Multi-model drought evaluation at regional and global scales

Accurate and consistent mapping of drought is important in water resources planning and management as well as for monitoring the social and economic impacts of drought related stress. Here, we characterize the spatio-temporal patterns of drought at regional to global scales using a multi-model framework that is based on a unified database of atmospheric and hydrological forcing. To do this, the latest version of the GEWEX LandFlux dataset together with remote sensing products of vegetation phenology and soil moisture are used to estimate terrestrial evaporation via four evaporation models (SEBS, PT-JPL, PM-Mu and GLEAM) for the period 1979-2009. Widely used empirical drought indices (e.g. PDSI, PSI) as well as the recently developed ET-based diagnostic drought indicators (e.g. Evaporative Stress Index, Drought Severity Index), were estimated at daily to annual time scales to evaluate the consistency of the ET models in identifying drought signals, and to assess the relative skill of the various drought products to detect significant historical drought events.