IHY OVERARCHING ISSUES PLUS MAGNETOSPHERES

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IHY OVERARCHING ISSUESPLUSMAGNETOSPHERES
IONOSPHERES

• IHY pedigree
• Progressive program innovations leading to IHY
• Evolving program objectives leading to IHY
• Heliospheric plasma physics A universal science
  (an IHY theme)
• Comparative studies of heliospheric structures
  and processes (an IHY program)
• Examples
• A proposal for an IHY initiative in comparative
  planetary auroras

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IHY Pedigree

• Program Start Years After
• 1st International Polar Year 1882
• 2nd International Polar Year 1932 50
• International Geophysical Year 1957 25
• International Quiet Sun Year 1964 7
• International M'spheric Study 1976 12
• Solar-Terr. Energy Program 1990 14
• International Heliospheric Year 2007 17

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IPY 1 1882-1883Justification

• Polar expeditions should be driven by scientific
  research instead of exploration.
• Establish network of circumpolar stations.
• Synoptic studies of geomagnetism, auroras,
  atmospheric electricity, and meteorology.
• Common data format for recording observations.

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Evolution in Understanding the Auroral Oval
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Birkeland Connects Auroras to Space
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Concepts Advanced or Enabled by IPY 1

• Auroral oval structure and dynamics
• Currents flowing in the upper atmosphere produce
  magnetic perturbations on the ground
• Currents flow between upper atmosphere and space
• i.e. Synoptic data reveal global connectedness

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IPY 2 1932-1933Justification
Statement of the IMO "magnetic, auroral and
meteorological observations at a network of
stations in the Arctic and Antarctic would
materially advance present knowledge and
understanding (of geomagnetic, auroral, and
meteorological phenomena) not only within polar
regions but in generalThis increased knowledge
will be of practical application to problems
connected with terrestrial magnetism, marine and
aerial navigation, wireless telegraphy and
weather forecasting."
i.e. synoptic studies
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IPY 2 Instrumentation

• Magnetometer network (here a station in Hudson
  Bay)
• Kite radiosondes
• Balloon radiosondes
• Ionosondes (here at Tromso)

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IPY 2 Results

• Silsbee and Vestine use IPY 2 polar magnetic
  data to determine average current system for
  magnetic bay

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Also During IPY 2

• Chapman and Ferraro introduce concept of
  neutral ionized corpuscular steam from the sun
  (1931-1933)

• and an associated current system that
  compresses and confines the geomagnetic field
  (the Chapman-Ferraro current system)

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Innovations and Concepts Associated with IPY 2

• International polar observing network
• New instrumentation (radiosondes and ionosondes)
• Rapid run magnetometers
• Simultaneous measurements at multiple stations
• Global current pattern for specific magnetic
  disturbance (magnetic bays)
• i.e. Synoptic data in the third dimension
• Higher spatial and temporal resolution
• More evidence of global connectedness

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IGY 1957-1958Justification
"The IGY's main aim is to learn more about
the fluid envelope of our planetthe atmosphere
and oceansover all the earth and at all heights
and depths. These researches demand widespread
simultaneous observations." S. Chapman
i.e. expanded synoptic studies
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IGY Instrumentation and Innovations

• Antarctic stations
• All-sky cameras
• Scientific satellites
• Word Data Centers

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IGY Famous Result

• From all-sky camera data came the Akasofu
  model of the auroral substorm

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Even More Famous Result
From Explorer 1 and its followers, came the
Van Allen radiation belts
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New Concepts Associated with IGY

• Interhemispheric network of polar stations
• New instrumentation (all-sky cameras, satellites)
• Major discovery (radiation belts)
• New concepts (the magnetosphere, substorms)
• Exploration of space
• Global 3D synoptic data
• Evidence of time-dependent global dynamics

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IMS 1976-1979Justification
1977 IMS Report "Many new questions have
emerged, mainly concerning the cause-and-effect
relationship among the dynamical processes and
involving the magnetosphere as a single,
integral, dynamical system."
1971 IMS Report "The complexity and the
large spatial scale of the phenomena under
scrutiny demand simultaneous measurementsboth
in space and on the ground."
Expanded synoptic data acquisition justified
by "large spatial scale" (as before) and
"complexity" (new).
The magnetosphere seen as an interconnected
system.
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IMS Instrumentation and Innovations

• Magnetometer chains
• ISEE 1 and ISEE 3
• Satellite Situation Center
• Coordinated Data Analysis Workshops (CDAW 1 Dec.
  1978)

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IMS Famous Discovery

• Flux Transfer Events (FTEs) (Russell and
  Elphic, 1978)

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Also During IMS

• Magnetosphere and ionosphere linked through
  permanent set of macroscale, field-aligned
  current systems

• The region 1 current system links the
  ionosphere, the magnetosphere, and the solar wind

