Post on 29-Dec-2015
transcript
Arnold HanslmeierInstitut für Physik/Geophysik, Astrophysik und Meteorologie. Grazarnold.hanslmeier@kfunigraz.ac.at
Basic facts:G2V starT
Surface: 5800 K center: 15 000 000 K
Age: 4.5 Billion years150 000 000 km distanceConstant star ???
2-D Powerspectra:Velocity ~ k-5/3
Intensity ~ k-5/3 k<kc
~ k-17/3 k>kc
Kc separates convectivefrom diffusive range
Kolmogorov Theory of isotropicturbulence
Variation with solar activity cycle Observatoire Pic du Midi, Univ. Toulouse
Generation of acoustic flux and its relation to shocks and turbulence Instituto de Astrofisica de Canarias, Tatranska Lomnica, Kiepenheuer Institut, Univ. of Colorado, Univ. of Chicago
3-D HD and MHD simulations Univ. of Vienna, Univ. of Colorado
The surface intensity shows the sunspot with the dark central umbra surrounded by the somewhat brighter, filamentary penumbra.
The second plane cuts from the surface to 24000 km deep showing areas of faster sound speed as reddish colors and slower sound speed as bluish colors.
The third plane (bottom) is a horizontal cut at a depth of 22000 km showing the horizontal variation of sound speed.
Magnetic fieldConvection zone – surfaceMagnetic buoyancyDifferential rotation Stellar dynamo Intermittency??
Magnetic flux
Tachocline
Sunspots, bipolar groups
Photosphere
Chromosphere
Faculae, Flares
Corona
CMEs, Solar Wind
A variety of effects from the particles:
Total doseLattice displacement damageSingle events upsets (SEE)Noise in sensorSpacecraft charging
Cosmic radiation: (protons, highly ion. Heavier nuclei); production of atmospheric secondaries (effects in aircraft systems and sea level electronics); SEEs, background noise
Solar particle events: increase of SEEs; significant enhancements in the radiation at supersonic aircraft altitudes.
Inner Radiation Belt: dose damage, noise and SEE Outer Radiation Belt: energetic electrons; cummulative
dose and dammage effects; deep dielecrtic charging (responsible for anomalies and losses); surface charging anomalies.
Temperature, composition and horizontal winds in the Earth‘s atmosphere at orbital altitudes above 120 km are all influenced by variations of solar and geomagnetic activity.
Atmospheric drag: F=C ½ v^2A Solar radiation force: F=C I/cS, S cross sectional area perpendicular to the direction of solar rays.
Red: density increase by20% during a magnetic storm.
Emissions from the sun:UV, X; if in additionMagnetic activity is triggeredat Earth, intense currentsflowing through the upperAtmosphere and energy deposited by high speedparticles increase the heatingand expansion of theAtmosphere.
Dynamics of the solar atmopshere Solar convection – models and observations Flares and CMEs Wave phenomena in the upper solar atmosphere Space Weather Kanzelhöhe: Monitoring Cooperations:
Hvar Observatory, Cro Tatranska Lomnica, Sk Observatoire Pic du Midi, F Instituto de Astrofisica de Canarias, E University of Glasgow, UK Niels Bohr Institute of Astrophysics, Copenhagen, Dk Kiepenheuer Institut f. Sonnenphysik, Freiburg, D Astrophysikal. Institut Potsdam, D Univ. of Colorado, Boulder, USA Big Bear Solar Observatory, USA Bangalore Indian Institute of Astrophysics, India