VoyagerUVS
50nm<λ<170nmΔ=3.0nm
Broadfootetal.,UltravioletspectrometerexperimentfortheVoyagermission,SpaceSci.Rev.,21,183,1977.
Date Paper
Atomic Results
Database
1979 Broadfootetal.,Extreme
Home V1-SIII,SIV,OIIIonly.Ne>2100cm-3,Te=105K=8.6eV.Pcooling~2TW
ultravioletobservationsfrom
(DES?) S++(95cm-3),S+++(55cm-3),O++(<850cm-3)
Voyager1Encounterwith
Jupiter,Science,204,979-982
1979 Sandeletal.,Extremeultraviolet
Home V2-SIII,SIV,OIIIonly.X2brighter,40%lowerTe.AscribedGBobsofSIIand
observationsfromVoyager2
(DES?)
OIItocoldinnertorus.
EncounterwithJupiter,
Science,206,962-66
1980a Shemansky,RadiativeCooling
Home Ne>2100,Te=105K=8.6eV,Pcooling2.5TW.
efficienciesandpredicted
S++(95cm-3),S+++(80cm-3),O++(290-740cm-3)
spectraofspeciesoftheIo
Admitsatomicdata<911Aarenotwellestablished.
plasmatorus,ApJ.236,1043
OII(833)<<OIII(834)becausenoOII(539).Netmodel:
Sn+production>4a10-4cm-3s-1On+production>5a10-4cm-3s-1
S+(25)S++(95),S+++(80),S4+(<12)O+(<46)O++(190-740)O+++(<21)
1980 Strobel&Davis,Propertiesof
NRL&Los Matchtospectrum->composition.AbsenceofOII539->834A.
theIoplasmatorusinferred
Alamos Te=8x104K~7eV,Thot~100eV,Fehot<5%.
S+(<300)S++(500),S+++(160),O+(300)O++(110)
fromVoyagerEUVdata,ApJ.,
HintsatFehotmodulatingS+++O/S>0.8->2,insupportofSO2source.
238,L49-L52,1980
1980b Shemansky,Mass-loadingand
Home Source<1027s-1duetolackoflocalemissionnearIo.Timescale~100d.
diffusion-lossratesoftheIo
Power~3TW,energydeficitfrompurepick-up.Te=105K=8.6eV,Ti=4x
plasmatorus,ApJ.,242,1266
105K=35eV.
4K~600eV,Ne=1850
ChangesincollisionstrengthsforOIII834A.
Home V1–“acollisionalmodel”Fehot=0.05%,Thot=8x10
1981 Shemansky,Smith,TheVoyager
EUVspectrumoftheIo
S+(44±20)S++(160),S+++(220),S4+(<11)O+(50)O++(340)O+++(<17)
plasmatorus,JGR,86,9179
τ~months,ΣOn+/ΣSn+=0.9
1
1981
Broadfootetal.,Overviewof
Voyagerultraviolet
spectrometerresultsthrough
Jupiterencounter,JGR,86,
8259-8284,1981
1982a Sandel,Broadfoot,Discoveryof
anIo-correlatedenergy
sourceforIo’shotplasma
torus,JGR,87,2231
1982b Sandel, Broadfoot, Io’s hot
plasma torus: A synoptic
view from Voyager, JGR 87,
212
Home
(DES)
1982
Shemansky,
Sandel,
The
injectionofenergyintotheIo
plasma torus, JGR, 87, 219229
1983
Brown,
Pilcher,
Strobel,
Spectrophotometric studies
oftheIotorus,Physicsofthe
Jovian
Magnetosphere,
Dessler(ed),CUP
Shemansky, Ratio of oxygen to
sulfurintheIoplasmatorus,
JGR,92,6141
various
Sandel,Dessler,Dualperiodicity
ofthejovianmagnetosphere,
JGR,93,
5487
1987
1988
DES
TorusanalysisbasedonShemansky&Smith1981.
S+(44±20)S++(160),S+++(220),S4+(<11)O+(49)O++(336)O+++(<17)
AllUVSdatafromV1+V2(44days).
Just685A(SIII+OIII)
VariationinbrightnesswithphaseofIo.
PeakatLT=19:00,SysIIIcomparisonwithGBobservations
V1in/outbound->duskbrighterthandawn–25%
V23/8caseswherenodawn/duskeffect
NosystemIIIeffect
Te~constantfor0.5yrwithshort-termvariations.