Solar wind-magnetosphere- ionosphere system
seen as interactive.
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STEP 1990-1997Justification
The 1988 report "Framework for Action" states
the "main scientific goal is to advance the
quantitative understanding of the coupling
mechanisms that are responsible for the transfer
of energy and mass from one region of the
solar-terrestrial system to another."
It continues "The program will involve
coordinated observations with instruments on the
ground, in the air and in space theory and
simulation studies and data and information
systems."
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STEP Emphases

• 3D global synoptic studies
• Quantitative understanding (numerical modeling)
• Coupling mechanisms (exchanges between system
  components)
• Solar-terrestrial system
• Data and information exchange and systems

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S-RAMP 1998 - 2003An effort to optimize the
analysis of data obtained during the STEP period,
1990-1997

• Major Objectives
• Facilitate understanding of coupling mechanisms
  between regions of the Sun-Earth system.
• Facilitate data and information transfer
  experimenters, theoreticians, and modelers.
• Demonstrate results of STEP of use and interest
  to funding agencies, the media, and the public.

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What IPY, IGY, etc. Programs Do
IPY 1 Map the phenomena IPY 2 Explore upper
atmosphere IGY Explore space IQSY Complement
IGY IMS Study system complexity STEP Study
integrated interactive system IHY Universalize
heliospheric structures and processes
Emerging nations
IPY 1 Synoptic obs network of polar
stations IPY 2 Add third dimension IGY Add
Antarctica and space IQSY Add solar min. to IGY
solar max. IMS Add SSC and CDAWs STEP Add
numerical modeling IHY Add comparative
heliospheric studies
IHY CDF for comparative studies Web accessible
data for comparative studies CDAWs for
comparative studies IHY Hubble proposal for
comparative planetary auroras

• Organize coordinate data gathering analysis
• Provide thematic emphases
• Justify resource allocations under program themes

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Justification for Suggested IHY Objectives
It cannot be emphasized too strongly that
the development of a solid understanding of the
magnetic activity, occurring in so many forms in
so many circumstances in the astronomical
universe, can be achieved only by coordinated
study of the various forms of activity that are
accessible to quantitative observation in the
solar system. E. Parker Cosmical Magnetic
Fields
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Heliospheric Plasma Physics A Universal Science

• I. Division of the Universe
• Gravitationally organized matter planets, stars,
  galaxies
• Magnetically organized matter sunspots,
  magnetospheres, stellar and galactic spiral
  fields, galactic plumes
• Interactions between them planetary ionospheres,
  solar and stellar winds, galactic cosmic rays

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Organization of the Universe
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Heliospheric Exemplars of Magnetic Organization
of the Universe
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Directly Driven
Blocking-Release
CME
Thermal
Dynamo
SUBSTORM
Blast
Drctly Drvn
IMF
Connec.
Recon.
Inst.
Config.
Inst.
Current.
Blocking-Release
Inst.
Mass
Exchng.
MIC
Inst.
Dis- eqlb.
Triggered.
Diseqlib.
Figure 6.7 Pairings between similar CME and
substorm scenarios
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The IHY and Comparative Planetary Magnetospheres
John T. Clarke and George Siscoe Boston
University
IHY Planning Workshop Sunspot NM April 2004
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• Why include Comparative Magnetospheres in IHY?
• The Earth and the other planets are in the
  heliosphere.
• Every planet with a magnetic field and a
  collisionally
• thick atmosphere also displays aurora.
• The interaction of the solar wind with planetary
• magnetospheres is one of the most fundamental
• processes in the heliosphere.
• Understanding the scaling laws between
  magnetospheres
• will be required to understand the more than
  100 newly
• discovered exo-planets.

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Comparative Planetary Magnetospheres
Mercury
Jupiter
Earth
Solar Wind Dominated
Solar Wind Driven
Rotationally Driven - Solar Wind Triggered?
3 flybys MESSENGER
100 missions since 1957

• Comparative Magnetospheres
• expands our understanding of
• Sun-Earth Connections through
• examination of common processes at other
  planetary systems
• The scale of magnetospheres varies by a factor of
  100 from
• Mercury to Jupiter

6 flybys, 1 orbiter
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Jupiter
Jupiters aurora have been imaged by HST since
the early 1990s with high sensitivity and
resolution. A campaign of imaging during the
Cassini flyby in Dec. 2000 / Jan. 2001 was
successful but short
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Jupiters Three Auroral Processes

• The main oval appears driven by currents
  resulting
• from the breakdown in corotation of internal
  plasma.
• The satellite footprints are produced by their
• interactions with Jupiters magnetic field.
• The polar emissions map to the outer
  magnetosphere,
• and these interactions are not yet well
  understood.

