No abstract

Studying solar flares and their characteristics is significant for understanding the dynamics of the sun. In this work, a new view for studying the  duration time of solar flares is presented. Regarding the analysis of the duration time, one of the solar flares parameters is introduced for the solar cycles 23 and 24. This is done by ordering the duration time of solar flares into five groups of minutes (<30, 30-60, 60 90, 90-120, >120) and calculating the total annual duration time of solar flares for each group. The total annual duration time is also calculated for each class of solar flare classification (B, C, M, X). Their relationship with both F10.7 and Kp-index are also studied. We found that approximately 41% of solar flares occur within 6-12 minutes for both solar cycles. Additionally, the total average of their duration time is 19.1 and 19.6 minutes, respectively.Also, the average duration time of the ascending phase is less than the descending phase of both  solar cycles for all classes of solar flares, except for B-class, which is vice versa. The relationship between the duration time of solar  flares with F10.7 is strong. In contrast, the relationship with the Earth’s magnetic field is weak.

No abstract

Studying the impact of solar activity on the Earth's climate is significant for predicting the change of its elements for long periods. Most studies have focused on the relationship between sunspots and changes in one of the climate elements. In this research, the effect of the solar activities that consist of coronal mass ejections and solar flare, and the sunspots number on thunderstorms that occur during the winter season in Iraq for the period from (1996-2019) representing the Solar-Cycles 23 & 24, respectively, were investigated in this study. In general, the statistical results show that, the monthly average increase for each of the following: energies of coronal mass ejections, solar flares, and the sunspots number, the monthly frequency of thunderstorms decreases. The Solar-Cycle 24 is the weakest among the cycles of the last century; therefore, its results were not precise.