sing mhd simulations to characterize the parker … · d d d chirality used in the final prediction...

USING MHD SIMULATIONS TO CHARACTERIZE THE

PARKER SOLAR PROBE CORONA Zoran Miki!, Cooper Downs, Jon A. Linker, Ronald C. Caplan,

Roberto Lionello, Tibor Török, Viacheslav Titov, Pete Riley Predictive Science, Inc., San Diego, CA, USA

Duncan Mackay University of St. Andrews, UK

Lisa Upton High Altitude Observatory, Boulder, CO, USA

Presented at the Parker Solar Probe SWG Meeting, Johns Hopkins University, Applied Physics Lab, MD, USA, October 2-6, 2017

Supported by NASA’s LWS and HSR Programs

AUGUST 21, 2017 SOLAR ECLIPSE PREDICTION • We used an MHD model with improved energy transport

(including parallel thermal conduction, radiation loss, and Alfvén wave heating and solar wind acceleration)

• This model can directly produce images of measured quantities (especially emission in EUV and X-rays)

• We used radial magnetic field synoptic maps from SDO/HMI for CR2192 + “Near Real Time” synoptic data for CR2193 measured up to 12:00UT on August 11, 2017

• We scaled Br by the factor 1.4 to make it comparable with our prior calibrations with MDI data (Liu et al. 2012)

• Mesh size: 295 ! 315 ! 699 (r,!,") mesh (65 million points) • We ran for the code for ~ 2–3 days on NASA’s Pleiades

supercomputer using 4,200 processors • The preliminary prediction was posted on July 31, 2017 • The final prediction was posted on August 15, 2017

(http://predsci.com/eclipse)

INNOVATIONS FOR THIS PREDICTION • We used our new wave-turbulence-driven (WTD) model to heat

the corona and accelerate the solar wind (Verdini et al. 2010; Lionello et al. 2014a,b; Downs et al. 2016), using Alfvén waves injected at the photosphere

• We energized (twisted) the coronal magnetic field in filament channels

• We used a flexible “restart” capability to do more efficient runs: - Change the mesh resolution (e.g., use a coarse-mesh solution to start a

new higher-resolution case) - Change the radial photospheric magnetic field (e.g., update magnetic

field data) - Add magnetic field energization (e.g., add in a twisted zero-# coronal

field)

• New diagnostics: visualization of the magnetic squashing factor, Q • Major decisions:

• How to heat the corona, and by how much? • How to energize the corona, and by how much?

MHD EQUATIONS B = 4c J

E = 1c Bt

E + 1c v B = J

t + ( v) = 0

( vt + v v) = 1c J B p pw + g + ( v)

pt + (pv) = ( 1)( p v q – nenpQ(T) + H)

= 5/3 q = ||b̂b̂ T (Close to the Sun, r <~ 10Rs) q = 2 neT b̂b̂ v/( – 1) (Far from the Sun, r >~ 10Rs)

+ Equations for Alfvén wave propagation

MHD EQUATIONS B = 4c J

E = 1c Bt

E + 1c v B = J

t + ( v) = 0

( vt + v v) = 1c J B p pw + g + ( v)

pt + (pv) = ( 1)( p v q – nenpQ(T) + H)

= 5/3 q = ||b̂b̂ T (Close to the Sun, r <~ 10Rs) q = 2 neT b̂b̂ v/( – 1) (Far from the Sun, r >~ 10Rs)

+ Equations for Alfvén wave propagation

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CORONAL HEATING MODEL • Extensive experimentation with CR2189 (April 2–29, 2017) • We ran multiple simulations with the WTD model and the

empirical heating model (v2), comparing with observations of coronal holes in EUV, EUV images in AIA (171Å, 193Å, 211Å), and pB from MLSO

• For the WTD model, we varied the wave amplitude zo, correlation scale length $, and other parameters

• The empirical heating model we used for the July 2010 and November 2012 eclipse predictions produced reasonable solutions with very similar parameters

