GFZ GNSS-derived precipitable water vapor for climate reference network GRUAN

The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN, https://www.gruan.org/ ) of the World Meteorological Organization (WMO) is an international observing network, designed to meet climate requirements. Upper air observations within the GRUAN network will provide long-term high-quality climate records. A GNSS receiver is part of the GRUAN station equipment with highest priority for measuring of atmospheric water vapor. GRUAN observations are intended to provide long-term high-quality data for the reliable determination of climatological trends and to provide further insight into atmospheric processes. Precise GNSS data analysis is a key to reach data quality on the highest level. Due to its long-term experience in GNSS data processing, GFZ was selected as a Central GRUAN GNSS Data Processing Centre. This data publicatoion includes the GRUAN Data Product (GDP) of GFZ: GNSS Precipitable Water (PW).