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Solar and Interplanetary Sources of Geomagnetic disturbances Yu.I. Yermolaev, N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev Space Research Institute.

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Presentation on theme: "Solar and Interplanetary Sources of Geomagnetic disturbances Yu.I. Yermolaev, N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev Space Research Institute."— Presentation transcript:

1 Solar and Interplanetary Sources of Geomagnetic disturbances Yu.I. Yermolaev, N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev Space Research Institute (IKI - ), RAS, Moscow, Russia Several results have been published and may be found in Space Weather Effects on Humans:in Space and on Earth International Conference IKI, Moscow, June 4-8, 2012

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3 History After Richard Carrington’s observation of strong solar flare on 1 September 1859 and strong magnetic storm in 18 hours after flare there was point of view that solar flares are sources of magnetic storms. Modern observations showed that after most part of flares there is no magnetic storms and many storms are observed without any solar activity.

4 Solar flares and magnetic storms during

5 Main reason of magnetospheric disturbances is negative (southward) component of Interplanetary Magnetic Field (IMF Bz < 0) Non-disturbed solar wind contains IMF which lies in ecliptic plane => Bz =0 ! Only disturbed types of solar wind may be geoeffective.

6 Large-scale types of solar wind (From Yermolaev, Cos.Res.,1990; Planet. Space Sci., 1991)

7 General concept of storm effectiveness of solar and interplanetary events Fast stream Slow stream

8 Aims of research Occurrence rate of different types of solar wind Geoeffectiveness (number of selected type of solar wind resulted in magnetic storm with Dst < - 50 nT divided by total number of this type) Efficiency (with `output/input` criteria) in generation of magnetic storms by different types of solar wind

9 Example of OMNI data and calculated parameters in our database ftp://ftp.iki.rssi.ru/pub/omni (  left) and identification of solar wind types ftp://ftp.iki.rssi.ru/pub/omni/catalog/ (  bottom) ftp://ftp.iki.rssi.ru/pub/omni

10 Yearly number of different types of large-scale solar wind phenomena Heliospheric current sheet HCS ~ 124±81per year (maximum near solar minimum) Corotating interaction region CIR ~ 63±15 (at decrease of cycle) Interplanetary СМЕ or Ejecta ~ 99±38 (at increase and decrease of cycle) Magnetic cloud МС ~ 8±7 (at decrease of cycle) Sheath before Ejecta and МС are observed at half of Ejecta и МС (near maximum of cycle)

11 Durations of different types of large-scale solar wind phenomena ~ 29±5 h for IСМЕ (Ejecta), ~ 24±11 for magnetic cloud МС, ~ 20±4 for CIR, ~16±3 for Sheath before ICME (Ejecta), ~ 9±5 for Sheath before MC, ~5±2 for HCS.

12 Distribution of different types of solar wind during

13 Distribution of interplanetary sources of magnetic storms

14 Distribution of interplanetary sources of magnetic storms (taking data gaps into account)

15 Distribution of interplanetary sources of magnetic storms

16 Geoeffectiveness of different types of large-scale solar wind phenomena Geoeffectiveness solar wind phenomena

17 Duration of main phases of magnetic storms and double superposed epoch method

18 Behavior of parameters obtained by double superposed epoch method

19 Variations of parameters obtained by double superposed epoch method

20 Behavior of solar wind parameters in various types of streams during magnetic storms with Dst ≤ –50 nT

21 Connection of magnetospheric indexes with Bz component of IMF

22 Connection of magnetospheric indexes with Ey component of electric field

23 Efficiency of various types of solar wind streams

24 Number of events N, geoeffectiveness (probability) P and efficiency Ef=Dst/Ey

25 Conclusions On the basis of our «Catalog of large-scale solar wind phenomena during » (see data on site ftp://ftp.iki.rssi.ru/omni/ and paper by Yermolaev et al., Cosmicftp://ftp.iki.rssi.ru/omni/ Research, 2009, №2) we obtained: 1. Occurrence rate of different types of solar wind:  average number: 124±81 events per year for HCS, 8±6 for МС, 99±38 for Ejecta, 46±19 for Sheath before Ejecta, 6±5 for Sheath before МС, и 63±15 for CIR;  duration of events: ~ 29±5h for Ejecta, ~ 24±11 for МС, ~ 20±4 for CIR, ~16±3 for Sheath before Ejecta, ~ 9±5 for Sheath before MC, ~5±2 for HCS;  Time distribution: steadt types of solar wind (FAST+ SLOW + HCS) 60%, CIR 10%, MC 2%, EJECTA 20%, Sheath 9%. 2. Geoeffectiveness of events: for MC, for Ejecta, for CIR, for MC with Sheath, for MC without Sheath, for Ejecta with Sheath, 0.08 for Ejecta without Sheath. These results are published in Cosmic Research. 2009, № 5 and 2010, № 1

26 Conclusions(2) 3. Efficiency Dependencies of Dst (or Dst*) on the integral of Bz (or Ey) over time are almost linear and parallel for different types of drivers (time evolution of main phase of storms depends not only on current values of Bz and Ey but also on their prehistory). We estimated efficiency of storm generation as “output/input”= Dst/integated Ey(Bz) ratio. Efficiency of storm generation by MC is the lowest one (i.e. at equal values of integrated Bz or Ey the storm is smaller than for another drivers) and Efficiency for Sheath is the highest one. Several results have been published in Ann.Geophys and Journal Geophys. Res., 2012 may be found in


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