posted by Dr. Amber Jenkins
An interesting recent paper from Dr. Son Nghiem at NASA’s Jet
Propulsion Laboratory and colleagues finds that the bottom of the Arctic Ocean
controls the pattern of sea ice thousands of feet above on the water’s surface.
The seafloor topography exerts its control not
only locally, in the Bering, Chukchi, Beaufort, Barents and Greenland Seas, but
also spanning hundreds to thousands of miles across the Arctic Ocean.
How? The seafloor influences the distribution of cold and warm waters in the Arctic Ocean where sea ice can preferentially grow or melt. Geological features on the ocean bottom also guide how the sea ice moves, along with influence from surface winds.
Interestingly, the study also links the bottom of the Arctic Ocean with cloud patterns up in the sky. The ocean bottom affects sea ice cover, which affects the amount of vapor coming from the surface of the ocean out into the air, which in turn influences cloud cover.
The researchers, who also come from NASA's Goddard Space Flight Center, the Applied Physics Laboratory and the National/Naval Ice Center in the U.S., use sea ice maps taken from space with NASA’s
QuickSCAT satellite, as well as measurements from drifting buoys in the Arctic
Ocean. They compare the sea ice and seafloor topography patterns to identify
the connection between the two.
Since the seafloor does not change significantly over many
years, sea ice patterns can form repeatedly and persist around certain
underwater geological features. So computer models need to incorporate these
features in order to improve their forecasts of how ice cover will change over
the short- and long-term. This ‘memory’ of the underwater topography
could help refine our predictions of what will happen to ice in the Arctic as
the climate changes.
“Seafloor Control on Sea Ice,” S. V. Nghiem, P. Clemente-Colon, I.G. Rigor, D.K. Hall & G. Neumann, Deep Sea Research Part II: Topical Studies in Oceanography, Volumes 77-80, pp 52-61 (2012).