High-frequency precipitation and stream water quality time series from Plynlimon, Wales: an openly accessible data resource spanning the periodic table

This scientific briefing announces the availability of a new multi-element highfrequency water quality data set that is openly accessible to the research community. The data set comprises up to 2 years of 7-hourly water quality data for two streams and one rainfall site in the Upper Severn catchment at Plynlimon in Mid-Wales. The measurements cover 50 analytes ranging from H+ to U and spanning six orders of magnitude in concentration, including major, minor and trace elements as well as nutrients, and they complement decades of weekly measurements of the same analytes at the Upper Severn. Together, the weekly and 7-hourly time series provide a unique data set for studying both long-term trends and short-term dynamics. The data show complex behaviour over a wide range of timescales, challenging our understanding of catchment processes and informing future modelling efforts.