Statistical Analysis Of Sunspot Number And Area

Abstract

The statistical analysis on the sunspot number and sunspot area for sunspot cycles 1-23 (i.e. from the year 1755-2008) was carried out. In general, the sunspot variation showed a period of approximately 11 years cycle, while the areas covered by the sunspot in the Southern Hemisphere are systematically higher than the areas covered by the sunspot in the Northern Hemisphere. The sunspot number variation showed a completely random process at work except in its period. Our analysis did not observe any systematic variation in the year within the cycle that maximum sunspot number will occur and the expected value, its definite duration and the minimum value. Our results showed that sunspot maximum occurred in the 4^th year of the cycles for 6 times;  5^th year, 9 times; 6^th year,  4 times and 7^th year, 4 times, while the minimum occurrence in the  10^th, 11^th, 12^th, 13^th, 14^th& 15^th year of the cycle for different solar cycles. The sunspot area variation analysis, showed that the Southern Hemisphere has the highest rate of occurrence of sunspot number compare to Northern hemisphere for the solar cycles 12 to 23 analyzed. For the cycles, the sunspot area in the Southern Hemisphere showed more sudden variations within a given cycle, dropping suddenly and rising again, whereas in the Northern Hemisphere, the variation is more gradual, increasing to a maximum from the beginning of the cycle and maintaining the maximum for some time before gradually decreasing to a minimum towards the end of the cycle.