!"#$%&'()'*$+,$%-(.#$+/0!&-1/2$"3+4/•! 56$/!"#$/&'()'*$+,$/-(.#$+/0!&-1/78$+9:$+9*94;/<9/:9=$*/,9(9+"*/8$"3+4/)"6$=/

9+/>*?#@+/A"#$/($B$,39+/"+=/=.66.7"39+C//

•! &8.6/67$,.D,/?9(:'*"39+/.6/)"6$=/9+/*.+$"(/7(97"4"39+/"+=/($B$,39+/<$(:6/0E$**./FGGH1I/"+=/A"6/*"<$(/$J7*9($=/);/E$(=.+./$</"*C/KLFLI/M.9+$**9/$</"*C/0KLFN1I/"+=/-9A+6/$</"*C/0KLFO1C/

•! P9*#$/$#9*'39+"(;/$Q'"39+6/?9(/<8$/A"#$/<'()'*$+,$/.+/<8$/R$(9%?($Q'$+,;/*.:.<C/S9'7*$/<8$6$/<9/<8$/8;=(9=;+":.,/9(/T2-/$Q'"39+6/<8(9'48/<8$/$+$(4;/"+=/:9:$+<':/$Q'"39+6C/

//•! P$$/-9A+6/$</"*C/0KLFO1/?9(/"/=$<".*$=/6<'=;/9?/<8$/:9=$*/9+/,*96$=/,9(9+"*/*9976C//

–! U;/=$6.4+/<8$/8$"3+4/("<$/6,"*$6/A.<8/:"4+$3,/D$*=/6<($+4<8I/)'</"*69/+"<'("**;/"="7<6/<9/<8$/*997/7(97$(3$6/0*997/*$+4<8/"+=/$J7"+6.9+/?",<9(1C/

•! &8$/:9=$*/is 6.:.*"(/.+/67.(.</<9/<8$/>!P9T/:9=$*/.+/U>&P%V%5PW/#"+/=$(/29*6</$</"*C/0KLFH1I/X("+/$</"*C/0KLFY1C//–! 29A$#$(I/<8$($/"($/Z$;/=.[$($+,$6/.+/<8$/=$<".*6C//–! &8$6$/=$<".*6/6<(9+4*;/.+B'$+,$/<8$/7(9D*$/"+=/=.6<(.)'39+/9?/8$"3+4C/

&

∂z±∂t

+ [�v ± �va] ·∇z± = R1z± +R2z∓ +

|z∓|z±2λ

Qheat = ρ|z−|z2+ + |z+|z2−

4λI/

z+ z−

z+ z−

z−

z+

/ WKBAdvection

Injection

Loop

Reflection

Dissipation

Positive open

field line or

loop leg

Negative open

field line or

loop leg

100

500

-50

-100

B r [G

auss

]

Radial Magnetic FieldAugust 21, 2017 Total Solar Eclipse

LongitudeLa

titud

e180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°

CR 2191 (May 26 – June 23, 2017)

Longitude

Latit

ude

180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°

CR 2192 + 2193 NRT (July 20 – August 11, 2017)Longitude

Latit

ude

180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°

CR 2192 (June 23 – July 20, 2017)

CR2193CR2192

Longitude

Aug 12Jul 18Jul 20 Aug 7 Jul 29 Jul 24Jul 27Jul 31Aug 5Aug 9 Jul 22 Jul 20Aug 2

Latit

ude

30150-15-30Br [Gauss]

Radial Magnetic Field (HMI Synoptic Data × 1.4)

180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°

August 21, 2017 Total Solar Eclipse

CR2192

Polarity InversionLine at r = 1.05R

CR2193

CMLELWL

On Eclipse DayCML: Central Meridian LongitudeEL: East Limb LongitudeWL: West Limb Longitude

August 21, 2017 Total Solar EclipseMagnetic Field Lines

Terrestrial North up

Simulated Polarized Brightness



Simulated Polarized Brightness (Log Unsharp)


