Accessibility navigation


A mechanism for Atlantic multidecadal variability in the Kiel Climate Model

Ba, J., Keenlyside, N. S., Park, W., Latif, M., Hawkins, E. and Ding, H. (2013) A mechanism for Atlantic multidecadal variability in the Kiel Climate Model. Climate Dynamics, 41 (7-8). pp. 2133-2144. ISSN 0930-7575

Full text not archived in this repository.

To link to this article DOI: 10.1007/s00382-012-1633-4

Abstract/Summary

Atlantic Multidecadal Variability (AMV) is investigated in a millennial control simulation with the Kiel Climate Model (KCM), a coupled atmosphere–ocean–sea ice model. An oscillatory mode with approximately 60 years period and characteristics similar to observations is identified with the aid of three-dimensional temperature and salinity joint empirical orthogonal function analysis. The mode explains 30 % of variability on centennial and shorter timescales in the upper 2,000 m of the North Atlantic. It is associated with changes in the Atlantic Meridional Overturning Circulation (AMOC) of ±1–2 Sv and Atlantic Sea Surface Temperature (SST) of ±0.2 °C. AMV in KCM results from an out-of-phase interaction between horizontal and vertical ocean circulation, coupled through Irminger Sea convection. Wintertime convection in this region is mainly controlled by salinity anomalies transported by the Subpolar Gyre (SPG). Increased (decreased) dense water formation in this region leads to a stronger (weaker) AMOC after 15 years, and this in turn leads to a weaker (stronger) SPG after another 15 years. The key role of salinity variations in the subpolar North Atlantic for AMV is confirmed in a 1,000 year long simulation with salinity restored to model climatology: No low frequency variations in convection are simulated, and the 60 year mode of variability is absent.

Item Type:Article
Refereed:Yes
Divisions:Interdisciplinary centres and themes > Walker Institute for Climate System Research
Faculty of Science > School of Mathematical and Physical Sciences > NCAS
Faculty of Science > School of Mathematical and Physical Sciences > Department of Meteorology
ID Code:30543
Publisher:Springer

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation