What Drives Upper-Ocean Temperature Variability in Coupled Climate Models and Observations?

Small, R. Justin; Bryan, Frank O.; Bishop, Stuart P.; Larson, Sarah; Tomas, Robert A.

doi:10.1175/JCLI-D-19-0295.1

Title: What Drives Upper-Ocean Temperature Variability in Coupled Climate Models and Observations?

Full Record
Other Related Research

Abstract

Abstract A key question in climate modeling is to what extent sea surface temperature and upper-ocean heat content are driven passively by air–sea heat fluxes, as opposed to forcing by ocean dynamics. This paper investigates the question using a climate model at different resolutions, and observations, for monthly variability. At the grid scale in a high-resolution climate model with resolved mesoscale ocean eddies, ocean dynamics (i.e., ocean heat flux convergence) dominates upper 50 m heat content variability over most of the globe. For deeper depths of integration to 400 m, the heat content variability at the grid scale is almost totally controlled by ocean heat flux convergence. However, a strong dependence on spatial scale is found—for the upper 50 m of ocean, after smoothing the data to around 7°, air–sea heat fluxes, augmented by Ekman heat transports, dominate. For deeper depths of integration to 400 m, the transition scale becomes larger and is above 10° in western boundary currents. Comparison of climate model results with observations show that the small-scale influence of ocean intrinsic variability is well captured by the high-resolution model but is missing from a comparable model with parameterized ocean-eddy effects. In the deep tropics, ocean dynamics dominatesmore »« less

Authors:

Small, R. Justin ^[1]; Bryan, Frank O. ^[1]; Bishop, Stuart P. ^[2]; Larson, Sarah ^[2]; Tomas, Robert A. ^[1]

National Center for Atmospheric Research, Boulder, Colorado
North Carolina State University, Raleigh, North Carolina

Publication Date:: 2019-12-19

Research Org.:: University Corporation for Atmospheric Research, Boulder, CO (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Biological and Environmental Research (BER); National Aeronautics and Space Administration (NASA); National Science Foundation (NSF)

OSTI Identifier:: 1580011

Alternate Identifier(s):: OSTI ID: 1801719

Grant/Contract Number:: SC0006743; NNX16AH60G; 80NSSC18K0769; OCI-0725070; ACI-1238993; ACI-1516624; 1852977

Resource Type:: Published Article

Journal Name:: Journal of Climate

Additional Journal Information:: Journal Name: Journal of Climate Journal Volume: 33 Journal Issue: 2; Journal ID: ISSN 0894-8755

Publisher:: American Meteorological Society

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; meteorology & atmospheric sciences; ocean dynamics; atmosphere-ocean interactoin; climate models

Citation Formats


                    Small, R. Justin, Bryan, Frank O., Bishop, Stuart P., Larson, Sarah, and Tomas, Robert A.. What Drives Upper-Ocean Temperature Variability in Coupled Climate Models and Observations?.  United States: N. p., 2019. 
Web.  doi:10.1175/JCLI-D-19-0295.1.

Copy to clipboard


                    Small, R. Justin, Bryan, Frank O., Bishop, Stuart P., Larson, Sarah, & Tomas, Robert A.. What Drives Upper-Ocean Temperature Variability in Coupled Climate Models and Observations?.  United States.  https://doi.org/10.1175/JCLI-D-19-0295.1

Copy to clipboard


                    Small, R. Justin, Bryan, Frank O., Bishop, Stuart P., Larson, Sarah, and Tomas, Robert A.. Thu .  
"What Drives Upper-Ocean Temperature Variability in Coupled Climate Models and Observations?".  United States.  https://doi.org/10.1175/JCLI-D-19-0295.1.

Copy to clipboard


                    
@article{osti_1580011,

  title        = {What Drives Upper-Ocean Temperature Variability in Coupled Climate Models and Observations?},

  author       = {Small, R. Justin and Bryan, Frank O. and Bishop, Stuart P. and Larson, Sarah and Tomas, Robert A.},

  abstractNote = {Abstract A key question in climate modeling is to what extent sea surface temperature and upper-ocean heat content are driven passively by air–sea heat fluxes, as opposed to forcing by ocean dynamics. This paper investigates the question using a climate model at different resolutions, and observations, for monthly variability. At the grid scale in a high-resolution climate model with resolved mesoscale ocean eddies, ocean dynamics (i.e., ocean heat flux convergence) dominates upper 50 m heat content variability over most of the globe. For deeper depths of integration to 400 m, the heat content variability at the grid scale is almost totally controlled by ocean heat flux convergence. However, a strong dependence on spatial scale is found—for the upper 50 m of ocean, after smoothing the data to around 7°, air–sea heat fluxes, augmented by Ekman heat transports, dominate. For deeper depths of integration to 400 m, the transition scale becomes larger and is above 10° in western boundary currents. Comparison of climate model results with observations show that the small-scale influence of ocean intrinsic variability is well captured by the high-resolution model but is missing from a comparable model with parameterized ocean-eddy effects. In the deep tropics, ocean dynamics dominates in all cases and all scales. In the subtropical gyres at large scales, air–sea heat fluxes play the biggest role. In the midlatitudes, at large scales >10°, atmosphere-driven air–sea heat fluxes and Ekman heat transport variability are the dominant processes except in the western boundary currents for the 400 m heat content.},

  doi          = {10.1175/JCLI-D-19-0295.1},

  journal      = {Journal of Climate},

  number       = 2,

  volume       = 33,

  place        = {United States},

  year         = {2019},

  month        = {12}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Publisher's Version of Record
https://doi.org/10.1175/JCLI-D-19-0295.1

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 29 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Air–Sea Turbulent Heat Fluxes in Climate Models and Observational Analyses: What Drives Their Variability?

