Abstract
Anthropogenic influences have led to a strengthening and poleward shift of westerly winds over the Southern Ocean, especially during austral summer. We use observations, an idealized eddy-resolving ocean sea ice channel model, and a global coupled model to explore the Southern Ocean response to a step change in westerly winds. Previous work hypothesized a two time scale response for sea surface temperature. Initially, Ekman transport cools the surface before sustained upwelling causes warming on decadal time scales. The fast response is robust across our models and the observations: We find Ekman-driven cooling in the mixed layer, mixing-driven warming below the mixed layer, and a small upwelling-driven warming at the temperature inversion. The long-term response is inaccessible from observations. Neither of our models shows a persistent upwelling anomaly, or long-term, upwelling-driven subsurface warming. Mesoscale eddies act to oppose the anomalous wind-driven upwelling, through a process known as eddy compensation, thereby preventing long-term warming.
| Original language | English |
|---|---|
| Pages (from-to) | 4365-4377 |
| Number of pages | 13 |
| Journal | Geophysical Research Letters |
| Volume | 46 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2019 Apr 28 |
Bibliographical note
Funding Information:E. W. D. acknowledges support from the NSF's FESD program. J. M. acknowledges support from the MIT-GISS collaborative agreement and the NSF Polar Antarctic Program. H. S. was supported (in part) by the Yonsei University Future-leading Research Initiative of 2018 (2018-22-0053). We gratefully acknowledge Hannah Zanowski, David Ferreira, and an anonymous reviewer for their insightful comments that substantially improved this manuscript. Climate modeling at NASA-GISS is supported by the NASA Modeling, Analysis, and Prediction program. Computational resources for the E2.1 simulations in this study were provided by the NASA High-End Computing Program through the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. We are grateful to Douglas Kinnison for assistance with the ozone perturbation for the GISS simulations. The National Center for Atmospheric Research (NCAR) is sponsored by the U.S. National Science Foundation (NSF). WACCM is a component of NCAR's Community Earth System Model (CESM), which is supported by the NSF and the Office of Science of the U.S. Department of Energy. Computing resources were provided by NCAR's Climate Simulation Laboratory, sponsored by NSF and other agencies. This research was enabled by the computational and storage resources of NCAR's Computational and Information Systems Laboratory (CISL). The WACCM model output and data used in this paper are listed in the references or available from the NCAR Earth System Grid. The numerical simulations presented in this study relied on numerous contributions to the literature that are detailed in the supporting information (Adcroft et al.,; Dee et al.,; Garcia et al.,; Gaspar et al.,; Gent & Mcwilliams,; Gent et al.,; Hunke & Dukowicz,; Kinnison et al.,; Kunz et al.,; Lamarque et al.,; Large & Pond,; Large & Yeager,; Large et al.,; Lin,; Locarnini et al.,; Losch et al.,; Marsh et al.,; Marshall, Hill, et al., , Marshall, Adcroft, et al.,; Morgenstern et al.,; Neale et al.,; Redi,; Rienecker et al.,; Schmidt et al.,; Solomon et al.,; Tilmes et al.,; Visbeck et al.,; Winton,; Zweng et al.,).
Funding Information:
E. W. D. acknowledges support from the NSF's FESD program. J. M. acknowledges support from the MIT-GISS collaborative agreement and the NSF Polar Antarctic Program. H. S. was supported (in part) by the Yonsei University Future-leading Research Initiative of 2018 (2018-22-0053). We gratefully acknowledge Hannah Zanowski, David Ferreira, and an anonymous reviewer for their insightful comments that substantially improved this manuscript. Climate modeling at NASA-GISS is supported by the NASA Modeling, Analysis, and Prediction program. Computational resources for the E2.1 simulations in this study were provided by the NASA High-End Computing Program through the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center. We are grateful to Douglas Kinnison for assistance with the ozone perturbation for the GISS simulations. The National Center for Atmospheric Research (NCAR) is sponsored by the U.S. National Science Foundation (NSF). WACCM is a component of NCAR's Community Earth System Model (CESM), which is supported by the NSF and the Office of Science of the U.S. Department of Energy. Computing resources were provided by NCAR's Climate Simulation Laboratory, sponsored by NSF and other agencies. This research was enabled by the computational and storage resources of NCAR's Computational and Information Systems Laboratory (CISL). The WACCM model output and data used in this paper are listed in the references or available from the NCAR Earth System Grid. The numerical simulations presented in this study relied on numerous contributions to the literature that are detailed in the supporting information (Adcroft et al., 1997; Dee et al., 2011; Garcia et al., 2007, 2017; Gaspar et al., 1990; Gent & Mcwilliams, 1990; Gent et al., 1995; Hunke & Dukowicz, 1997; Kinnison et al., 2007; Kunz et al., 2011; Lamarque et al., 2012; Large & Pond, 1982; Large & Yeager, 2009; Large et al., 1994; Lin, 2004; Locarnini et al., 2013; Losch et al., 2010; Marsh et al., 2013; Marshall, Hill, et al., 1997, 1998, Marshall, Adcroft, et al., 1997; Morgenstern et al., 2017; Neale et al., 2013; Redi, 1982; Rienecker et al., 2011; Schmidt et al., 2014; Solomon et al., 2015; Tilmes et al., 2016; Visbeck et al., 1997; Winton, 2000; Zweng et al., 2013).
Publisher Copyright:
©2019. American Geophysical Union. All Rights Reserved.
All Science Journal Classification (ASJC) codes
- Geophysics
- Earth and Planetary Sciences(all)