Short-term space weather forecast A.A. Petrukovich

2. Short-term space weather forecast A.A. Petrukovich Space Research Institute, Russian Academy of Sciences with contributions from G.N.Zastenker, V.M.Linkin, N.A.Eismont • What is space weather ? • Why is it important ? • Short-term forecast - concept - quality - real-time system

3. Sun is a very stable star Total solar energy flux - SOLAR CONSTANT 1.5 kW per 1 sq. m.

4. active sun: ~0.1% solar constant cycle with 11 (22) years energy from heat is accumulated in extra magnetic field and released sun spots solar flares coronal mass ejections geomagnetic storms

5. 1. Sunspot – signature of extra magnetic energy 2. Solar flare in soft X rays – explosive release of energy 3. Subsequent coronal mass ejection:

6. Summary of solar emissions • Solar UV - variable • 2. Solar X-ray - sporadic from solar flares • 3. Solar cosmic rays - sporadic from solar flares • 4. Solar wind and interplanetary magnetic field • - permanent flow thermal expansion of solar plasma • - magnetic clouds sporadic from solar flares

7. Solar wind & interplanetary magnetic field interact • with Earth magnetic field • Steady solar wind flow create magnetosphere from the pure dipole • Everyday interplanetary variations create geomagnetic activity energy from solar wind powers up magnetospheric dynamics • Magnetic clouds – anomalously intense solar wind and IMF create geomagnetic storms

8. Earth is inside an electromagnetic system: energy of geomagnetic storm is measured by megatons of TNT All sorts of radiation and Electromagnetic influence: Radio, satellites, …, humans

9. Radiation damage to electronics Radiation threat to crews, Especially future interplanetary flights Spacecraft effects Electrostatic discharge on spacecraft surface

10. Telecommunications In XIX cent. space weather effects were observed in wire telegraph lines short wave telecom radars space telecom GPS/GLONASS

11. Effects on climate and biosphere ?

12. Summary of space weather Space weather is due to solar activity and plasma environment of Earth Sporadic intensifications “storms” are due to solar flares and magnetic clouds in solar wind affecting Earth Space weather is basically “one for all” – storms are global Monitoring and forecast are important for many technical systems in space and on ground

13. Our interest Summary of forecast long term (months and years) – cycle progression time-series analysis no hurry mid term (weeks) – variability due to rotation (27 days) “recurrence” no hurry flare warning (days & hours) – probability of a flare in given sunspot complexity analysis real time short term (days & hours) – probability of magnetic storm after flare registration propagation analysis real time short term (hours) – storm development based on near Earth solar wind time series analysis real time Physics-based models (requiring HPC) are not competitive currently but will be ?

14. solar wind-based short-term forecast: IKI studies Monitoring of interplanetary medium in front of the Earth is currently the only tool to provide reliable quantitative, but short-term, space weather forecast. A L1 Sun-Earth libration point, 1.5 mln km from the Earth, is a convenient place with the lead time of a forecast of about 1 hour. Solar wind: 400-1000 km/s: 1.5-3 days Geomagnetic storm Solar storm 3-day forecast 50% reliability Solar light: 300 000 km/s: 8 min 1 hour forecast >90% reliability Libration point 1.5 mln km 150 mln km

15. reliability of the L1 monitor due to natural variability of solar wind measurements of solar wind and IMF (1996-1999) Wind (distant) and Interball (near-Earth)

16. probability of different (by 15%) measurements of energy input ~VB2 to the magnetosphere magnetic storm (> 1016 J) predictions are reliable, while substorm predictions are uncertain. ! role of small variations and discontinuities Petrukovich et al,JASTP, 2001.

17. Geomagnetic indices AL and Kp (measures of magnetic fluctuations) are used as general indicators Future or current indices might be estimated with real-time solar wind. the main problem: significant scatter of index (uncertainty of magnetospheric dynamics) with respect to solar wind input solar wind driving function ~ VBns

18. ACE L1 monitoring available in INTERNET

19. ACE L1monitoring Unreliable measurements (marked by team) error codes ACE in 2001 IMF 5.5% SW 20% intervals > 20 min long IMF 3.9% SW 3.9% IMF & SW 2.1% major reserve: accept data even if it is flagged Internet availability errors add less than 1 %

20. ACE L1 monitoring ACE data physical quality: real-time and final data compared 2001 IMF clock angle wrong by 20-50o in 1997-2004! 30% error in Bns! corrected only in 2004

21. Space Research Institute Index models Format & delivery Internet Activity estimates Consumer Blocks NOAA/ SEC download & check IKI solar wind forecast system • download • data quality check and filling gaps • advection time to Earth • activity estimates • specific predictions • product delivery

22. IKI solar wind forecast system Examples of general products Overview plots for “now” and +1 hour http://www.iki.rssi.ru/forecast since 1999

23. future solar wind monitors • using micro satellites • placing monitor further away from the Earth • Not so far to preserve forecast quality • Solar sail is the only solution to keep spacecraft with Earth solar wind: 400-1000 km/s: 1.5-3 days geomagnetic storm solar storm 2 hour forecast 1 hour forecast >90% reliability Libration point 1.5 mln km 3 mln km from Earth solar gravity in balance with Earth gravity+ light pressure solar gravity in balance with Earth gravity Earth gravity larger than solar gravity

24. future solar wind monitors • hardware • instruments: • Magnetometer • solar wind sensor • Cosmic ray sensor • total data flow ~100 bits/sec. • Total scientific payload weight 2 kg "standing point" at 3 mln km requires a spacecraft ~ 25 kg with solar sail ~1000 sq m or ~ 150 kg with solar sail ~6000 sq m sails are made with thin polymer films initial Solar sail deployment tests are underway world wide.

25. A 2009 forecast Grand solar minima A 2007 forecast Solar wind now on minimum level in 50 years of observations Solar min In 2008 a very deep solar min in 2009 What about a new solar cycle ? A 2004 forecast Solar min in 2007

26. Earth as space ecosystem Life depends on Space: Earth climate driven by constant solar energy

27. Earth as spaceecosystem Life depends on Space: Earth climate driven by constant solar energy ! Solar system climate: solar activity, solar evolution, orbit interactions

28. Earth as spaceecosystem Life depends on Space: Earth climate driven by constant solar energy Solar system climate: solar activity, solar evolution, orbit interactions ! Galaxy climate: local interstellar medium and galactic cosmic rays

29. CONCLUSIONS • Short-term forecast is an important part of space weather services and is relatively novel technology • Real-time data analysis tools (image and time series processing) • are necessary • Internet technologies are vital to create and use such forecast • Proper data conditioning is an important task Thank you !