The Europa Plasma Environment Tristan Weber LASP Fran Bagenal, - - PowerPoint PPT Presentation

The Europa Plasma Environment

Tristan Weber – LASP

Fran Bagenal, Robert Wilson, Vincent Dols

Friday, August 9, 2013

Europa Overview

 Our interest in Europa  Our current understanding  Success/Limitations of our data  Refinement/Compilation of the

data

 Future improvements for the

study of Europa

http://photojournal.jpl.nasa.gov/catalog/PIA00502 Friday, August 9, 2013

Interest in Europa

 Europa is “the first step in understanding the

potential of the outer solar system as an abode for life” (Space Studies Board 2011, p.1)

 Enough energy and

water to sustain life

Friday, August 9, 2013

Our Current Set of Data

Variety of sources

Ground Based Galileo Voyager

1. http://solarsystem.nasa.gov/galileo 2. http://www.cfa.harvard.edu/sma/ 3. http://voyager.jpl.nasa.gov/

Friday, August 9, 2013

Galileo

• Failed Antenna Deployment
• Lack of data resolution
• Large range of trajectories
• Wide spread of data if we could

analyze it

Friday, August 9, 2013

What We Know So Far

Water Oceans

Ice on surface shown from ground-based observations

• Changing Magnetic Field

Induces Currents

• Seen by Galileo

Hard to separate from Ionosphere

Friday, August 9, 2013

What We Know So Far

Water Oceans

Ice on surface shown from ground-based observations

• Changing Magnetic Field

Induces Currents

• Seen by Galileo

Hard to separate from Ionosphere

Friday, August 9, 2013

What We Know So Far

Water Oceans

Ice on surface shown from ground-based observations

• Changing Magnetic Field

Induces Currents

• Seen by Galileo

Hard to separate from Ionosphere

Friday, August 9, 2013

What We Know So Far

Water Oceans

Ice on surface shown from ground-based observations

• Changing Magnetic Field

Induces Currents

• Seen by Galileo

Hard to separate from Ionosphere

Friday, August 9, 2013

What We Know So Far

Alfvén Wings

Europa’s Footprint

Friday, August 9, 2013

What We Know So Far

Sputtered Atmosphere

• Radiolysis embeds

incoming particles and ejects others

• Oxygen Atmosphere
• Sulfur Deposits

Friday, August 9, 2013

What We Know So Far

Sputtered Atmosphere

• Radiolysis embeds

incoming particles and ejects others

• Oxygen Atmosphere
• Sulfur Deposits
• Mostly Observed through

Spectroscopy

• Direct data has issues…

Friday, August 9, 2013

Modeling

 Working on a

simulation with Vincent Dols

 Magnetic Field

Modeling

 Data from NASA

PDS

Friday, August 9, 2013

Modeling

E04 Flyby - 1996

 Working on a

simulation with Vincent Dols

 Magnetic Field

Modeling

 Data from NASA

PDS

Friday, August 9, 2013

Modeling

E04 Flyby - 1996

!! !" # " ! $ % !&## !'# # '# ()*+,*-

• *./01

()*.231 !! !" # " ! $ % !'# # '# &## &'# (4*+,*-

• *./01

(4*.231 !! !" # " ! $ % !'# # '# &## &'# (5*+,*-

• *./01

(5*.231 !! !" # " ! $ % # '# &## &'# "## (676*+,*-

• *./01

(676*.231

Friday, August 9, 2013

!! !" # " ! $ % !&## !'# # '# &## ()*+,*-

• *./01

()*.231 !! !" # " ! $ % !""# !"## !&%# !&$# !&!# !&"# (4*+,*-

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(4*.231 !! !" # " ! $ % !!"# !!&' !!&# !!#' !!## !56' !56# (7*+,*-

