The Additional Criterion for the Determination of the Time of Minimum of a Solar Cycle

Habibullo I. Abdussamatov

.

DOI: 10.4236/jemaa.2010.23019                

Abstract

The sunspot number is becoming an increasingly insufficiently reliable parameter for the determination of the time of minimum of a solar cycle during the prolonged and deep minimum of the 23rd solar cycle. Moreover, the sunspot number does not quantitatively reflect physical processes and is a practically conventional qualitative “noisy” parameter. Introduction of an additional criterion for the determination of the time of minimum of a solar cycle is becoming particularly topical due to the upcoming common descent of the level of the 2-secular cycle, when the amplitude of sunspot activity variation will sequentially decrease during several subsequent cycles (after the 23rd cycle). We propose the adoption of the smoothed minimal level of the total solar irradiance (TSI) as an additional physically justified criterion for the determination of the time of minimum of a solar cycle during the minimum of sunspot activity. The minimal level of the monthly average values of the TSI smoothed for 13 months when the last two of its values exceed the preceding value at the point of minimum will additionally indicate the time of minimum of a cycle. The additional criterion has been successfully used for the determination of the time of minima of the preceding 21st and 22nd cycles.

Keywords

Sun, Solar Cycle, Solar Cycle Minimum, TSI, Sunspot Activity

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	H. I. Abdussamatov, “Long-term variations of the integral radiation flux and possible temperature changes in the solar core,” Kinematics and Physics of Celestial Bodies, Vol. 21, No. 6, pp. 328–332, 2005.
[2]	H. I. Abdussamatov, “The time of the end of the current solar cycle and the relationship between duration of 11-year cycles and secular cycle phase,” Kinematics and Physics of Celestial Bodies, Vol. 22, pp. 141–143, 2006.
[3]	H. I. Abdussamatov, “Optimal prediction of the peak of the next 11-year activity cycle and of the peaks of several succeeding cycles on the basis of long-term variations in the solar radius or solar constant,” Kinematics and Physics of Celestial Bodies, Vol. 23, pp. 97–100, 2007.
[4]	S. Duhau, “An early prediction of maximum sunspot number in solar cycle 24,” Solar Physics, Vol. 213, pp. 203–212, 2003.
[5]	C. Fr?hlich, “Solar constant,” 2009. http://www.pmodwrc. ch/pmod.php?topic=tsi/composite/SolarConstant
[6]	S. Sello, “Solar cycle activity: A preliminary prediction for cycle 24,” Astronomy and Astrophysics, Vol. 401, pp. 691–693, 2003.
[7]	SIDC (Solar Influences Data Analysis Center), 2009. http://sidc.oma.be/sunspot-data/