Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.kosmofizika.ru/open/papers06/lkp.htm
Дата изменения: Thu May 11 11:16:02 2006
Дата индексирования: Tue Oct 2 01:28:45 2012
Кодировка: koi8-r
CREATION AND DESTRUCTION OF THE SOLAR PROTON BELTS IN THE INNER MAGNETOSPHERE DURING MAGNETIC STORMS

CREATION AND DESTRUCTION OF THE SOLAR PROTON BELTS IN THE INNER MAGNETOSPHERE DURING MAGNETIC STORMS

(Abstract, conclusion and some figures)

Lazutin L.L., Kuznetsov S.N., and Podorolsky A.N.


Moscow State University, Scobeltsyn Institute for Nuclear Physics, Space Physics Division Vorob'evy Gory, Moscow 119992, Russia

Last version of the paper in .PDF format     in WORD     this page in Russian

TIME HISTORY:
October 30, 2005 Presented at SEE-2 International Symposium, Erevan. Accepted for publication in SEE-2 proceedings.
January 26, 2006 Rejected by "Annales Geophysique"
February 28, 2006 Presented at Apatity Seminar on the Magnetospheric disturbanced
April 29, 2006 Accepted by "Geomagnetism ans Aeronomie"

Abstract
Along with the stable inner proton belt, temporal variations of the 1-15 MeV protons at L=2.5-3.5 have been reported, with intensity increases and decreases registered during and after strong magnetic storms. As a source of this additional proton population, energetic plasmasheet ions and solar protons were considered.
For the explanation of the origin of the additional proton belt the models of resonant acceleration and radial particle injection were introduced, with strong electric field induced by the compression of the magnetosphere as a driver.

Our study presents experimental evidences that creation and destruction of solar proton belts in the inner magnetosphere may be produced by the fast shifts of the proton penetration boundary without additional acceleration and injection.
Our conclusions are based on the solar protons and ions measurements by low altitude polar orbiter Coronas-F during October - November 2003 magnetic storms events. Several times creation and destruction of solar cosmic ray belts were observed during this interval. Compression of the magnetosphere make possible direct penetration of the solar protons deep into the magnetosphere.
Inside the proton penetration boundary particle trajectories are open and previously trapped particles are free to escape. During magnetosphere reconfiguration when penetration boundary shifts away from the Earth, solar protons and alpha particles with relatively low magnetic drift velocity became stable trapped. Therefore discussed effect differs from the SC induced solar proton injection events by the restricted energy range of the trapped protons.


Fig. 1 Measurements of the double proton boundary by Coronas-F spectrometer, 30/10/03, two consequent crossings in the evening sector of the South hemisphere. PB of 50 MeV protons are shown by black lines, and of 1-5 MeV ones by red color. Intensity in the 50 MeV channel was normalized to the 1-5 MeV flux in polar cap.

Fig. 2. Penetration boundary motion during double-boundary event. Diamonds and red crosses belong to 1-5 and 50-90 MeV outer boundary measured at the intensity level of 0.5 from the polar cap level. Green crosses are positions of the inner boundary.

Fig 3 Traces of the energetic protons in transitory SCR belt 29/10/03

Fig.4-6 Ezamples of the 1-5 MeV proton belts registered over Brasil Magnetic Anomaly. Two solar 1-5 MeV solar proton belts created after the main phase of the 30-31/10/05 extreme storm as seen during several Coronas-F flights over BMA in the morning on 31/10/03. Black line shows the 50-90 MeV proton profiles. Three solar proton belts after November 4 magnetic storm and only one survived after November 21 magnetic storm.

Fig.7 SCR belts maximum intensity versus time, vertical broken lines indicate start of the superstorm at 29.10 and the end of the main phase at 31/10, the end of 04.11 magnetic storm and the beginning of the 20/11/03 superstorm.

Fig 8 SPS maximum intensity versus position L, the signs are the same as in fig. 7

Fig. 9 Reconstruction of the main inner proton belt (0) and three solar proton belts (1-3) from the Coronas-F measurements of 17/11/03. (4) - current position penetration boundary. Fig. 10 SCR 1-5 MeV belt intensity versus time. L=2.05 before and 1.95 after November 20, 2003 magnetic storm

4. CONCLUSIONS

Solar proton trapping into the inner magnetosphere (L=2-4) have been observed previously during several magnetic bays. Accepted explanations were based on resonant particle radial injection during SC. SC-type injection was registered by CRRES satellite particle detectors, receive theoretical explanation and reproduced by computer modeling.
This mechanism demand large amplitude of the SC impulse for deep injection into the inner magnetosphere and is restricted for the solar protons with energies >15 MeV.
SCR belt created by SC injection might be destroyed during the main phase by inward motion of the SCR penetration boundary as described in present paper.

In a present paper we propose new type of SCR trpping into the inner magnetosphere supported by the analysis of the experimental data. The trapping of solar protons (ions) which penetrate into the inner magnetosphere during the main phase occurs as a result of the transition from the open to the closed drift paths during the recovery of the magnetosphere configuration without additional acceleration and injection.
Injection effect was recorded, but it did not play the major role.
Considered mechanism works effectively only if the impulsive recovery of the magnetosphere configuration was rather fast as compared with the particle magnetic drift period. It imply restriction on the energy of the protons and alpha particles. Particles with the energy larger than 5-15 MeV/nuclon might be trapped only in a rare occasions.
Following foundings might be listed:

1. Solar protons with energy 1 MeV and higher after earthward shift of the penetration boundary might be trapped during the boundary retreat, creating solar cosmic ray belt on L= 2 - 4.

2. In some cases 2 or even 3 SCB can be created.

3. In new SCB stable trapping condition became established quickly. The flux of precipitation protons decrease exponentially as N=No exp(-kt) , where t= 1.15 hours.

4. After the storms, position and intensity of the SCB might remains constant as long as 20 days.

5. SCB can be destroyed by the new strong enough magnetic storm.

6. During magnetic storm SCB may be shifted earthward for 0.1 - 0.2 L.

7. Energy spectrum of the protons in SCB decreases steeply from 4-10 MeV. Protons and alpha particles with E > 4 лЩб were recorded only occasionally and with small intensity. The efficiency of the trapping decreases with the energy as P ~ E-2