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Living with our starHenrik Lundstedt
Swedish Institute of Space Physicswww.lund.irf.se
The Sun drives a space weather, that influences the atmosphere, technological systems and us. Our society has become more susceptible tothese effects. We therefore need to start learninghow to live with our star! I will tell how!
OutlineOutline
• How and why does the Sun vary?• How does the Earth respond?• What are the impacts on life and society?• How can we forecast it?• What services exist?• Teach space weather.• Today’s space weather.
The SunThe Sun
Diameter:1 390 000 km(109 x Earth)
Mass:1.99x1030 kg(330 000 x Earth)
Density:Core 151x103 kg/m-3
Average 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 K 4 protons --> He + 2 positrons + 2 neutrinos + 2 fotons (26.2 MeV)
Xspace from UCLAXspace from UCLA
Magnetohydrodynamic (MHD) approximation
Magnetohydrodynamic (MHD) approximation
Induction equation
Equation of continuity
Equation of motion
Maxwell’ equations and Ohm’s law give the induction equation.
We need to observe V and B.
Solar observationsSolar observations
• Where do we observe the Sun?
• How do we observe the solar rotation and oscillations?
• How do we observe the solar magnetic field?
Solar observations in California Solar observations in California
Mount Wilson Observatory
Big Bear Solar Observatory Wilcox Solar
Observatory
Internet-accessible robotic solar telescope in Livermore
Solar observations with the Swedish solar telescope on La Palma
Solar observations with the Swedish solar telescope on La Palma
SOHO has given us a totally new picture of the Sun- always activeSOHO has given us a totally new picture of the Sun- always active
• Solar 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?
How do we observe the solar rotation and oscillation?
I =12I 0(λ+ΔλB)+I0(λ −ΔλB)[ ],V =
12I0(λ+ΔλB)−I0(λ −ΔλB)[ ]
vB =ΔλB /ΔλD,ΔλB =4.7⋅10−8gλ2B,ΔλD =(2RT/A)λ /c,v=Δλ / ΔλD
ΔλB <<ΔλD ⇒ V =vBdIdv
,λ =525.05nm,ΔλD =42mÅ,g =3,r0 =0.7⇒
V / I ≈9.6×10−4B,B=10gauss⇒ 1%−cirkulär−polarisation
Dopplergram shows the solarrotation
Dopplergram shows the solarrotation
Dopplergrams show the solaroscillations
Dopplergrams show the solaroscillations
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krävs för att kunna se bilden.
The oscillations reveal solar interior
The oscillations reveal solar interior
How do we observe the solar magnetic field?
How do we observe the solar magnetic field?
I =12I 0(λ+ΔλB)+I0(λ −ΔλB)[ ],V =
12I0(λ+ΔλB)−I0(λ −ΔλB)[ ]
vB =ΔλB /ΔλD,ΔλB =4.7⋅10−8gλ2B,ΔλD =(2RT/A)λ /c,v=Δλ / ΔλD
ΔλB <<ΔλD ⇒ V =vBdIdv
,λ =525.05nm,ΔλD =42mÅ,g =3,r0 =0.7⇒
V / I ≈9.6×10−4B,B=10gauss⇒ 1%−cirkulär−polarisation
When the solar magnetic field emerges thru the solar suface sunspots appearWhen the solar magnetic field emerges thru the solar suface sunspots appear
MDI/SOHO reveals the interiorMDI/SOHO reveals the interior
MDI shows how magnetic elements form sunspots
MDI shows how the dynamo changes
Sunspots are footpointsof emerging magnetic flux tubes
Sunspots observed on solar surface
Sunspots observed on solar surface
Schwabe found the 11- year sunspot solar cycle. R = k(10g + f)
The two peaks of solar activity, 1.3 years separated!
At solar maximum 100 times brighter X-ray emission and 0.1 % brighter in
visible
At solar maximum 100 times brighter X-ray emission and 0.1 % brighter in
visible
Coronal mass ejectionsCoronal mass ejections
CMEs cause the most severe space weather effects
CMEs cause the most severe space weather effects
• Halo CMEs are most geoeffective
• Mass: 5-50 billion tons
• Frequency: 3.5/day (max), 0.2/day (min)
• Speed: 200-2000 km/s
Solar flares and sun quakesSolar flares and sun quakes
The source of the fast solar wind The source of the fast solar wind
Earth’s responseEarth’s response
• Geomagnetic disturbances
• Aurora
• Ionospheric disturbances
• Climate and weather changes
Earth’s magnetosphere and current systems
Aurora ovalAurora oval
The aurora observed inStockholm
Aurora was observed in Italy 6-7 April and on July 15-16, 2000!
Aurora during severe solar storms
Aurora during severe solar storms
Solar activity and North Atlantic Oscillation Index
Solar activity and North Atlantic Oscillation Index
The NAO response on increased solar wind E, one month later! That makes forecasts one month ahead possible.
North Atlantic Oscillation and solar wind activity
North Atlantic Oscillation and solar wind activity
11 års, 1.3 variations are seen both insolar wind and NAO.
