Biomes simulated by BIOME4 using CESM2 lig127k, midHolocene, and piControl climate data on a global 0.5-degree grid

This data set consists of simulated biomes for the last interglacial (127 ka), middle Holocene (6 ka), and preindustrial (1850 CE) time periods displayed in Figure 14 of Otto-Bliesner et al. (2020). Biomes were simulated with BIOME4 (ver. 4.2, https://pmip2.lsce.ipsl.fr/synth/biome4.shtml; Kaplan et al., 2003, https://doi.org/10.1029/2002JD002559), an equilibrium vegetation model, using CESM2 (ver. 2.1.0) simulated climate data produced under PMIP4/CMIP6 (Paleoclimate Modelling Intercomparison Project phase 4 / Coupled Model Intercomparison Project phase 6) lig127k, midHolocene, and piControl experiments (Otto-Bliesner et al., 2017, https://doi.org/10.5194/gmd-10-3979-2017; Otto-Bliesner et al., 2020, https://doi.org/10.1029/2020PA003957). To create input climate data for BIOME4, we used CESM2 reference-height temperature (tas), total precipitation rate (pr), and vertically integrated total cloud (clt), with tas converted from K to degrees C, pr converted to monthly total precipitation (mm) from precipitation rate (kg/m2/s), and clt converted from decimal fraction to %. The climate data were regridded to a 0.5-degree global grid using bilinear interpolation and bias-corrected by calculating long-term mean differences (lig127k minus piControl, midHolocene minus piControl, piControl minus historical 1961-1990 CE 30-year mean) and applying the differences to CRU CL 2.0 (1961-1990 CE 30-year mean) climate data (New et al., 2002, https://doi.org/10.3354/cr021001), also on a 0.5-degree grid. The lig127k and midHolocene data were calendar adjusted using PaleoCalAdjust (v1.0; Bartlein and Shafer, 2019, https://doi.org/10.5194/gmd-12-3889-2019). Cloud data were converted to sunshine (%) using the approach of Doorenbos and Pruitt (1977, http://www.fao.org/3/a-f2430e.pdf). This approach follows closely that described in more detail by Harrison et al. (2014, https://doi.org/10.1007/s00382-013-1922-6). Other BIOME4 input data included orbital eccentricity (ecc) and obliquity (obliq) values for each time period (Bartlein and Shafer, 2019). Atmospheric CO2 concentration was 275.0 ppm for 127 ka, 264.4 ppm for 6 ka, and 284.7 ppm for 1850 CE (Otto-Bliesner et al., 2020).