SUN COURSE SLIDE SHOW 3 Show sunspots Today

SUN COURSE - SLIDE SHOW 3 Show & sunspots Today: 1 -- photosphere SOHO Show 2 -- corona & solar cycle

1. SOHO (Solar & Heliospheric Observatory) Computer animation of trip to orbit 1% of distance to Sun New collaborative ESA/NASA mission - launched Dec 1995 --> 1 st comprehensive view of Sun

SOHO Orbiting Sun at L 1 point in phase with Earth Observing Sun continuously for first time Results breathtaking MANY NEW SURPRISES --> only three

Suite 11 Instrument Packages Solar wind - SWAN, CELIAS, CEPAC Atmosphere: * LASCO - Visible Light Coronagraph UVCS - Ultraviolet Coronagraph * EIT - Extreme UV telescope - global images. CDS - Spectrum EUV -> n, T, v + raster SUMER - Spectrum EUV -> n, T, v + raster Interior * MDI - Oscillations Imager + B GOLF - Global Velocity Oscillations * VIRGO - Irradiance Variations

E. G. from CDS

The SUN Last Week The photo sphere (Big Bear)

The SUN TODAY The photo sphere (SOHOMDI)

Magnetic field (SOHOMDI)

Chromo sphere (Ha Big Bear)

Chromo sphere (Ca. K Big Bear)

Chromo sphere (SOHOEIT)

Corona at 1. 3 MK (EIT)

Corona at 1. 6 MK (EIT)

Corona at 2. 3 MK (EIT)

2. QNs. (i) -- ? Earth Influenced by S Variability Number of Sunspots Oscillates w. 11 -year Cycle

SURPRISE (1976) Realised NO sunspots in most of 17 th centy "Maunder Minimum" -- Little Ice Age So B on Sun affects climate of Earth !! How ? ?

SOHO --> Total Emission (t) 1996 -2000 Emission varies by 0. 2% -passage sunspots Increase by 0. 1% from sunspot min to max ? Contribution to global warming

SURPRISE (2001) Discovered that Global B of Sun doubled since 1900 ? Effect on Global T of Earth Observed increase in T (blue) Best estimate of increase caused by Sun (yellow) Only 1/3 global warming (1970 to 2000)? Mechanism couple Sun/climate caused by Sun

QN. (ii) -- ? Structure of Solar Interior Guitar string can oscillate in different normal modes Sun too Recently discovered several million

SOHO Measures velocity of Sun's surface at million pts/min Deduces frequencies: Deduced T(r) -agrees with model to < 1%

Deduce Internal Rotation Observe: * Faster at equator -Expect: * const. on cylinders * B generated throughout conv. zone Surprise: -- const on radial lines -- intense shear layer ? site dynamo

QN(iii)-? How Do Mass Ejections Occur SOHO Coronagraph -- Artificial eclipse Discovered huge ejections of plasma Can reach Earth - communications / satellites

Comet + Comet

Next

TODAY SOHO LASCO Coronagraph

Further Out (LASCO C 3)

? Effect on the Earth -- Space Weather

Other Consequences Damage to satellites, astronauts Disruption to radio/phone communications, power grids

Cause of Eruption Magnetic Catastrophe (2 D)

3 D Model Magnetic Catastro phe