Abstract
The shadows of the Sun and Moon have been detected in the ID TeV cosmic-ray flux by the Tibet air shower array at an altitude of 4300 m above sea level. The observation covers the period 1990 June-1993 October, which almost coincides with a near-maximum and decreasing phase of the latest solar activity cycle. Using the data obtained in this period, we examined a yearly variation of the Sun's shadow, and found for the first time that the position of the Sun's shadow changed considerably every year with the phase of the solar activity. A different variation of the Sun's shadow was also found between the "away" and "toward" sectors of the interplanetary magnetic field. These results seem to suggest a causal relation between the shadow's movement and the changing inclination of the helio-spheric current sheet of the large-scale magnetic field. Further observation with higher statistics will provide a new clue to obtain direct information on the relation between a time variation of the large-scale structure of the solar and interplanetary magnetic fields and the phase of the solar activity cycle.
| Original language | English |
|---|---|
| Pages (from-to) | 954-958 |
| Number of pages | 5 |
| Journal | Astrophysical Journal |
| Volume | 464 |
| Issue number | 2 PART I |
| Publication status | Published - 1996 |
| Externally published | Yes |
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Keywords
- Cosmic rays
- Interplanetary medium
- Magnetic fields
- Solar wind
- Solar-terrestrial relations
ASJC Scopus subject areas
- Space and Planetary Science
Cite this
Shadowing of cosmic rays by the sun near maximum or at the declining phase of solar activity. / Amenomori, M.; Dai, B. Z.; Ding, L. K.; Feng, Z. Y.; Hibino, K.; Hotta, N.; Huang, Q.; Huo, A. X.; Jia, H. Y.; Kajino, F.; Kasahara, K.; Labaciren; Liu, S. M.; Mei, D. M.; Meng, L.; Meng, X. R.; Mizutani, K.; Mu, J.; Nanjo, H.; Nishizawa, M.; Ohnishi, M.; Ohta, I.; Ouchi, T.; Ren, J. R.; Saito, To; Sakata, M.; Shi, Z. Z.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Taira, K.; Tan, Y. H.; Tateyama, N.; Torii, Shoji; Wang, H.; Yamamoto, Y.; Yu, G. C.; Yuan, P.; Yuda, T.; Zhang, C. S.; Zhang, H. M.; Zhasang; Zhaxiciren; Zhou, W. D.
In: Astrophysical Journal, Vol. 464, No. 2 PART I, 1996, p. 954-958.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Shadowing of cosmic rays by the sun near maximum or at the declining phase of solar activity
AU - Amenomori, M.
AU - Dai, B. Z.
AU - Ding, L. K.
AU - Feng, Z. Y.
AU - Hibino, K.
AU - Hotta, N.
AU - Huang, Q.
AU - Huo, A. X.
AU - Jia, H. Y.
AU - Kajino, F.
AU - Kasahara, K.
AU - Labaciren,
AU - Liu, S. M.
AU - Mei, D. M.
AU - Meng, L.
AU - Meng, X. R.
AU - Mizutani, K.
AU - Mu, J.
AU - Nanjo, H.
AU - Nishizawa, M.
AU - Ohnishi, M.
AU - Ohta, I.
AU - Ouchi, T.
AU - Ren, J. R.
AU - Saito, To
AU - Sakata, M.
AU - Shi, Z. Z.
AU - Shibata, M.
AU - Shiomi, A.
AU - Shirai, T.
AU - Sugimoto, H.
AU - Taira, K.
AU - Tan, Y. H.
AU - Tateyama, N.
AU - Torii, Shoji
AU - Wang, H.
AU - Yamamoto, Y.
AU - Yu, G. C.
AU - Yuan, P.
AU - Yuda, T.
AU - Zhang, C. S.
AU - Zhang, H. M.
AU - Zhasang,
AU - Zhaxiciren,
AU - Zhou, W. D.
PY - 1996
Y1 - 1996
N2 - The shadows of the Sun and Moon have been detected in the ID TeV cosmic-ray flux by the Tibet air shower array at an altitude of 4300 m above sea level. The observation covers the period 1990 June-1993 October, which almost coincides with a near-maximum and decreasing phase of the latest solar activity cycle. Using the data obtained in this period, we examined a yearly variation of the Sun's shadow, and found for the first time that the position of the Sun's shadow changed considerably every year with the phase of the solar activity. A different variation of the Sun's shadow was also found between the "away" and "toward" sectors of the interplanetary magnetic field. These results seem to suggest a causal relation between the shadow's movement and the changing inclination of the helio-spheric current sheet of the large-scale magnetic field. Further observation with higher statistics will provide a new clue to obtain direct information on the relation between a time variation of the large-scale structure of the solar and interplanetary magnetic fields and the phase of the solar activity cycle.
AB - The shadows of the Sun and Moon have been detected in the ID TeV cosmic-ray flux by the Tibet air shower array at an altitude of 4300 m above sea level. The observation covers the period 1990 June-1993 October, which almost coincides with a near-maximum and decreasing phase of the latest solar activity cycle. Using the data obtained in this period, we examined a yearly variation of the Sun's shadow, and found for the first time that the position of the Sun's shadow changed considerably every year with the phase of the solar activity. A different variation of the Sun's shadow was also found between the "away" and "toward" sectors of the interplanetary magnetic field. These results seem to suggest a causal relation between the shadow's movement and the changing inclination of the helio-spheric current sheet of the large-scale magnetic field. Further observation with higher statistics will provide a new clue to obtain direct information on the relation between a time variation of the large-scale structure of the solar and interplanetary magnetic fields and the phase of the solar activity cycle.
KW - Cosmic rays
KW - Interplanetary medium
KW - Magnetic fields
KW - Solar wind
KW - Solar-terrestrial relations
UR - http://www.scopus.com/inward/record.url?scp=21344440927&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=21344440927&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:21344440927
VL - 464
SP - 954
EP - 958
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 PART I
ER -