For a fuller description of the paper itself, go to the end of this web page.
Each simulation published in this paper corresponds to a unique 5 or 6 character code on the web pages.
The following table lists the name of the simulation as used in the paper, and the corresponding code name
The webpage gives you the ability to examine the published simulations, but you can also download the raw (netcdf) files to perform your own analysis. Detailed instructions on how to use the webpages and access the data can be found here: Using_BRIDGE_webpages.pdf
These are the key simulations showing two sets of 109 simulations covering the whole of the Phanerozoic using Scotese paleogeography and two altnerative CO2 reconstructions.
You can have make you own analysis and plots by going here
| Name of sequence of simulations as in Paper | Simulation sequence name as in web pages | Detailed description of individual simulations within sequence |
|---|---|---|
| scotese_spinupa - Sequence of simulations using the smoothedCO2 curve. This is the last 500 years from a 5500 year spinup run | scotese_spinupa | Detailed List of Runs |
| scotese_02 - Sequence of simulations using the Foster et al 2017 CO2 reconstructions. These are at the end of simulations, totalling up to 5000 years | scotese_02 | Detailed List of Runs |
This paper present initial results from two unique sets of paleogeographic simulations covering the whole of the Phanerozoic at stage level resolutions. The climate model is HadCM3L (Hadley Centre climate model) which is a coupled atmosphere-ocean-vegetation model.
| Name | Valdes et al 2021 |
|---|---|
| Brief Description | This paper present initial results from two unique sets of paleogeographic simulations covering the whole of the Phanerozoic at stage level resolutions. The climate model is HadCM3L (Hadley Centre climate model) which is a coupled atmosphere-ocean-vegetation model. |
| Full Author List | Valdes, P.J., Scotese, C.R., and Lunt, D.J. |
| Title | Deep Ocean Temperatures through Time |
| Year | 2021 |
| Journal | Climates of the Past |
| Volume | xx |
| Issue | 3-4 |
| Pages | xx |
| DOI | xx |
| Contact's Name | Paul Valdes |
| Contact's email | p.j.valdes@bristol.ac.uk |
| Abstract | Benthic oxygen isotope records are commonly used as a proxy for global mean surface temperatures during the late Cretaceous and Cenozoic, and the resulting estimates have been extensively used in characterising major trends and transitions in the climate system, and for analysing past climate sensitivity. However, some fundamental assumptions governing this proxy have rarely been tested. Two key assumptions are: (a) benthic foraminiferal temperatures are geographically well mixed and are linked to surface high latitude temperatures, and (b) surface high latitude temperatures are well correlated with global mean temperatures. To investigate the robustness of these assumptions through geological time, we performed a series of 109 climate model simulations using a unique set of paleogeographical reconstructions covering the entire Phanerozoic at the stage-level. The simulations have been run for at least 5000 model years to ensure that the deep ocean is in dynamic equilibrium. We find that the correlation between deep ocean temperatures and global mean surface temperatures is good for the Cenozoic and thus the proxy data are reliable indicators for this time period, albeit with a standard error of 2K. This uncertainty has not normally been assessed and needs to be combined with other sources of uncertainty when, for instance, estimating climate sensitivity based on using δ18O measurements from benthic foraminifera. The correlation between deep and global mean surface temperature becomes weaker for pre-Cenozoic time periods (when the paleogeography is significantly different than the present-day). The reasons for the weaker correlation includes variability in the source region of the deep water (varying hemispheres but also varying latitudes of sinking), the depth of ocean overturning (some extreme warm climates have relatively shallow and sluggish circulations weakening the link between surface and deep ocean), and the extent of polar amplification (e.g. ice albedo feedbacks). Deep ocean sediments prior to the Cretaceous are rare, so extending the benthic foram proxy further into deeper time is problematic, but the model results presented here would suggest that the predicted deep ocean temperatures would probably be unreliable. |