Simulation of the tropical oceans with an ocean GCM coupled to an atmospheric mixed-layer model

Murtugudde, R; Seager, R; Busalacchi, A

doi:10.1175/1520-0442(1996)009<1795:SOTTOW>2.0.CO;2

Title: Simulation of the tropical oceans with an ocean GCM coupled to an atmospheric mixed-layer model

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Abstract

A reduced gravity, primitive equation, ocean general circulation model (GCM) is coupled to an advective atmospheric mixed-layer (AML) model to demonstrate the importance of a nonlocal atmospheric mixed-layer parameterization for a proper simulation of surface heat fluxes and sea surface temperatures (SST). Seasonal variability of the model SSTs and the circulation are generally in good agreement with the observations in each of the tropical oceans. These results are compared to other simulations that use a local equilibrium mixed-layer model. Inclusion of the advective AML model is demonstrated to lead to a significant improvement in the SST simulation in all three oceans. Advection and diffusion of the air humidity play significant roles in determining SSTs even in the tropical Pacific where the local equilibrium assumption was previously deemed quite accurate. The main, and serious, model flaw is an inadequate representation of the seasonal cycle in the upwelling regions of the eastern Atlantic and Pacific Oceans. The results indicate that the feedback between mixed-layer depths and SSTs can amplify SST errors, implying that increased realism in the modeling of the ocean mixed layer increases the demand for realism in the representation of the surface heat fluxes. The performance of the GCM withmore »« less

Authors:

Murtugudde, R ^[1]; Seager, R ^[2]; Busalacchi, A ^[3]

Universities Space Research Association, Greenbelt, MD (United States)
Lamont-Doherty Earth Observatory of Columbia Univ., Palisades, NY (United States)
NASA/GSFC, Greenbelt, MD (United States)

Publication Date:: Thu Aug 01 00:00:00 EDT 1996

OSTI Identifier:: 381027

Resource Type:: Journal Article

Journal Name:: Journal of Climate

Additional Journal Information:: Journal Volume: 9; Journal Issue: 8; Other Information: PBD: Aug 1996

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; GENERAL CIRCULATION MODELS; PERFORMANCE; SEAS; HEAT FLUX; ADVECTION; EQUILIBRIUM; HUMIDITY; UPWELLING; TEMPERATURE DEPENDENCE; SEASONAL VARIATIONS; AIR-WATER INTERACTIONS; AMBIENT TEMPERATURE

Citation Formats


                    Murtugudde, R, Seager, R, and Busalacchi, A. Simulation of the tropical oceans with an ocean GCM coupled to an atmospheric mixed-layer model.  United States: N. p., 1996. 
        Web.  doi:10.1175/1520-0442(1996)009<1795:SOTTOW>2.0.CO;2.

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                    Murtugudde, R, Seager, R, & Busalacchi, A. Simulation of the tropical oceans with an ocean GCM coupled to an atmospheric mixed-layer model.  United States.  https://doi.org/10.1175/1520-0442(1996)009<1795:SOTTOW>2.0.CO;2

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                    Murtugudde, R, Seager, R, and Busalacchi, A. 1996.  
        "Simulation of the tropical oceans with an ocean GCM coupled to an atmospheric mixed-layer model".  United States.  https://doi.org/10.1175/1520-0442(1996)009<1795:SOTTOW>2.0.CO;2.

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@article{osti_381027,

  title        = {Simulation of the tropical oceans with an ocean GCM coupled to an atmospheric mixed-layer model},

  author       = {Murtugudde, R and Seager, R and Busalacchi, A},

  abstractNote = {A reduced gravity, primitive equation, ocean general circulation model (GCM) is coupled to an advective atmospheric mixed-layer (AML) model to demonstrate the importance of a nonlocal atmospheric mixed-layer parameterization for a proper simulation of surface heat fluxes and sea surface temperatures (SST). Seasonal variability of the model SSTs and the circulation are generally in good agreement with the observations in each of the tropical oceans. These results are compared to other simulations that use a local equilibrium mixed-layer model. Inclusion of the advective AML model is demonstrated to lead to a significant improvement in the SST simulation in all three oceans. Advection and diffusion of the air humidity play significant roles in determining SSTs even in the tropical Pacific where the local equilibrium assumption was previously deemed quite accurate. The main, and serious, model flaw is an inadequate representation of the seasonal cycle in the upwelling regions of the eastern Atlantic and Pacific Oceans. The results indicate that the feedback between mixed-layer depths and SSTs can amplify SST errors, implying that increased realism in the modeling of the ocean mixed layer increases the demand for realism in the representation of the surface heat fluxes. The performance of the GCM with a local-equilibrium mixed-layer model in the Atlantic is as poor as previous simple ocean model simulations of the Atlantic. The conclusion of earlier studies that the simple ocean model was at fault may, in fact, not be correct. Instead the local-equilibrium heat flux parameterization appears to have been the major source of error. Accurate SST predictions may, hence, be feasible by coupling the AML model to computationally efficient simple ocean models. 69 refs., 18 figs., 1 tab.},

  doi          = {10.1175/1520-0442(1996)009<1795:SOTTOW>2.0.CO;2},

  url          = {https://www.osti.gov/biblio/381027},
  journal      = {Journal of Climate},
number       = 8,

  volume       = 9,

  place        = {United States},

  year         = {Thu Aug 01 00:00:00 EDT 1996},

  month        = {Thu Aug 01 00:00:00 EDT 1996}

}

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https://doi.org/10.1175/1520-0442(1996)009<1795:SOTTOW>2.0.CO;2

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