Long and short term solar variability

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Long and short term solar variability

• Arnold Hanslmeier
• University of Graz
• Austria
• Arnold.hanslmeier_at_uni-graz.at

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Outline

• The Sun as a star
• Solar variability
• Observations
• Variations
• Short term
• Long term
• Need for coordinated observations
• New data archives

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The Sun as a star

• G2 V main sequence star
• 10 on the main sequence
• Observation of the sun
• Details, below 1000 km
• Phenomena spots, granulation, flares, CMEs
• Solar activity
• Relevance for Earth
• Space weather
• Sun and climate

Solar like stars ?? Habitable planets
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Sunspots indicator for solar activity
Sunspots easily observable UV flux more
difficult to measure
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On Earth

• Protection
• Magnetic field ? charged particles
• Atmosphere ? radiation (UV, X)
• Heliosphere ? charged particles
• Variability
• short term (min, hours)
• Activity cycle 11, 22 years, Gleissberg cycle
• Long term evolution

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Observations

• Ground based
• High spatial resolution
• Easy access
• Monitoring worldwide
• Space based
• No atmospheric disturbance
• Observations at all wavelengths

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Solar monitoring

• Worldwide like H-Alpha
• ? space weather relevant data
• ? data archives easy access to data
• Also digitize old data (films of H-Alpha)

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High resolution observations

• Understand basic physics
• Difficult to get long term cycle studies

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Space missions

• Hinode
• Stereo
• SOHO
• TRACE

Visible photosphere UV chromosphere X Corona
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Short term variability

• Energetic events such as Bastille day event,
  Halloween Event
• ?direct effects on Earths atmosphere
• ?habitable planets

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• Flare-ionospheric coupling
• Oct 28, 2003 30 increase of TEC
• For the X-class Bastille day event, July 14,
  2000 mesospheric temperature increase of 200 K.

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Bastille day event

• Bastille day event followed throughout
  heliosphere to V2 (63 AU in 2001) and V1 (80 AU
  in 2001)
• decreases started 180 days after the event was
  on the Sun at V2 and 245 at V2.
• ?propagation speed about 600 km/s
• Intensity decrease was 13.1 at V2 and 9.3 at V1
• Recovery 150 120 days

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Solar Cycle Variations

• Change of total irradiance 0.1
• Change of UV irradiance between 200nm and 300 nm
  1.5 change.
• UV increase?ozone increase?stratospheric heating
  ?poleward displacement of stratospheric and
  tropospheric wind systems
• Changes in solar wind and magnetic flux
• Heliosphere?cosmic ray ionization in Earths
  atmosphere changes???
• Effects on clouds
• Changes in Earths albedo (Earthshine-decreas 5)
• Cosmic ray particles as condensation nuclei

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FP7SOTERIA
SOTERIA Solar Terrestrial Investigations Archive
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Solar observations

• High resolution VTT, SST, GREGOR, EST
• Monitoring worldwide
• Satellite based
• SOTERIA Solar Terrestrial Investigations Archive
• JIS Joint information system
• Google www.solarjis.com

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• Thank you

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Solar rotation
SOLAR ROTATION RATE WITH DEPTH IMAGE MDI This
image is made from continuous observations over a
period of twelve months beginning in May 1996.
The false colors represent speed red material is
rotating the fastest, dark blue, the slowest. at
the surface of the Sun red material at the
equator is moving approximately three thousand
miles per hour faster than the blue material at
the poles. The cutaway on the right reveals
rotation speed inside the Sun.
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Acceleration of solar wind particles Charged
particles in the solar wind spiral around lines
of magnetic force, and these lines oscillate back
and forth to create outward-propagating waves.
When the particles' spiraling frequencies match
the wave frequencies, the particles can absorb
the waves' energy this spins up the particles
into larger orbits, gives them an added outward
boost, and damps out the waves.
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Is there anything new in solar physics?

• Dynamo,
• Energetic processes
• Variability
• Space weather

Costumers Telecommunication operators Navigation
systems Airlines Power systems Space
activities Climatology
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