Input Data for Figure 7.13 from Chapter 7 of the Working Group I (WGI) Contribution to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6).

Figure 7.13 shows polar amplification in paleo proxies and models of the Early Eocene Climatic Optimum (EECO), the Mid-Pliocene Warm Period (MPWP) and the Last Glacial Maximum (LGM).

---------------------------------------------------
How to cite this dataset
---------------------------------------------------
When citing this dataset, please include both the data citation below (under 'Citable as') and the following citation for the report component from which the figure originates:
Forster, P., T. Storelvmo, K. Armour, W. Collins, J.-L. Dufresne, D. Frame, D.J. Lunt, T. Mauritsen, M.D. Palmer, M. Watanabe, M. Wild, and H. Zhang, 2021: The Earth’s Energy Budget, Climate Feedbacks, and Climate Sensitivity. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 923–1054, doi:10.1017/9781009157896.009.

---------------------------------------------------
Figure subpanels
---------------------------------------------------
The figure has 12 subpanels, with input data provided for panels a-l.

---------------------------------------------------
List of data provided
---------------------------------------------------
This dataset contains:

Temperature anomalies compared with pre-industrial (equivalent to CMIP6 simulation ‘piControl’) for:
- the high-CO2 EECO and MPWP time periods
- the low-CO2 LGM (expressed as pre-industrial minus LGM)

(a), (b) and (c) Modelled near-surface air temperature anomalies for ensemble-mean simulations of the (a) EECO (Lunt et al., 2021); (b) MPWP (Haywood et al., 2020; Zhang et al., 2021); and (c) LGM (Kageyama et al., 2021; Zhu et al., 2021). Also shown are proxy near-surface air temperature anomalies (coloured circles).

(d), (e) and (f) Proxy near-surface air temperature anomalies (grey circles), including published uncertainties (grey vertical bars), model ensemble mean zonal mean anomaly (solid red line) for the same model ensembles as in (a–c), light-red lines show the modelled temperature anomaly for the individual models that make up each ensemble (LGM, N=9; MPWP, N=17; EECO, N=5).

(g), (h) and (i) Proxy sea surface temperature (SST) anomalies, including published uncertainties (grey vertical bars), model ensemble mean zonal mean anomaly (solid red line) for the same model ensembles as in (j-l), light-red lines show the modelled temperature anomaly for the individual models that make up each ensemble (LGM, N=9; MPWP, N=17; EECO, N=5).

(j), (k) and (l) Modelled sea surface temperature (SST) for ensemble-mean simulations of the (a) EECO (Lunt et al., 2021); (b) MPWP (Haywood et al., 2020; Zhang et al., 2021); and (c) LGM (Kageyama et al., 2021; Zhu et al., 2021).

Black dashed lines show the average of the proxy values in each latitude band: 90°S–30°S, 30°S–30°N, and 30°N–90°N.
Red dashed lines show the same banded average in the model ensemble mean, calculated from the same locations as the proxies.
Black and red dashed lines are only shown if there are five or more proxy points in that band.

Mean differences between the 90°S/N to 30°S/N and 30°S to 30°N bands are quantified for the models and proxies in each plot.

For the EECO maps – (a) and (j) – the anomalies are relative to the zonal mean of the pre-industrial, due to the different continental configuration. Proxy datasets are: (a) and (d) Hollis et al. (2019); (b) and (e) Salzmann et al. (2013); Vieira et al. (2018), (c) and (f) Cleator et al. (2020) at the sites defined in Bartlein et al. (2011); (g) and (j) Hollis et al. (2019); (h) and (k) McClymont et al. (2020); (i) and (l) Tierney et al. (2020b). Where there are multiple proxy estimations at a single site, a mean is taken.

Model ensembles are:
(a), (d), (g) and (j) DeepMIP (only model simulations carried out with a mantle-frame paleogeography, and carried out under CO2 concentrations within the range assessed in Table 2.2, are shown);
(b), (e), (h) and (k) PlioMIP;
(c), (f), (i) and (l) PMIP4.

Further details on data sources and processing are available in the chapter data table (Table 7.SM.14).

---------------------------------------------------
Data provided in relation to figure
---------------------------------------------------
Data provided in relation to Figure 7.13:

Observed data:
- Data file: Figure7_13_obs.csv

Model data:
- model data in net-CDF files is contained in the directory 'Figure_7_13_mod' in separate directories for Eocene '/eocene', Mid-pliocene '/pliocene' and Last Glacial Maximum '/lgm' periods

landsea mask data:
- Data file: Plio_enh_topo_v1.0_regrid.nc
- Data file: peltier_ice4g_orog_21_regrid.nc
- Data file: herold_etal_eocene_topo_1x1.nc

CMIP6 is the sixth phase of the Coupled Model Intercomparison Project.
DeepMIP is The Deep-Time Model Intercomparison Project.
PlioMIP is the Pliocene Model Intercomparison Project
PMIP4 is the Paleoclimate Modelling Intercomparison Project phase 4.

---------------------------------------------------
Notes on reproducing the figure from the provided data
---------------------------------------------------
The data provided is the input data of plotting scripts which can be used to reproduce the figure. Plotting scripts for reproducing this figure are linked in the Related Documents section of this catalogue record. The notebook 'ipcc_figure_7.13.ipynb' can be run with the provided data to reproduce the figure, you need to edit the directory paths to match your local directory within the notebook.
The original script for plotting this figure can be found in the Chapter 7 GitHub repository also linked but requires IDL.

---------------------------------------------------
Sources of additional information
---------------------------------------------------
The following weblinks are provided in the Related Documents section of this catalogue record:
- Link to the figure on the IPCC AR6 website
- Link to the report component containing the figure (Chapter 7)
- Link to the Supplementary Material for Chapter 7, which contains details on the input data used in Table 7.SM.1 to 7.SM.7.
- Link to the plotting scripts to reproduce the figure
- Link to the Chapter 7 GitHub repository
- Link to the code for Chapter 7, archived on Zenodo