scholarly journals The long sunspot cycle 23 predicts a significant temperature decrease in cycle 24

2012 ◽  
Vol 80 ◽  
pp. 267-284 ◽  
Author(s):  
Jan-Erik Solheim ◽  
Kjell Stordahl ◽  
Ole Humlum
Keyword(s):  
Sunspot Cycle ◽  
Temperature Decrease ◽  
Significant Temperature ◽  
Cycle 24

Cosmic Ray 11-Year Modulation for Sunspot Cycle 24

Solar Physics ◽  
2014 ◽  
Vol 290 (2) ◽  
pp. 635-643 ◽  
Author(s):  
H. S. Ahluwalia ◽  
R. C. Ygbuhay
Keyword(s):  
Sunspot Cycle ◽  
Cosmic Ray ◽  
Cycle 24

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

Current Forecast for Sunspot Cycle 24 Parameters

2010 ◽  
Author(s):  
H. S. Ahluwalia ◽  
R. C. Ygbuhay ◽  
M. Maksimovic ◽  
K. Issautier ◽  
N. Meyer-Vernet ◽  
...  
Keyword(s):  
Sunspot Cycle ◽  
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 A Novel Bimodal Forecasting Model for Solar Cycle 25

2022 ◽  
Vol 924 (2) ◽  
pp. 59
Author(s):  
J. Y. Lu ◽  
Y. T. Xiong ◽  
K. Zhao ◽  
M. Wang ◽  
J. Y. Li ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Goodness Of Fit ◽  
Moving Average ◽  
Sunspot Cycle ◽  
Missing Information ◽  
Geometric Information ◽  
Precursor Method ◽  
Peak Structure ◽  
Cycle 24 ◽  
Precursor Information

Abstract In this paper, a novel bimodal model to predict a complete sunspot cycle based on comprehensive precursor information is proposed. We compare the traditional 13 month moving average with the Gaussian filter and find that the latter has less missing information and can better describe the overall trend of the raw data. Unlike the previous models that usually only use one precursor, here we combine the implicit and geometric information of the solar cycle (peak and skewness of the previous cycle and start value of the predicted cycle) with the traditional precursor method based on the geomagnetic index and adopt a multivariate linear approach with a higher goodness of fit (>0.85) in the fitting. Verifications for cycles 22–24 demonstrate that the model has good performance in predicting the peak and peak occurrence time. It also successfully predicts the complete bimodal structure for cycle 22 and cycle 24, showing a certain ability to predict whether the next solar cycle is unimodal or bimodal. It shows that cycle 25 is a single-peak structure and that the peak will come in 2024 October with a peak of 145.3.

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.

scholarly journals Sunspot numbers: Implications on Eastern African rainfall

2014 ◽  
Vol 110 (1/2) ◽  
pp. 1-5 ◽  
Author(s):  
Francis Gachari ◽  
David M. Mulati ◽  
Joseph N. Mutuku
Keyword(s):  
Sunspot Cycle ◽  
Total Rainfall ◽  
Sunspot Numbers ◽  
Predictive Skill ◽  
Solar Declination ◽  
Monthly Total ◽  
Current Maximum ◽  
Cycle 24 ◽  
Sahel Region ◽  
Greater Horn Of Africa

Following NASA’s prediction of sunspot numbers for the current sunspot cycle, Cycle 24, we now include sunspot numbers as an explanatory variable in a statistical model. This model is based on fitting monthly rainfall values with factors and covariates obtained from solar–lunar geometry values and sunspot numbers. The model demonstrates high predictive skill in estimating monthly values by achieving a correlation coefficient of 0.9 between model estimates and the measurements. Estimates for monthly total rainfall for the period from 1901 to 2020 for Kenya indicate that the model can be used not only to estimate historical values of rainfall, but also to predict monthly total rainfall. We have found that the 11-year solar sunspot cycle has an influence on the frequency and timing of extreme hydrology events in Kenya, with these events occurring every 5±2 years after the turning points of sunspot cycles. While solar declination is the major driver of monthly variability, sunspots and the lunar declinations play a role in the annual variability and may have influenced the occurrence of the Sahelian drought of the mid-1980s that affected the Sahel region including the Greater Horn of Africa. Judging from the reflection symmetry, the trend of the current maximum and the turning point of the sunspot minimum at the end of the Modern Maximum, with a 95% level of confidence, drought conditions similar to those of the early 1920s may reoccur in the year 2020±2.

