Presented at LASP, 7 March 2016

W. S. Kurth, G. B. Hospodarsky

University of Iowa

Auroral Physics at Jupiter: Radio and Plasma Wave Observations by Juno

JunoScienceObjec-ves

OriginDetermineO/Hra.o(waterabundance)andconstraincoremasstodecideamongalterna.vetheoriesoforigin.

InteriorUnderstandJupiter'sinteriorstructureanddynamicalproper.esbymappingitsgravita.onalandmagne.cfields

AtmosphereMapvaria.onsinatmosphericcomposi.on,temperature,cloudopacityanddynamicstodepthsgreaterthan100barsatallla.tudes.

MagnetosphereCharacterizeandexplorethethree-dimensionalstructureofJupiter'spolarmagnetosphereandauroras.

JunoPayload

X and Ka Band Gravity Science (JPL/ASI) Six Microwave Radiometers— MWR (JPL) Magnetometer— MAG (GSFC/DTU) Camera - JunoCam (Malin) Three Energetic Particle Detectors—JEDI (APL) Four Jovian Auroral Distributions — JADE (SwRI) Waves (U of Iowa) UV Spectrometer— UVS (SwRI) IR Camera/Spec –JIRAM (ASI)

PolarMagnetosphereExplora-on

Location is Key: Juno passes directly through auroral field lines. A suite of instruments is used to understand the physics: JADE, JEDI, MAG, Waves, JIRAM, UVS

OutstandingQues-ons:PolarMagnetosphere

•  Whatstructureofthepolarmagnetosphere?HowdoesitcomparetoEarth’s?

•  Whereandhowareauroralpar.clesaccelerated?•  Whereandhowareauroralradioemissionsgenerated?•  Whatcausesthetransientpolaraurora?•  Whatisthetopologyofthepolarmagne.cfield?Howmuchconnectstothesolarwindandhowvariableisthis?

•  Howdointernalmagnetosphericdynamicsandsolarwindvariabilityaffectthemainaurora?

•  Howdoesthepolarmagnetospherecoupletothedistantmagnetotail?

ARerBagenaletal.,SpaceSci.Rev.,2014.

OtherOutstandingQues-ons

•  Howareradia.onbeltpar.clesacceleratedandwhatprocessesdrivethestructureanddynamicsoftheradia.onbelts?

•  Howisthemagnetospherecoupledtothesolarwind?Howmuchmassandmomentumaretransferred?

•  Whatroledoesthesolarwindplayinmagnetosphericdynamicsandhowdeepdoesitsinfluencepenetrate?

ARerBagenaletal.,SpaceSci.Rev.,2014.

Paschmannetal.(2002)

Junowillenablecomparisonswithterrestrialauroralphysics

JunoMissionPlanBaselinemission:

32polarorbits,12degreenetPerijove~5000km14dayperiodSpinning,solarpowered

OrbitalTrajectory

JunoWavesScienceObjec-ves

•  Waves primary objectives: –  Explore radio and plasma waves

in Jupiter’s polar magnetosphere –  Examine the role of plasma waves

in the auroral acceleration region –  Identify source regions for

Jupiter’s primary radio emissions and observe these in situ

•  Additionally, Waves will: –  Observe the structure and

dynamics of the plasmasheet –  Monitor radio emissions as a

proxy for magnetospheric dynamics

–  Measure dust impacts between the ring system and the atmosphere

JunoWavesOverview

InstrumentCharacteris-csSpectralCoverage 50Hz–20kHzMagne.c

SpectralCoverage 50Hz–40MHzElectric

SpectralResolu.on ~20Channels/decade

PeriapsisModeCadence 1spectrum/s

LFandMFBurstModes WaveformCapturesinallbandsto150kHztriggeredonboard

HFBurstModes Abilitytoselecta1-MHzbandincludingfce

Preamps&Electronics

SearchCoil

ElectricAntenna

Ergunetal.

PrimeWavesTargets

8

6

4

2

0

Voyager 1March 6, Day 65, 1979Start SCET 0345:32

Time :40 :50 0346:00 :10 :20

1

0

-10 10 20 30 40 50

Time (ms)

10.

1.0

0.1

A-G00-88

R = 16.0 RJ λm = -7.7E λII I = 7E

Barbosaetal.,1981

1 2 3 4 5 6 7 8BEN (BSKG)

1

2

3

4

-6

-5

-4

Log

Elec

tric

Fiel

d(V

rms/m

)

Log

Freq

uenc

y (H

z)

Day 63 64 65 66SCET 00 12 00 12 00 12 00

R (RJ) 30 25 20 15 10 5 5 10 15 20 25 30

Voyager 1, March 4 - 7, Days 63 - 65, 1979A-G00-143

fCE

CouplingtheMiddleMagnetospheretotheAurora

AuroralRadioEmissions

Zarkaetal.,2004.