Solar North up

Simulated Polarized Brightness

Predicted Polarization Brightness (Movie of pB as the Sun Rotates)August 21, 2017 Total Solar Eclipse

Equivalent Heat Flux at r = Ro


log10{q(θ,φ) [erg/cm2/s]}7.06.56.05.55.0

Latit

ude

Longitude180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°

ENERGIZATION OF THE MAGNETIC FIELD • We collaborated with Duncan Mackay and Lisa Upton to get the

filament chirality • Duncan ran a magnetofricitional model (e.g., Yeates et al. 2008),

starting the model on January 1, 2017 (solar time), and feeding in newly emerged active regions, as determined from the evolving photospheric field produced by the Advective Flux Transport model (e.g., Upton & Hathaway, 2014a,b)

• This produced a model with sheared magnetic fields that matched the observed neutral lines quite well

• We used Duncan’s “run 4” on July 29, 2017 to determine the chirality of filaments as input to our model

• We used an ad hoc prescription for injecting transverse field in the filament channels, followed by flux cancellation at the PILs

Mackay Magnetofricitional Modelrun4: July 29, 2017

Blue = Sinistral

Green = Neither

Red = Dextral

ENERGIZATION OF THE MAGNETIC FIELD • The magnitudes of the injected fields were determined by trial and

error from several runs to energize the magnetic field slightly below the eruption threshold

• The emergence phase is followed by a flux cancellation phase, to create flux ropes, so we add flux to the initial synoptic map that is cancelled during the later phase

• This procedure was first used in modeling the March 20, 2015 total solar eclipse (ISSI team led by A. Yeates; publication in preparation)

EMERGING TRANSVERSE MAGNETIC FIELD Bt • Transverse magnetic field emergence is accomplished by applying

a transverse electric field at r = Ro: Et = ""t " # r̂ + ""t $#

with # = 0. This does not change Br at r = Ro. • We specify $ such that the injected Bt is aligned along the PIL • Define

$ ~ M · S · f (Br) where

M is a “mask function,” to localize the electric field S is a “step function,” that changes sign across the PIL f (Br) is a “saturation function”

EMERGING TRANSVERSE MAGNETIC FIELD Bt • Let d = d(x) be the signed distance from the PIL • Define the localization mask M as:

M = e%(d/do)2 , where do is a parameter that controls the width of the emergence region

• Step and saturation function: S · f (Br) = Bo tanh(Br/Bo) ,

where Bo is a parameter that controls the saturation • The emergence phase is followed by a flux cancellation phase,

using a # potential (with $ = 0), determined from

1c &Br

o

&t = "t2#

Br (HMI × 1.4), CR2192+2193_20170811

[Scaled @ 30G]

90°

45°

0

-45°

-90°0 45° 90° 135° 180° 225° 270° 315° 360°

Longitude

Latit

ude


Polarity Inversion Line at r = 1.05R90°

45°

0

-45°

-90°0 45° 90° 135° 180° 225° 270° 315° 360°

Longitude

Latit

ude


015S060N

105N120N

120S150S

215N265N

300N300S

Filament Channels (v3)90°

45°

0

-45°

-90°0 45° 90° 135° 180° 225° 270° 315° 360°

Longitude

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015S060N

105N120N

120S150S

215N265N

300N300S

D

SS

D

DD

S

D

D

D

Chirality Used in the Final Prediction90°

45°

0

-45°

-90°0 45° 90° 135° 180° 225° 270° 315° 360°

Longitude

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Φ Potential v7015S060N

105N120N

120S150S

215N265N

300N300S

90°

45°

0

-45°

-90°0 45° 90° 135° 180° 225° 270° 315° 360°

Longitude

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Evolution of Magnetic Field Lines (Emergence Phase)August 21, 2017 Total Solar Eclipse

Evolution of Magnetic Field Lines (Flux Cancellation Phase)August 21, 2017 Total Solar Eclipse

Magnetic Field Lines (Movie as the Sun Rotates)August 21, 2017 Total Solar Eclipse

