1. 20th ESA Symposium Lev Dorman (1, 2) for the Team (A. Belov, I. Ben Israel, U. Dai, L. Dorman,, E. Eroshenko, N. Iucci, Z. Kaplan, O. Kryakunova, A. Levitin, M. Parisi, N. Ptitsyna, L. Pustil’nik, A. Sternlieb, M. Tyasto, E. Vernova, G. Villoresi, V. Yanke, I. Zukerman) 1. Israel Cosmic Ray and Space Weather Center, affiliated to Tel Aviv University, Golan Research Institute, and Israel Space Agency 2. Cosmic Ray Department of IZMIRAN, Russian Academy of Sciences

2. Results of the Project, which aims to improve the methods of safeguarding satellites in the Earth’s magnetosphere from the negative effects of the space environment, are presented. Anomaly data from the “Kosmos” series satellites in the period 1971–1999 are combined in one database, together with similar information on other spacecrafts. This database contains, beyond the anomaly information, various characteristics of the space weather: geomagnetic activity indices (Ap, AE and Dst), fluxes and fluencies of electrons and protons at different energies, high energy cosmic ray variations and other solar, interplanetary and solar wind data. A comparative analysis of the distribution of each of these parameters relative to satellite anomalies was carried out for the total number of anomalies (about 6000 events), and separately for high (5000 events) and low (about 800 events) altitude orbit satellites. No relation was found between low and high altitude satellite anomalies. Daily numbers of satellite anomalies, averaged by a superposed epoch method around sudden storm commencements and proton event onsets for high (>1500 km) and low (<1500 km) altitude orbits revealed a big difference in a behavior. Satellites were divided on several groups according to the orbital characteristics (altitude and inclination). The relation of satellite anomalies to the environmental parameters was found to be different for various orbits that should be taken into account under developing of the anomaly frequency models. 20th ESA Symposium

3. The main contribution was from NGDC satellite anomaly database, created by J. Allen and D. Wilkinson. + “Kosmos” data (circular orbit at 800 km altitude and 74º inclination) + 1994 year anomalies - Walter Thomas report (Thomas, 1995). + The satellites characteristics - from different Internet sources: http://spacescience.nasa.gov/missions/index.htm http://www.skyrocket.de/space/index2.htm http://hea-www.harvard.edu/QEDT/jcm/space/jsr/jsr.html http://www.astronautix.com/index.htm

4. 20th ESA Symposium ~300 satellites ~6000 satellite anomalies

5. 20th ESA Symposium

6. Upper panel – cosmic ray activity near the Earth: variations of 10 GV cosmic ray density; solar proton (> 10 MeV and >60 MeV) fluxes. Lower panel – geomagnetic activity: Kp- and Dst- indices. Vertical arrows on the upper panel correspond to the malfunction moments. 20th ESA Symposium

7.  Upper panel – cosmic ray activity near the Earth: variations of 10 GV cosmic ray density; electron (> 2 MeV) fluxes – hourly data.  Vertical arrows correspond to the malfunction moments. Lower row – all malfunctions.  Lower panel – geomagnetic activity: Kp- and Dst-indices. 20th ESA Symposium

8. Anomaly’s frequency (all orbits) with statistical errors 27-day averaged frequencies and corresponding half year wave

9. 20th ESA Symposium Satellite anomalies frequency and Ap-index averaged over the period 1975-1994. The curve with points is the 27-day running mean values; the grey band corresponds to the 95 % confidence interval. The sinusoidal curve is a semiannual wave with maxima in equinoxes best fitting the frequency data.

10. 20th ESA Symposium 27-day averaged frequencies and corresponding half year wave for different satellite groups

11. 20th ESA Symposium

12.  Solar activity  Solar wind  Geomagnetic activity  Solar protons  Electrons  Ground Level Cosmic Rays ~30 indices in total 20th ESA Symposium

13. 27-day running averaged Sunspot Numbers and Solar Radio Flux We use SSN and F 10.7 – daily Sunspot Numbers and radio fluxes; SSN 27, SSN 365 – 1 year and 1 rotation running averaged SSN

14. 20th ESA Symposium Daily Ap-index and minimal (for this day) Dst-index We use Apd, Apmax – daily and maximal Ap-index; AEd, AEmax – daily and maximal AE-index; DSTd, DSTmin – daily and minimal Dst-index;

