ICE DYNAMICS AND ICE RIDGES EXPLORATION IN OB BAY, 2003-04

摘要

The SAR satellite imagery of Ob bay ice conditions in June 2003-04 demonstrates explicitly pronounced ice ridge structures throughout the area of observation. The ice variability was studied by direct and remote sensing methods based on ice measurements of Ob bay, 2003-04. These spatial and temporal variations were analyzed by means of topology approach and their fractal dimensions were numerically assessed. Widely applied in ice dynamics models the Coulomb criterion of a flaw growth is based on internal slide angle approach and defines directions of the most probable flaw propagation as a function of sliding coefficient. It causes discrete fractal spectrum of Mohr-Coulomb criterion. These values are compared with ones, followed from satellite imagery analysis. Besides, the sea ice dynamics models need the data of ice deformation and failure processes of different scales. The paper reflects the results of sea ice investigation joined with ice ridges distribution and failure. The results demonstrate that observed ice ridge structures in Ob bay are in agreement with Mohr-Coulomb criterion. The Ob bay SAR imagery in 2003-04 demonstrates the range of ice ridges fractal dimension varying from 1.05 to 1.5.