• *./01

(7*.231 !! !" # " ! $ % !"# !5# !!# !'# !$# !8# (9:9*+,*-

• *./01

(9:9*.231

Modeling

E11 Flyby - 1997

Friday, August 9, 2013

!! !" # " ! $ % !"# !&# # &# "# '# !# ()*+,*-

• *./01

()*.231 !! !" # " ! $ % !"# !&# # &# "# '# !# 4# (5*+,*-

• *./01

(5*.231 !! !" # " ! $ % !&# # &# "# '# !# (6*+,*-

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(6*.231 !! !" # " ! $ % # &# "# '# !# 4# (787*+,*-

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Modeling

E11 Flyby - 1997

Friday, August 9, 2013

Modeling

E04 Flyby - 1996

 Magnetic Field

Modeling has been fairly successful

 See Effects of

Induced Currents and Alfvén Wings



Kivelson et al. (1997)

Friday, August 9, 2013

Modeling the Plasma Properties

 Want to compare model to direct plasma data.  Obtained plasma parameters with Rob Wilson’s fitting routine

Friday, August 9, 2013

Modeling the Plasma Properties

 Want to compare model to direct plasma data.  Obtained plasma parameters with Rob Wilson’s fitting routine

!!" !!# !" # " !# !" # "# !## !"# $## $"# %## &'()*+ ,*-./01'(23!%+

' '

45.*67*8 9/3:;<0*8

Friday, August 9, 2013

Modeling the Plasma Properties

 Want to compare model to direct plasma data.  Obtained plasma parameters with Rob Wilson’s fitting routine

!!" !!# !" # " !# !" # "# !## !"# $## $"# %## &'()*+ ,*-./01'(23!%+

' '

45.*67*8 9/3:;<0*8

?

Friday, August 9, 2013

Problems with the PLS data

 Fitting routine originally designed

for full magnetosphere.

Friday, August 9, 2013

Problems with the PLS data

 Fitting routine originally designed

for full magnetosphere.

!!" !!# !" # " !# !" "# !## !"# $## $"# %## %"# &## &"# "## '()*+,

• +./+01230+

( (

456+07+8

At moon encounters, the plasma might be changing too quickly to find a fit

Friday, August 9, 2013

A Possible Remedy

 If the issue is over-averaging, edit the fitting to only run each

spin individually

 Danger of not having enough appreciable detections.

Friday, August 9, 2013

A Possible Remedy

10 10

1

10

2

10

3

Anode 1 Counts/Accum.

• Obs. Data

Background

• Sim. Data

+23.96:1.71 m:q

10 10

1

10

2

10

3

Anode 2 Counts/Accum. 10 10

1

10

2

10

3

Anode 3 Counts/Accum. 10 10

1

10

2

10

3

Anode 4 Counts/Accum. 10 10

1

10

2

10

3

Anode 5 Counts/Accum. 52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 6 Counts/Accum. 52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

DE run 1, Iter. = 1, Cost = 4.00001e+06

Friday, August 9, 2013

10 10

1

10

2

10

3

Anode 1 Counts/Accum.

• Obs. Data

Background

• Sim. Data

+23.96:1.71 m:q

10 10

1

10

2

10

3

Anode 2 Counts/Accum. 10 10

1

10

2

10

3

Anode 3 Counts/Accum. 10 10

1

10

2

10

3

Anode 4 Counts/Accum. 10 10

1

10

2

10

3

Anode 5 Counts/Accum. 52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 6 Counts/Accum. 52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

!"#$#%&'()*'$&+,-'.//0!.1!./'23456'7085.844

A Possible Remedy

Friday, August 9, 2013

10 10

1

10

2

10

3

Anode 1 Counts/Accum.

