A propagating freshwater mode in the Arctic Ocean with multidecadal time scale



T. Schmith, S. M. Olsen, and I. M. Ringgaard 
Abstract: The variability of liquid freshwater in the Arctic Ocean is believed to be governed mainly by variations in the wind stress via Ekman convergence. Here, this view is challenged by the analysis of the spatiotemporal pattern of the Arctic Ocean freshwater content from a 500 year long control run with a global climate model. By applying POP-analysis two modes emerge: A dominant mode, which is a clockwise propagating freshwater signal with a period of around 80 years, and a less dominant stationary mode with a decadal time scale and center in the Beaufort Gyre. It is concluded that why the second mode is the wind-driven gyre mode identified in earlier work the first mode is a baroclinic Rossby mode. This last conclusion is supported by theoretical considerations of reduced gravity idealized Arctic Ocean. 

Date: 26.10.2017 11:00-12:00

Location: Auditorium, DMI