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Enhanced hydrological cycle increases ocean heat uptake and moderates transient climate change


The large-scale moistening of the atmosphere in response to increasing greenhouse gases amplifies the existing patterns of precipitation minus evaporation (P − E), which, in turn, amplifies the spatial contrast in sea surface salinity. Here, by performing a series of transient CO2 doubling experiments, we demonstrate that surface salinification driven by the amplified dry conditions (P − E < 0), primarily in the subtropical ocean, accelerates ocean heat uptake. The salinification also drives the sequestration of upper-level heat into the deeper ocean, reducing the thermal stratification and increasing the heat uptake through positive feedback. The change in Atlantic Meridional Overturning Circulation due to salinification has a secondary role in heat uptake. Consistent with the heat uptake changes, the transient climate response would increase by approximately 0.4 K without this process. Observed multidecadal changes in subsurface temperature and salinity resemble those simulated, indicating that anthropogenically forced changes in salinity are probably enhancing ocean heat uptake.

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Fig. 1: The response of surface temperature to transient CO2 forcing.
Fig. 2: The impact of fixed SSS on the response of OHC and TOA net radiation to CO2 forcing.
Fig. 3: The impact of fixed SSS on the model response to CO2 doubling.
Fig. 4: The impact of fixed SSS on the response of ocean stratification to CO2 doubling.
Fig. 5: Comparison between FLOR model experiments and observations.

Data availability

The NCEI ocean salinity and temperature data are available online ( The JMA data are available online ( The IAP data are available at The ORAS4 data are available at The input data for running the FLOR experiments presented in this work and processed data for graphics from the four datasets and FLOR model outputs are available at tigress-web at Princeton University (

Code availability

The climate model used in this study is GFDL FLOR with code available at the NOAA/GFDL website ( All graphics were produced using Python v.3.6 ( The codes needed to set up the FLOR experiment and Python scripts used for analyses and producing main figures are available at GitHub (;


  1. 1.

    Mitchell, J. F. B., Manabe, S., Meleshko, V. & Tokioka, T. in IPCC Climate Change: The IPCC Scientific Assessment (eds Houghton, J. T., Jenkins, G. J. & Ephraums, J. J.) (Cambridge Univ. Press, 1990).

  2. 2.

    Cheng, L., Abraham, J., Hausfather, Z. & Trenberth, K. E. How fast are the oceans warming? Science 363, 128–129 (2019).

    CAS  Article  Google Scholar 

  3. 3.

    Trenberth, K. E., Fasullo, J. T. & Balmaseda, M. A. Earth’s energy imbalance. J. Clim. 27, 3129–3144 (2014).

    Article  Google Scholar 

  4. 4.

    Li, G. et al. Increasing ocean stratification over the past half-century. Nat. Clim. Chang. 10, 1116–1123 (2020).

    Article  Google Scholar 

  5. 5.

    Stevens, S. W., Johnson, R. J., Maze, G. & Bates, N. R. A recent decline in North Atlantic subtropical mode water formation. Nat. Clim. Chang. 10, 335–341 (2020).

    Article  Google Scholar 

  6. 6.

    Ishii, M. et al. Accuracy of global upper ocean heat content estimation expected from present observational data sets. Sola 13, 163–167 (2017).

    Article  Google Scholar 

  7. 7.

    Cheng, L. et al. Improved estimates of ocean heat content from 1960 to 2015. Sci. Adv. 3, e1601545 (2017).

    Article  Google Scholar 

  8. 8.

    Domingues, C. M. et al. Improved estimates of upper-ocean warming and multi-decadal sea-level rise. Nature 453, 1090–1093 (2008).

    CAS  Article  Google Scholar 

  9. 9.

    Abraham, J. P. et al. A review of global ocean temperature observations: implications for ocean heat content estimates and climate change. Rev. Geophys. 51, 450–483 (2013).

    Article  Google Scholar 

  10. 10.

    von Schuckmann, K. et al. Heat stored in the Earth system: where does the energy go? Earth Syst. Sci. Data 12, 2013–2041 (2020).

    Article  Google Scholar 

  11. 11.

    Meyssignac, B. et al. Measuring global ocean heat content to estimate the earth energy imbalance. Front. Mar. Sci. 6, 432 (2019).

    Article  Google Scholar 

  12. 12.

    Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).

    Article  Google Scholar 

  13. 13.

    Larson, E. J. L., Portmann, R. W., Solomon, S. & Murphy, D. M. Decadal attribution of historic temperature and ocean heat content change to anthropogenic emissions. Geophys. Res. Lett. 47, e2019GL085905 (2020).