SystemIIIvariationsinTe.EnergybalanceusingprimarilySIII685A
TehotterLT=22:30duskvs10:30dawn
e-heating:ioncollisionalheatingtooslow(6-10d).
Fehot<1%(Scudder1981,Shamansky1980)
V1/V2comparison.Model+data–Collisionaldiffusiveequilibrium.
O:S~equal.OII,SII,SIII–plusGBOI,SI–Skinner&Durrance1986
Bigchangesin833/834collisionstrengths.OII/OIIIdependenceonTe.
ArguesforS(O)/S(S)~4.IncludesCHEX–whichremovesO++
ConfinedtoSIII–lookingforSystemIII&IVvariations.
(pityinhindsightgivenlaterworkshowingSIandSIVmore)
42daysofV2data(235scans).AlsonKOM
Lotsofideas–notanysolidconclusions
2
1992
Dessler,Sandel,SystemIII
variationsinapparent
distanceoftheIoplasma
torusfromJupiter,GRL,19,
2099
1992 Bagenal,Shemansky,McNutt,et
al.,TheabundanceofO++in
thejovianmagnetosphere,
GRL,19,79-82
1993 Smith,Chutjian,Mawhorter,
Williams,Shemansky,
Excitationofpositiveionsby
low-energyelectrons:
relevancetothetorus,JGR,
98,5499-5504
1995 Herbert,Sandel,Radialprofiles
ofiondensityandparallel
temperatureintheIoplasma
torusduringtheVoyager1
encounter
1995 Tayloretal.Comparisonofthe
Voyager1ultraviolet
spectrometerandplasma
sciencemeasurementsofthe
Ioplasmatorus
1997a Volwerk,etal.Evidencefor
shortcoolingtimeintheIo
plasmatorus.GRL,25,11471150
1997b Volwerk,SystemsIIIandIV
modulationoftheIophase
effectintheIoplasmatorus,
JGR,A11,24,403-24,410
DES
COREQ
CITEP
COREQ
COREQ
COREQ
Lookingatlocationofpeakemission–varyingindistancefromJupiter(0.10.2RJ)–differentfordawn&dusk–drivenbytailflows(IG,BK)butwhy
modulatedbySystemIII?
Whenmodifiedfor0.12RJoffsetofOTDthemodulationondawndisappears
–butnotdusk.
GB–B,S,J1983–limits.Moos(HUT)O++detectionat1661/6A
UsedUVSdataanalyzedDonShemanskyat5.75vs.8.25Rj
Workedon600AOIIIfeature.
TriestoexplainlackofOIIIbyBSJandMoosasduetolackofFehot.
Labexperimentstodeterminecrosssectionsfore-excitation.
MostlyMgIIwithlittleonOII.
Radialprofiles–data=V1
O++/O+leastwell-determinedsogivenlowweight.
O++profileinagreementwithB92(fromShemansky)
Derivesradialprofilesofne,TeandcompositionthatarecomparewithB94.
InfersT||fromH–verynoisy.
V1-48spectraaveragedtomakeaverageat5.85±0.75RJ
Factor1.06to2.3tocorrectmodellinestofitdata.
WhydoesusingB94composition(fromShemansky)withCOREQnotfit?
UsedHolberg1991correctiontoUVSinstrumentresponse(~40-60%).
Ifthereisalackofcorrelationbetweendawn-duskansasinbrightnessthen
theremustbea<~2hrcoolingtime.Thisrequireshighdensity(10,000)
andquestionaboutsourceofelectronheating.
SystemIII&IVmodulationoftheIophaseeffect(~30%).
Cleaneratdawn(wheredimmer,farther)thanatdusk(brighter,closer).
MaybepartofproblemisthatSIIIemissions(lessvariable)dominatethe
totalbrightness.
3
2000
Herbert,Sandel,Azimuthal
variationofiondensityand
electrontemperatureintheIo
plasmatorus,JGR,105,1603516052
COREQ
AzimuthalvariationsindensityandTe.47huorsofV1data.
EmpiricalfitstoSystemIII,IV,LT,IPEfunctionsofbrightness.
ExplainedasBirkelandcurrents.
