OceanRAIN – The global ocean surface-reference dataset for characterization, validation and evaluation of the water cycle

OceanRAIN—the Ocean Rainfall And Ice-phase precipitation measurement Network—is the first comprehensive in-situ surface-reference dataset comprising all water cycle parameters to meet the requirements of the international scientific teams for high-quality precipitation data over the global oceans. OceanRAIN is aimed at satellite retrieval calibration and product validation of the GPM (Global Precipitation Measurement) era, to improve the representation of precipitation and air-sea interactions in re-analyses and models, and to enhance our understanding of water cycle processes over the global oceans. For this purpose, OceanRAIN version 1.0 provides in-situ data of precipitation, evaporation and the resulting freshwater flux at 1-min resolution from June 2010 to April 2017. More than 6.83 million minutes with 75 parameters from 8 ships cover all routinely measured atmospheric and oceanographic state variables along with those required to derive the turbulent heat fluxes. The precipitation parameter is based on measurements of the optical disdrometer ODM470 specifically designed for all-weather shipboard operations. The occurrence, intensity and accumulation of rain, snow and mixed-phase precipitation are derived from particle size distributions. Additionally, all relevant microphysical precipitation and radar-related parameters are provided.