Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2019GL086524 |
Using the aa Index Over the Last 14 Solar Cycles to Characterize Extreme Geomagnetic Activity | |
Chapman, S. C.1; Horne, R. B.2; Watkins, N. W.1,3,4 | |
2020-02-16 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS |
ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2020 |
卷号 | 47期号:3 |
文章类型 | Article |
语种 | 英语 |
国家 | England |
英文摘要 | Geomagnetic indices are routinely used to characterize space weather event intensity. The D-ST index is well resolved but is only available over five solar cycles. The aa index extends over 14 cycles but is highly discretized with poorly resolved extremes. We parameterize extreme aa activity by the annual-averaged top few percent of observed values, show that these are exponentially distributed, and they track annual DST index minima. This gives a 14-cycle average of similar to 4% chance of at least one great (D-ST < -500 nT) storm and similar to 28% chance of at least one severe (D-ST < -250 nT) storm per year. At least one D-ST = -809 [-663,-955] nT event in a given year would be a 1:151 year event. Carrington event estimate D-ST similar to -850 nT is within the same distribution as other extreme activity seen in aa since 1868 so that its likelihood can be deduced from that of more moderate events. Events with D-ST < -1, 000 nT are in a distinct class, requiring special conditions. Plain Language Summary Here we use measurements of disturbances in the Earth's magnetic field that go back to 1868, and we present a novel way of analyzing the data to identify the largest magnetic storms going back some 80 years longer than has been done before. As a result, we are able to state the chance of at least one superstorm occurring in a year. We find that on average there is a 4% (28%) chance of at least one great (severe) storm per year and a 0.7% chance of a Carrington class storm per year, which can be used for planning the level of mitigation needed to protect critical national infrastructure. |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000529107400067 |
WOS关键词 | SPACE WEATHER ; MAGNETIC STORM ; STATISTICS ; SUPERSTORM ; INTENSITY ; PARAMETER ; IMPACT ; EVENT |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/279582 |
专题 | 气候变化 |
作者单位 | 1.Univ Warwick, Ctr Fus Space & Astrophys, Phys Dept, Coventry, W Midlands, England; 2.British Antarctic Survey, Cambridge, England; 3.London Sch Econ & Polit Sci, Ctr Anal Time Series, London, England; 4.Open Univ, Fac Sci Technol Engn & Math, Milton Keynes, Bucks, England |
推荐引用方式 GB/T 7714 | Chapman, S. C.,Horne, R. B.,Watkins, N. W.. Using the aa Index Over the Last 14 Solar Cycles to Characterize Extreme Geomagnetic Activity[J]. GEOPHYSICAL RESEARCH LETTERS,2020,47(3). |
APA | Chapman, S. C.,Horne, R. B.,&Watkins, N. W..(2020).Using the aa Index Over the Last 14 Solar Cycles to Characterize Extreme Geomagnetic Activity.GEOPHYSICAL RESEARCH LETTERS,47(3). |
MLA | Chapman, S. C.,et al."Using the aa Index Over the Last 14 Solar Cycles to Characterize Extreme Geomagnetic Activity".GEOPHYSICAL RESEARCH LETTERS 47.3(2020). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论