Mixed layer depth in the PMIP4 midHolocene simulations: comparison to proxy data in North Atlantic deep convection regions
- 1Geotop and Centre ESCER, Université du Québec à Montréal (UQAM), Montréal, Québec H3C 3P8, Canada
- 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
Abstract
The ocean mixed layer plays an essential role in the climate system, regulating energy fluxes at the ocean-atmosphere interface. Its representation in climate models is thus critical. Here, we evaluate the mixed layer depth (MLD) in 15 models from the Paleoclimate Modelling Intercomparison Project 4 (PMIP4) against dinocyst-based MLD reconstructions from the subpolar North Atlantic for the mid-Holocene (MH, 6 ka BP). We find a large spread in MLD responses to MH forcings across the models in the present-day deep-water formation areas, underscoring the importance of model uncertainty. Most models fail to capture the direction of MLD change, and the ensemble mean does not necessarily outperform individual models. While the ensemble mean aligns broadly with proxy data in the Nordic Seas, pronounced proxy-model discrepancy in the Labrador Sea suggests that meltwater forcing is a missing parameter, and that deep-water formation in the Labrador Sea may be particularly vulnerable under a future scenario of global warming and ice-sheet melting.
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BibTeX
@article{wu2026mixed,
title = {{Mixed layer depth in the PMIP4 midHolocene simulations: comparison to proxy data in North Atlantic deep convection regions}},
author = {Xiner Wu and Anne de Vernal and Paul G. Myers},
journal = {Climate of the Past},
year = {2026},
month = sep,
doi = {10.5194/cp-22-1609-2026},
url = {https://doi.org/10.5194/cp-22-1609-2026},
note = {CC BY},
}
RIS
TY - JOUR
TI - Mixed layer depth in the PMIP4 midHolocene simulations: comparison to proxy data in North Atlantic deep convection regions
AU - Xiner Wu
AU - Anne de Vernal
AU - Paul G. Myers
PY - 2026
DA - 2026/09/01
JO - Climate of the Past
DO - 10.5194/cp-22-1609-2026
UR - https://doi.org/10.5194/cp-22-1609-2026
AB - The ocean mixed layer plays an essential role in the climate system, regulating energy fluxes at the ocean-atmosphere interface. Its representation in climate models is thus critical. Here, we evaluate the mixed layer depth (MLD) in 15 models from the Paleoclimate Modelling Intercomparison Project 4 (PMIP4) against dinocyst-based MLD reconstructions from the subpolar North Atlantic for the mid-Holocene (MH, 6 ka BP). We find a large spread in MLD responses to MH forcings across the models in the present-day deep-water formation areas, underscoring the importance of model uncertainty. Most models fail to capture the direction of MLD change, and the ensemble mean does not necessarily outperform individual models. While the ensemble mean aligns broadly with proxy data in the Nordic Seas, pronounced proxy-model discrepancy in the Labrador Sea suggests that meltwater forcing is a missing parameter, and that deep-water formation in the Labrador Sea may be particularly vulnerable under a future scenario of global warming and ice-sheet melting.
SN - 1814-9324
SN - 1814-9332
ER -