(1) Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia(2) Institute of Experimental Physics, Slovak Academia of Science, Kosice, Slovakia

1.1. MMain tasksain tasks

2.2. CORONAS-F and “Tatiana” satellitesCORONAS-F and “Tatiana” satellites

3.3. Experimental data 2001-2006 yearsExperimental data 2001-2006 years

4.4. Statistical studiesStatistical studies

5.5. SummarySummary

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.

SEP penetration boundaries into the Earth’s SEP penetration boundaries into the Earth’s magnetosphere 27/10/2003 and 29/10/2003magnetosphere 27/10/2003 and 29/10/2003

- invariant latitude (L = 1/cos**2 ).

- invariant latitude (L = 1/cos**2 ).

View to Poles

28-30 /10/03

01-05/11/03

CComplex omplex ORORbital bital OObservations in bservations in NNear-Earth ear-Earth space of the space of the AActivity of the ctivity of the SSunun

• operated from August , 2001 to December 2005 till 12, December, 2005

• circular orbit with altitude in 2005 ~ 500-350 km~ 500-350 km

• inclination ~ 82.5~ 82.5We used data obtained by 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)

«Universitetskiy-Tatyana» supersmall satellite - Space Scientific and Education project of the Lomonosov Moscow State University was operated from

January 20th, 2005 till March 8th, 2007

circular orbit with altitude ~ 1000 km inclination ~ 83This 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.

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.

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 is known that penetration SCR is maximal in evening and night sectors MLT due to weaker intensity 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.

Oct-Dec 01 Oct-Dec 01

M+X Flares =135M+X Flares =135

Oct-Dec 01 Oct-Dec 01

M+X Flares =135M+X Flares =135

Aug-Sep 01

M+X Flares =79M+X Flares =79

Aug-Sep 01

M+X Flares =79M+X Flares =79

Jan-Mar 02Jan-Mar 02M+X Flares=55M+X Flares=55

Jan-Mar 02Jan-Mar 02M+X Flares=55M+X Flares=55

Apr-Jun 02Apr-Jun 02

M+X flares=45M+X flares=45

Apr-Jun 02Apr-Jun 02

M+X flares=45M+X flares=45

Jul-Sep 02Jul-Sep 02 M+X Flares=95M+X Flares=95

Jul-Sep 02Jul-Sep 02 M+X Flares=95M+X Flares=95

Apr-Jun 03Apr-Jun 03 M+X Flares=70M+X Flares=70

Apr-Jun 03Apr-Jun 03 M+X Flares=70M+X Flares=70

Oct-Dec 03Oct-Dec 03M+X Flares=98M+X Flares=98

Oct-Dec 03Oct-Dec 03M+X Flares=98M+X Flares=98

Jul-Sep 04Jul-Sep 04M+X Flares=71M+X Flares=71

Jul-Sep 04Jul-Sep 04M+X Flares=71M+X Flares=71

Oct-Dec 04Oct-Dec 04 M+X Flares=34M+X Flares=34

Oct-Dec 04Oct-Dec 04 M+X Flares=34M+X Flares=34

Jan-Mar 05Jan-Mar 05M+X Flares=28M+X Flares=28

Jan-Mar 05Jan-Mar 05M+X Flares=28M+X Flares=28

Apr-Jun 05Apr-Jun 05M+X Flares=17M+X Flares=17

Apr-Jun 05Apr-Jun 05M+X Flares=17M+X Flares=17

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 48 such 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 Kp were 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.

Boundaries of SEP Boundaries of SEP penetration for 50-90 penetration for 50-90 MeV protons (4-8 MeV protons (4-8 November, 2001) for November, 2001) for morning and evening morning and evening MLT sectors and Dst-MLT sectors and Dst-variations.variations.

SEP penetration boundaries variations into the Earth’s magnetosphere SEP penetration boundaries variations into the Earth’s magnetosphere during the 4-9 of November, 2001 and SEE2004 – “one year after 2003” during the 4-9 of November, 2001 and SEE2004 – “one year after 2003”

Boundaries of SEP Boundaries of SEP penetration for 1-5 MeV penetration for 1-5 MeV protons (5-9 November, protons (5-9 November, 2004) for morning and 2004) for morning and evening MLT sectors and evening MLT sectors and Dst-variations.Dst-variations.

SEP during 2005-2006 yearsSEP during 2005-2006 years

1. 20 – 26/01/05 2. 05 – 20/ 05/05

3. 16-19 /06/05 4. 13-21 /07/055. 26/07– 6/08/056. 22/08/– 3/09/05 7. 07-20/05

8. 05 – 17/12/06

р 40-100 МeV

р 2-14 МeV

Solar protons Solar protons 2005, May2005, May

4 6 8 10 12 14 16 18 20D ay of M ay, 2005

1E-2

1E-1

1E+0

1E+1

1E+2

1E+3

1E+4

1E+5

Sol

ar p

roto

n flu

x,1/

(sm

**2-

s-sr

)

Tatiana 40-100 MeV

Tatiana 7-16 M eV

C O R O N AS-F 1-5 M eVAC E 1.91-4.75 M eV

G O ES > 30 M eV

Tatiana 2-14 M eV

C O R O NAS-F 50-90 M eV

CORONAS-F CORONAS-F 1-5 MeV1-5 MeV

«Universitetskiy«Universitetskiy--TatyanaTatyana»» p 2-14 p 2-14 and and 40-100 MeV40-100 MeV - SEP penetration - SEP penetration

boundaries boundaries variationsvariations

6 8 10 12 14 16 18 20D ay of M ay, 2005

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

Dst

, nT

2

3

4

5

6

7

8

L

p 2-14 (open - morninig MLT 3-6 h, closed evening 15-17 h)p 40-100 (open - morninig MLT 3-6 h, closed evening 15-17 h)CORONAS-F p 1-5 (closed - night 1:30-4:00 h)

Solar Solar protonsprotons 20052005, August and , August and SeptemberSeptember

-250

-200

-150

-100

-50

0

50

100

23.08.2005 0:00 23.08.2005 12:00 24.08.2005 0:00 24.08.2005 12:00 25.08.2005 0:00 25.08.2005 12:00 26.08.2005 0:00

Дата

Ин

де

кс

Ds

t

2,5

3

3,5

4

4,5

5

5,5

6

6,5

7

L

DST p 40-100 МэВ MLT = 15.00-3.00 p 2-14 МэВ MLT = 15.00-3.00 p 40-100 МэВ MLT = 3.00-15.00 p 2-14 МэВ MLT = 3.00-15.00

2006, December, Solar Protons (polar caps)

Solar protons 40-100 MeV penetration boundaries

• 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 storm a maximum in evening and night sectors MLT, are described by of geomagnetic indexes Dst and Kp with 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.

The authors would like to acknowledge the other members of CORONAS-F and “Tatiana” teams, Slovak Research and Development Agency (Slovakia, contract APVV-51-053805) and Russian Fond of Fundamental Researches (grant 08-02-08600-z)