High- resolution East Antarctic landfast sea-ice extent and variability from 2000 to 2008

This work presents the first time series of high spatio-temporal resolution (2 km, 20 day) maps of East Antarctic landfast sea ice (10° W to 172° E), as well as a detailed study of the interannual variability of fast ice, from 2000 to 2008. Fast-ice maps are generated from cloud-free MODIS composite imagery, augmented by AMSR-E ASI sea-ice concentration composite images when necessary. Several key fast-ice-related parameters have been retrieved in this area for the first time, including: the ratio of winter maximum extent to summer minimum (~3.1:1); the timing of maximum (DOY 261–280) and minimum (DOY 61–80) extent; and the shape of the annual cycle (a broad maximum, with a much more pronounced minimum). A small but significant (at the 99% level) positive trend in fast-ice area/extent was identified from the fast-ice extent time series, though the 9 year length of the time series provided is likely too short to provide a true indication of longer-term variability. This is compared with the large-scale behaviour of the pack ice in this region over this time period. The location of annually recurring fast-ice features was found to be closely related to the distribution of grounded icebergs, both large (with fast ice often forming on the eastern side due to dynamic advection) and small (with fast ice forming between groups of small, subpixel-scale icebergs). Wind speed and direction were investigated as important factors in local fast-ice growth/breakout events.