This repository includes the HadCM3L model priors used in the Phanerozoic data assimilation, PhanDA (Judd et al., submitted). The model simulations were carried out by the Bristol Research Initiative for the Dynamic Global Environment (BRIDGE) group using the computational facilities of the Advanced Computing Research Centre at the University of Bristol (Bristol, UK). Included in this repository is 1 excel file containing the details of each simulation ("ExperimentInfo.xlsx") and 32 sets of zipped files, each containing 545 netCDFs. The naming convention of these files is as follows: ExperimentName_ExperimentNumber_ExperimentAge_CO2_ExperimentMean_VariableName.nc There are 8 sets, or "suites" of model simulations, indicated by the ExperimentName. They all begin with "scotese," referencing that they use the paleogeographic reconstructions of Scotese (2016). The different suites were run assuming different CO2 values and model versions (see Judd et al, submitted and Valdes et al., 2021 for further details): Experiment Name CO2 HadCM3L Configuration PUMA ID* scotese_solara 1 x PI Original texva1, tExve1 scotese_2co2a 2 x PI Original texza1, tExze1 scotese_4co2a 4 x PI Original teyaa1, tEyae1 scotese_spinupa smoothed Foster et al. (2017) Original texya, tExye scotese_02 Foster et al. (2017) Original texpa1, texqe scotese_06 Foster et al. (2017) Update A tfgwa, tFgwe scotese_07 Foster et al. (2017); Rae et al, 2021 Update B tfkea, tFkee scotese_08 to match GMST of Scotese et al. (2021) Update B tfksa, tFkse *PUMA refers to the "Providing Unified Model Access" service. Here, we have provided the database names of the youngest (0 Ma) and oldest (541 Ma) simulations, respectively. Note that the scotese_spinupa and scotese_02 suites were originally published in Valdes et al., 2021. The ExperimentNumber, ExperimentAge, and CO2 values are linked to each specific model simulation. In total, each of the 8 suites was run at a total of 109 time slices, for a total of 872 discrete model simulations (8 x 109). Details can be found in the ExpInfo excel file included in the repository. As outlined in Judd et al. (submitted), each model simulation was spun up for at least 3,000 yrs. To boost natural variability in the model prior, the last 100 yrs of each simulation was subdivided into 5 x 20-yr averages, as indicated by the ExperimentMean label. This results in 4,360 unique model priors (8 x 109 x 5). We have included four variables: tas (2m air temperature), tos (sea surface temperature), so (sea surface salinity), and pr (precipitation). Each variable has its own file, for a total of 17,440 netCDFs (8 x 109 x 5 x 4).