Perspectives for predicting North Atlantic decadal sea surface temperature variability

• Main Author: Klöwer, Milan
• Format: Thesis
• Language: English
• Published: 2013
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: https://oceanrep.geomar.de/id/eprint/23208/; https://oceanrep.geomar.de/id/eprint/23208/1/thesis.pdf

The predictability of North Atlantic sea surface temperature (SST), that results from the delayed oceanic response to atmospheric forcing is investigated by means of a partial coupling experiment performed with the Kiel Climate Model. Observed North Atlantic Oscillation (NAO)-related heat flux anomalies from 1865 to 2000 force the model's ocean component to the climatic trajectory of the NAO but enable an otherwise free interaction between ocean and atmosphere. Hence, the model simulates a Meridional Overturning Circulation (MOC) that is consistent with the NAO and with observed SST. However, the simulated SST variability suffers from systematic errors. Statistical investigations with Canonical Correlation Analysis (CCA) identify a delayed link of 21 years between MOC and observed SST that corresponds to the Atlantic Multidecadal Oscillation (AMO). Using CCA as predictive tool leads to a prognosis of future changes in North Atlantic SST variability until 2021. Subsequently to the current positive phase of the AMO the results yield that North Atlantic SST is expected to cool after 2015.