Download The Solar and Space Weather Reseach Group in Lund

Living with our star
Henrik Lundstedt
Swedish Institute of Space Physics
www.lund.irf.se
The Sun drives a space weather, that influences
the atmosphere, technological systems and us.
Our society has become more susceptible to
these effects. We therefore need to start learning
how to live with our star! I will tell how!
Outline
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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 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 million
Photosphere 5800 K
Chromosphere 4300104K
Corona 1-30 million K
4 protons --> He + 2 positrons + 2 neutrinos + 2 fotons (26.2 MeV)
Xspace from UCLA
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 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
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
SOHO 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?
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I 0 (    B )  I0 (   B ),V  I0 (    B )  I0 (   B )
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v B   B /  D , B  4.7108 g2 B,  D  (2RT / A) / c,v   /  D
dI
  B    D  V  v B ,   525.05nm,  D  42mÅ,g  3, r0  0.7 
dv
4
V / I  9.6  10 B, B  10gauss  1%  cirkulär  polarisation
I
Dopplergram shows the solar
rotation
Dopplergrams show the solar
oscillations
The oscillations reveal solar
interior
QuickTime och en
Cinepak-dekomprimerare
krävs för att kunna se bilden.
How do we observe the solar
magnetic field?
1
1
I 0 (    B )  I0 (   B ),V  I0 (    B )  I0 (   B )

2
2
v B   B /  D , B  4.7108 g2 B,  D  (2RT / A) / c,v   /  D
dI
  B    D  V  v B ,   525.05nm,  D  42mÅ,g  3, r0  0.7 
dv
4
V / I  9.6  10 B, B  10gauss  1%  cirkulär  polarisation
I
When the solar magnetic field emerges
thru the solar suface sunspots appear
MDI/SOHO reveals the interior
MDI shows how the dynamo changes
Sunspots are footpoints
of emerging magnetic flux tubes
MDI shows how magnetic elements form sunspots
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
Coronal mass ejections
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 quakes
The source of the fast solar wind
Earth’s response
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Geomagnetic disturbances
Aurora
Ionospheric disturbances
Climate and weather changes
Earth’s magnetosphere and current systems
Aurora oval
Aurora during severe solar
storms
Aurora was
observed in Italy
6-7 April and on
July 15-16, 2000!
The aurora observed in
Stockholm
Solar activity and
North Atlantic Oscillation Index
North Atlantic Oscillation and
solar wind activity
The NAO response on increased
solar wind E, one month later!
That makes forecasts one month
ahead possible.
11 års, 1.3 variations are seen both in
solar wind and NAO.
Impacts 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 event
The proton event caused
problems for ACE,
SOHO, Ørsted,
Japanese X-ray satellite,
star trackers on board
commercial 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
Mars
Between Apollo 16 and 17 a proton
event occurred, which should have
been deadly to the astronautes within
10 hours (i.e. above 4000 mSv).
Radiation risks and aviation
The radiation
exposure is
doubled every 2.2
km.
Solar flares can
increase the
radiation by 2030 times.
The intensive solar flare of
April 2, 2001, which caused
major communication problems
also made Continental
Airlines to change
their route between
Hong Kong and New York.
Pilots get cancer
more often than
average.
New EU law:
Pregnant (aircrew)
should
not be exposed to more
than 1 (1-6)
millisievert/year
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 systems
are effected at times of geomagnetic storms
QuickTime och en
GIF-dekomprimerare
krävs för att kunna se bilden.
This severe electrojet
caused the failure of
Quebec’s power
system March 13-14,
One of the generators of OKG’s
1989.
(Sydkraft’s) nuclear plants was
heated due to the
geomagnetically induced
current in March 13-14 1989.
Measured (SydGas)
geomagnetically induced
disturbance at time of the
Nordic GIC meeting in Lund
September 23-24, 1999.
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.
Forecasts
• 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 us
Workshops on ”Artificial Intelligence Applications in
Solar-Terrestrial Physics” were held in Lund 1993
and 1997.
Artificial 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
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 forecasts
Space weather service
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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
Solar input data
Solar observations
with SOHO make
warnings 1-3
days ahead
possible.
Solar wind observations with ACE make
accurate forecasts 1-3 hours ahead possible.
ESA/Lund Space Weather
Forecast Service
Near and farside solar activity
from MDI/SOHO observations
Latest information on arrival of
halo CME at L1
Latest info on forecasts of
satellite anomalies (SAAPS)
Latest information on forecasts
of Kp, Dst, AE and GIC
Regional Warning Centers
RWC-Sweden in Lund
Forecasts of aurora as SMS,
voice messages or WAP service
Teach 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?
Today’s Space Weather
Stanford collaboration
Space weather effects
on technological systems
Artificial Neural networks
x1
x2
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w1
w2
wn
f(Swixi)
y
xn
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(Swixi), 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).
User of NAO forecasts
Proton events give positive
NAO within days!
A User: Power sytem operators