Impacts on life and societyImpacts on life and society
• Human radiation exposure (space station, space exploration (Mars), high altitude flights)
• Impacts on technology (space systems (satellites), communications, navigation, terrestrial systems (electric power grids))
• Terrestrial climate
Satellite anomalies of July 14-16, 2000 eventSatellite anomalies of July 14-16, 2000 event
The proton event causedproblems for ACE,SOHO, Ørsted, Japanese X-ray satellite,star trackers on boardcommercial satellites.
Proton flux (pfu) > 10 MeV,24000 pfu (July 15, 12.30 UT). Third largest!
Largest 43 000 pfu, (March 24, 1991). Second 40 000 pfu (October 20, 1989).
Today IRF-Lund has real-time neural networks forecasts of satellite anomalies one day in advance (ESA project SAAPS). The work has been in collaboration with Swedish satellite operators (ESRANGE).
Solar proton events are dangerous to man in space
Solar proton events are dangerous to man in space
Between Apollo 16 and 17 a proton event occurred, which should have been deadly to the astronautes within10 hours (i.e. above 4000 mSv).
Mars
Radiation risks and aviationRadiation risks and aviation
The radiation exposure is doubled every 2.2 km.
Solar flares can increase the radiation by 20-30 times.
Pilots get cancer more often than average.
New EU law:Pregnant (aircrew) should not be exposed to morethan 1 (1-6) millisievert/year
The intensive solar flare of April 2, 2001, which causedmajor communication problemsalso made ContinentalAirlines to changetheir route betweenHong Kong and New York.
IRF-Lund collaborates with the Swedish Radiation Protection Institute and Medical University in Stockholm to develop forecasts of radiation doses for Aviation Industry.
Power systems and pipeline systemsare effected at times of geomagnetic storms
Power systems and pipeline systemsare effected at times of geomagnetic storms
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This severe electrojet caused the failure of Quebec’s power system March 13-14, 1989. One of the generators of OKG’s
(Sydkraft’s) nuclear plants was heated due to the geomagnetically induced current in March 13-14 1989.
We in Lund have collaborated with the Swedish power industry during more than twenty years. Today we have real-time neural network forecasts of local GICs, based on ACE solar wind and warnings based on SOHO (LASCO and MDI) data.
Measured (SydGas)geomagnetically induced disturbance at time of theNordic GIC meeting in Lund September 23-24, 1999.
ForecastsForecasts
• Forecasting is a central problem within science• Forecasts based on knowledge-based neural model
(KBNM) have been most succesful• Why not teach students how to forecast and model with
KBNM?
Workshops arranged by usWorkshops arranged by us
Workshops on ”Artificial Intelligence Applications in Solar-Terrestrial Physics” were held in Lund 1993 and 1997.
Artificial neural networksArtificial neural networks
The basic element of every ANN is an artificial neuron or simply a neuron (which is an abstract model of a biological neuron (nerve cell)).
Download Lund Dst model in Java
Download Lund Dst model in Java
The ARMA filter is obtained by adding auto-regressive terms to a MA filter.The partial recurrent network (Elman) becomes identical to a linear ARMA filter if it is assigned linear
activations functions.
Test Dst forecastsTest Dst forecasts
Space weather serviceSpace weather service
• Real-time solar data
• International Space Environment Service (ISES)
• 11 Regional Warning Centers (RWC)
• RWC-Sweden in Lund
• H. Lundstedt Deputy Director
Real-time forecasts and warnings based on KBN Real-time forecasts and warnings based on KBN
Solar wind observations with ACE make accurate forecasts 1-3 hours ahead possible.
Solar observations with SOHO make warnings 1-3days ahead possible.
Solar input data
ESA/Lund Space Weather Forecast Service
ESA/Lund Space Weather Forecast Service
Near and farside solar activity from MDI/SOHO observationsNear and farside solar activity from MDI/SOHO observations
Latest information on arrival of halo CME at L1
Latest information on arrival of halo CME at L1
Latest info on forecasts of satellite anomalies (SAAPS)Latest info on forecasts of
satellite anomalies (SAAPS)
Latest information on forecasts of Kp, Dst, AE and GIC
Latest information on forecasts of Kp, Dst, AE and GIC
Regional Warning CentersRWC-Sweden in Lund
Regional Warning CentersRWC-Sweden in Lund
Forecasts of aurora as SMS, voice messages or WAP service
Forecasts of aurora as SMS, voice messages or WAP service
Teach space weatherTeach space weather
• Web sites (SOHO Explore links, Lund Space Weather Center)
• Software packages (Xspace, Lund Dst-model in Java or Matlab
• Books
• CD-ROM ”SOHO - Explore the Sun”
Where to learn more?Where to learn more?
Today’s Space WeatherToday’s Space Weather
Stanford collaborationStanford collaboration
Space weather effects on technological systems
Space weather effects on technological systems
The basic element of every ANN is an artificial neuron or simply a neuron (which is an abstract model of a biological neuron (nerve cell)).
The neuron receives signals (information) from other nerve cells thru the dendrites. The axons take information away from the neuron. The output of the neuron is y=f(wixi), with x as input vector.The value y is the state of the neuron. If f=sgn then the state of the neuron is (+1,-1).
x1x2xnyw1w2wnf(wixi)l
l
l
Artificial Neural networksArtificial Neural networks
Proton events give positiveNAO within days!
A User: Power sytem operators
User of NAO forecastsUser of NAO forecasts