Mechanisms of multidecadal Atlantic meridional overturning circulation variability diagnosed in depth versus density space
Citable URI
https://hdl.handle.net/1912/7041As published
https://doi.org/10.1175/JCLI-D-14-00228.1DOI
10.1175/JCLI-D-14-00228.1Keyword
North Atlantic Ocean; Meridional overturning circulation; Ocean circulation; Thermocline circulation; Climate variability; Multidecadal variabilityAbstract
Multidecadal variability of the Atlantic meridional overturning circulation (AMOC) is examined based on a comparison of the AMOC streamfunctions in depth and in density space, in a 700-yr present-day control integration of the fully coupled Community Climate System Model, version 3. The commonly used depth-coordinate AMOC primarily exhibits the variability associated with the deep equatorward transport that follows the changes in the Labrador Sea deep water formation. On the other hand, the density-based AMOC emphasizes the variability associated with the subpolar gyre circulation in the upper ocean leading to the changes in the Labrador Sea convection. Combining the two representations indicates that the ~20-yr periodicity of the AMOC variability in the first half of the simulation is primarily due to an ocean-only mode resulting from the coupling of the deep equatorward flow and the upper ocean gyre circulation near the Gulf Stream and North Atlantic Current. In addition, the density-based AMOC reveals a gradual change in the deep ocean associated with cooling and increased density, which is likely responsible for the transition of AMOC variability from strong ~20-yr oscillations to a weaker red noise–like multidecadal variability.
Description
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 27 (2014): 9359–9376, doi:10.1175/JCLI-D-14-00228.1.
Collections
Suggested Citation
Journal of Climate 27 (2014): 9359–9376Related items
Showing items related by title, author, creator and subject.
-
A review of the role of the Atlantic meridional overturning circulation in Atlantic multidecadal variability and associated climate impacts
Zhang, Rong; Sutton, Rowan; Danabasoglu, Gokhan; Kwon, Young-Oh; Marsh, Robert; Yeager, Stephen G.; Amrhein, Daniel E.; Little, Christopher M. (American Geophysical Union, 2019-04-29)By synthesizing recent studies employing a wide range of approaches (modern observations, paleo reconstructions, and climate model simulations), this paper provides a comprehensive review of the linkage between multidecadal ... -
Gulf Stream variability in the context of quasi‐decadal and multidecadal Atlantic climate variability
McCarthy, Gerard D.; Joyce, Terrence M.; Josey, Simon A. (John Wiley & Sons, 2018-10-20)The Gulf Stream plays an important role in North Atlantic climate variability on a range of timescales. The North Atlantic is notable for large decadal variability in sea surface temperatures (SST). Whether this variability ... -
Atlantic meridional overturning circulation: Observed transport and variability
Frajka-Williams, Eleanor; Ansorge, Isabelle; Baehr, Johanna; Bryden, Harry L.; Chidichimo, Maria Paz; Cunningham, Stuart A.; Danabasoglu, Gokhan; Dong, Shenfu; Donohue, Kathleen A.; Elipot, Shane; Heimbach, Patrick; Holliday, Naomi Penny; Hummels, Rebecca; Jackson, Laura C.; Karstensen, Johannes; Lankhorst, Matthias; Le Bras, Isabela A.; Lozier, M. Susan; McDonagh, Elaine L.; Meinen, Christopher S.; Mercier, Herlé; Moat, Bengamin I.; Perez, Renellys; Piecuch, Christopher G.; Rhein, Monika; Srokosz, Meric; Trenberth, Kevin E.; Bacon, Sheldon; Forget, Gael; Goni, Gustavo J.; Kieke, Dagmar; Koelling, Jannes; Lamont, Tarron; McCarthy, Gerard D.; Mertens, Christian; Send, Uwe; Smeed, David A.; Speich, Sabrina; van den Berg, Marcel; Volkov, Denis L.; Wilson, Christopher G. (Frontiers Media, 2019-06-07)The Atlantic Meridional Overturning Circulation (AMOC) extends from the Southern Ocean to the northern North Atlantic, transporting heat northwards throughout the South and North Atlantic, and sinking carbon and nutrients ...