The SSP2-COM scenario is a global 2°C emission scenario that both aligns with global temperature control targets and closely follows realistic emission trends. To overcome the limitations of the traditional use of spatially uniform degree‑day factors, we utilize long‑term observational meteorological and ablation data from Greenland automatic weather stations. A surface energy balance model is employed to simulate hourly ablation, which supplements the missing ablation observations. By applying the positive degree‑day (PDD) method for inversion, we calibrate the snow and ice degree‑day factors (DDF) for the eight major drainage basins of Greenland, thereby obtaining basin‑specific snow and ice DDFs with high spatial representativeness. The estimated surface mass balance (SMB) is then input into the PoLarIS land‑ice model and compared with input data from other scenarios.