    CAS  Article  Google Scholar 

  14. 14.

    Bronselaer, B. & Zanna, L. Heat and carbon coupling reveals ocean warming due to circulation changes. Nature 584, 227–233 (2020).

    CAS  Article  Google Scholar 

  15. 15.

    Bilbao, R. A. F., Gregory, J. M., Bouttes, N., Palmer, M. D. & Stott, P. Attribution of ocean temperature change to anthropogenic and natural forcings using the temporal, vertical and geographical structure. Clim. Dyn. 53, 5389–5413 (2019).

    Article  Google Scholar 

  16. 16.

    Levitus, S. et al. World ocean heat content and thermosteric sea level change (0-2000 m), 1955-2010. Geophys. Res. Lett. 39, L10603 (2012).

    Article  Google Scholar 

  17. 17.

    Vecchi, G. A. et al. Tropical cyclone sensitivities to CO2 doubling: roles of atmospheric resolution, synoptic variability and background climate changes. Clim. Dyn. 53, 5999–6033 (2019).

    Article  Google Scholar 

  18. 18.

    Capotondi, A., Alexander, M. A., Bond, N. A., Curchitser, E. N. & Scott, J. D. Enhanced upper ocean stratification with climate change in the CMIP3 models. J. Geophys. Res. Oceans 117, C04031 (2012).

    Article  Google Scholar 

  19. 19.

    Durack, P. J. & Wijffels, S. E. Fifty-year trends in global ocean salinities and their relationship to broad-scale warming. J. Clim. 23, 4342–4362 (2010).

    Article  Google Scholar 

  20. 20.

    Durack, P. J., Wijffels, S. E. & Matear, R. J. Ocean salinities reveal strong global water cycle intensification during 1950 to 2000. Science 336, 455–458 (2012).

    CAS  Article  Google Scholar 

  21. 21.

    Skliris, N. et al. Salinity changes in the World Ocean since 1950 in relation to changing surface freshwater fluxes. Clim. Dyn. 43, 709–736 (2014).

    Article  Google Scholar 

  22. 22.

    Terray, L. et al. Near-surface salinity as nature’s rain gauge to detect human influence on the tropical water cycle. J. Clim. 25, 958–977 (2012).

    Article  Google Scholar 

  23. 23.

    Lago, V. et al. Simulating the role of surface forcing on observed multidecadal upper-ocean salinity changes. J. Clim. 29, 5575–5588 (2016).

    Article  Google Scholar 

  24. 24.

    Held, I. M. & Soden, B. J. Robust responses of the hydrological cycle to global warming. J. Clim. 19, 5686–5699 (2006).

    Article  Google Scholar 

  25. 25.

    IPCC Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).

  26. 26.

    Bindoff, N. L. et al. IPCC Special Report on the Ocean and Cryosphere in a Changing Climate 477–587 (IPCC, 2019).

  27. 27.

    Vecchi, G. A. et al. On the seasonal forecasting of regional tropical cyclone activity. J. Clim. 27, 7994–8016 (2014).

    Article  Google Scholar 

  28. 28.

    Gregory, J. M. & Mitchell, J. F. B. The climate response to CO2 of the Hadley Centre coupled AOGCM with and without flux adjustment. Geophys. Res. Lett. 24, 1943–1946 (1997).

    CAS  Article  Google Scholar 

  29. 29.

    Raper, S. C. B., Gregory, J. M. & Stouffer, R. J. The role of climate sensitivity and ocean heat uptake on AOGCM transient temperature response. J. Clim. 15, 124–130 (2002).

    Article  Google Scholar 

  30. 30.

    Stott, P. A., Sutton, R. T. & Smith, D. M. Detection and attribution of Atlantic salinity changes. Geophys. Res. Lett. 35, L21702 (2008).

    Article  Google Scholar 

  31. 31.

    Pierce, D. W., Gleckler, P. J., Barnett, T. P., Santer, B. D. & Durack, P. J. The fingerprint of human-induced changes in the ocean’s salinity and temperature fields. Geophys. Res. Lett. 39, 2–7 (2012).

    Article  Google Scholar 

  32. 32.

    Stouffer, R. J. et al. Investigating the cause of the response of the thermohaline circulation to past and future climage changes. J. Clim. 19, 1365–1387 (2006).

    Article  Google Scholar 

  33. 33.

    Liu, W., Fedorov, A. V., Xie, S.-P. & Hu, S. Climate impacts of a weakened Atlantic Meridional Overturning Circulation in a warming climate. Sci. Adv. 6, eaaz4876 (2020).

