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 Agency2. Cosmic Ray Department of IZMIRAN, Russian Academy of Sciences

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

20th ESA Symposium

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.htmhttp://www.skyrocket.de/space/index2.htmhttp://hea-www.harvard.edu/QEDT/jcm/space/jsr/jsr.htmlhttp://www.astronautix.com/index.htm

20th ESA Symposium

~300 satellites~6000 satellite anomalies

20th ESA Symposium

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

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

20th ESA Symposium

Anomaly’s frequency

(all orbits) with statistical errors

27-day averaged frequencies and correspondinghalf year wave

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.

20th ESA Symposium

27-day averaged frequencies and correspondinghalf year wave for different satellite groups

20th ESA Symposium

Solar activity Solar wind Geomagnetic activity Solar protons Electrons Ground Level Cosmic Rays

~30 indices in total

20th ESA Symposium

20th ESA Symposium

27-day running averaged Sunspot Numbers and Solar Radio Flux

We use

SSN and F10.7 – daily Sunspot Numbers and radio fluxes;

SSN27, SSN365 – 1 year and 1 rotation running averaged SSN

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;

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);

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;

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);

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 nT20th ESA Symposium

Averaged behavior Ap, Dst – indices of geomagnetic activity and satellite malfunction frequency near Sudden Storm Commencements

Malfunctions start later and last longer than magnetic storms

20th ESA Symposium

20th ESA Symposium

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

20th ESA Symposium

Mean satellite anomaly frequencies in 0- and 1-days of proton enhancements

in dependence on the maximal > 10 MeV flux

20th ESA Symposium

Probability of any anomaly (high altitude – high inclination group) in dependence on the maximal proton > 10 and >60 MeV flux

20th ESA Symposium

Mean proton and electron fluencies on the anomaly day

20th ESA Symposium

Mean behavior of Ap-index in anomaly periods (GEO satellites)

20th ESA Symposium

Mean behavior of >2 MeV electron fluence in anomaly periods (GEO satellites)

20th ESA Symposium

Mean behavior of solar wind speed in anomaly periods (GEO satellites)

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

3

5

2

5

5

52.1

4

13 Bz105.1Vsw109.1Ap103.8e2104.1f HL

da10sfdpp 4375.0435.04 105.1102)60(106.1)100(101.1

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 MeVCRAApd, AEd, sfVsw, Bzd

high alt.-high incl. cc=0.7

p>100 MeV, p60d Eak, Bznsum, SSN365

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

20th ESA Symposium

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 observations20th ESA Symposium