Predicting the maximum amplitude for the sunspot cycle from the rate of rise in sunspot number

Solar Physics ◽  
1988 ◽  
Vol 117 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Robert M. Wilson
Keyword(s):  
Sunspot Number ◽  
Sunspot Cycle ◽  
Maximum Amplitude

Reassessing the Predictions of Sunspot Cycle 24

2018 ◽  
Vol 13 (S340) ◽  
pp. 319-320
Author(s):  
Nipa J. Bhatt ◽  
Rajmal Jain
Keyword(s):  
Sunspot Number ◽  
Data Center ◽  
Activity Index ◽  
Sunspot Cycle ◽  
Prediction Method ◽  
Maximum Amplitude ◽  
Annual Maximum ◽  
Sunspot Minimum ◽  
Cycle 24 ◽  
Geomagnetic Activity Index

AbstractPredictions of sunspot cycle are important due to their space weather effects. Bhattet al.(2009) predicted sunspot cycle 24 (Maximum amplitude: 92.8±19.6; Timing:October 2012±4 months) using relative sunspot number (International Sunspot Number), and average geomagnetic activity indexaaconsidering 2008 as the year of sunspot minimum. Owing to the extended solar minimum till 2009, we re-examine our prediction model. Also, the newly calibrated international sunspot number reduces many discrepancies in the old dataset and is available from Solar Influences Data Center (SIDC) website. Considering 2009 as sunspot minimum year and newly calibrated international sunspot number, (i) The annual maximum amplitude of cycle 24 = 118.5±24.4 (observed = 113.3±0.1), (ii) A smoothed monthly mean sunspot number maximum in January 2014±4 months (observed in February 2014). Our prediction method appears to be a reliable indicator for the predictability of cycle 25.

Cyclic Evolution of Sunspots: Gleaning New Results from Old Data

2000 ◽  
Vol 179 ◽  
pp. 163-165
Author(s):  
S. K. Solanki ◽  
M. Fligge ◽  
P. Pulkkinen ◽  
P. Hoyng
Keyword(s):  
Sunspot Number ◽  
Sunspot Cycle ◽  
Preliminary Results ◽  
Butterfly Diagram

AbstractThe records of sunspot number, sunspot areas and sunspot locations gathered over the centuries by various observatories are reanalysed with the aim of finding as yet undiscovered connections between the different parameters of the sunspot cycle and the butterfly diagram. Preliminary results of such interrelationships are presented.

A Clock in the Sun?

2019 ◽  
Vol 15 (S354) ◽  
pp. 127-133
Author(s):  
C. T. Russell ◽  
J. G. Luhmann ◽  
L. K. Jian
Keyword(s):  
Sunspot Number ◽  
Solar Minimum ◽  
Sunspot Cycle ◽  
Solar Dynamo ◽  
The Sun ◽  
Average Period ◽  
Magnetic Cycle ◽  
Number Cycle ◽  
As If

AbstractThe sunspot cycle is quite variable in duration and amplitude, yet in the long term, it seems to return to solar minimum on schedule, as if guided by a clock with an average period of close to 11.05 years for the sunspot number cycle and 22.1 years for the magnetic cycle. This paper provides a brief review of the sunspot number cycle since 1750, discusses some of the processes controlling the solar dynamo, and provides clues that may add to our understanding of what controls the cadence of the solar clock.

Prediction of the Maximum Amplitude and Timing of Sunspot Cycle 24

Solar Physics ◽  
2009 ◽  
Vol 260 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Nipa J. Bhatt ◽  
Rajmal Jain ◽  
Malini Aggarwal
Keyword(s):  
Sunspot Cycle ◽  
Maximum Amplitude ◽  
Cycle 24

scholarly journals Estimating the maximum of the smoothed highest 3-hourly <i>a</i><i>a</i> index in 3 d by the preceding minimum for the solar cycle

2020 ◽  
Vol 38 (6) ◽  
pp. 1237-1245
Author(s):  
Zhanle Du
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Sunspot Cycle ◽  
Maximum Amplitude ◽  
Maximum Intensity ◽  
Activity Intensity ◽  
Future Space ◽  
Cycle 24 ◽  
Ap Index ◽  
Aa Index

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 (aaH∕aaL) 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 aaH (aaHmax) is well correlated with the preceding minimum of either aaH (aaHmin, r=0.85) or aaL (aaLmin, r=0.89) for the solar cycle. Based on these relationships, the intensity of aaHmax for solar cycle 25 is estimated to be aaHmax(25)=83.7±6.9 (nT), about 29 % stronger than that of solar cycle 24. This value is equivalent to the ap index of apmax(25)=47.4±4.4 (nT) if employing the high correlation between ap and aa (r=0.93). The maximum of aaL (aaLmax) is also well correlated with the preceding aaHmin (r=0.80). The maximum amplitude of the sunspot cycle (Rm) is much better correlated with high geomagnetic activity (aaHmax, r=0.79) than with low geomagnetic activity (aaLmax, r=0.37). The rise time from aaHmin to aaHmax is weakly anti-correlated to the following aaHmax (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.

scholarly journals Predictability of the 12-month Running Averaged Sunspot Number in the Presence of an 8-month Quasi-periodicity on a Solar Cycle

