Justin kasper (Harvard-smithsonian)

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Summary of Major Scientific Advancements since
2006 Roadmap

• Justin kasper (Harvard-smithsonian)
• Geoff reeves (lanl)
• Nasa heliophysics town hall meeting
• May 19, 2008

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Purpose and outline

• We are gathering the major scientific advances in
  heliophysics that have occurred since the last
  roadmap
• Goals
• Identify the most compelling heliophysics so we
  are able to present the strongest case possible
  in our revised roadmap
• Identify observational gaps prohibiting discovery
• Determine if changes need to be made in Research
  Focus Area organizational structure
• This presentation
• Not going to try and review all Heliophysics
  accomplishments since 2006!
• Describe the review process
• Solicit input
• Present several examples
• Explain the splinter session goals

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Heliophysics Research Elements in 2005

• Heliophysics sorted into Research Focus Areas
  (RFAs)
• Full review of the RFAs will be presented this
  afternoon by Lynn Kistler, so just a summary here
• F Open the Frontier to Space Environment
  Prediction
• Magnetic reconnection, particle acceleration,
  dynamos
• H Understand the Nature of Our Home in Space
• Disturbances, solar input and climate
• J Safeguard the Journey
• Radiation extremes, early warning

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Assessment Strategy - Input

• Recent discoveries and recently appreciated work
• Observations, models, theory
• Need more input on models and theory
• Sources of input
• Senior Review
• Each mission requested to submit summary of
  recent accomplishments
• Literature reviews
• Committee knowledge
• Community input
• Created email address helio.progress_at_gmail.com

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Assessment Strategy - Analysis

• Created spreadsheet to track accomplishments
• Sort by Research Focus Area
• For each result
• Short description
• Identify primary topic addressed by result
• Secondary topics addressed
• Contributing missions (include theory and model
  as missions)
• References

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Highlights and Emerging Themes

• Discoveries at the boundaries of the heliosphere
• Magnetic reconnection
• Multi-spacecraft research

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Discoveries at the boundaries of the heliosphere

• Three examples of recent discoveries
• Voyager spacecraft crossed the termination shock
• AIM sees formation of H2O regions over broad
  range in altitude
• SOHO produces statistical evidence of g-modes at
  3-sigma level
• Results, new questions

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Initial AIM observations of Polar Mesopheric
Clouds (PMCs)
CIPS image on July 10, 2007 showing an ice void
When the AIM observatory was launched on April
25, 2007, the science focus was on a thin (1.5
km thick) visible ice cloud layer centered at
83 km above the earth surface known as PMCs. What
was found in the first season of observations was
a previously suspected but never before seen
population of very small ice particles that exist
over a much broader altitude range.
Large regions virtually devoid of ice suggest
that the mesosphere may share some of the same
dynamical processes that are responsible for
weather near the surface.
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The Termination Shock

• Voyager 1 crossed termination shock in December
  2006
• Anomalous cosmic ray source not seen!
• Voyager 2 crossed in August of 2007
• Termination shock is deformed
• Plasma heating is 10x low and the outflow is 2x
  too fast!
• Implications
• Radiation plays significant role in termination
  shock physics
• Voyager 2 will cross the heliopause within a
  decade
• IBEX will have a strong energetic particle
  population to detect

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A Statistical Detection of G-modes

• Helioseismology is the inference of solar
  interior properties through the observation of
  oscillations on the solar surface
• Travelling waves probe sound speed, temperature,
  velocity at different depths
• G-modes have never been seen, but if detected
  would probe the solar core
• Global Oscillation at Low Frequency (GOLF)
  instrument on SOHO
• Instead of looking for an individual ripple, they
  looked for the signature of the cumulative effect
  of a large number of these ripples separated by
  about 24 minutes.
• They combined ten years of data from GOLF and
  then searched for any hint of the signal at 24
  minutes. They found it. We must be cautious but
  if this detection is confirmed, it will open a
  brand new way to study the Suns core, says
  García.
• Until now, the rotation rate of the solar core
  was uncertain. If the GOLF detection is
  confirmed, it will show that the solar core is
  definitely rotating faster than the surface.
• important constraint for investigating how the
  entire Solar System formed
• because it represents the hub of rotation for the
  interstellar cloud that eventually formed the Sun
  and all the planets, asteroids, etc., around it

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Magnetic reconnection

• The 2005 Roadmap called for the discovery of
  magnetic reconnection across the heliosphere
• Reconnection is ubiquitous
• Within the solar corona (flares and coronal
  holes)
• Interplanetary space (CMEs and quiet solar wind)
• Magnetosphere

F.1 Understand magnetic reconnection as revealed in solar flares, coronal mass ejections, and geospace storms
F.1.1 What are the fundamential physical processes of reconnection on the space scales where particles decouple from the magnetic field?
F.1.2 What is the magnetic field topology for reconnection at the Earth and at what size scales does magnetic reconnection occur on the Sun?
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Coronal Magnetic Reconnection
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Magnetospheric Reconnection

• Comparison between the observed (left panel) and
  simulated (right panel) plasma and field profiles
  of Rumba (Cluster-1) crossing the reconnection
  electron jet close to a reconnection site.
• January 2003, the four Cluster satellites were
  crossing the magnetosheath when they encountered
  an electron diffusion region.
• Cluster confirmed the existence of an elongated
  electron diffusion region
• The length observed by Cluster is 3000 km, or
  300 times longer than the earlier theoretical
  expectations

T. Phan (Berkeley) M. Shay (Delaware)
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Reconnection Exhausts in the Solar Wind
2D projection
Br
Vr
Bt
Vt
Bn
Vn
J. Gosling (LANL)
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Statistical Studies of IP Reconnection
Rate vs solar wind conditions
No energetic particles!
J. Gosling (LANL)
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Multispacecraft studies

• Reconnection exhaust observed by five spacecraft
• Reconnection exhaust is very stable and
  geometrically simple
• Gosling et al. (2007)
• Halloween 2003 CMEs observed by entire
  Heliophysics Great Observatory
• Are there equivalent solar minimum heliosphere
  observations?
• Strong correlation between spectra of hard x-ray
  bursts (RHESSI) and interplanetary electrons
  (Wind) indicating common source
• First stereo STEREO observations
• Filaments
• Coronal Mass Ejections
• Co-rotating interaction regions

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Food for thought
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Snapshot of current study
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Format of the First Splinter Session

• 1030 1230 Today

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The First Splinter

• The purpose of the first splinter group is to
  receive input from the community on the following
  questions
• In your view, what is the most compelling and
  enabling science that will advance Heliophysics
  in the next 5-10 years?
• In the next 10-20 years?
• Your participation will help us
• Lead with the most compelling science
• Identify any game-changing recent results
• develop better ways to portray our Heliophysics
  goals and long-term strategy.

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• We will divide the main room into three smaller
  rooms, and meet around the tables for two
  one-hour sessions.
• In the first hour we will discuss what our short
  term scientific goals should be, based on recent
  results and our current understanding of the
  Heliosphere.
• In the second hour we will examine our
  longer-term scientific strategy and develop ways
  to portray this strategy.

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• Mission timelines portray

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Summary

• Help us identify any missing pieces to this story
• Spacecraft not under senior review
• Guest Investigator and other independent research
• Are advances in some fields not captured by this
  process (aerobraking, exoplanets)
• Resources
• Electronic copy of spreadsheet available
• Comments and suggestions greatly appreciated
• Helio.progress_at_gmail.com