Solar cycle distribution of great geomagnetic storms
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The distribution properties of great geomagnetic storms (Dst≤−200 nT) and super geomagnetic storms (Dst≤−300 nT) across the solar cycles (19–23) are investigated. The results show that 73.2% of the great geomagnetic storms took place in the descending phase of the solar cycles. 72.7% of super geomagnetic storms occurred in the descending phase of the solar cycles. About 83% of the great geomagnetic storms appeared during the period from the two years before solar cycle peak and the three years after solar cycle peak time. 90.9% of the super geomagnetic storms appeared between the two years before solar cycle peak and the three years after solar cycle peak. When a solar cycle is very strong, the phenomenon that great geomagnetic storms concentrated during the period from the two years before the solar cycle peak time to the three years after the solar cycle peak time is very prominent. The launch time of space science satellite is suggested according to the distribution properties of great geomagnetic storms and super geomagnetic storms in solar cycles.
KeywordsSolar activity Great geomagnetic storms Sun-earth connection
We are very grateful to the unknown referee for his/her reviewing the paper and helpful suggestion. The Dst indices dada used in the paper are obtained from the World Data Center for Geomagnetism, Kyoto (http://wdc.kugi.kyoto-u.ac.jp/dstdir/). The smoothed monthly sunspot numbers are obtained from the Solar Influences Data Analysis Center (http://sidc.oma.be). This work is supported by the National Natural Science Foundation of China (Grant No. 41074132, 40931056), National Basic Research Program of China (973 Program, Grant No. 2011CB811406). National High Technology Research and Development Program of China (Grant No. 2009AA12Z150), National Standard Research Program (Grant No. 10-123).
- Mayaud, P.N.: A hundred year series of geomagnetic data 1868–1967, indices aa, storm sudden commencements. IAGA Bull. 33 Google Scholar
- Tsurutani, B.T., Gonzalez, W.D.: The interplanetary causes of magnetic storms: a review. In: Tsurutani, B.T., et al. (ed.) Magnetic Storms. Geophys. Monogr. Ser., vol. 98, pp. 77–89 (1997). AGU, Washington Google Scholar