PNNL: Studying Water in the Mountain Air

An ambitious Department of Energy (DOE) field campaign seeks to better understand the timing and availability of mountainous water resources. Pacific Northwest National Laboratory (PNNL) scientists are taking part.

The Surface Atmosphere Integrated Field Laboratory (SAIL) in the Rocky Mountains near Crested Butte, Colorado, will attempt to capture elusive data. Led by DOE’s Atmospheric Radiation Measurement (ARM) user facility, the SAIL campaign aims to provide clues about the timing and availability of water resources from mountains. Previous research has shown the difficulty of gathering the data in complex terrain with limited atmospheric or land-surface observations.

“It is critical to understand clouds and precipitation, which closely tie to land-surface properties, topography, and aerosols in this high-altitude watershed region because of their important role in determining water availability in the region,” said Jiwen Fan, a PNNL Earth scientist and Lab Fellow, who is among the PNNL scientists contributing to SAIL.

The SAIL campaign began last September and is scheduled to run through June 2023. SAIL seeks to quantify and characterize mountainous atmospheric processes through more than 100 continuous measurements, collected with more than four dozen advanced atmospheric instruments. Data are being collected in the Upper Colorado River Basin, which supplies water for seven states and 40 million people from Denver, Colorado, to Los Angeles, California.

SAIL focuses on five interrelated science objectives in the Upper Colorado River: precipitation processes, sublimation and wind distribution, aerosol regimes and radiation, aerosol–precipitation interactions, and surface energy balance.

“The measurements obtained from SAIL will allow us to study and quantify how tiny aerosol particles would affect mountain meteorology, clouds, and precipitation in different weather and aerosol scenarios under this unique terrain setting,” said Fan.

Combining these atmospheric measurements with existing surface and subsurface data from the area will provide an atmosphere-through-bedrock understanding of developing conditions. This can help the team evaluate and improve working models of weather, climate, and mountain hydrology. “The data also allow us to look at seasonal variability,” Fan noted.

Scientists from Lawrence Berkeley National Laboratory are leading the SAIL campaign.

PNNL and eight other DOE labs work together to manage and operate the ARM user facility. ARM Technical Director Jim Mather and ARM Engineering and Process Manager Jennifer Comstock are based at PNNL. Other PNNL participants include Earth scientists Adam Varble, L. Ruby Leung, and ARM instrument and data experts, software developers, and communications and administrative staff.