Figure 2. Annual mean leaf water δ¹⁸O as predicted by the sites of evaporation model (green line: GIS model), and compared to published zonal averages from two GCM+LSM model outputs that also used a Craig-Gordon formulation to predict leaf water δ¹⁸O (blue lines: GISS+SLAVE and ECHAM+SILVAN; Hoffmann et al., 2004).

The differences between the Hoffmann et al. (2004) models result from both the isotope ratio values generated in the GCMs and the alterations of estimated leaf temperature necessary to fit the modern Dole effect.