Working Toward a Better Understanding of the Future of Water in the Western United States

About 40 million people across seven states depend on the Colorado River for their water. Droughts in the Colorado River Basin ripple out to affect agriculture and energy production in an even wider area.

In recent years, reservoir levels in the Colorado River Basin have dropped to record lows. In the summer of 2022, the federal government again had to reduce the amount of water some states could take from the river. As climate change drives more severe droughts, water cuts are likely to get even more drastic. These problems aren’t limited to the Colorado River Basin. Drought is one of our nation’s most pressing environmental and energy challenges.

Like most of the world’s freshwater supplies, the source of the Colorado River starts in snowpack high up in the mountains. Understanding the intricacies of these systems requires scientists to connect field measurements with predictive Earth system models. These details include understanding how much precipitation will fall as rain or snow at high elevations, how it moves its way downstream, and how climate change will affect these processes.

To tie these tools together, the Department of Energy’s (DOE) Office of Science is supporting a comprehensive field laboratory. The Surface Atmosphere Integrated Field Laboratory (SAIL) campaign in the Upper Colorado River Basin integrates the research of many of our national lab scientists. As an earth scientist who conducted research at a national lab early in my career, I’m proud that national lab scientists are leading such a critical endeavor. This project is also giving us the opportunity to pursue new research partnerships with other federal agencies, including the National Oceanic and Atmospheric Administration and the National Science Foundation.

Through SAIL, instruments from our Atmospheric Radiation Measurement (ARM) user facility are gathering data through June 2023 near Crested Butte, Colorado. About four dozen instruments are operating 24/7. These instruments are measuring precipitation, clouds, dust, smoke, solar and thermal energy, temperature, wind, ozone, and humidity.

SAIL is located in the same critical headwater basin as the Watershed Function Scientific Focus Area at DOE’s Lawrence Berkeley National Laboratory. This focus area has collected surface and subsurface measurements related to water availability since 2014. In addition, the measurements from ARM are providing important insights into certain atmospheric processes. These processes control when and how precipitation falls, in what form it falls, its amount, and its intensity in this critical watershed. An important aspect of SAIL is understanding how aerosols affect cloud and precipitation processes and the reflectivity of the snow. Aerosols are small atmospheric particles such as dust or those caused by wildfire smoke or pollution.

A unique aspect of SAIL is the ARM tethered balloon system. This system is collecting aerial observations of the vertical structure of temperature, humidity, and aerosols in the lower atmosphere. Scientists will analyze airborne particles collected from the balloon flights at the DOE Office of Science’s Environmental Molecular Science Laboratory user facility. This analysis will help us understand the aerosols’ detailed composition and physical properties. These properties affect how well aerosols can serve as seeds for clouds and how they might alter snowpack.

Working together, these efforts create a comprehensive field observatory. This observatory is allowing scientists to study the movement of water from the atmosphere to vegetation and soils to deep bedrock and often into the Colorado River. Unlike many atmospheric field campaigns that last a few months, the ARM user facility is taking comprehensive atmospheric measurements across two winter seasons. Coupled with the focus area’s measurements, these measurements are important for understanding how different years with different atmospheric conditions, precipitation, and levels of snowpack result in more or less streamflow.

Looking at a year’s worth of data so far, scientists are following clues about how drought and long-range dust and wildfire smoke could be affecting atmospheric processes, clouds, and precipitation. They are also examining how these events influence interactions between the land and atmosphere within the East River Watershed in Colorado. In particular, scientists are looking at the effects they have on when and how fast snowpack melts.

All of our data from Colorado will be freely available through the ARM Data Center and ESS-DIVE for future research. These databases will allow a diverse group of water stakeholders to take full advantage of DOE-funded data and findings.

Addressing the effects of climate change is one of our top priorities at DOE. We are committed to making investments in our science and people that will help secure a better, more resilient future for all.

The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit the Office Science website.

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