CESM1.2 global simulations with water isotopic tracers and water source tags for 1850 pre-industrial, historical, and RCP8.5 forcing conditions

Understanding sources of atmospheric moisture can help reveal the processes that set patterns of humidity, cloudiness, and precipitation. These patterns ultimately influence weather, water resources, and climate feedbacks. This dataset contains a four-member ensemble of global simulations from the Community Earth System Model (CESM) version 1.2 with both water isotopic tracers and water tags. Each ensemble member consists of an historical period and a future period, forced by the RCP8.5 high emissions scenario. The tags, which are simulated in three branched runs, each 30 years in length, explicitly track moisture from evaporative source regions defined at nominal 10 x 10 degree resolution. They provide an opportunity to evaluate the contributions of distinct source regions to the water vapor, cloud condensate, and precipitation amounts simulated. The isotopic tracers provide a means to map the moisture source information from the tags to observable quantities and link modern-day meteorological processes to climate records of the past.