Estimating the Sea Ice Compressive Strength from Satellite-Derived Sea Ice Drift and NCEP Reanalysis Data*

Abstract

Satellite-derived sea ice drift maps and sea level pressure from reanalysis data are used to infer upper and lower bounds on the large-scale compressive strength of Arctic sea ice. To this end, the two datasets are searched for special situations in which the wind forcing and its orientation with respect to the coastline allowed the authors to deduce a mean sea ice compressive strength from simple theory. Many estimates of ice compressive strength were possible for the winter of 1992/93 when the Arctic high was confined to the western Arctic and deep penetration of the Icelandic low produced wind patterns that pushed the ice perpendicular to the coastline in the Beaufort and East Siberian Seas. The winter of 1996/97, on the other hand, was characterized by a well-established Arctic high, producing wind patterns that generally pushed ice along coastlines rather than against them. Results show lower and upper bounds on the sea ice compressive strength parameter of 30 and 40 kN m Ϫ2 is also found in the East Siberian Sea in the first few hundred kilometers from the land, presumably associated with land-fast ice. The proposed mean ice compressive strength estimate is higher than those derived by minimizing the cumulative error between simulated and observed buoy drift trajectories. It is noted that the uncertainties in the estimates derived from models are large (with an unbiased estimate of standard deviation of 8.75 kN m Ϫ2). The estimates of yield strength in isotropic compression presented herein are in good agreement with a previous estimate made during the Arctic Ice Dynamic Joint Experiment, and with in situ ice compressive stress measurements made in the Beaufort Sea.

Relationships between Arctic sea ice drift and strength modelled by NEMO-LIM3.6

“…The experiment with P * = 27.5 kN m −2 gives higher ice strength P than the control simulation and corresponds to the value found by Hibler and Walsh (1982). The experiment with P * = 45 kN m −2 is the largest value of the likely range found by Tremblay and Hakakian (2006). The experiment with P * = 100 kN m −2 is close to the highest value of Steele et al (1997).…”

“…This is also the value used in the viscous-plastic models of SIMIP (Kreyscher et al, 1997) as well as in more recent modelling studies (Lipscomb et al, 2007;Juricke et al, 2013). Hibler and Walsh (1982) find that P * = 27.5 kN m −2 provides the best agreement between their 222 km resolution sea ice model and observations from the Soviet ice station NP-22 in terms of mean drift rates in 1974-1975. Tremblay and Hakakian (2006 find that the most likely value of P * lies in the range 30-45 kN m −2 based on satellite observations.…”

Simulated Interannual Variations of Freshwater Content and Sea Surface Height in the Beaufort Sea*

“…Observed values for the airice drag coefficient range from 0.5 3 10 23 to 5 3 10 23 , depending on the atmospheric boundary layer stability and surface roughness (Prinsenberg and Peterson 2002). Moreover, the optimal value for P* depends on the choice of air-ice drag coefficient; also, uncertainties in the air-ice drag coefficient are a major source of the uncertainties in P* (Tremblay and Hakakian 2006). For example, a value of 1.5 3 10 4 N m 22 was used by Kreyscher et al (1997), whereas Hibler and Walsh (1982) use 2.75 3 10 4 N m 22 in their ice models with the standard viscous-plastic rheology of Hibler (1979).…”

Perspective on the risk that sediment-laden ice poses to in-stream tidal turbines in Minas Passage, Bay of Fundy

“…First we expect deformation of the installation as though it had spring constant k. Second, there will be deformation (possibly fracture) of the ice cake if the contact force reaches the strength of the ice cake. Compressive strength and flexural strength have been measured for large-scale sea ice in the arctic [26,27] but not for the ice cakes found in the Bay of Fundy-although it is easy to section and fracture ice cakes using simple tools: a hand saw and an axe. Denote the compressive strength of ice cakes as S.…”