Rapid decrease in density diminishes the ionization and recombination processes in the plasma
– Ionization level is unchanged beyond the freeze-in height allowing to probe the plasma near the Sun
Ion Freeze-in Process
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 5
(Landi et al. 2012)
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 6
Rich
ard
son
an
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an
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01
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Interplanetary CMEs
• Plasma properties
- Low proton density • Magnetic Field
- Flux rope, field rotation
Collection of signatures used to identify ICMEs within the continuous solar wind
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 7
Interplanetary CMEs
• Energetic Particles - Counter-streaming
electrons • Forbush effect
- Reduction of cosmic ray flux
Yeimy Rivera | Linking ICMEs observed in-situ to their CME origin at the Sun | 8
Interplanetary CMEs
• Compositional anomalies (as compared to solar wind)
- O7+/O6+ enhancement - Higher average charge
state - Characterized by
period of alpha-to-proton >0.08
Deriving properties of Coronal Mass Ejections (CMEs) using in-situ charge state distributions
Yeimy Rivera1, Enrico Landi1, Sue Lepri 1 and Jason Gilbert1 1University of Michigan
July 29th 2018
Michigan Ionization Code
• The MIC is solves a time-dependent ionization equation that governs the evolution of ions in the plasma as they propagate from the Sun (Landi et al. 2012)
• Main inputs:
– Electron density
– Electron temperature
– Bulk flow
• Assumptions:
– Local Thermodynamic equilibrium at boundary
– Electron velocity Maxwellian distribution
Sources
Sinks
MIC Output
Yeimy Rivera | Deriving properties of CMEs using in-situ ion distributions | 10
Michigan Ionization Code
Χ2 calculation
Vary parameters to adjust input
profiles
Best fit results
MAIN INPUTS 1. Density, temperature
and velocity profiles 2. Parameter ranges
and increment size 3. In-situ relative
abundances for each ion species Search
Algorithm
Search Algorithm
Yeimy Rivera | Deriving properties of CMEs using in-situ ion distributions | 11
Final Distributions
χ2 =0.304, 95% confidence
level
Charge State Charge State
Re
lati
ve
A
bu
nd
an
ce
Re
lati
ve
A
bu
nd
an
ce
*Plasma Component (PC)
*
Yeimy Rivera | Deriving properties of CMEs using in-situ ion distributions | 12
Plasma Evolution
Yeimy Rivera | Deriving properties of CMEs using in-situ ion distributions | 13
Summary • A combination of ions generated from four plasma components undergoing
distinct thermodynamic evolution effectively reproduced the observed ionic distributions
• Plasma component properties at the Sun are similar to those found in prominences/PCTR also includes a warmer component resembling coronal plasma
Next Steps
• Compare results with heating mechanism – Current sheet dissipation
– Wave heating
Yeimy Rivera | Deriving properties of CMEs using in-situ ion distributions | 14
Heating rate
Thank you!
Yeimy Rivera | Deriving properties of CMEs using in-situ ion distributions | 15
Citations 1. Chen, P F, "Coronal mass ejections: Models and their observational basis", Living
Reviews in Solar Physics 8 (2011).
2. Gopalswamy, Nat and Lara, Alejandro and Yashiro, Seiji and Kaiser, Mike L and Howard,
Russell A, "Predicting the 1-AU arrival times of coronal mass ejections", Journal of
Geophysical Research: Space Physics 106, A12 (2001), pp. 29207--29217.
3. Hundhausen, A. J. and Gilbert, H. E. and S.J., Bame, "Ionization state of the
interplanetary plasma.", Journal of Geophysical Research 73, 13 (1968), pp. 5485--5493.
4. Landi, E and Raymond, J C and Miralles, M P and Hara, H, "Physical Conditions in a
Coronal Mass Ejection from HINODE, STEREO, and SOHO Observations", The
Astrophysical Journal 711, 1 (2010), pp. 75--98.
5. Landi, E. and Gruesbeck, J. R. and Lepri, S. T. and Zurbuchen, T. H., "New Solar Wind
Diagnostic Using Both in Situ and Spectroscopic Measurements", The Astrophysical
Journal 750, 2 (2012), pp. 159.
6. Parenti, S and Schmieder, B and Heinzel, P and Golub, L, "ON THE NATURE OF
PROMINENCE EMISSION OBSERVED BY SDO /AIA", The Astrophysical Journal 754, 1
(2012), pp. 66.
7. Richardson, I G and Cane, H V, "Near-earth interplanetary coronal mass ejections
during solar cycle 23 (1996 - 2009): Catalog and summary of properties", Solar Physics
264, 1 (2010), pp. 189--237.
8. Vršnak, B and Žic, T, "Transit times of interplanetary coronal mass ejections and the
solar wind speed", A&A 472 (2007), pp. 937--943.
SHINE Session:
Insights into CMEs
and Their
Substructure(s)