Northern Hemisphere in situ snow water equivalent dataset (NorSWE, 1979–2021)

Abstract. In situ observations of snow water equivalent (SWE) are critical for climate applications and resource management yet there is no global database of in situ SWE observations. We present a dataset the Northern Hemisphere in situ snow water equivalent dataset (NorSWE) consisting of over 11.5 million SWE observations from more than 10 thousand different locations across the Northern Hemisphere spanning the modern satellite era (1979–2021). NorSWE builds on an existing framework applied to Canadian data (CanSWE; Vionnet et al., 2021) and includes SWE observations from manual snow courses covering Canada, the United States, Finland and Russia. Snow pillows, automated passive gamma radiation sensors, and airborne passive gamma SWE estimates provide additional coverage over North America. In addition to SWE, snow depth (SD) and derived bulk snow density are included when available. A consistent quality control is applied to all records and the final dataset delivered as a single NetCDF file that is publicly available at https://doi.org/10.5281/zenodo.14503592 (Mortimer and Vionnet, 2024).