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Key Questions about Jupiters Aurora

• Which processes in Jupiters magnetosphere are
• influenced by the solar wind (as at Earth),
  and which
• processes are controlled by Io?
• Does plasma production depend on Ios volcanic
  activity,
• or is it controlled by Ios magnetospheric
  interaction?
• How does the magnetosphere respond to internal
  plasma
• production?
• What are the causes of Jupiters three aurora?
• How are these processes similar to Earths and
  how do
• they differ?

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Saturn

• Saturns aurora were studied during the Voyager
  flybys
• then more recently by HST and Cassini (Jan.
  2004)
• - Saturn has an aligned magnetic field and much
  lower ?
• plasma than Jupiter, but greater than the Earth
• - Saturns magnetosphere has been thought to be
• intermediate between the solar-wind driven
  Earth and
• the corotation-driven Jupiter
• - The recent campaign observations show the
  picture to
• be much more complicated than this

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16 Jan. 2004
26 Jan. 2004
28 Jan. 2004
30 Jan. 2004
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• Saturn Summary
• Auroral emissions vary only slowly, min.s to
  10s of min. - this is much slower than Jupiters
  polar regions, more similar to Jovian main oval
• Some rotational modulation of auroral power is
  seen, based mainly on 8 Jan. images
• Isolated bright emissions move at 75
  corotation
• Auroral oval always offset toward midnight by 3-4
  deg.
• Dawn side oval is narrow, dusk side more diffuse

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• Saturn Summary (contd)
• Auroral color ratio not obviously changing with
  time or location, suggests incoming particles
  5-10 KeV
• Total auroral power 3-10 x 1010 W, 2-3 ordersof
  magnitude less than at Jupiter
• Total auroral powers vary by at least 4-5X,
  correlated with both SKR emission and solar wind
• Auroral oval contracts with increased solar wind
  pressure
• Auroral oval fills in during storm on 26 Jan.
  2004

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Proposed planetary magnetosphere component
for IHY

• The only existing instrument for imaging the
  aurora on
• both Jupiter and Saturn is HST.
• Submit a large guest investigator proposal for
  HST time
• in Jan.-June 2007 (request 100 orbits).
• This program would permit imaging of each planet
  every
• other day for 3 months centered on opposition.
  Solar
• wind conditions at each planet could be scaled
  from
• 1 AU measurements. Other correlations
  possible?

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JMEX is a mission in Phase A study which would
greatly assist the IHY program, but it would
not fly before 2008.
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The JMEX Science Driver Comparative
Magnetospheres from Earth Orbit

• JMEX will repeatedly image Jupiters aurora, Ios
  atmosphere, and the plasma torus to establish the
  cause and effect relations between them
• JMEX enables a comparison of key magnetospheric
  processes at Jupiter vs. Earth. Comparative
  magnetospheres is an integral part of the
  Sun-Earth Connections roadmap

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Jupiter Science is Now Ready for a Global,
Remote Study

• To date, we have only snapshots of the
  magnetospheric emissions from the Jupiter system
• JMEX will provide the time coverage needed to
  establish understand the physics of the system,
  much as has been done for the Earth since the IGY

JMEX will do for Jupiterwhat IMAGE does for
Earth
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What the IHY Program Can Do

• Organize coordinate data gathering analysis
• Comparative heliospheric studies
• Provide thematic emphases
• Universalize heliospheric structures and
  processes Emerging nations
• Justify resource allocations for IHY initiatives
  (comparative studies and emerging nations)
• CDF for comparative heliospheric studies
• Web accessible data for comparative studies
• CDAWs for comparative heliospheric studies
• IHY Hubble proposal for comparative planetary
  auroras

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Heliospheric Plasma Physics A Universal Science

• II. Features and Processes of
• Magnetically Organized Matter
• Spontaneous generation of structures and
  transients Flux ropes Cellular
  structures (magnetospheres, stream interfaces)
  Actions occur at cell boundaries Turbulence
  Self-organized criticality
• Explosive energy conversions Solar (stellar)
  flares CMEs Magnetospheric substorms
• Generation of penetrating radiation GCRs,
  SCRs, ACRs, planetary radiation belts
• Couplings Cross-scale (microscale-mesoscale-m
  acroscale) Non-local (magnetosphere-ionospher
  e) Large-scale coherence through magnetic
  coupling Neutral-plasma
• Creation and annihilation of magnetic field
  Dynamos (galactic, stellar, solar, planetary)
  Reconnection

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Progressive Innovations

• PROGRAM INNOVATION
• IPY 1 Synoptic obs network of polar stations
• IPY 2 Add third dimension
• IGY Add Antarctica and space
• IQSY Add solar min. to IGY solar max.
• IMS Add SSC and CDAWs
• STEP Add numerical modeling
• IHY Add comparative heliospheric studies

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Evolving Objectives

• IPY 1 Map the phenomena
• IPY 2 Explore upper atmosphere
• IGY Explore space
• IQSY Complement IGY
• IMS Study system complexity
• STEP Study integrated interactive system
• IHY Universalize heliospheric structures
• and processes