Image taken by Lorenzo Comolli in Glendo, WYPosted to http://spaceweathergallery.com/

PSI Final PredictionPolarized Brightness

August 21, 2017 Eclipse: Preliminary Comparison


Image taken by Lorenzo Comolli in Glendo, WYPosted to http://spaceweathergallery.com/

PSI Final PredictionMagnetic Squashing Factor, Q

August 21, 2017 Eclipse: Preliminary Comparison


Image proccessed by Miloslav DruckmüllerMitchell, OR

PSI Final PredictionPolarized Brightness

August 21, 2017 Eclipse: Comparison


Image proccessed by Miloslav DruckmüllerMitchell, OR

PSI Final PredictionMagnetic Field Lines

August 21, 2017 Eclipse: Comparison


Miloslav Druckmüller Image + Predicted pBAugust 21, 2017 Total Solar Eclipse

Miloslav Druckmüller Image + Predicted Magnetic Field LinesAugust 21, 2017 Total Solar Eclipse

Squasing Factor Q (Movie as the Sun Rotates)August 21, 2017 Total Solar Eclipse

Effect of Energization in the Low Corona

CONCLUSIONS • Our coronal prediction captured the large-scale structure of the

corona quite well • Coronal heating models have advanced considerably; models with

fewer parameters (WTD) are now practical • Techniques to energize the magnetic field have been developed • This could be done more quantitatively using vector magnetic field

observations • It is time to make a constantly evolving magnetic field model of

the corona that is driven with a flux transport model • Essentially, we can reproduce what the magnetofrictional model is

doing, with a better physical model (MHD), and more accurate photospheric field evolution

• Predictive models may be useful for PSP and SO observation planning; models using magnetic data surrounding an observation may be useful for data analysis

WHAT ABOUT THE MISSING NW PSEUDOSTREAMER? • The disagreement between the prediction and the observed corona

in the area of the NW limb may be due to the use of out-of-date magnetic field data in that region.

• The pseudostreamer seen in the NW was not prominent in our prediction. The neutral line in the data we used (from July 16–20) changed considerably in the updated data from CR2193 (August 12–16). Namely, in the data we used, a PIL was absent in that region (longitude ~ 30°, latitude ~ 50°N), but it does become more apparent in newer data.

• Perhaps this played a role in the absence of this pseudostreamer in our prediction. We are currently investigating this.

Longitude

Aug 12Jul 18Jul 20 Aug 7 Jul 29 Jul 24Jul 27Jul 31Aug 5Aug 9 Jul 22 Jul 20Aug 2

Latit

ude

30150-15-30Br [Gauss]

Radial Magnetic Field (HMI Synoptic Data × 1.4)

180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°


CR2192


CR2193

CMLELWL


mikic

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Longitude

Aug 12Aug 14Aug 16 Aug 7 Jul 29 Jul 24Jul 27Jul 31Aug 5Aug 9 Jul 22 Jul 20Aug 2

Latit

ude

30150-15-30Br [Gauss]

CR 2193 Radial Magnetic Field (HMI Synoptic Data × 1.4)

180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°



CMLELWL


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Longitude

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180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

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-60°

30°

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PFSS Coronal Holes (Rss = 2.5R )

CMLELWL


CR2192 CR2193Aug 12Jul 18Jul 20 Aug 7 Jul 29 Jul 24Jul 27Jul 31Aug 5Aug 9 Jul 22 Jul 20Aug 2

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Longitude

Latit

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180°60°0° 240° 300° 360°120°

0°

90°N

-90°S

60°

-60°

30°

-30°



CR 2193 PFSS Coronal Holes (Rss = 2.5R )

CMLELWL


Aug 12Aug 14Aug 16 Aug 7 Jul 29 Jul 24Jul 27Jul 31Aug 5Aug 9 Jul 22 Jul 20Aug 2

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sing mhd simulations to characterize the parker … · d d d chirality used in the final prediction...

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