Oscillatory sensitivity of Atlantic overturning to high-latitude forcing

Czeschel, Lars, Marshall, David P. and Johnson, Helen L. (2010) Oscillatory sensitivity of Atlantic overturning to high-latitude forcing Geophysical Research Letters, 37 (10). L10601. DOI 10.1029/2010GL043177.

[img]
Preview
Text
Czeschel.pdf - Published Version

Download (313Kb) | Preview

Supplementary data:

Abstract

The Atlantic Meridional Overturning Circulation (AMOC) carries warm upper waters into northern high-latitudes and returns cold deep waters southward. Under anthropogenic greenhouse gas forcing the AMOC is expected to weaken due to high-latitude warming and freshening. Here, we show that the sensitivity of the AMOC to an impulsive forcing at high latitudes is an oscillatory function of forcing lead time. This leads to the counter-intuitive result that a stronger AMOC can emerge as a result of, although some years after, anomalous warming at high latitudes. In our model study, there is no simple one-to-one correspondence between buoyancy forcing anomalies and AMOC variations, which retain memory of surface buoyancy fluxes in the subpolar gyre for 15-20 years. These results make it challenging to detect secular change from short observational time series

Document Type: Article
Keywords: AMOC variability; decadal variability; Oceanography; GENERAL-CIRCULATION MODEL; NORTH-ATLANTIC; MULTIDECADAL VARIABILITY; OCEAN CIRCULATION; ADJOINT; INSTABILITY; ANOMALIES; CLIMATE
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-TM Theory and Modeling
Refereed: Yes
DOI etc.: 10.1029/2010GL043177
ISSN: 0094-8276
Projects: RAPID
Date Deposited: 10 Jan 2012 13:19
Last Modified: 27 Jul 2017 13:21
URI: http://eprints.uni-kiel.de/id/eprint/13354

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...