Diagnosis of GLDAS LSM based aridity index and dryland identification

► UNEP aridity index (AI) is refined by incorporating soil moisture accounting. ► Three global aridity indices are created based on three GLDAS LSMs. ► The VIC AI identifies dryland areas better than the other two LSM based indices. ► Results show that the UNEP AI classifies areas drier than the LSM based indices. ► The LSM based aridity indices may identify drylands better than the UNEP AI.