Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability

Abstract Most coupled climate models simulate an overly shallow thermocline over the southeastern equatorial Indian Ocean (SEIO). Through the Bjerknes feedback loop, the associated unrealistic thermocline tilt leads to warmer sea surface temperature (SST) over the western equatorial Indian Ocean tha...

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Main Authors: Guojian Wang, Wenju Cai, Agus Santoso
Format: Article
Language:English
Published: Wiley 2021-03-01
Series:Geophysical Research Letters
Online Access:https://doi.org/10.1029/2020GL091902
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author Guojian Wang
Wenju Cai
Agus Santoso
author_facet Guojian Wang
Wenju Cai
Agus Santoso
author_sort Guojian Wang
collection DOAJ
description Abstract Most coupled climate models simulate an overly shallow thermocline over the southeastern equatorial Indian Ocean (SEIO). Through the Bjerknes feedback loop, the associated unrealistic thermocline tilt leads to warmer sea surface temperature (SST) over the western equatorial Indian Ocean than the SEIO, which is conducive to equatorial easterly winds. Similar to phase 5 of the Coupled Model Intercomparison Project (CMIP), phase 6 of the CMIP continues to simulate such overly tilted thermocline. On the one hand, this leads to overly strong SST variability, and on the other hand, it provides an inherent limit for the thermocline to incline further under greenhouse warming. Consequently, models with a more realistic tilt in the present‐day climate project a greater shoaling of the thermocline under global warming, which facilities upwelling of cool subsurface water, leading to stronger increase in SST variability over the SEIO, compared to models with an overly large thermocline tilt.
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institution Kabale University
issn 0094-8276
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language English
publishDate 2021-03-01
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series Geophysical Research Letters
spelling doaj-art-34fb7843898e47cf9cee3ec975e1ad342025-08-20T03:48:43ZengWileyGeophysical Research Letters0094-82761944-80072021-03-01486n/an/a10.1029/2020GL091902Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature VariabilityGuojian Wang0Wenju Cai1Agus Santoso2Key Laboratory of Physical Oceanography–Institute for Advanced Ocean Studies Ocean University of China and Qingdao National Laboratory for Marine Science and Technology Qingdao ChinaKey Laboratory of Physical Oceanography–Institute for Advanced Ocean Studies Ocean University of China and Qingdao National Laboratory for Marine Science and Technology Qingdao ChinaCenter for Southern Hemisphere Oceans Research (CSHOR) CSIRO Oceans and Atmosphere Hobart TAS AustraliaAbstract Most coupled climate models simulate an overly shallow thermocline over the southeastern equatorial Indian Ocean (SEIO). Through the Bjerknes feedback loop, the associated unrealistic thermocline tilt leads to warmer sea surface temperature (SST) over the western equatorial Indian Ocean than the SEIO, which is conducive to equatorial easterly winds. Similar to phase 5 of the Coupled Model Intercomparison Project (CMIP), phase 6 of the CMIP continues to simulate such overly tilted thermocline. On the one hand, this leads to overly strong SST variability, and on the other hand, it provides an inherent limit for the thermocline to incline further under greenhouse warming. Consequently, models with a more realistic tilt in the present‐day climate project a greater shoaling of the thermocline under global warming, which facilities upwelling of cool subsurface water, leading to stronger increase in SST variability over the SEIO, compared to models with an overly large thermocline tilt.https://doi.org/10.1029/2020GL091902
spellingShingle Guojian Wang
Wenju Cai
Agus Santoso
Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability
Geophysical Research Letters
title Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability
title_full Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability
title_fullStr Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability
title_full_unstemmed Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability
title_short Simulated Thermocline Tilt Over the Tropical Indian Ocean and Its Influence on Future Sea Surface Temperature Variability
title_sort simulated thermocline tilt over the tropical indian ocean and its influence on future sea surface temperature variability
url https://doi.org/10.1029/2020GL091902
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AT wenjucai simulatedthermoclinetiltoverthetropicalindianoceananditsinfluenceonfutureseasurfacetemperaturevariability
AT agussantoso simulatedthermoclinetiltoverthetropicalindianoceananditsinfluenceonfutureseasurfacetemperaturevariability