The Wasatch Environmental Observatory: A mountain to urban research network in the semi‐arid western US

The 2085 km2 Jordan River Basin, and its seven sub‐catchments draining the Central Wasatch Range immediately east of Salt Lake City, UT, are home to an array of hydrologic, atmospheric, climatic and chemical research infrastructure that collectively forms the Wasatch Environmental Observatory (WEO). WEO is geographically nested within a wildland to urban land‐use gradient and built upon a strong foundation of over a century of discharge and climate records. A 2200 m gradient in elevation results in variable precipitation, temperature and vegetation patterns. Soil and subsurface structure reflect systematic variation in geology from granitic, intrusive to mixed sedimentary clastic across headwater catchments, all draining to the alluvial or colluvial sediments of the former Lake Bonneville. Winter snowfall and spring snowmelt control annual hydroclimate, rapid population growth dominates geographic change in lower elevations and urban gas and particle emissions contribute to episodes of severe air pollution in this closed‐basin. Long‐term hydroclimate observations across this diverse landscape provide the foundation for an expanding network of infrastructure in both montane and urban landscapes. Current infrastructure supports both basic and applied research in atmospheric chemistry, biogeochemistry, climate, ecology, hydrology, meteorology, resource management and urban redesign that is augmented through strong partnerships with cooperating agencies. These features allow WEO to serve as a unique natural laboratory for addressing research questions facing seasonally snow‐covered, semi‐arid regions in a rapidly changing world and an excellent facility for providing student education and research training. The Wasatch Environmental Observatory (WEO) combines an array of infrastructure supporting hydrologic, hydrochemical, atmospheric, climatic, meteorologic and ecologic research within the semi‐arid 2085‐km2 Jordan River Basin, Utah, USA. This basin is characterized by steep gradients in elevation and a mix of wildland montane to urban land uses. The diverse suite of fixed and mobile instrumentation managed by WEO is augmented by sensor networks operated by cooperative agencies that have recorded hydrologic and climatic data for over a century. Recent observations from the WEO network have revealed connections between water supply, water quality and atmospheric processes, all of which are responding to rapid environmental change and population growth within t