Transcript progress in space weather predictions and applications

PROGRESS IN
SPACE WEATHER
PREDICTIONS AND
APPLICATIONS
ZEYNEP KOCABAŞ
METU AEE 2005
INTRODUCTION
SPACE WEATHER:
 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 can endanger human life and health.
 Blasts of particles from the sun that impact
the magnetosphere.
IMPORTANCE OF PREDICTIONS
Like severe weather on Earth , severe space
weather can be costly.
 Widespread power system voltage control
problems
 Complete collapse in grid systems
 Damage on transformers
 Extensive surface charging in space crafts
 Orientation and tracking problems on
satellites
 Degradation on satellite navigation
 Problems with low frequency radio
navigation
TYPES OF SOLAR STORMS
Solar Radiation Storm: Sharp increase
in the amount of protons in the solar
wind.
Geomagnetic Storm (CME): Clouds of
electrified magnetic gases weighing
billions of tons ejected by the sun.
Solar Flare: Violent explosions in the
atmosphere of the sun caused by
sudden release of magnetic energy.
FORECAST METHODS
First Principal Based Methods
Linear Non-Linear Filters
Knowledge Based Neural Models
KNOWLEDGE-BASED NEURAL
MODEL
A neural network is a group of
interconnected computing elements:
NEURONS
APPLICATIONS OF SPACE
WEATHER PREDICTIONS
 Prediction of long-term and medium-term
solar activity
 Prediction of short term solar activity and
transient phenomena
 Prediction of solar wind parameters
 Prediction of electron flux in
magnetosphere
 Prediction of geomagnetic activity
 Local geomagnetic field
 Prediction of communication conditions
 Prediction of effects
“S” MARKS THE SPOT
The ejections occur when solar
magnetic field lines snake around each
other, forming letter “S”.
Usually they don’t touch each other
But if they connect the mid-section
breaks and drives out a CME.
To measure the amount of magnetic
energy stored in a region they use
Solar Vector Magnetograph.
Visible “S” shaped structure
→qualitative indicator
Vector magnetograph
→quantitative indicator
SOLAR FLARE≈AVALANCHE
 To have an avalanche large amount of
snow is required.
To power flares large electrical currents
are required.
 Once the required amount of snow is
reached then the avalanche can occur at
any time
Once the required amount of electrical
power is reached then the flare can happen
at any time
The required amount of electrical
current must build up over several
hours.
Computer model of 3-D solar magnetic
field
Images taken from satellites.
The differences between the two
indicate the presence of large
electrical currents.
CAN CROMOSPHERE BE USED
FOR PREDICTIONS?
Cromosphere is stretched thin, below
coronal coronal holes.
Cromosphere is compressed below
magnetically closed regions.
∴The wider the cromosphere is, the
faster the solar wind blows.
CME SPEED α SOLAR STORM SPEED
CME is slowing down to solar wind
speed after they leave the sun 4-5
times faster.
This method can be used to predict
solar storm arrival time hours before.
FURTHER INFORMATION
www.sciencedaily.com
www.nsstc.org
www.spaceweather.com
www.nasa.gov
www.space.com
www.lunds.irf.se