Nonlinear dynamical analysis of a fractional-order El Niño Southern Oscillation system Angana Das Mahapatra, Ankur Jyoti Kashyap, Gautam Choudhury, Santu Das and Hemanta Kumar Sarmah Eur. Phys. J. Plus, 140 7 (2025) 704 Published online: 28 July 2025 DOI: 10.1140/epjp/s13360-025-06617-1