Elevation change around Dome A region of Antarctica from EnviSat satellite radar altimetry during 2002–2012

摘要

The expected responses of ice sheets to climate warming are growth in the thickness of the inland ice areas and thinning near the margins.In recent decades,researchers have identified glacier acceleration along Antarctic ice sheet coastal margins.However,the study of ice sheet interiors where seasonal accumulation eventually balances ice wastage at the lower elevation is poorly understood.In this paper,the ice sheet elevation change around Dome A region is analyzed from 2002 to 2012 using two million elevation change measurements from EnviSat satellite radar altimeter data covering an area of about 7000 km2.A declining trend of 0.572±1.31 mm/year which means that the Dome A region was in balance during the last decade can be captured.In addition,two obvious changes in accumulation which divide elevation change time series into three independent equilibration stages are also extracted.In order to explain this phenomenon,two speculations related to snowfall and firn compaction are proposed in this paper.