A Preliminary Estimate of the Size of the Coming Solar Cycle 24, based on Ohl’s Precursor Method

Solar Physics ◽  
2007 ◽  
Vol 243 (2) ◽  
pp. 205-217 ◽  
Author(s):  
R. P. Kane
Keyword(s):  
Solar Cycle ◽  
Preliminary Estimate ◽  
Precursor Method ◽  
Solar Cycle 24 ◽  
Cycle 24

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.

scholarly journals Predicting amplitude of solar cycle 24 based on a new precursor method

2010 ◽  
Vol 28 (2) ◽  
pp. 417-425 ◽  
Author(s):  
A. Yoshida ◽  
H. Yamagishi
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Solar Minimum ◽  
Physical Phenomenon ◽  
Late Phase ◽  
The Sun ◽  
Precursor Method ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
The Imf

Abstract. It is shown that the monthly smoothed sunspot number (SSN) or its rate of decrease during the final years of a solar cycle is correlated with the amplitude of the succeeding cycle. Based on this relationship, the amplitude of solar cycle 24 is predicted to be 84.5±23.9, assuming that the monthly smoothed SSN reached its minimum in December 2008. It is further shown that the monthly SSN in the three-year period from 2006 through 2008 is well correlated with the monthly average of the intensity of the interplanetary magnetic field (IMF). This correlation indicates that the SSN in the final years of a solar cycle is a good proxy for the IMF, which is understood to reflect the magnetic field in the corona of the sun, and the IMF is expected to be smallest at the solar minimum. We believe that this finding illuminates a physical meaning underlying the well-known precursor method for forecasting the amplitude of the next solar cycle using the aa index at the solar minimum or its average value in the decaying phase of the solar cycle (e.g. Ohl, 1966), since it is known that the geomagnetic disturbance depends strongly on the intensity of the IMF. That is, the old empirical method is considered to be based on the fact that the intensity of the coronal magnetic field decreases in the late phase of a solar cycle in parallel with the SSN. It seems that the precursor method proposed by Schatten et al. (1978) and Svalgaard et al. (2005), which uses the intensity of the polar magnetic field of the sun several years before a solar minimum, is also based on the same physical phenomenon, but seen from a different angle.

A Prediction of Solar Cycle 24 Using a Modified Precursor Method

Solar Physics ◽  
2008 ◽  
Vol 250 (1) ◽  
pp. 171-181 ◽  
Author(s):  
R. S. Dabas ◽  
Kavita Sharma ◽  
Rupesh M. Das ◽  
K. G. M. Pillai ◽  
Parvati Chopra ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Precursor Method ◽  
Solar Cycle 24 ◽  
Cycle 24

Regression Analysis of Sunspot Numbers for the Solar Cycle 24 in Comparison to Previous Three Cycles

2014 ◽  
Vol 4 (2) ◽  
pp. 477-483
Author(s):  
Debojyoti Halder
Keyword(s):  
Regression Analysis ◽  
Solar Cycle ◽  
Sunspot Number ◽  
The Sun ◽  
Sunspot Numbers ◽  
Solar Cycle 24 ◽  
Current Cycle ◽  
Cycle 24

Sunspots are temporary phenomena on the photosphere of the Sun which appear visibly as dark spots compared to surrounding regions. Sunspot populations usually rise fast but fall more slowly when observed for any particular solar cycle. The sunspot numbers for the current cycle 24 and the previous three cycles have been plotted for duration of first four years for each of them. It appears that the value of peak sunspot number for solar cycle 24 is smaller than the three preceding cycles. When regression analysis is made it exhibits a trend of slow rising phase of the cycle 24 compared to previous three cycles. Our analysis further shows that cycle 24 is approaching to a longer-period but with smaller occurrences of sunspot number.

Empirical Relationship Between CME Parameters and Geo-effectiveness of Halo CMEs in the Rising Phase of Solar Cycle 24 (2011 – 2013)

Solar Physics ◽  
2015 ◽  
Vol 290 (5) ◽  
pp. 1417-1427 ◽  
Author(s):  
A. Shanmugaraju ◽  
M. Syed Ibrahim ◽  
Y.-J. Moon ◽  
A. Mujiber Rahman ◽  
S. Umapathy
Keyword(s):  
Solar Cycle ◽  
Empirical Relationship ◽  
Solar Cycle 24 ◽  
Halo Cmes ◽  
Cycle 24

scholarly journals Vertical Thermospheric Density Profiles From EUV Solar Occultations Made by PROBA2 LYRA for Solar Cycle 24

Space Weather ◽  
2017 ◽  
Vol 15 (12) ◽  
pp. 1649-1660 ◽  
Author(s):  
E. M. B. Thiemann ◽  
M. Dominique ◽  
M. D. Pilinski ◽  
F. G. Eparvier
Keyword(s):  
Solar Cycle ◽  
Density Profiles ◽  
Solar Cycle 24 ◽  
Cycle 24
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