GB=ground-based,DES=DonE.Shemansky,Fehot=fractionofhotelectrons,Thot=temperatureofhotelectrons
SI=SSII=S+SIII=S++SIV=S+++SV=S4+OI=OOII=O+OIII=S++OIV=S+++OV=S4+
COREQ=
CITEP=
CHIANTI=
CHEX=chargeexchange
1980–bluecoloreddatemeansalsoincludedunderNeutralCloudTheorybibliography
1992–greencoloreddatemeansalsoincludedunderTorusVariabilitybibliography
4
InternationalUltravioletExplorer(IUE)&HopkinsUltravioletTelescope(HUT)onAstro-1,2
117.5nm<λ<195nmΔ=1.1nm&41.5nm<λ<186.4nmΔ=0.3nm
Date Paper
Atomic Results
Database
May1981soundingrocket–115-175nmΔ=1.2nm.
1983 Durrance,Feldman,Weaver,
SI(1425A),OI(1304).OI:SI~2:1
RocketdetectionofUVemission
LackofOIIIat1664A
fromneutraloxygen&sulfurin
theIotorus,Ap.J.,267,L125L129
1981 Moos,Clarke,Ultraviolet
Strobel& 3in1979,1in1980–8hourseach
SII,SIII,weakOIII,SIV
observationsoftheIotorus
Davis
Ne~2000Te~10eVτ~80d
fromtheIUEobservatory,ApJ, 1980
S+(140)S++(320-160),S+++(19,40),O++(110)
247,354-361
OI~12-25S(O)~2x1027s-1,SI~23-47S(S)~4x1027s-1
1983
Moosetal.,IUEspectrumoftheIo Various
plasmatorus:Identificationof
the5S2->3P2,1transitionof
SIII,ApJ,275,L19-L23
NeutralsfromDurrancerocket.
Sept198213.4hrexposure
Te=8x104K~7eV(Brown&Shemansky1982)
1985
Moosetal.,Long-termstabilityof Various
theIohigh-temperatureplasma
torus,ApJ,275,L19-L23
1991
Moosetal.,Determinationofionic abundancesintheIotorus
usingtheHopkinsUltraviolet
Telecope,Ap.J.,382,L105-L108
13obs.1979-1984–onlysmallvariations
Te=5-6x104K~4-5.5eV±<10%
Compared5,6,7RJ.Calculatedmixingratiovs.Te~andτ∼40-120d
c.f.Smyth&Shemansky1983
S+/Ne~0.11±28%S++/Ne~0.36±4%,S+++/Ne~0.023±<21%
HUT~1274sobservationofeast=dawnansa
834AassumedallOII.Ne~2000.L~4RJ
S+(356)S++(436),S+++(81),O+(530)
1994
Hall,Bednar,Durrance,Feldman,
McGrath,Moos,Strobel,HUT
determinationoftheIotorus
electrontemperature,Ap.J.,
420,L45-L48
COREQ
HUT–1990–ComparedS2+andS3+lineratiostogetTe.
T(S2+)~2.7-4.8eV,T(S3+)~4.4-8.2eV
Dusk~0.5eVhotter
5
ExtremeUltraVioletExplorer-EUVE
7.0nm<λ<76.0nmΔ=0.1-0.2nm
Abbottetal.Astrophys.J.,Suppl.Ser.,107,451,1996.
Date Paper
Atomic
Results
Database
1994 Halletal.,ExtremeUltraviolet
2daysin1993=1.1Ioperiods.Time-tagged
Explorersatelliteobservationof
O/S~2(c.f.Shemansky1.3)Te~3-10eV,Fehot<1%
Jupiter’sIoplasmatorus,Ap.J.,
Na+/Ne~1%SIII680,OII539.ModeledwithTe=5eV
426,L51-L54
SysIIIvariation<20%,Dawn-dusk~2.3-2.7
S+/Ne~0.08-0.15S++/Ne~0.06-0.17,S+++/Ne~0.016-0.036
O+/Ne~0.4-0.66O++/Ne~0.008-0.017
1995 Halletal.,IotorusEUVemissions Emissionsstableto~20%(contraryto2Sciencepapersclaiming30-50%
duringtheCometShoemakerdecline-actuallyduetoEarthatmos.Absorption)
Levy/9impacts,GRL,22,34413444
1998 Gladstone,Hall,Recentresultsfrom COREQ
1992-1996EUVE–83orbitsJune19-241996.
