The Role of the AMOC in Forecast Cooling of the Atlantic Subpolar Gyre and Its Associated Impacts

Thursday, 18 December 2014: 11:50 AM
Leon Hermanson1, Rosemary Eade1, Niall Robinson2, Nick Dunstone2, Martin Andrews2, Jeff Knight2, Adam A Scaife2 and Doug Smith2, (1)Met Office Hadley center for Climate Change, Exeter, EX1, United Kingdom, (2)Met Office Hadley center for Climate Change, Exeter, United Kingdom
Decadal variability in the North Atlantic and its subpolar gyre (SPG) has been shown to be predictable in climate models initialized with the concurrent ocean state. Numerous impacts over ocean and land have also been identified. Here we use three versions of the Met Office Decadal Prediction System to provide a multimodel ensemble forecast of the SPG and related impacts. The recent cooling trend in the SPG is predicted to continue in the next 5 years due to a decrease in the SPG heat convergence related to a slowdown of the Atlantic Meridional Overturning Circulation. We present evidence that the ensemble forecast is able to skilfully predict these quantities over recent decades. We also investigate the ability of the forecast to predict impacts on surface temperature, pressure, precipitation, and Atlantic tropical storms and compare the forecast to recent boreal summer climate.