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Model projections of the North Atlantic thermohaline circulation for the 21st century assessed by observations
Author(s) -
Schmittner A.,
Latif M.,
Schneider B.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024368
Subject(s) - thermohaline circulation , climatology , forcing (mathematics) , atlantic multidecadal oscillation , environmental science , shutdown of thermohaline circulation , general circulation model , hydrography , climate change , representative concentration pathways , climate model , ocean current , greenhouse gas , abrupt climate change , circulation (fluid dynamics) , north atlantic deep water , oceanography , global warming , effects of global warming , geology , physics , thermodynamics
Most climate models predict a weakening of the North Atlantic thermohaline circulation for the 21st century when forced by increasing levels of greenhouse gas concentrations. The model spread, however, is rather large, even when the forcing scenario is identical, indicating a large uncertainty in the response to forcing. In order to reduce the model uncertainties a weighting procedure is applied considering the skill of each model in simulating hydrographic properties and observation‐based circulation estimates. This procedure yields a “best estimate” for the evolution of the North Atlantic THC during the 21st century by taking into account a measure of model quality. Using 28 projections from 9 different coupled global climate models of a scenario of future CO 2 increase (SRESA1B) performed for the upcoming fourth assessment report of the Intergovernmental Panel on Climate Change, the analysis predicts a gradual weakening of the North Atlantic THC by 25(±25)% until 2100.