1. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Spatiotemporal properties of dB/dt: setting limits for the highest achievable accuracy of GIC forecasts Pulkkinen A., A. Klimas, and D. Vassiliadis NASA Goddard Space Flight Center, USA

2. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Contents The ground effects of space weather: the physical quantities of interest The event-based view to the dynamics of dB/dt (actually, the geoelectric field) The statistical view to the dynamics of dB/dt Summary and discussion

3. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The ground effects of space weather Energy Dynamic variations of the electric currents

4. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The ground effects of space weather GIC Induction Spatiotemporal characteristics?

5. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The event-based view October 29-31, 2003 geomagnetic storm Blackout in Malmö, southern Sweden Details can be found from Pulkkinen, A., S. Lindahl, A. Viljanen, R. Pirjola, “October 29-31, 2003 geomagnetic storm: geomagnetically induced currents and their relation to problems in the Swedish high-voltage power transmission system”, AGU Space Weather, 2005. Malmö

6. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Oct 29, 2003 High-pass filtering Region of the highest activity Failures in the Swedish system

7. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Equivalent currents and E, Oct 30 Oct 30, 2003 Time of the blackout (20:07 UT)

8. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The event-based view (summary) “GIC view”

9. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view Quantify the complexity of the spatiotemporal behavior Structure function analysis of the IMAGE magnetometer array data (years 2002-2003) White noise (no predictability):

10. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view  S (  ) Correlated signal Break (change in the dynamics) Disappearance of correlations (or saturation of )

11. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view Details can be found from Pulkkinen, A., A. Klimas, D. Vassiliadis, V. Uritsky, and E. Tanskanen, “Spatiotemporal scaling properties of the ground geomagnetic field variations”, submitted to J. Geophys. Res., 2005.

12. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view (dB/dt) } } Substorms after continuation to the ionosphere Break in 80 - 100 s dX/dt dY/dt Scaling behavior same for substorms and the entire data set

13. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view (dB/dt) Conditional probability P(dIE|IE) Local variant of AE

14. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view (dB/dt) Details can be found from Pulkkinen, A., R. Pirjola, and A. Viljanen, “Estimation of geomagnetically induced current levels from different input data”, to be submitted to AGU Space Weather, 2005.

15. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view (dB/dt) IE = 150, 450, 750, 1050, 1350 nT Statistics for different geomagnetic environments

16. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view (dB/dt) Above scales of 80-100 s, dB/dt is essentially white noise both in spatial and temporal sense (substorms and all data)! It may not be possible to predict the behavior of dB/dt (phase and amplitude) deterministically

17. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands The statistical view (dB/dt) The amplitude of dB/dt fluctuations is modulated by the overall geomagnetic activity (seen also in the Oct 2003 example) It may be possible to estimate the likelihood of large dB/dt based on the estimates of the “background” geomagnetic activity

18. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Summary and discussion The complexity of the spatiotemporal variations in the magnetosphere reflected also in the variation of auroral ionospheric currents, as anticipated Due to the stochastic nature of the phenomenon, deterministic forecasting of GIC may not be possible

19. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Summary and discussion Statistical approach for GIC forecasts likely needed Example: Estimate the approximate location and time of intensification of large-scale convection-related ionospheric currents  statistical estimate of GIC levels based on the estimate of the intensity of the currents

20. Nov 17, 2005, ESWW 2005, Noordwijk, The Netherlands Summary and discussion Understanding GIC behavior requires “high resolution” understanding of the solar wind-magnetosphere-ionosphere system