Cassini RPWS September 18, Day 262, 2000

10.0

1.0

0.1

Freq

uenc

y (M

Hz)

0

2

4

6

dB

Abo

ve B

ackg

roun

d

A-G01-165-4

UTR (RJ)8I I I (E)NIo (E)

HectometricRadiation

Kilometric Radiation

Io-ControlledDecametricRadiation

000013533567

0200135210884

04001351180101

06001350253118

08001349325135

1000134838152

AuroralRadioEmissionSource

3.95 60.68 -13.34 22.77 4.17

4.21 71.24 -39.03 23.39 6.97

4.75 76.42 -59.25 0.37

18.15

5.45 82.29 -71.76 2.33

55.56

6.21 83.73 -74.20 5.32

83.86

04:00 06:00 08:00 10:00 12:00RS

Inv. LatLatLT

L

101

102

103

104

105

106

Freq

uenc

y (H

z)

10-13

10-12

10-11

10-10

10-9

10-8

10-7

10-6

V2 m

-2H

z-1

Cassini Orbit 89October 17, Day 291, 2008

Saturn Kilometric Radiation

fce

Auroral Hiss

Narrowband Z-modeEmissions

fpe

D (RS)

Z (R

S)

0 2 4 6 8

2

0

-2

-4

-6L = 25

L=30

04:00

08:00

A-G10-001

SolarWind/MagnetosphericInterac-ons

Observa-onPlanning

PJ 52016-11-30T15:52:00.001Z2016-328 16:23 to 2016-356 14:16

0. 10. 20. 30. 40. 50.

-20.

-10.

0.

10.

20.

IntermediatePeriapsisBurst

Apoapsis

PlasmaWavesinEarth’sRadia-onBelts

TerrestrialLightningWhistlers

InterplanetaryShockAssociatedwithX4.9flareon2/25/2014

•  Class X4.9 flare occurred early on 25 February •  Associated with coronal mass ejection •  Juno/Waves observed type III solar radio

emission •  Disturbance propagated to Juno as an

interplanetary shock shown here •  Upstream plasma oscillations caught in Waves

burst mode.

JunoDustImpact

0. 20. 40. 60. 80. 100. 120.

0.

1×104

2×104

3×104

4×104

5×104

6×104

Juno Waves December 2, Day 336, 2011 20:38 SCET

~ 200 mV

Time (ms)

Volta

ge (d

n)

Earth-basedSuppor-ngObserva-ons•  GlennOrtonisresponsiblefororganizingEarth-basedobserva.onsinsupportoftheJunomission–  Amateurs–  Professionals

•  Specificallyforauroralphysics,professionalsupportisexpectedfrom:–  HSTUV(e.g.NicholsCycle23coincidingwithJuno’sorbitinser.on)–  IRTFH3

+

–  GiantTelescopes:COMICS,VISIR,CanariCam(Mid-IR)

•  PhilipZarkawasaskedtocoordinateground-baseddecametricradioobserva.onsunderanad-hocgroupnamed“JunoGroundRadio”:–  NançayDecameterArray(France)–  LOFAR(variousEuropeanloca.ons)–  UTR-2,URAN1-4(Ukraine)–  LWA,LWA1(USA)–  TohokuU.,FukuiInst.Tech.,U.Elect.&Comm.,KochiU.(Japan)–  Others

Summary

•  Theexplora.onofthepolarmagnetosphereisabasicobjec.veofJuno.

•  Thepolarorbitwithverylowperiapsisisidealtosurveytheexpectedauroralaccelera.onregion.

•  Junohasawell-balancedpayloadallowingacomprehensiveexamina.onofauroralprocessesatJupiter

•  JunoWavesinves.ga.onshouldallowcomparisonswiththeterrestrialauroralsitua.on,therebyadvancingourunderstandingofJupiter’spolarmagnetosphere.

•  ArrivalonJuly4,2016!

UVSandJIRAMobserveauroralemissionsonapproach&departure

Insituinstrumentsmeasurepar-cles&fieldsover

polesandinplasmadisk

25

TheauroraisthesignatureofJupiter’sa\empttospinupitsmagnetosphere

?

?

Upward ~ OK

Downward ???

Hill; Cowley et al.,