Annual cycle of landfast sea ice in Prydz Bay, east Antarctica

Under the Chinese National Antarctic Research Expedition program in 2006, the annual thermal mass balance of landfast ice in the vicinity of Zhongshan Station, Prydz Bay, east Antarctica, was investigated. Sea ice formed from mid-February onward, and maximum ice thickness occurred in late November. Snow cover remained thin, and blowing snow caused frequent redistribution of the snow. The vertical ice salinity showed a "question-mark- shaped'' profile for most of the ice growth season, which only turned into an "I-shaped'' profile after the onset of ice melt. The oceanic heat flux as estimated from a flux balance at ice-ocean interface using internal ice temperatures decreased from 11.8 (+/- 3.5) W m(-2) in April to an annual minimum of 1.9 (+/- 2.4) W m(-2) in September. It remained low through late November, in mid-December it increased sharply to about 20.0 W m(-2). Simulations applying the modified versions of Stefan's law, taking account the oceanic heat flux and ice-atmosphere coupling, compare well with observed ice growth. There was no obvious seasonal cycle for the thermal conductivity of snow cover, which was also derived from internal ice temperatures. Its annual mean was 0.20 (+/- 0.04) W m(-1) degrees C-1.