EUVEobservationsoftheIo
Dawn-duskasymmetry~20-30%
plasmatorusandJupiter,JGR,
Ne=1000,Te=4eV–model(notfittodata)
103,19927-19933
S+/Ne~0.17S++/Ne~0.18,S+++/Ne~0.017
O+/Ne~0.37O++/Ne~0.01
1998 Herbert,Hall,Disentangling
Osterbrock Lackofcollisionstrengths350-600A
electrontemperatureand
SeparateNeandTe–anticorrelated
densityintheIoplasmatorus,
UsedBagenal1994->profiles.Fit5species,NeNi,Te,pluscollisionstrengths
JGR,103,19915-19925
toget78variables,99equations!GetsresultsconsistentwithB94because
startedwiththat?
S+/Ne~0.1S++/Ne~0.2,S+++/Ne~0.02
O+/Ne~0.3-0.4O++/Ne~0.03
2001
Herbert,Gladstone,Ballester,
COREQ
ExtremeUltravioletExplorerof CHIANTI
theIotorus:improvedspectral
resolutionandnewresults,
JGR,106,26293-26309
EUVEsummary.165hduringI24+1996duringJ0ofGLL
IssueswithEUVcross-sections.UsedCHIANTIforS+
BothunderestimateOIIandSIII
1996brighterthan1999.Compositionwithtime.
6
HubbleSpaceTelescope-HST
GHRS244.4nm<λ<249.1nmΔ=nmSTIS115nm<λ<172nmΔ=
Date Paper
Atomic
Results
Database
1993 McGrathetal.,Detectionof[OII] GHRS.DetectionofOII2471
2471fromtheIoplasmatorus,
N(O+)/Ne~0.26±0.05inagreementwithMoos(IUE)butnotShemansky.
Ap.J.,415,L55-L58
GoodreviewofO+/O++issues.DifferenceswithVoyagercouldbeeitherNe
orTe
2003 Herbert,Schneider,Hendrix,
COREQ
STIS.Late1999and2000.GLLorbitsC23,I24,I27
Bagenal,HSTobservationsof CHIANTI LikeHerbert1999,usedBagenal1994->profiles,thenfitdatawith3D
sulfurionsintheIoplasma
model–toderivecompositionvs.R
torus:Newconstraintsonthe
Te~4eV.NosignificantvariationwithSysIII.
plasmadistribution,JGR,108,
UsedbothCHIANTIandCOREQ–withmajordifferencesinS++/S+butnotin
1167
S+++/S++-biggestfactor~2-2.5
S+morevariableandmoreconfinedtoCentEq–equiv.to40%colder.Peak
closertoJupiter.
7
FarUltravioletSpectroscopicExplorer-FUSE
99.5nm<λ<118.7nmΔ=0.026nm
Moosetal.,ApJ.,538,L1,2000
Date Paper
Atomic
Results
Database
CHIANTI Jan20005orbits
3.0
PrimaryfocusdetectionofCl++ionsat1%oftorus.
2001
Feldman,Ake,Berman,Moos,
Sahnow,Strobel,Weaver,
Detectionofchlorineionsin
theFUSEspectrumoftheIo
plasmatorus,ApJ.,554,L123,
2004
Feldman,Strobel,Moos,Weaver, CHIANTI
TheFar-ultravioletspectrumof 4.0
theIoplasmatorus,Ap.J.,601,
583-591
Jan20015orbits.Te~6.9eV,
S+:S++:S+++
=0.30:1:0.23–paper1
=0.41:1:0.17–paper2
=0.30:1:0.15–StefflI–
Discussionofsuprathermals,Kappas,
Ti=60-70eV
8
CassiniUVIS
56.1nm<λ<118.1nmEUV114nm<λ<191.3nmFUVΔ=0.3nm
Espositoetal.,TheCassiniUltravioletImagingSpectrograph,SpaceSci.Rev.,115,299-361,2004.
Date Paper
Atomic Results
Databa
se
2004a Steffl,Stewart,Bagenal,Cassini
CHIANTI
Overview.Fig3=AefffromBillMcClintock.Fig5=AverageEUVspectrum
UVISobservationsoftheIo
over164spectralimages–concentratedin6-7.2RJ
plasmatorus.I:initialresults,
ComparisonofV2UVS,EUVEandUVISsystem3variations.
