Sea ice ridging in the eastern Weddell Sea

Measurements of sea ice ridge heights and spatial frequency in the eastern Weddell Sea using a shift-based acoustical sounder are reported. A total of 933 ridges were measured along a track length of 415 km using a minimum ridge sail height of 0.75 m. The ridge frequency varied from 0.4 to 10.5 ridges per km. The mean height of the ridges was found to be about 1.1 m regardless of the ridge frequency. These results are compared to other ridging statistics from the Ross Sea and found to be similar. Comparison with Arctic data indicates that the height and frequency of the ridges are considerably less in the Weddell Sea than in the Arctic. Whereas in the Arctic, the mean ridge height tends to increase with the ridge frequency, this was not found to be the case in the Weddell Sea, where the mean ridge height remained constant irrespective of the ridge frequency. Estimates of the contribution of deformed ice to the total ice thickness are generally low except for a single 53-km section where the ridge frequency increased by an order of magnitude.