KMS National Astronomical Observatories, CAS
| Estimating the maximum of the smoothed highest 3-hourly aa index in 3 d by the preceding minimum for the solar cycle | |
| Du, Zhanle1,2 | |
| 2020-12-15 | |
| Source Publication | ANNALES GEOPHYSICAE
 |
| ISSN | 0992-7689 |
| Volume | 38Issue:6Pages:1237-1245 |
| Abstract | Predicting the maximum intensity of geomagnetic activity for an upcoming solar cycle is important in space weather service and for planning future space missions. This study analyzed the highest and lowest 3-hourly aa index (aa(H)/aa(L)) in a 3 d interval, smoothed by 363 d to analyze their variation with the 11-year solar cycle. It is found that the maximum of aa(H) (aaHmax) is well correlated with the preceding minimum of either aa(H) (aa(Hmin), r = 0.85) or aa(L) (aa(Lmin), r = 0.89) for the solar cycle. Based on these relationships, the intensity of aa(Hmax) for solar cycle 25 is estimated to be aa(Hmax)(25) = 83.7 +/- 6.9 (nT), about 29 % stronger than that of solar cycle 24. This value is equivalent to the ap index of ap(max)(25) = 47.4 +/- 4.4 (nT) if employing the high correlation between ap and aa (r = 0.93). The maximum of aa(L) (aa(Lmax)) is also well correlated with the preceding aa(Hmin) (r = 0.80). The maximum amplitude of the sunspot cycle (R-m) is much better correlated with high geomagnetic activity (aa(Hmax), r = 0.79) than with low geomagnetic activity (aa(Lmax), r = 0.37). The rise time from aaHmin to aa(Hmax) is weakly anti-correlated to the following aa(Hmax) (r = -0.42). Similar correlations are also found for the 13-month smoothed monthly mean aa index. These results are expected to be useful in understanding the geomagnetic activity intensity of solar cycle 25. |
| Funding Organization | National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) |
| DOI | 10.5194/angeo-38-1237-2020 |
| WOS Keyword | LONG-TERM VARIATIONS ; GEOMAGNETIC-ACTIVITY ; MAGNETIC-FIELD ; SUNSPOT NUMBER ; PRECURSOR ; VARIABILITY ; AMPLITUDE ; CLIMATE ; SHAPE |
| Language | 英语 |
| Funding Project | National Science Foundation of China (NSFC)[1973058] ; National Science Foundation of China (NSFC)[11603040] |
| Funding Organization | National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) ; National Science Foundation of China (NSFC) |
| WOS Research Area | Astronomy & Astrophysics ; Geology ; Meteorology & Atmospheric Sciences |
| WOS Subject | Astronomy & Astrophysics ; Geosciences, Multidisciplinary ; Meteorology & Atmospheric Sciences |
| WOS ID | WOS:000600068600001 |
| Publisher | COPERNICUS GESELLSCHAFT MBH |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.bao.ac.cn/handle/114a11/80278 |
| Collection | 中国科学院国家天文台 |
| Corresponding Author | Du, Zhanle |
| Affiliation | 1.Chinese Acad Sci, Natl Astron Observ, Key Lab Solar Act, Beijing 100101, Peoples R China 2.Univ Chinese Acad Sci, Beijing, Peoples R China |
| Recommended Citation GB/T 7714 | Du, Zhanle. Estimating the maximum of the smoothed highest 3-hourly aa index in 3 d by the preceding minimum for the solar cycle[J]. ANNALES GEOPHYSICAE,2020,38(6):1237-1245. |
| APA | Du, Zhanle.(2020).Estimating the maximum of the smoothed highest 3-hourly aa index in 3 d by the preceding minimum for the solar cycle.ANNALES GEOPHYSICAE,38(6),1237-1245. |
| MLA | Du, Zhanle."Estimating the maximum of the smoothed highest 3-hourly aa index in 3 d by the preceding minimum for the solar cycle".ANNALES GEOPHYSICAE 38.6(2020):1237-1245. |
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