Earth Planets Space, Vol. 56 (No. 5), pp. e13-e16, 2004

Nonlinear variability of SYM-H over two solar cycles

J. A. Wanliss

Department of Physical Sciences, Embry-Riddle Aeronautical University, 600 S. Clyde Morris Blvd, Daytona Beach, FL 32114-3900, USA

(Received March 31, 2004; Revised June 3, 2004; Accepted June 7, 2004)

Abstract: Fractal fluctuation analysis is applied to ground-based SYM-H data during quiet times and during magnetic storm times spanning two solar cycles between 1981-2002. On the basis of Kp, intervals were selected that corresponded to quiet and active magnetospheric dynamics. A nonlinear detrended fluctuation analysis (DFA) was applied to monitor nonlinear variability over the solar cycles. We find significant variations in nonlinear statistics between quiet and active intervals, which indicates a difference in statistical variability for quiet times, and storm times.
Key words: SYM-H, fractals, nonlinear, space weather, indices, geomagnetism, Dst, prediction.