Complexity in Dst index values over Solar Cycle 24

Rabiu B., KILÇIK A., Fuwape I., Ogunjo S.

Astrophysics and Space Science, cilt.370, sa.7, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 370 Sayı: 7
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1007/s10509-025-04468-x
  • Dergi Adı: Astrophysics and Space Science
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, INSPEC, Metadex, zbMATH, Civil Engineering Abstracts
  • Anahtar Kelimeler: Chaos, Dst index, Multifractal, Solar cycle
  • Akdeniz Üniversitesi Adresli: Evet

Özet

The intrinsic nature of the magnetosphere is important in understanding the role of different drivers in its dynamics. In this study, an attempt was made to characterize and quantify the complexity in the magnetosphere during Solar Cycle 24 using the Dst index as a measure. Two approaches were considered: chaos and multifractal analysis. The chaotic analysis using the Lyapunov exponent, correlation dimension, and entropy measures revealed that the magnetosphere is chaotic for every year of Solar Cycle 24. Furthermore, there was no significant difference between the complexity in Solar Cycle 24 and the previous 4 solar cycles (20-23). Chaotic parameters (sample entropy, Lyapunov exponent, and correlation dimension) showed strong correlations with annual mean Dst values throughout Solar Cycle 24. Multifractal detrended fluctuation analysis parameters showed weak relationships with annual means but revealed underlying structures in Dst values.