scholarly journals Sunspot Cycle 24 and the Advent of Dalton-Like Minimum

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
H. S. Ahluwalia ◽  
R. C. Ygbuhay
Keyword(s):  
Temperature Change ◽  
20Th Century ◽  
21St Century ◽  
Sunspot Cycle ◽  
Historical Record ◽  
Global Temperature ◽  
Global Temperature Change ◽  
Cycle 24

Ahluwalia and Jackiewicz (2011) have predicted that sunspot cycle 24 will be only half as active as cycle 23, reaching its peak in May2013±6months. Here, we discuss the timeline for cycle 24 since its onset in December, 2008 and compare it to the timelines for the last ten cycles (14 to 23) of the 20th century; cycle 24 is rising the slowest. We speculate that cycle 24 may herald the onset of a Dalton-like minimum in the 21st century. The implications of this outcome on global temperature change and ensuing socioeconomic and political scenarios are discussed, on the basis of the historical record.

scholarly journals How much more can sunspots tell us about the solar dynamo?

2012 ◽  
Vol 8 (S294) ◽  
pp. 25-36
Author(s):  
Aimee A. Norton ◽  
Eric H. Jones ◽  
Y. Liu ◽  
K. Hayashi ◽  
J. T. Hoeksema ◽  
...  
Keyword(s):  
Sunspot Cycle ◽  
Solar Dynamo ◽  
Dynamo Theory ◽  
Similar Time ◽  
Optical Telescope ◽  
The North ◽  
Doppler Imager ◽  
Average Maximum ◽  
Cycle 24 ◽  
Maximum Field

AbstractSunspot observations inspired solar dynamo theory and continue to do so. Simply counting them established the sunspot cycle and its period. Latitudinal distributions introduced the tough constraint that the source of sunspots moves equator-ward as the cycle progresses. Observations of Hale's polarity law mandated hemispheric asymmetry. How much more can sunspots tell us about the solar dynamo? We draw attention to a few outstanding questions raised by inherent sunspot properties. Namely, how to explain sunspot rotation rates, the incoherence of follower spots, the longitudinal spacing of sunspot groups, and brightness trends within a given sunspot cycle. After reviewing the first several topics, we then present new results on the brightness of sunspots in Cycle 24 as observed with the Helioseismic Magnetic Imager (HMI). We compare these results to the sunspot brightness observed in Cycle 23 with the Michelson Doppler Imager (MDI). Next, we compare the minimum intensities of five sunspots simultaneously observed by the Hinode Solar Optical Telescope Spectropolarimeter (SOT-SP) and HMI to verify that the minimum brightness of sunspot umbrae correlates well to the maximum field strength. We then examine 90 and 52 sunspots in the north and south hemisphere, respectively, from 2010 - 2012. Finally, we conclude that the average maximum field strengths of umbra 40 Carrington Rotations into Cycle 24 are 2690 Gauss, virtually indistinguishable from the 2660 Gauss value observed at a similar time in Cycle 23 with MDI.

scholarly journals Size of the coming solar cycle 24 based on Ohl's Precursor Method, final estimate

2010 ◽  
Vol 28 (7) ◽  
pp. 1463-1466 ◽  
Author(s):  
R. P. Kane
Keyword(s):  
Solar Cycle ◽  
Sunspot Cycle ◽  
Preliminary Estimate ◽  
Precursor Method ◽  
Solar Cycle 24 ◽  
False Signal ◽  
Final Estimate ◽  
Cycle 24 ◽  
Maximum Sunspot ◽  
Aa Index

Abstract. In Ohl's Precursor Method (Ohl, 1966, 1976), the geomagnetic activity during the declining phase of a sunspot cycle is shown to be well correlated with the size (maximum sunspot number Rz(max)) of the next cycle. For solar cycle 24, Kane (2007a) used aa(min)=15.5 (12-month running mean), which occurred during March–May of 2006 and made a preliminary estimate Rz(max)=124±26 (12-month running mean). However, in the next few months, the aa index first increased and then decreased to a new low value of 14.8 in July 2007. With this new low value, the prediction was Rz(max)=117±26 (12-month running mean). However, even this proved a false signal. Since then, the aa values have decreased considerably and the last 12-monthly value is 8.7, centered at May 2009. For solar cycle 24, using aa(min)=8.7, the latest prediction is, Rz(max)=58.0±25.0.

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