Dynamic topography of the ice-covered Arctic Ocean from ICESat

Abstract

We construct the dynamic ocean topography (DOT) of the Arctic Ocean, for five ICESat campaigns (winter of 2004-2008), using sea surface height estimates in open leads. Results show that the mean winter DOT over the Arctic Ocean varies by ∼1 m and features a distinct dome of ∼40 cm over the Beaufort Sea. Standard deviation of the mean field is ∼20 cm. Spatial coherence between the five winter DOTs is consistently high (>0.9), whereas the coherence between the DOTs and the winter (DJFM) sea-level pressure fields over the Arctic Basin is variable. This suggests persistence of the underlying hydrodynamic processes at interannual time-scales compared to seasonal atmospheric forcing. Comparison of dynamic heights (DH) from hydrographic surveys and the DOT in 2008 shows a remarkable correlation of 0.92. The geostrophic velocity fields computed from the DOT and interpolated DH fields highlight the smaller scale oceanographic features in the satellite estimates. Copyright © 2011 by the American Geophysical Union.