15. 20th ESA Symposium Daily proton and electron fluencies We use p10, p100 – daily proton (>10, >100 MeV) fluencies (GOES); p10d, p60d – daily proton (>10, >60 MeV) fluxes (IMP); p10max, p60max – maximal hourly proton (>10, >60 MeV) fluxes (IMP); e2 – daily electron (>2 MeV) fluence (GOES); e2d, e2max – daily and maximal electron (>2 MeV) fluх (GOES);

16. 20th ESA Symposium Daily solar wind speed and intensity of interplanetary magnetic field We use Vsw, Vmax – daily and maximal solar wind speed; Bm – daily IMF intensity; Bzd, Bzmin – daily and minimal z-component IMF (GSM); Bznsum – sum of negative z-component values;

17. 20th ESA Symposium Daily CRA-indices and sum of negative IMF z-component We use da10, CRA – indices of cosmic ray activity, obtained from ground level CR observations (Belov et al., 1999); Eakd, Eakmax – estimation of daily and maximal energy, transferred from solar wind to magnetosphere (Akasofu, 1987);

18.  Averaged behavior of satellite anomalies frequency near Sudden Storm Commencements  634 days with SSC in total  a – all storms  b – storms with Ap>50 nT  c – storms with Ap>80 nT 20th ESA Symposium

19.  Averaged behavior Ap, Dst – indices of geomagnetic activity and satellite malfunction frequency near Sudden Storm Commencements  Malfunctions start later and last lon ger than m agnetic storms 20th ESA Symposium

20. Averaged behavior of p>10, p>100 MeV and satellite malfunction frequency during proton event periods. The enhancement with >300 pfu were used

21. 20th ESA Symposium Mean satellite anomaly frequencies in 0- and 1-days of proton enhancements in dependence on the maximal > 10 MeV flux

22. 20th ESA Symposium Probability of any anomaly ( high altitude – high inclination group) in dependence on the maximal proton > 10 and >60 MeV flux

23. 20th ESA Symposium Mean proton and electron fluencies on the anomaly day

24. 20th ESA Symposium Mean behavior of Ap-index in anomaly periods (GEO satellites)

25. 20th ESA Symposium Mean behavior of >2 MeV electron fluence in anomaly periods (GEO satellites)

26. 20th ESA Symposium Mean behavior of solar wind speed in anomaly periods (GEO satellites)

27. 20th ESA Symposium Example of frequency model (GEO): We checked ~ 30 different Space Weather parameters and a lot of their combinations We used the parameters for anomaly day and for several preceding days Only simplest linear regression models were checked (exclusions for e and p indices) Obtained models contain 3-8 different geo- heliophysical parameters The models appear to be different for different satellite groups

28. high alt.- low incl. cc=0.39  e>2 MeV  Apd, AEd, sf  p60d, p100 Vsw  Bzd, da10 20th ESA Symposium low alt.-high incl. cc=0.2 e>2 MeV CRA Apd, AEd, sf Vsw, Bzd high alt.-high incl. cc=0.7 p>100 MeV, p60d Eak, Bznsum, SSN365

29.  1. AUTOMATICALLY DETERMINATION OF THE SEP EVENT START BY NEUTRON MONITOR DATA  2. DETERMINATION OF ENERGY SPECTRUM OUT OF MAGNETOSPHERE BY THE METHOD OF COUPLING FUNCTIONS  3. DETERMINATION OF TIME OF EJECTION, SOURCE FUNCTION AND PARAMETERS OF PROPAGATION BY SOLVING AN INVERSE PROBLEM  4. FORECASTING OF EXPECTED SEP FLUXES AND COMPARISON WITH OBSERVATIONS; CORRECTION OF THE INVERSE PROBLEM SOLUTION  5. COMBINED FORECASTING ON THE BASIS OF NEUTRON MONITOR AND SATELLITE DATA 20th ESA Symposium

31.  The relation between Space Weather parameters and frequency of satellite anomalies are different for different satellite groups (orbits)  The models simulated anomaly frequency in different orbits are developed and could be adjusted for forecasting (mainly energetic particles and magnetic activity)  The models for forecasting of energetic particle events and magnetic activity can be developed in near future on the basis of ground and satellite observations 20th ESA Symposium