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Universal Processes in Neutral Media Roger Smith Chapman Meeting on Universal Processes Savannah, Georgia November 2008
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AGU Chapman Meeting on Universal Processes 11/2008 2 Contents of Talk Big picture view on universal processes Processes in plasma and neutral media Examples of universal processes in neutral and mixed media Need for a balanced approach developing Heliophysics as a new scientific discipline.
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AGU Chapman Meeting on Universal Processes 11/2008 3 Big Picture of universal processes Galactic view of heliosphere shows the sun with surrounding plasma envelope and planets. Expect universal processes to be found throughout the heliosphere. Universal Heliophysical Processes include those in all regimes of the heliosphere. Hence in sun, solar wind, comets and planets.
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5 EESSE E EEE EEE SEEEE ESE E E CME and flaresSolar WindSolar CycleGranulationCosmic RayModulationIrradiation Reconnection Particle Acceleration Shocks and Waves Dynamo Turbulence, Convection Multiscale Structures Energy storage, release Radiative Transfer Phenomena Universal Processes S = Speculative E = Established
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6 Solar Dynamo Magnetic Flux Emergence Sunspots, Active Regions Electromagnetic Radiation Solar Wind Flares: Reconnection Electromagnetic flashes Energetic Particles CMEs: Mass ejection Magnetic flash ejection Energetic Particles CME Shock Formation CIR Shock Formation Magnetic Cloud Pressure PulseSEPs Geomagnetic Storms: Aurora, radiation belts, ring current, ionospheric effects. Climate effects: Thermosphere, mesosphere, stratosphere, troposphere. Slide by Gopalswamy
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AGU Chapman Meeting on Universal Processes 11/2008 7 General importance of universal processes in neutral media Major receptors of solar energy are found in the planets, asteroids, comets and other massive bodies. Apart from the sun, much of the mass of the heliosphere is found in uncharged objects such as those listed above.
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AGU Chapman Meeting on Universal Processes 11/2008 8 Examples of universal processes involving neutral media Turbulence
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AGU Chapman Meeting on Universal Processes 11/2008 9 Turbulence in Atmospheres Transport of energy and momentum by gravity waves, establishing turbulent regions in upper atmospheres. Micro-turbulence in the atmospheric boundary layer. –Coupling heat from the ground into the atmosphere (scintillation observed) –Raising dust and sand leading to mass transport and modulation of solar radiation
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AGU Chapman Meeting on Universal Processes 11/2008 10 Examples of universal processes involving neutral media Acoustic gravity waves
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AGU Chapman Meeting on Universal Processes 11/2008 11 Extensive NLC Layer (5.5 hours duration)
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AGU Chapman Meeting on Universal Processes 11/2008 12 Unique event: Large intensity perturbation I/I: ~ 50%, Horizontal wavelength H : 27 km. High intrinsic phase speed: 80m/s Short intrinsic period: 5.6 mins. Formation of turbulent-like features. Instability duration: 40 mins. Small-Scale Wave Breaking Into “Turbulence” Large amplitude Momentum flux: ~900 m 2 /s 2 Mean-flow acceleration: ~ 80m/s in < 1 hr. Japan For a breaking wave, the momentum flux F M can be estimated by: (Fritts et al., 2002) (Yamada, et al, 2001) 16:40 UT 16:52 UT
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AGU Chapman Meeting on Universal Processes 11/2008 13 Gravity Waves on: Mars Global Surveyor Mars ! Lee Waves at mid-latitudes and polar regions. Wavelength ~ 50 km
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AGU Chapman Meeting on Universal Processes 11/2008 14 Examples of universal processes involving neutral media Ionization and recombination
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AGU Chapman Meeting on Universal Processes 11/2008 15 Equatorial Plasma Fountain and Anomaly Process
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AGU Chapman Meeting on Universal Processes 11/2008 17 Rayleigh-Taylor Instability Mechanism
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AGU Chapman Meeting on Universal Processes 11/2008 19 Examples of universal processes involving neutral media Cloud condensation
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AGU Chapman Meeting on Universal Processes 11/2008 20 Formation of clouds Cloud layers absorb and scatter light reducing solar illumination and heating. Turbulence enhanced dust clouds in desert areas on Earth and Mars. Cloud nucleation and droplet growth not fully represented in climate and weather forecasting codes. Major source of uncertainty for planets and moons with atmospheres, for example Earth, Venus, Mars, Jupiter.
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AGU Chapman Meeting on Universal Processes 11/2008 21 Examples of universal processes involving neutral media Aurora
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AGU Chapman Meeting on Universal Processes 11/2008 22 Jupiter’s 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 Jupiter’s magnetic field. The polar emissions map to the outer magnetosphere, and these interactions are not yet well understood.
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AGU Chapman Meeting on Universal Processes 11/2008 23 Jupiter’s aurora have been imaged by HST since the early 1990’s with high sensitivity and resolution. A campaign of imaging during the Cassini flyby in Dec. 2000 / Jan. 2001 was successful but short… HST/WFPC2 HST/STIS Jupiter
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AGU Chapman Meeting on Universal Processes 11/2008 24 Examples of universal processes involving neutral media Dusty plasma processes
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AGU Chapman Meeting on Universal Processes 11/2008 26 Examples of universal processes involving neutral media Planetary outflow
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AGU Chapman Meeting on Universal Processes 11/2008 27 Examples of universal processes involving neutral media Loading of interplanetary field lines
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AGU Chapman Meeting on Universal Processes 11/2008 30 Conclusion: universal processes involving neutral media Turbulence Ionization and recombination Dusty plasma processes Planetary outflow Loading of interplanetary field lines Acoustic gravity waves Cloud condensation Aurora
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