Icarus,172,78-90
Temporalevents-correlatedwithaurora?–mostlyinSIII680A
2004b Steffl,Bagenal,Stewart,Cassini
CHIANTI Radialvariations.Jan2000scan
UVISobservationsoftheIo
4.2
Estimated10%differencebetweenCOREQandCHIANTI
plasmatorus.II:radial
O+/O++issues.O++constrainedby703(exceptSIIIat702)and1666A(first
variations,Icarus,172,91-103
detectedbyMoosetal.1991).Roleofhotelectrons(kappafn).
2006 Steffl,Bagenal,Stewart,Cassini
CHIANTI SystemIII&IV.4pagesofreview.
UVISobservationsoftheIo
4.2
WeakvariationinO+andS++.
plasmatorus.III:Observations
StrongvariationsinS+andS+++-anticorrelated
oftemporalandazimuthal
Periodogram
variability,Icarus,180,124-140
2006 Steffl,Bagenal,Stewart,Cassini
CHIANTI SystemIII&IV.
UVISobservationsoftheIo
4.2
FitfunctionstosystemIIIandIVvariations–modulationofelectrons
plasmatorus.IV:Modeling
Tableofproductionandlosslifetimesfordifferentspeciesviadifferent
temporalandazimuthal
processes
variability,Icarus,180,124-140
Roleofhotelectrons
2011 Yoshioka,Yoshikawa,Tsuchia,
Chianti Concentratedon5.9RJ.30images.<64.2nmignoredbecauseofissueswith
Kagitani,Murakami,Hot
6.0.1
atomicdata.
electroncomponentintheIo
Thot~350eV(fromFrank&Paterson).6parameters:Electrondensity,Te,
plasmatorusconfirmed
Fehot,O+/S++,S+/S++,S+++/S++
throughEUVspectralanalysis,
O++/O+assumed0.1,S4+/S++assumed0.
JGR,116,A09204
5separatedaystogetDawn-duskasymmetry.
9
Hisaki/EXCEED
52nm<λ<148nmΔ=0.3-0.5nm
Yoshikawaetal.,Extremeultravioletradiationmeasurementforplanetaryatmospheres,magnetospheresfromEarth-orbiting
spacecraft(EXCEED),SpaceSci.Rev.,184,237-258,2010.
Date Paper
Atomic Results
Database
2013 Yoshiokaetal.,Theextreme
Pre-launchdescriptionofinstrument,includingresponses,resolution,etc.
ultravioletspectroscopefor
PredictionofIotorusemissions.
planetarscience,EXCEED,
Planet.SpaceSci.,83,250-260
2014
Yoshiokaetal.,Evidencefor
globalelectrontransportation
intothejovianinner
magnetosphere,Science,345,
1581-1584
CHIANTI Torusspectrum(withaurora,tobeanalyzedseparately)5.9-7.6RJsummed
7.1
in0.4RJbins(outermost0.8RJ).Dawnvs.Dusk.O+/S++fixedat1.5
BecauseofconcernaboutgeocoronalcontaminationoftheOII833Aline.
FittogetNe,Te,Fehot(assumingThot~46eV),S+/S++,S+++/S++
Fehotof2-10%-seemshighcomparedwithSteffl.
S+/S++profiledifferentdawn(decreasing)&dusk(~constant->increasing)
LaststatementsuggestsmisunderstandingofcauseofE-Welectricfield.
2015
Tsuchiyaetal.,Localelectron
heatingintheIoplasmatorus
associatedwithIofromthe
Hisakisatelliteobservation,
JGR,120,10,317-10,333
CHIANTI Iophaseeffect.EXCEEDdataendDec2013–midJan2014(~25days)
7.1.4 2lineseachforSII,SIII,SIV,Dawn&Dusk.
PeriodogrampicksupSystemIII,IV,Ioperiod.
LongitudeexplainedasduetoIomovingup&downrelativetocenteroftorus
BigdifferenceinSystemIIIeffectfordawnvs.dusk(likeDessler,Sandel)
IophaseeffectshowspeakemissionjustbeforeIoreacheselongation–
suggestedduetohotelectronsintail–needsabout140GWofpowerinto
theelectronstoproducea10%modulation
12-40%effect
10