A modeling study of the interannual variability in the wintertime North Atlantic Ocean

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Journal of Climate

DOI:https://doi.org/10.1175/1520-0442(1995)008<3067:AMSOTI>2.0.CO;2· OSTI ID:255673

Battisti, D S ^[1]; Bhatt, U S ^[2]; Alexander, M A ^[3]

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1. Univ. of Washington, Seattle, WA (United States)
2. Univ. of Wisconsin, Madison, WI (United States)
3. Univ. of Colorado, Boulder, CO (United States)

A new model for the upper North Atlantic Ocean is presented and used to hindcast the SST from 1950 to 1988. The model consists of a matrix of one-dimensional (independent) columns in which a variable-depth, bulk mixed layer overlies a diffusive convective thermocline. The climatological annual cycle of heat flux convergence by the oceanic circulation is implicitly included in the formulation of the forcing. The 39-yr control integration of the model includes as surface forcing the shortwave and net longwave radiation from a control integration of the community climate model. Sensible and latent heat fluxes are determined from instantaneous values of surface temperature, humidity, and wind speed from the atmospheric model, and the SST simulated by the ocean model using the bulk formulae. The ability of the model to hindcast the wintertime interannual variations in SST is demonstrated by simple correlations with observed anomalies and by comparing the composite of warm and cold events observed with those simulated by the model. The results confirm the hypothesis that wintertime interannual to subdecadal variability in SST is mainly due to local anomalies in the air-sea flux of sensible and latent heat and not to anomalies in oceanic advection. Both the sensible and latent heat flux anomalies are shown to contribute substantially to the wintertime anomalies in SST in the subpolar Atlantic, while the heat flux anomalies are predominantly determined by the latent heat flux in the subtropics. Entrainment anomalies contribute to a lesser extent to the mixed layer temperature anomalies throughout the basin. Sensitivity studies are performed to highlight the atmospheric processes and variability that account for the surface heat flux anomalies.

• OSTI ID: 255673
• Journal Information: Journal of Climate, Journal Name: Journal of Climate Journal Issue: 12 Vol. 8; ISSN JLCLEL; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ANNUAL VARIATIONS
ATLANTIC OCEAN
HEAT FLUX
MATHEMATICAL MODELS
OCEANIC CIRCULATION