• Obs. Data

Background

• Sim. Data

+23.96:1.71 m:q

10 10

1

10

2

10

3

Anode 2 Counts/Accum. 10 10

1

10

2

10

3

Anode 3 Counts/Accum. 10 10

1

10

2

10

3

Anode 4 Counts/Accum. 10 10

1

10

2

10

3

Anode 5 Counts/Accum. 49 98 10 10

1

10

2

10

3

Record # Anode 6 Counts/Accum. 49 98 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

DE run 1, Iter. = 150, Cost = 1.76856

A Possible Remedy

Friday, August 9, 2013

New PLS Results

 Very Mixed – Several unreasonable features removed

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670,89,: ;15<=>2,:

Friday, August 9, 2013

New PLS Results

 But lack of enough data points sometimes makes for

enormous errors.

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, ,

9:3/;</= >48?@A5/=

Friday, August 9, 2013

New PLS Results

 But lack of enough data points sometimes makes for

enormous errors.

!! !" !# !$ !% & % $ # " & %&& $&& #&& "&& !&& '&& (&& )&& *&& %&&& +,-./0 1/23456,-78!#0

, ,

9:3/;</= >48?@A5/=

Regardless, the simulation is not matching up…

Friday, August 9, 2013

A Final Issue/Interest

52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

DE run 1 Iter = 10 Cost = 4 00

Double peaks show two plasma species – in this case we have pickup ions

Friday, August 9, 2013

A Final Issue/Interest

52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

DE run 1 Iter = 10 Cost = 4 00

Double peaks show two plasma species – in this case we have pickup ions Spacing shows they’re in the same plane

Friday, August 9, 2013

A Final Issue/Interest

52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

DE run 1 Iter = 10 Cost = 4 00

Double peaks show two plasma species – in this case we have pickup ions Spacing shows they’re in the same plane Energy differs by a factor of ~8 (4 for pickup ions)

Friday, August 9, 2013

A Final Issue/Interest

52 104 156 208 260 312 364 416 10 10

1

10

2

10

3

Record # Anode 7 Counts/Accum.

DE run 1 Iter = 10 Cost = 4 00

Double peaks show two plasma species – in this case we have pickup ions Spacing shows they’re in the same plane How can we figure out what ion is being picked up?

Friday, August 9, 2013

Ion Cyclotron Waves

 Resonance between gyrofrequency and magnetic waves.

http://www.efda.org/fusion Friday, August 9, 2013

Ion Cyclotron Waves

 Resonance between gyrofrequency and magnetic waves

Frequency (Hz) Time

18 23 32 64

06:40 06:45 06:50 06:55 07:00 07:05 07:10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Friday, August 9, 2013

Frequency (Hz) Time

18 23 32 64

06:40 06:45 06:50 06:55 07:00 07:05 07:10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Ion Cyclotron Waves

 Remove the background magnetic field

Friday, August 9, 2013

Frequency (Hz) Time

18 23 32 64

06:40 06:45 06:50 06:55 07:00 07:05 07:10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Ion Cyclotron Waves

 Remove the background magnetic field

Is this actually a result?

Friday, August 9, 2013

Frequency (Hz) Time

18 23 32 64

06:40 06:45 06:50 06:55 07:00 07:05 07:10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Ion Cyclotron Waves

 Remove the background magnetic field

Is this actually a result?

Probably Not

Friday, August 9, 2013

Final Compilations – Where We Are

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Friday, August 9, 2013

Final Compilations – Where We Are

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Some things we can explain Pickup ions in wake

Friday, August 9, 2013

Final Compilations – Where We Are

!!"" " !"" #$%&'() Orbit12

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18 23 32 64

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Some things we can explain Fluid flow around the moon

Friday, August 9, 2013

Final Compilations – Where We Are

!!"" " !"" #$%&'() Orbit12

$ $

#* #+ #, " "-. / %0'12'34+$56,7

18 23 32 64

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/

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$ $

<'0=') >&3=('

Some things we can’t… Fluid flow around the moon No matching density spike? Densities don’t match far from the moon?

Friday, August 9, 2013

The Future For Europa Data

 Hope in the Europa Clipper

http://www.jpl.nasa.gov

• Higher resolution MAG data?
• Better plasma data?

Hope to better understand the induced fields and the surface composition.

Friday, August 9, 2013