Global impacts of a subaerial Barents Sea on the mid-Pliocene climate

A long-standing challenge for mid-Pliocene climate simulations is large underestimation of simulated surface warming in the Nordic Seas in comparison to sea surface temperature (SST) proxy records (e.g. Dowsett et al., 2013; McClymont et al., 2020). Previous modelling studies have proposed that geographic changes in the Barents-Kara Sea are of great importance for surface temperature change in the Nordic Seas (e.g., Hill, 2015). That is, changing the Barents Sea from a marine to a subaerial setting can give rise to evident warming in the Nordic Seas. Nevertheless, this geographic change has so far not been well considered in the Pliocene Modelling Intercomparison Project (Haywood et al., 2016 a,b), potentially due to the lack of quantitative reconstruction of this paleogeographic change. Recently, Lien et al. (2022) provided such reconstruction, which enables a test of the impact of a subaerial Barents Sea on mid-Pliocene climate. Based on iCESM1.2, we accordingly conducted sensitivity experiments where we changed bathymetry in the eastern Nordic Sea and topography in the Barents-Kara Sea region in a setup of otherwise unaltered PRISM4 mid-Pliocene boundary conditions (Dowsett et al., 20016). Our results hint that a subaerial Barents-Kara Sea might contribute to a reduction of the data-model SST mismatch during the mid-Pliocene.

References:

Dowsett, H., Foley, K., Stoll, D., et al., 2013. Sea Surface Temperature of the Mid-Piacenzian Ocean: A Data-Model Comparison: Science Reports, vol. 3. https://doi.org/10.1038/srep02013.

Dowsett, H., Dolan, A., Rowley, D., Moucha, R., Forte, A. M., Mitrovica, J. X., Pound, M., Salzmann, U., Robinson, M., Chandler, M., Foley, K., and Haywood, A., 2016. The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction, Clim. Past, 12, 1519–1538, https://doi.org/10.5194/cp-12-1519-2016.

Haywood, A.M., Dowsett, H.J., Dolan, A.M., 2016a. Integrating geological archives and climate models for the mid-Pliocene warm period. Nat. Commun. 7, 10646. https://doi.org/10.1038/ncomms10646.

Haywood, A.M., Dowsett, H.J., Dolan, A.M., Rowley, D., Abe-Ouchi, A., Otto-Bliesner, B., Chandler, M.A., Hunter, S.J., Lunt, D.J., Pound, M., Salzmann, U.,2016b. The Pliocene model Intercomparison project (PlioMIP) phase 2: scientific objectives and experimental design. Clim. Past 12, 663e675. https://doi.org/10.5194/cp-12-663-2016.

Hill, D.J., 2015. The non-analogue nature of Pliocene temperature gradients. Earth Planet Sci. Lett. 425, 232e241. https://doi.org/10.1016/j.epsl.2015.05.044

Lien, Ø. F.,  Hjelstuen, B. O.; Zhang, X.; Sejrup H. P., 2022. Late Plio-Pleistocene evolution of the Eurasian Ice Sheets inferred from sediment input along the northeastern Atlantic continental margin. Quat. Sci. Rev. 282, 107433. https://doi.org/10.1016/j.quascirev.2022.107433

McClymont, E. L., Ford, H. L., Ho, S. L., Tindall, J. C., Haywood, A. M., Alonso-Garcia, M., Bailey, I., Berke, M. A., Littler, K., Patterson, M. O., Petrick, B., Peterse, F., Ravelo, A. C., Risebrobakken, B., De Schepper, S., Swann, G. E. A., Thirumalai, K., Tierney, J. E., van der Weijst, C., White, S., Abe-Ouchi, A., Baatsen, M. L. J., Brady, E. C., Chan, W.-L., Chandan, D., Feng, R., Guo, C., von der Heydt, A. S., Hunter, S., Li, X., Lohmann, G., Nisancioglu, K. H., Otto-Bliesner, B. L., Peltier, W. R., Stepanek, C., and Zhang, Z., 2020: Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago, Clim. Past, 16, 1599–1615, https://doi.org/10.5194/cp-16-1599-2020.