    Article  Google Scholar 

  34. 34.

    Levang, S. J. & Schmitt, R. W. What causes the AMOC to weaken in CMIP5? J. Clim. 33, 1535–1545 (2019).

    Article  Google Scholar 

  35. 35.

    Silvy, Y., Guilyardi, E., Sallée, J.-B. & Durack, P. J. Human-induced changes to the global ocean water masses and their time of emergence. Nat. Clim. Chang. 10, 1030–1036 (2020).

    CAS  Article  Google Scholar 

  36. 36.

    Robson, J., Ortega, P. & Sutton, R. A reversal of climatic trends in the North Atlantic since 2005. Nat. Geosci. 9, 513–517 (2016).

    CAS  Article  Google Scholar 

  37. 37.

    Jackson, L. C., Peterson, K. A., Roberts, C. D. & Wood, R. A. Recent slowing of Atlantic overturning circulation as a recovery from earlier strengthening. Nat. Geosci. 9, 518–522 (2016).

    CAS  Article  Google Scholar 

  38. 38.

    Thornalley, D. J. R. et al. Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years. Nature 556, 227–230 (2018).

    CAS  Article  Google Scholar 

  39. 39.

    Caesar, L., Rahmstorf, S. & Feulner, G. On the relationship between Atlantic meridional overturning circulation slowdown and global surface warming. Environ. Res. Lett. 15, 24003 (2020).

    Article  Google Scholar 

  40. 40.

    Armour, K. C., Marshall, J., Scott, J. R., Donohoe, A. & Newsom, E. R. Southern Ocean warming delayed by circumpolar upwelling and equatorward transport. Nat. Geosci. 9, 549–554 (2016).

    CAS  Article  Google Scholar 

  41. 41.

    Meehl, G. A. et al. Context for interpreting equilibrium climate sensitivity and transient climate response from the CMIP6 Earth system models. Sci. Adv. 6, eaba1981 (2020).

    Article  Google Scholar 

  42. 42.

    Jia, L. et al. Improved seasonal prediction of temperature and precipitation over land in a high-resolution GFDL climate model. J. Clim. 28, 2044–2062 (2015).

    Article  Google Scholar 

  43. 43.

    Soden, B. J. et al. Quantifying climate feedbacks using radiative kernels. J. Clim. 21, 3504–3520 (2008).

    Article  Google Scholar 

  44. 44.

    Zhang, B., Kramer, R. J. & Soden, B. J. Radiative feedbacks associated with the Madden–Julian oscillation. J. Clim. 32, 7055–7065 (2019).

    Article  Google Scholar 

  45. 45.

    Kramer, R. J., Matus, A. V., Soden, B. J. & L’Ecuyer, T. S. Observation-based radiative kernels from CloudSat/CALIPSO. J. Geophys. Res. Atmos. 124, 5431–5444 (2019).

    Article  Google Scholar 

  46. 46.

    Cerovecki, I., Talley, L. D. & Mazloff, M. R. A Comparison of Southern Ocean air-sea buoyancy flux from an ocean state estimate with five other products. J. Clim. 24, 6283–6306 (2011).

    Article  Google Scholar 

  47. 47.

    Cheng, L. et al. Improved estimates of changes in upper ocean salinity and the hydrological cycle. J. Clim. 33, 10357–10381 (2020).

    Article  Google Scholar 

  48. 48.

    Balmaseda, M. A., Mogensen, K. & Weaver, A. T. Evaluation of the ECMWF ocean reanalysis system ORAS4. Q. J. R. Meteorol. Soc. 139, 1132–1161 (2013).

    Article  Google Scholar 

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This work was supported by award 80NSSC20K0879 from the National Aeronautics and Space Administration and award DE-SC0021333 from the US Department of Energy. The simulations presented in this paper were performed on computational resources managed and supported by Princeton Research Computing at Princeton University.

Author information




B.S., G.V. and M.L. designed the research. G.V., M.L. and W.Y. performed the simulations. M.L. and B.Z. performed the analysis. M.L. wrote the draft. All of the authors contributed to interpreting the results and writing the paper.

Corresponding author

Correspondence to Maofeng Liu.

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The authors declare no competing interests.

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Peer review information Nature Climate Change thanks Veronique Lago, M. Cameron Rencurrel and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Text 1 and 2, Figs. 1–20 and Table 1.

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Liu, M., Vecchi, G., Soden, B. et al. Enhanced hydrological cycle increases ocean heat uptake and moderates transient climate change. Nat. Clim. Chang. 11, 848–853 (2021).

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