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Extreme values of SEP penetration boundaries in the Earths magnetosphere

Extreme values of SEP penetration boundaries in the Earths magnetosphere. Myagkova I.N. (1), Panasyuk M.I. (1), Kudela K. (2), Yushkov B.Yu (1). (1) Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia

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Extreme values of SEP penetration boundaries in the Earths magnetosphere

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  1. Extreme values of SEP penetration boundaries in the Earths magnetosphere Myagkova I.N. (1), Panasyuk M.I. (1), Kudela K. (2), Yushkov B.Yu (1) (1) Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia (2) Institute of Experimental Physics, Slovak Academia of Science, Kosice, Slovakia

  2. Outline Main tasks CORONAS-F and “Tatiana” satellites Experimental data 2001-2006 years Statistical studies Summary

  3. Main tasks Solar protons penetration in the polar caps during the main phase of magnetic storms is one of the important sources of radiation danger in the near-Earth space, especially for low-altitude satellites. Low-altitude polar satellites demonstrate that for the estimation of possible SEP damage both the intensity of energetic solar particles and data concerning the boundaries of solar particle penetration in the Earth's magnetosphere are very important. The size of the energetic particle penetration area depends on proton energy and on geomagnetic conditions. Main goal of presented studies was to find the possibility to estimate the extreme (the most low latitude) solar proton penetration boundary location during the strong magnetic storms using such geomagnetic indexes like Dst and Kp.

  4. SEP penetration boundaries into the Earth’s magnetosphere 27/10/2003 and 29/10/2003  - invariant latitude (L = 1/cos**2 ).

  5. View to Poles 28-30 /10/0301-05/11/03

  6. «CORONAS-F» Complex ORbital Observations in Near-Earth space of the Activity of the Sun • operated from August , 2001 to December 2005 till 12, December, 2005 • circular orbit with altitude in 2005 ~ 500-350 km • inclination ~ 82.5 We used data obtainedby SCR (Solar Cosmic Rays) with the help of three detector types in the following energy ranges • protons 1 - 5 MeV (semiconductor telescope) • protons 50-90 MeV (plastic scintillator + semiconductor detector)

  7. «Universitetskiy-Tatiana » satellite «Universitetskiy-Tatyana» supersmall satellite - Space Scientific and Education projectof the Lomonosov Moscow State Universitywas operatedfrom January 20th, 2005 till March 8th, 2007 circular orbit with altitude ~ 1000 km inclination ~ 83 This satellite is intended for monitoring of radiation conditions near the Earth. In this work we used data about protons with the energies 15-40 and 400-100 MeV, obtained with the help of BD instruments, which consist of semiconductor detector (1000 mkm Si) and scintillation detector (CsJ(Tl) 15×20 mm). Scientific goals of MSU-250 project 1. SEP fluxes dyinamics.2. SEP penetration boundaries variations during magnetic storms 3. Radiation belt dynamics during magnetic storms.

  8. Experimental data 2001-2005 - CORONAS-F The most intensive SEP were measured during Solar Extreme Events periods of 2003 and 2005 years and besides that during August, September and November 2001, April and August 2002, May and July 2003, November 2004, May 2005. Some of these SEP event were accompanied by the powerful geomagnetic storms (e.g. November 6, 2001 (Dst=-292 nT), November 24, 2001 (Dst=-221 nT), October 29-30, 2003 (Dst=-400 nT), November 2004, (Dst =-374 nT)) and during the main phase on these storms energetic solar particles have penetrate extremely deep in the Earth’s magnetosphere. As it isknown that penetration SCR is maximal in evening and night sectors MLT due to weakerintensity of the geomagnetic field from the night side, so we used only the data received in evening and night sector for the estimations of extreme SCR penetration boundaries. Aug-Sep 01 M+X Flares =79 Oct-Dec 01 M+X Flares =135

  9. 2002-2003 - CORONAS-F Jan-Mar 02 M+X Flares=55 Apr-Jun 02 M+X flares=45 Jul-Sep 02 M+X Flares=95 Apr-Jun 03 M+X Flares=70 Oct-Dec 03 M+X Flares=98

  10. 2004-2005 - CORONAS-F Jul-Sep 04 M+X Flares=71 Oct-Dec 04 M+X Flares=34 Jan-Mar 05 M+X Flares=28 Apr-Jun 05 M+X Flares=17

  11. Previous studies

  12. Statistical studies We take into account the strong storms – ones in which the maximum amplitude of a Dst-index exceeded 100 nТ. During operating time CORONAS-F has occurred 48such storms. During 22 ones in experiment on CORONAS-F in polar caps solar protons 1-5 MeV were observed and during 14 - protons with energy of 50-90 MeV. For this data file factors of correlation of values  with Dst have made 0.9 (1-5 MeV) and 0.84 (50-90 MeV) in evening and night sectors of magnetic local time MLT. The obtained R corr  and Kpwere ave made from 0.58-0.64. Application of multiple regression for estimation  on values of both indexes simultaneously (Dst and Kp) has shown that at the moment of a maximum of a Dst-variation the Dst allows to estimate boundaries of penetration  without Kp.

  13. SEP penetration boundaries variations into the Earth’s magnetosphere during the 4-9 of November, 2001 and SEE2004 – “one year after 2003” Boundaries of SEP penetration for 50-90 MeV protons (4-8 November, 2001) for morning and evening MLT sectors and Dst-variations. Boundaries of SEP penetration for 1-5 MeV protons (5-9 November, 2004) for morning and evening MLT sectors and Dst-variations.

  14. Comparing with the previous studies This work

  15. р 40-100 МeV SEP during 2005-2006 years 1. 20 – 26/01/05 2. 05 – 20/ 05/05 3. 16-19 /06/05 4. 13-21 /07/05 5. 26/07– 6/08/05 6. 22/08/– 3/09/05 7. 07-20/05 8. 05 – 17/12/06 р 2-14 МeV

  16. Solar protons 2005, May

  17. CORONAS-F 1-5 MeV«Universitetskiy-Tatyana» p 2-14 and 40-100 MeV - SEP penetration boundaries variations

  18. Solar protons2005, August and September L

  19. 2006, December, Solar Protons (polar caps)

  20. Solar protons 40-100 MeV penetration boundaries

  21. Statistical studies (2)

  22. SUMMARY • Experiments on board CORONAS-F and «Universitetskiy-Tatyana » satellites permits us to to measure SEP penetration boundary variations during strong magnetic storms. • Variations of extreme positions of protons SCR (with the energy 1-100 MeV) penetration boundaries in the Earth’s magnetosphere, measured near the geomagnetic storma maximum in evening and night sectors MLT, are described by of geomagnetic indexes Dst and Kpwith sufficient reliability. • The maximal amplitude of Dst-variation is suffisient for preliminary estimations of extreme position (most low-latitude) SEP penetration boundaries observed duting the strong storms in night-evening MLT sector.

  23. Acknowledgements The authors would liketoacknowledge the other members of CORONAS-F and “Tatiana” teams, Slovak Research and Development Agency (Slovakia, contractAPVV-51-053805) and Russian Fond of Fundamental Researches (grant 08-02-08600-z)

  24. THANK YOU FOR YOUR ATTENTION!

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