Title: On the Relative Roles of the Atmosphere and Ocean in the Atlantic Multidecadal Variability

Journal Article · · Geophysical Research Letters
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [2]; ORCiD logo [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Ocean Univ. of China, Qingdao (China)
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In this study, the relative roles of the ocean and atmosphere in driving the Atlantic multidecadal variability (AMV) are investigated by isolating anomalous sea surface temperature (SST) components forced by anomalous surface heat fluxes and ocean dynamics in fully and partially coupled simulations. The impact of the ocean dynamics-forced SST on air-sea interaction is disabled in the partially coupled simulation in order to isolate the atmosphere-forced variability. The atmosphere-forced AMV component shows weak but significant variability on interdecadal timescales (10- to 30-year periods), while the ocean-forced component exhibits a strong multidecadal variability (25- to 50-year periods). When coupled to the atmosphere, this ocean-forced variability weakens and is imprinted on the coupled surface heat fluxes that further act to damp the ocean-forced SST variability, causing a much weaker fully coupled AMV. In conclusion, our results suggest that the AMV is largely driven by ocean circulation variability, but its power is also affected by the strength of air-sea coupling.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Grant/Contract Number:
AC02-05CH11231; AC05-76RL01830
OSTI ID:
1544210
Journal Information:
Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 17 Vol. 45; ISSN 0094-8276
Publisher:
American Geophysical UnionCopyright Statement
Country of Publication:
United States
Language:
English

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Cited By (2)

Key Role of Internal Ocean Dynamics in Atlantic Multidecadal Variability During the Last Half Century journal December 2018
A Review of the Role of the Atlantic Meridional Overturning Circulation in Atlantic Multidecadal Variability and Associated Climate Impacts journal June 2019

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54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
Atlantic multidecadal variability
air-sea interactions
climate variability