Using science to understand the future of water
The first snows of fall draw our eyes to the high peaks of northern New Mexico every year. Some people just enjoy the view. For others, this first dusting announces a good ski season to come. And many New Mexicans are hoping that means we’ll have water in our streams, rivers, and reservoirs next year. Lately, this has been less certain, thanks to climate change.
Throughout the Rocky Mountains and beyond, the highland winter snowpack and waters that flow from it are essential for healthy ecosystems, thriving agriculture, and a vibrant economy. With global climate change, scientists know that higher temperatures and different patterns of rain and snow will affect all downstream water users. When flow rates are low, farmers find it difficult to irrigate a large area of the southwest; cities face water shortages; hydroelectric power generation is compromised; and recreational users, such as rafters, kayakers and paddleboarders, are harmed during water sports season. A lack of fresh water from melting snow can also decrease the quantity and quality of water in reservoirs, making it unsafe for swimming.
We are already seeing these effects. But we still don’t know how soil moisture influences the amount of rain that actually reaches a river, or how airborne dust affects the timing of spring snowmelt.
By capturing, storing and distributing rain, snow and runoff, mountain watersheds provide the majority of the world’s water resources. With the help of scientists, policymakers rely on models of the Earth system to predict the timing and availability of these resources and plan their use, but current models have high uncertainties about the water entering and leaving these resources. watersheds in the form of precipitation, evaporation, runoff to watercourses. and rivers, uptake in soil, uptake by plants, and storage in aquifers.
To address these uncertainties, the Los Alamos National Laboratory and collaborators launched a unique large-scale research campaign called the Surface Atmosphere Integrated Field Laboratory (SAIL) near Crested Butte in the high Rockies of Colorado. SAIL is a Department of Energy funded research campaign managed by the DOE Office of Science’s User Facility for Atmospheric Radiation Measurement (ARM) and led by the Lawrence Berkeley National Laboratory.
Los Alamos leads the overall management and operations of the ARM Mobile Observatory, which includes a wide range of instruments for studying the atmosphere. With a team of researchers from various scientific disciplines, national laboratories, universities and government agencies, we study everything related to water in the mountains – what falls from the sky, what flows in the watershed of the Colorado River and what is stored in bedrock.
Over the next two years, we will use radars, lidars (remote sensing with lasers), cameras, weather balloons and other advanced equipment to collect data on precipitation, wind, clouds, aerosols. , solar and thermal. energy, temperature, humidity, ozone and more. I’m going to study aerosols. These tiny particles, several times smaller than the width of a human hair, have a disproportionate effect when they float in the atmosphere. If you want to see aerosols, just look at the sky – they play a key role in cloud formation. Without the aerosols, we wouldn’t even have rain and snow.
By studying the different sources of aerosols in the region, we hope to determine which ones are important in cloud formation during heavy precipitation and storms. Dust and other aerosols can also absorb solar radiation, raising the temperature of clouds or, similarly, snow when they land on the ground, and they can block sunlight, causing a cooling effect on the Earth below. Understanding this better provides an important puzzle piece in the big picture of water.
It takes a big research project to paint the big picture and SAIL is a particularly ambitious study of a mountain watershed. The data we collect will improve models of the Earth system for a more complete picture of the surface and groundwater situation in this mountainous area, helping scientists to predict future water availability. The results will also provide insight into similar mountain water towers around the world.
Since a number of communities, including Santa Fe and Albuquerque, depend on the Colorado River watershed for their drinking water, our research will have benefits close to home. Mountains around the world play a similar role for billions of people and we hope our research will help ensure water security for all in this changing climate.
Allison C. Aiken is a senior researcher on SAIL and analytical chemist at Los Alamos National Laboratory, specializing in aerosols, field measurements and laboratory studies to better understand processes in the atmosphere and improve their representation in models. .