Space weather: solar drivers, impacts and forecastsHenrik Lundstedt Swedish Institute of Space PhysicsLundWe live inside the continuously expanding solar corona, i.e. the solar wind, which can be very strong e.g. at times of CMEs. Earth is also exposedto very intense radiation at times of so called solar flares. The Sun is also inside a stellar wind and a flow of cosmic rays. This space weather hasimpacts on both Earths atmosphere and technological systems. To mitigate the effects of the space weatherwe need to forecast it and start to learn to live with the Sun.

Outline

How do we define space weather?How do we observe it? (solar weather)What drives it? (solar activity and solar phenomena)Which are the impacts on: the Earths atmosphere and technological systems?How can we forecast it?What services exist?Todays space weather.

Space weather

Rymdvder was mentioned the first time in media 1991!The US National Space Weather Program 1995: Space weather refers to conditions on the sun, and in the solar wind, magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and endanger human life or health. LWS 2001 and ILWS 2002.ESA Space Weather Programme started in April 1999. ESA Space Weather Pilot projectsstart in April 2003. SWWT, EU COST 724 Space Weather.HD 1981 (cykel 21)SDS 1991 (cycle 22)SDS 1991 (cycle 22)Arbetet 1981 (cycle 21)

Workshops arranged in LundWorkshops on Artificial Intelligence Applications in Solar-Terrestrial Physics were held in Lund 1993 and 1997.John Freeman (Rice University, Houston, TX) coined the word space weather

The SunDiameter:1 390 000 km(109 x Earth)

Mass:1.99x1030 kg(330 000 x Earth)

Density:Core 151x103 kg/m-3Average 1.41x103 kg/m-3

The Sun consits of:H ( 90%)Helium ( 10%)C,N,O ( 0.1%)

Temperature:Core 15 millionPhotosphere 5800 K Chromosphere 4300-104KCorona 1-30 million K4 protons --> He + 2 positrons + 2 neutrinos + 2 fotons (26.2 MeV)

A plasma A plasma is a quasineutral gas of charged and neutral particles, which exhibits collevtive behavior. Three conditions aplasma must satisfy.

Xspace from UCLA

Plasma equationsMacroscopic plasma quantities:By taking velocity moments of the particle distribution function fs(x,v,t) for particles of species s in six-dimensional phase space we obtain macroscopic measurable quantities such as bulk velocity, pressureand the temperature.

Macroscopic equations:By taking velocity moments of the Vlasov equation we obtain the fluidequations of a plasma in terms of the macroscopic variables. The zerothand first order moments, result in continuity equation and fluid equation of motion.

Magnetohydrodynamic (MHD) approximationInduction equation

Equation of continuity

Equation of motionMaxwell equations and Ohms law give the induction equation.We need to observe V and B.

Solar observations

Where on Earth do we observe the Sun?What spacecrafts observe the Sun?How do we observe V and B on the Sun?

Solar observations in CaliforniaMount Wilson ObservatoryBig Bear Solar ObservatoryWilcox Solar ObservatoryInternet-accessible robotic solar telescope in Livermore

French solar observation facilitiesPic du Midi (Coronagraph, (Lyot)THEMIS on Tenerife (solar magnetic field) Radioheliograph at Nancay (CMEs)

Solar observations with the Swedish solar telescope on La Palma

Advanced Technology Solar Telescope 4-m telescope0.1 resolutionOperational 2009National SolarObservatory

Probing CMEs in radio wavelengths with a solar radar in Sweden 2003-200615 000 antennas with receivers and senders,arranged in 100 clusters distributed withi a circle of 350 kmsdiameter. Data transfer rate 25 Tbits/s. Frequency 10-250 MHz (30-1.5m)

ACE was launched in August 25, 1997Solar wind observations with ACE make accurate forecasts 1-3 hours ahead possible.

STEREO - planned launch November 2005

Solar Orbiter - planned launch 2009Study the Sun fromclose-up (45 solar radii,.21 au), (0.05 arcsec) latitude as highas 38 degrees

SDO - planned launch April 2008Geosynchronous orbit

Living with a Star (LWS)

SOHO was launched on 2 December 1995

SOHO has given us a totally new picture of the Sun- always activeSolar Heliospheric Observatory was launched on December 2, 1995

SOHO carries three instruments observing the solar interior, six the solar corona and three the solar wind

How do we observe the solar rotation and oscillation?

Dopplergram shows the solarrotation

Dopplergrams show the solaroscillations

How do we observe the solar magnetic field?

When the solar magnetic field emerges thru the solar suface sunspots appear

The SunDiameter:1 390 000 km(109 x Earth)

Mass:1.99x1030 kg(330 000 x Earth)

Density:Core 151x103 kg/m-3Average 1.41x103 kg/m-3

The Sun consits of:H ( 90%)Helium ( 10%)C,N,O ( 0.1%)

Temperature:Core 15 millionPhotosphere 5800 K Chromosphere 4300-104KCorona 1-30 million K4 protons --> He + 2 positrons + 2 neutrinos + 2 fotons (26.2 MeV)

The oscillations reveal solar interiorThe oscillations at the surface of the Sun are reflections of thestanding sound waves that fill the interior. Each standing wave(or n, l, m mode) is trapped between the surface and some critical depth.

A standard solar modelL = luminosity (amount of energy radiated per unit time, measured in watts)e = energy generated per unit mass per unit time in the corek = opacityEnergy transferred by radiation by convection The mass equation, equation of hydrostatic equilibrium, equation for energy balance and equation for radiation energy transfer determine the evolution of the Sun.

