1. PROGRESS IN SPACE WEATHER PREDICTIONS AND APPLICATIONS ZEYNEP KOCABAŞ METU AEE 2005

2. 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.

3. 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

4. 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.

5. FORECAST METHODS First Principal Based Methods Linear Non-Linear Filters Knowledge Based Neural Models

6. KNOWLEDGE-BASED NEURAL MODEL A neural network is a group of interconnected computing elements: NEURONS

7. 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

8. 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. “S” MARKS THE SPOT

9. Visible “S” shaped structure →qualitative indicator Vector magnetograph →quantitative indicator

10. 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

11. 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.

12. 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.

14. 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.

16. FURTHER INFORMATION www.sciencedaily.com www.nsstc.org www.spaceweather.com www.nasa.gov www.space.com www.lunds.irf.se