Summary
Sea-ice drift and deformation in the Western Weddell Sea during austra; summer of 2004 are characterised using in situ data from a meso-scale array of 24 drifting ice buoys. About 30 days of data during late November and December 2004 are available from the buoy array. Another six months plus of Langrangian data are available from three buoys, which were left in the sea ice after the conclusion of drift station ISPOL. Sea-ice drift was obtained from the horizontal GPS-derived location measurements from all buoys, albeit at various temporal resolutions and with different spatial accuracies. Analysis of the sea-ice velocities reveals a correlation length scale of 70km. Sea-ice drift at separations of less than 80 km are isotrop, while at larger separations zonal ice drift remain correlated, while meridional ice drift becomes uncorrelated. This and an east-west gradient in ice velocities indicate the influence of bathymetry on local dynamic processes. However, the ice drift is largely dominated by atmospheric forcing: About 80% of variability in the sea-ice velocity are explained by changes in wind velocity. Sea-ice deformation has also been derived for the overall array and subsets. During ISPOL net divergence was in excess of 30%, with largest contributions from the north-eastern section of the overall ISPOL array. Variability in divergence/convergence are dominated by high-frequency processes, namely via tidal forcing and inertial response. Peaks in sea-ice divergence generally coincided with atmospheric changes. About 70% of variability in sea-ice divergence can be related to wind velocity.