On the classifications of the solar active regions (ARs); Case study for solar cycles 23 and 24

• Main Authors: Wael Mohamed, Shahinaz Yousef, Mosalam Shaltout
• Format: Article
• Language: English
• Published: Elsevier 2018-12-01
• Series: Egyptian Journal of Remote Sensing and Space Sciences
• Online Access: http://www.sciencedirect.com/science/article/pii/S1110982316301296

The declining phase of solar cycle 23 is an important case of study. Many high energetic solar flares occurred in 2003. The occurrence of high energetic solar X-ray flares (X-type) is related to solar cycle’s phases and the state of the active regions producing them. In some cases, the declining phases may be more active than the maximum phase. A statistical study is performed for solar flares (X-class) occurrence at declining and maximum phases of solar activity. The relationships between the X-class flares, SSN and active regions (ARs) will be investigated. The active region productivity of X-flares is in coherence with the number of days of (β – γ – δ) magnetic field. The active regions energies are consumed in the acceleration of protons and production of X-flares among other things (e.g. CME lifting up). The higher the energy of X-flares the lower the proton flux (pfu @ >10 MeV) and vice versa. Keywords: Solar cycle, Declining phase, X-class flare, Active region