Journal Article Small, R. Justin ; Bryan, Frank O. ; Bishop, Stuart P. ; ... - Journal of Climate

A traditional view is that the ocean outside of the tropics responds passively to atmosphere forcing, which implies that air–sea heat fluxes are mainly driven by atmosphere variability. This paper tests this viewpoint using state-of-the-art air–sea turbulent heat flux observational analyses and a climate model run at different resolutions. It is found herein that in midlatitude ocean frontal zones the variability of air–sea heat fluxes is not predominantly driven by the atmosphere variations but instead is forced by sea surface temperature (SST) variations arising from intrinsic oceanic variability. Meanwhile in most of the tropics and subtropics wind is the dominantmore »« less
Cited by 42
https://doi.org/10.1175/JCLI-D-18-0576.1
Surface Water Mass Transformation in the Southern Ocean: The Role of Eddies Revisited

Journal Article Small, R. Justin ; Bryan, Frank O. ; Bishop, Stuart P. - Journal of Physical Oceanography

The water mass transformation (WMT) framework describes how water of one class, such as a discrete interval of density, is converted into another class via air–sea fluxes or interior mixing processes. Here, this paper investigates how this process is modified at the surface when mesoscale ocean eddies are present, using a state-of-the-art high-resolution climate model with reasonable fidelity in the Southern Ocean. The method employed is to coarse-grain the high-resolution model fields to remove eddy signatures, and compare the results with those from the full model fields. This method shows that eddies reduced the WMT by 2–4 Sv (10%–20%; 1more »« less
https://doi.org/10.1175/jpo-d-21-0087.1

Full Text Available
Variability of bottom carbonate chemistry over the deep coral reefs in the Florida Straits and the impacts of mesoscale processes

Journal Article Jiang, Mingshun ; Pan, Chudong ; Barbero, Leticia ; ... - Ocean Modelling

Abundant and diverse cold-water coral and fish communities can be found in the deep waters of the Florida Straits, which are believed to be living under suboptimal conditions impacted by increasing oceanic CO₂ levels. Yet, little is known regarding the spatial-temporal variability of bottom carbonate chemistry parameters and their dynamic drivers in this area. To address this issue, we present results from numerical simulations of a coupled physical-biogeochemical model for the south Florida shelf and Florida Straits. Our exploratory analysis focuses on two well-known deep-coral habitats: Pourtalès Terrace (200-450 m) and Miami Terrace (270-600 m). Results suggest that bottom watersmore »« less
Cited by 2
https://doi.org/10.1016/j.ocemod.2019.101555

Full Text Available
Role of Ocean and Atmosphere Variability in Scale-Dependent Thermodynamic Air-Sea Interactions

Journal Article Laurindo, Lucas C. ; Small, R. Justin ; Thompson, LuAnne ; ... - Journal of Geophysical Research. Oceans

Abstract This study investigates the influence of oceanic and atmospheric processes in extratropical thermodynamic air‐sea interactions resolved by satellite observations (OBS) and by two climate model simulations run with eddy‐resolving high‐resolution (HR) and eddy‐parameterized low‐resolution (LR) ocean components. Here, spectral methods are used to characterize the sea surface temperature (SST) and turbulent heat flux (THF) variability and co‐variability over scales between 50 and 10,000 km and 60 days to 80 years in the Pacific Ocean. The relative roles of the ocean and atmosphere are interpreted using a stochastic upper‐ocean temperature evolution model forced by noise terms representing intrinsic variability in each medium, definedmore »« less
https://doi.org/10.1029/2021jc018340

Full Text Available
Using ARM Measurements to Understand and Reduce the Double ITCZ Biases in the Community Atmospheric Model

Technical Report Zhang, Minghua

1. Understanding of the observed variability of ITCZ in the equatorial eastern Pacific. The annual mean precipitation in the eastern Pacific has a maximum zonal band north of the equator in the ITCZ where the maximum SST is located. During the boreal spring (referring to February, March, and April throughout the present paper), because of the accumulated solar radiation heating and oceanic heat transport, a secondary maximum of SST exists in the southeastern equatorial Pacific. Associated with this warm SST is also a seasonal transitional maximum of precipitation in the same region in boreal spring, exhibited as a weak doublemore »« less
https://doi.org/10.2172/1334768

Full Text Available

Similar Records