Transcript The Sun and Space Weather

Arnold Hanslmeier
Institut für Physik/Geophysik, Astrophysik und Meteorologie. Graz
[email protected]



Basic facts:
G2V star
T
 Surface: 5800 K
 center: 15 000 000 K
Age: 4.5 Billion years
 150 000 000 km
distance
 Constant star ???

Earth
Kolmogorov Theory of isotropic
turbulence
2-D Powerspectra:
Velocity ~ k-5/3
Intensity ~ k-5/3 k<kc
~ k-17/3 k>kc
Kc separates convective
from diffusive range



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
Umbra: T 4000 K
Penumbra: T 5500 K
Photosphere: T 6000 K
Sunspots: strong magnetic
Fields –
Umbra: vertical
Penumbra: horizontal
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.
a w Dynamo
Coriolis, Diff. Rotation
convection






Magnetic field
Convection zone – surface
Magnetic buoyancy
Differential rotation
 Stellar dynamo
 Intermittency??
Evidence of
magnetic activity
Activity on main
sequence:
types F  M
B-V > 0.4
Sunspot deficit compensation
Tachocline
Magnetic flux
Photosphere
Sunspots, bipolar groups
Chromosphere
Faculae, Flares
Corona
CMEs, Solar Wind
Modell für Protuberanzen. Auf der sog. Neutralen Linie befindet sich die Materie
u = u0+du






A variety of effects from the particles:
Total dose
Lattice displacement damage
Single events upsets (SEE)
Noise in sensor
Spacecraft 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 rv^2A
 Solar radiation force:
F=C I/cS,
S cross sectional area
perpendicular to the
direction of solar rays.

Red: density increase by
20% during a magnetic storm.
Emissions from the sun:
UV, X; if in addition
Magnetic activity is triggered
at Earth, intense currents
flowing through the upper
Atmosphere and energy
deposited by high speed
particles increase the heating
and expansion of the
Atmosphere.
Kanzelhöhe:
H-Alpha
Magnetograms
Intensity at various wavelengths
International network

EIT, 171
LASCO







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