EGU22-2076, updated on 27 Mar 2022
https://doi.org/10.5194/egusphere-egu22-2076
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Drivers and distribution of global ocean heat uptake over the last half century

Maurice Huguenin1,2, Ryan Holmes1,3,4, and Matthew England1,2
Maurice Huguenin et al.
  • 1Climate Change Research Centre and ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, New South Wales, Australia
  • 2Australian Centre of Excellence in Antarctic Science, University of New South Wales, Sydney, New South Wales, Australia
  • 3School of Mathematics and Statistics, University of New South Wales, Sydney, New South Wales, Australia
  • 4School of Geosciences, University of Sydney, Sydney, New South Wales, Australia

Since the 1970s, the ocean has absorbed almost all of the additional energy in the Earth system due to greenhouse warming. However, our knowledge of where ocean heat uptake (OHU) has occurred and where this heat is stored today is limited by sparse observations. Here, we use a global ocean-sea ice model forced by observationally constrained atmospheric fields to conduct hindcast simulations that are initialised from an equilibrated control simulation that improves on commonly used spin-up approaches. The hindcast with full interannual forcing captures the observed global ocean heat content evolution better than most previous ocean-sea ice model simulations. Applying trends in only surface winds or thermal properties reveals that each can explain ∼50% of the total ocean warming signal. These contributions, when restricted to the Southern Ocean, account for nearly all of the global OHU of 5.4 × 1021 J year-1. Integrated over the Southern Ocean, the sensible heat flux drives 75% more OHU than the longwave radiative flux in the simulation with only surface wind trends, while it is the opposite in the simulation with only trends in thermal properties. Almost 50% of the additional Southern Ocean-sourced heat signal is exported into the Atlantic Ocean where two-thirds of this added heat is then lost to the atmosphere.

How to cite: Huguenin, M., Holmes, R., and England, M.: Drivers and distribution of global ocean heat uptake over the last half century, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2076, https://doi.org/10.5194/egusphere-egu22-2076, 2022.

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