Sea Level Change in the Arctic Ocean from Ers, Envisat and Cryosat-2 Radar Altimetry

Monday, 15 December 2014: 8:15 AM
Thomas Armitage, Duncan Wingham and Andy Ridout, University College London, London, United Kingdom
Basin-scale and regional sea level trends in the Arctic Ocean are examined using an 18-year time series of radar altimeter sea level estimates, employing specialised sea ice processing that gives year-round complete coverage up to 82N. Since it was last surveyed the sea level in the western Arctic continued to rise, peaking in 2011 before levelling off, pointing to further accumulation of fresh water in the Beaufort Gyre. This convergence of fresh water is associated with a strengthening of the anti-cyclonic atmospheric circulation, particularly in the summer time. We also investigate how the changing state of the sea ice pack is influencing the atmosphere-ocean momentum exchange. As well as looking at long-term trends, the altimetry dataset allows us to examine the annual cycle of sea level in the western Arctic Ocean. This is compared with the annual cycles of liquid and solid fresh water in the region, incorporating state-of-the-art sea ice volume estimates from CryoSat-2.