Variability of scaling time series in the Arctic sea-ice drift dynamics

Abstract

Abstract. The motion of an individual ice floe in the ArcticOcean was monitored at the Russian research station North Pole 35 established on the ice pack in 2008. The ice floe speed (V ) was found to be correlated with wind speed (v) in main features, such as the positions of maxima and minima of V and v. However, the fine structure of the V -variation cannot be explained by the wind forcing alone. There were periods of time when the floe drift was affected by the interactions of ice floes between each other or by the periodical forcing due to either the Coriolis inertia effect or the tidal activity. These data were compared with the "waiting times" statistics that are the distributions of time intervals between subsequent, sufficiently strong changes in the kinetic energy of drifting ice floe. These distributions were measured in several time windows differing in the average wind speed and wind direction, and/or in the mechanical state of the ice pack. The distribution functions N(t > τ ), where N is the number of successive events of energy change separated by the time interval t that exceeds τ , constructed in different time windows demonstrate fractal or a multifractal nature of the time series during motion in the consolidated ice pack but were truly random when the ice floe drifted in the highly fragmented sea ice. The latter result shows the existence of a relationship between the long-range mechanical interactions in the pack and long-term memory (time scaling behaviour) of the sea-ice motion.

Quasi-seismic scaling processes in sea ice

“…On 5-8 March 2008, a strong mechanical perturbation in the Arctic ice pack occurred at a distance of ∼200 km from the Russian ice research camp North Pole 35 that drifted on the pack. A corresponding dramatic change in the speed and general direction of sea ice drift was detected at the research camp (figure 1) [22]. After the perturbation, a 'fault' consisting of fragmented sea ice was imaged by the NOAA satellite (figure 2).…”

Nonextensive Dynamics of Drifting Sea Ice

“…e changes in the ice �oe speed were measured in 10 minutes intervals. e measurement procedure and the accuracy of the determination of changes in the value of the ice �oe speed using GPS transducer are given in [15]. A time series of kinetic energy changes (proportional to the measured Δ 2 values) in the time period of dri from 1 February to 26 February 2004 is depicted in Figure 4(a).…”

Correlated Energy Exchange in Drifting Sea Ice

“…A detailed analysis of the accuracy of drift speed determination from the GPS data [4] showed that the standard error in values V measured in 2 min sampling intervals was about 0.009 m/s, while the changes in the drift speed, ΔV , were much larger. Only the values ΔV that exceeded the standard error of speed determination two times or more were taken into account in the subsequent data processing.…”

“…The Arctic sea ice cover (ASIC) is the open thermodynamic system that exhibits well-pronounced scaling properties [1][2][3][4][5]. The ASIC dynamics is determined by the sea ice drift, which is caused, predominantly, by irregular wind forcing [6][7][8].…”

“…Rothrock and Thorndike [12] were the first who reported the power-law floe size distribution and formulated the concept of scale invariance of fragmented sea ice. More recent studies showed that both the energy [13] and temporal [4,5] parameters of the drift are characterized by power-law distributions that are well known in geodynamics (Gutenberg-Richter law [14]), as well as in other nonequilibrium processes in nature including human activity (see [15]). …”