The relationship between the global mean deep-sea and surface temperature during the Early Eocene

Barbara Goudsmit-Harzevoort*, Angelique Lansu, Michiel L.J. Baatsen, Anna S. von der Heydt, Niels J. de Winter, Yurui Zhang, Ayako Abe-Ouchi, Agatha de Boer, Wing-Le Chan, Yannick Donnadieu, David K. Hutchinson, Gregor Knorr, Jean-Baptiste Ladant, Polina Morozova, Igor Niezgodzki, Sebastian Steinig, Aradhna Tripati, Zhongshi Zhang, Jiang Zhu, Martin Ziegler

*Corresponding author for this work

Research output: Contribution to journalArticleAcademic


Estimates of global mean near-surface air temperature (global SAT) for the Cenozoic era rely largely on paleo-proxy data of deep-sea temperature (DST), with the assumption that changes in global SAT covary with changes in the global mean deep-sea temperature (global DST) and global mean sea-surface temperature (global SST). We tested the validity of this assumption by analyzing the relationship between global SST, SAT, and DST using 25 different model simulations from the Deep-Time Model Intercomparison Project simulating the early Eocene Climatic Optimum (EECO) with varying CO 2 levels. Similar to the modern situation, we find limited spatial variability in DST, indicating that local DST estimates can be regarded as a first order representative of global DST. In line with previously assumed relationships, linear regression analysis indicates that both global DST and SAT respond stronger to changes in atmospheric CO 2 than global SST by a similar factor. Consequently, this model-based analysis validates the assumption that changes in global DST can be used to estimate changes in global SAT during the early Cenozoic. Paleo-proxy estimates of global DST, SST, and SAT during EECO show the best fit with model simulations with a 1,680 ppm atmospheric CO 2 level. This matches paleo-proxies of EECO atmospheric CO 2, indicating a good fit between models and proxy-data.

Original languageEnglish
Article numbere2022PA004532
Number of pages18
JournalPaleoceanography and Paleoclimatology
Issue number3
Early online date17 Feb 2023
Publication statusPublished - Mar 2023


  • Climatology
  • Global Change
  • Oceanography
  • Paleoclimatology
  • Sea-Air Interactions
  • climate sensitivity
  • deep-sea temperature
  • DeepMIP
  • model-data comparison
  • early Eocene


Dive into the research topics of 'The relationship between the global mean deep-sea and surface temperature during the Early Eocene'. Together they form a unique fingerprint.

Cite this