caa a22 4500 445346019 CHVBK 20180317142829.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s11207-011-9720-y doi (NATIONALLICENCE)springer-10.1007/s11207-011-9720-y Du Zhanle Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, 100012, Beijing, China aut The Relationship between Prediction Accuracy and Correlation Coefficient [Elektronische Daten] [Zhanle Du] The correlation coefficient (r) between the maximum amplitude (R m) of a sunspot cycle and the preceding minimum aa geomagnetic index (aa min), in terms of geomagnetic cycle, can be fitted by a sinusoidal function with a four-cycle periodicity superimposed on a declining trend. The prediction index (χ) of the prediction error relative to its estimated uncertainty based on a geomagnetic precursor method can be fitted by a sinusoidal function with a four-and-half-cycle periodicity. A revised prediction relationship is found between the two quantities: χ<1.2 if r varies in a rising trend, and χ>1.2 if r varies in a declining trend. The prediction accuracy of R m depends on the long-term variation in the correlation. These results indicate that the prediction for the next cycle inferred from this method, R m(24)=87±23 regarding the 75% level of confidence (1.2-σ), is likely to fail. When using another predictor of sunspot area instead of the geomagnetic index, similar results can be also obtained. Dynamo models will have better predictive powers when having considered the long-term periodicities. Springer Science+Business Media B.V., 2011 Solar activity, sunspots, solar cycle nationallicence Geomagnetic activity, geomagnetic indices nationallicence Prediction nationallicence Solar Physics Springer Netherlands 270/1(2011-05-01), 407-416 0038-0938 270:1<407 2011 270 11207 https://doi.org/10.1007/s11207-011-9720-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9720-y text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Du Zhanle Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, 100012, Beijing, China aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 270/1(2011-05-01), 407-416 0038-0938 270:1<407 2011 270 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer