Differing Drivers Of Atlantic Variability On Quasi- And Multi-Decadal Timescales

The North Atlantic is notable for large decadal variability in sea surface temperature (SST) manifested as Atlantic Multi-decadal Variability (AMV). Whether the AMV is driven by external atmospheric or internal oceanic influences is an oft-disputed point. Long time series of atmospheric and ocean va...

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Bibliographic Details
Main Author: McCarthy, Gerard D
Format: Conference Object
Language:unknown
Published: Zenodo 2018
Subjects:
Online Access:https://dx.doi.org/10.5281/zenodo.1284352
https://zenodo.org/record/1284352
Description
Summary:The North Atlantic is notable for large decadal variability in sea surface temperature (SST) manifested as Atlantic Multi-decadal Variability (AMV). Whether the AMV is driven by external atmospheric or internal oceanic influences is an oft-disputed point. Long time series of atmospheric and ocean variables, in particular long timeseries of Gulf Stream position, reveal differing drivers of SST variability on quasi- and multi-decadal timescales. On quasi-decadal timescales an oscillatory signal identified in the North Atlantic Oscillation controls SST evolution directly via air-sea heat uxes. However, on multi-decadal timescales this relationship with SST changes, while remaining consistent in phase. and resonant in amplitude with Gulf Stream position. A recent reversal of the long term positive trend in Gulf Stream position coincides with a weakening and broadening in the Gulf Stream Extension indicating the onset of an AMV decline.