The model must reproduce the observed luminosity and radiusof the Sun at its present age from the solar mass, initial chemicalcomposition and age.

Sound speed reveals temperature of solar interior

Sound speed reveals rotation conditions in solar interior

Solar waves reveal the source of solar magnetic activity

Why a flux tube emerges thru the solar surface

When the solar magnetic field emerges thru the solar suface sunspots appear

Why sunspots live so longMDI shows how magnetic elements form sunspots(local helioseismology)

Sunspots on far side

Butterfly diagram

Sunspot solar cycles Schwabe found the 11- year sunspot solar cycle. R = k(10g + f).Gleissberg found the 80-90 years cycle.Maunder-Sprer 207 years cycle,Houtermans cycle 2272 years and Sharma 100 000 years cycle.The two peaks of solar activity, 1.3 years separated!

A Maunder minimum suddenly?In the beginning of 1640 the sunspotnumber suddenly decreased to near zero.

The Maunder Minimum started1645 and ended1715.

Gleissberg maximum?The number of severe proton events follow the Gleissberg cycle and might increase with a factor 8-10. A maximum occurred 1980. A new warm Grand Maximum (1050-1250) has been suggested by J. Lean 2030-2040. (The Carington event 1859 September 1 produced a white light flare, >30MeV proton fluency 4-8 times worst case 1972, a CME v=2500km/s, 18h later a super-storm with Dst = -1760nT!).

Rapid changes for other solar type starsHD 149661 (K0V 17.4 +4.0 years) multiple cyclesHD 9562 (G2V) Maunder minimum stateHD101501 (G8V) chaoticHD 136202 (F8IV) 23 yearsSun (G2V) 10.0 yearsHD 10476 (K1V) 9.6 yearsFor a solar type star the luminosity decreased with 0.4%p in just a few years. Similar rapid changes happened during the Maunder minimum! (compare 1640-1645!)Mount Wilson studies

Non-linear chaotic solar dynamo (N. Weiss)

A complex generalization of the three ordinaryLorenz diff equations.The toroidal magnetic field for aaW dynamo. As the dynamo number D increasesD1 (no activity) ->D2 (cycle activity) ->D3 (chaotic activity)

aw, meridional-Dynamo

Peter Gillman and Mausumi Dikpati(Astrophys. J, 2001)

Our scientific approach

Web page www.lund.irf.se

Solar activity and temperatureduring longer periods

J. Eddy 1976Meton (in Greece) claimed400 B.C. that high solaractivity was related towet climate.

Christmas day 1690 - during Maunder minimum Its heavily snowing in Rome and on the French riviera.Children are skating on Thames River in London and they have annual frost fairs.In Amsterdam the canals are frozen.In Paris the snow is deep.Europa experienced Little Ice Age.

Lund during the Middle Ages and the Maunder minimum

The Danish kingdom during Knud the great (1016). During the Middle Ages Lund prospered, Lund was called the capital of Denmark (Metropolis Daniea). Rich could drink excellent wine from England (e.g. from Abbey of Abingdon). Today Bothy Vineyard, south of Oxford.The Swedish king Karl X Gustaf looks at theice before the crossing of the Belts 1658. The battle in Lund follows in December 4, 1676 and Lund becomes Swedish.

Wavelet studies of solar activityand global temperature - trendsThe Sun has neverbeen as active asafter 1940 during thelast 1000 years (Phys. Rev. Lett. 2003)

Solar Activity and Earths Climate

The evolution of the grand atmosphere: the solar atmosphereThe solar luminosity (total energy output per unit time in the form of electromagnetic radiation). The total flux at mean distance of the Earth from the Sun, the total irradiance at mean distance or solar constant S. S = L/4pA2. S=1367 3W/m2 , L=(3.844 0.010)x1026 WThe solar luminosity has increased during its main-sequence life from 0.7L to the present value. A reduction today of S by a factor 0.7 would probably have lead to a complete ice cover of Earth. Geological evidence suggests it never was. The solution of the puzzle probably lies in the evolution of the Earths atmosphere. The Suns radius has increased from about 0.87r to present radius. Three billions years from now, the Suns radius has increased so much that the oceans on earth has vaporized. About 7.5 billion years from now the Sun is transferred into giant star engulf Earth, melts away everything and then ends as a white dwarf not bigger than earth.

Solar radiation variation with the solar cycle

Real-time Helioseismological Data SDO 2007Historical Data SOHO/MDI

Solar activity --> UV-radiation --> Ozone --> North Atlantic Oscillation --> T Drew Shindells (NASA GSFC) models show that weak UV (i.e. low solar activity), results in lower amount of ozone, which influences AO/NAO and herwith cause a decrease of the temperature (MM locally1.5C).Maunder Minimum

Solar winds effect on climate(GRL, Vol 29, No.15, 2002)

A possible explanation of the solar influence on climate Many sunspots high solar activity

Less cosmic radiation

Less clouds formed

Increase temperature warmer climate The solar corona magnetic field has increased with131% since 1901.Cloudes have 100 times more effect on weather and climate than CO2. The effects of a doubling of the CO2, that is stated to happen within 100 years could a cloud coverage change Counteract in 3.5 years!The Maunder minimum could beexplained.

Will the change of Earths magnetic field influence climate?

The solar influence on Earths weather and climate

END

Part 1