1990 ◽  
Vol 43 (1) ◽  
pp. 107
Author(s):  
PK Pasricha ◽  
S Aggarwal ◽  
BM Reddy ◽  
V Baskakov ◽  
OP Kolomitsev
Keyword(s):  
Solar Cycle ◽  
Sunspot Number ◽  
Statistical Significance ◽  
Sunspot Cycle ◽  
Decay Phase ◽  
Sunspot Data ◽  
One Year

The method of McNish and Lincoln (1949) for the prediction of the 12-month running averaged sunspot number R12 is supposed to generate useful estimates of R12 for periods up to one year ahead. However, it has been noted that for prediction periods beyond about 8 months, the variance of the prediction of R12 (a~12) approaches the variance of the� 'average' solar cycle. Moreover, the variance a~12 for prediction periods greater than about 8 months is also of the order of the variance (a~l) of the observed monthly-mean sunspot data RI. Since the observed sunspot data RI is used to estimate R12, the variance of RI may be used to attach statistical significance to the predictions of R12. Thus, the sunspot number RI2 cannot be usefully predicted more than 8 months ahead, because the variance of the prediction becomes too large (Le. a~12 ~ a~l). However, a quasi-periodicity of about 8 months in RI is observed during the decay phase of solar cycle 21. It is shown in this paper that the variance a~l ought to be doubled in the presence of the 8-month quasi-periodicity of the sunspot cycle. Further, by taking account of this quasi-periodicity, it is possible to make useful predictions of RI2 up to a year (and more) ahead. An application of the RI2 predictions is in forecasting the ionospheric F2 layer critical frequencies a few months ahead.

scholarly journals Multiresolution Analysis of the Relationship of Solar Activity, Global Temperatures, and Global Warming

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Zhen Li ◽  
Jianping Yue ◽  
Yunfei Xiang ◽  
Jian Chen ◽  
Yankai Bian ◽  
...  
Keyword(s):  
Global Warming ◽  
Solar Activity ◽  
Sunspot Number ◽  
Global Climate ◽  
Sunspot Cycle ◽  
Least Square ◽  
Global Temperature ◽  
Causality Test ◽  
Industrial Age ◽  
Lag Effect

Sunspot number is an important parameter for presenting the intensity of solar activity. Based on the sunspot number series, which has been replaced by a new improved version since 2015, we confirm that the sunspot number has significant variations at 11-year and 112-year periods. The sunspot number has also increased from 1700 to 2016 with 0.08 annual increments on the basis of wavelet analysis and least-square fitting. We further confirm that global temperatures are remarkable in 22-year and 64-year cycles. The result of wavelet transform coherence (WTC) analysis suggests that solar activity has a positive lag effect on global temperatures in the period band of 22 years with a 3-year lag. However, the linearly increasing global temperature has hampered WTC analysis since 1960. Aiming to solve this problem, we apply wavelet decomposition and cross correlation to determine whether the aforementioned lag effect in the period band of 22 years has a 2-year lag rather than a 3-year lag. We find that the 22-year magnetic field solar cycle plays a greater role in global climate change than the 11-year sunspot cycle. In addition, we notice that the solar activity is not a representation of the driving force of the upward trend of global temperature after the industrial age. The Granger causality test results demonstrate that the phenomenon of the global warming is caused by excessive CO2 emissions.

scholarly journals Overlapping Magnetic Activity Cycles and the Sunspot Number: Forecasting Sunspot Cycle 25 Amplitude

Solar Physics ◽  
2020 ◽  
Vol 295 (12) ◽  
Author(s):  
Scott W. McIntosh ◽  
Sandra Chapman ◽  
Robert J. Leamon ◽  
Ricky Egeland ◽  
Nicholas W. Watkins
Keyword(s):  
Solar Cycle ◽  
Sunspot Number ◽  
Sunspot Cycle ◽  
Periodic Variation ◽  
Magnetic Activity ◽  
The Sun ◽  
Magnetic Cycle ◽  
Hilbert Transforms ◽  
Observational Astronomy ◽  
Activity Cycles

AbstractThe Sun exhibits a well-observed modulation in the number of spots on its disk over a period of about 11 years. From the dawn of modern observational astronomy, sunspots have presented a challenge to understanding—their quasi-periodic variation in number, first noted 175 years ago, has stimulated community-wide interest to this day. A large number of techniques are able to explain the temporal landmarks, (geometric) shape, and amplitude of sunspot “cycles,” however, forecasting these features accurately in advance remains elusive. Recent observationally-motivated studies have illustrated a relationship between the Sun’s 22-year (Hale) magnetic cycle and the production of the sunspot cycle landmarks and patterns, but not the amplitude of the sunspot cycle. Using (discrete) Hilbert transforms on more than 270 years of (monthly) sunspot numbers we robustly identify the so-called “termination” events that mark the end of the previous 11-yr sunspot cycle, the enhancement/acceleration of the present cycle, and the end of 22-yr magnetic activity cycles. Using these we extract a relationship between the temporal spacing of terminators and the magnitude of sunspot cycles. Given this relationship and our prediction of a terminator event in 2020, we deduce that sunspot Solar Cycle 25 could have a magnitude that rivals the top few since records began. This outcome would be in stark contrast to the community consensus estimate of sunspot Solar Cycle 25 magnitude.

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