How can dusty snowmelt influence future water flow in the Colorado River, which is responsible for supplying water to approximately 40 million people? This is what a recent study published in Geophysical Research Letters hopes to address as a team of researchers investigated how dust-covered mountain snowpacks resulting from nearby dry landscapes could cause greater snowmelt, leading to waterways drying up faster than anticipated. This study has the potential to help researchers, climate scientists, legislators, and the public better understand the long-term consequences of climate change and the steps that can be taken to mitigate them.
For the study, the researchers analyzed Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data obtained from 2001 and 2023 for snowmelt within the Rocky Mountains and Colorado Plateau, both of which are responsible for feeding the Colorado River with water. The goal of the study was to ascertain the rates and time periods of snow darkening from dust accumulation, which can increase heat absorption from the Sun, resulting in increased melting rates.
In the end, the researchers found that while normal snowmelt is considered between 10-15 millimeters per day, increased dust accumulation increases snowmelt by as much as 1 mm per hour at the Sun’s peak, along with an increase of 10 mm per day during extra dusty years. Additionally, the researchers propose ideas that can be used to mitigate long-term damages from reduced snowmelt on communities.
“The degree of darkening caused by dust has been related to water forecasting errors,” said Dr. McKenzie Skiles, who is an associate professor at the University of Utah’s School of Environment, Society & Sustainability and a co-author on the study. “The water comes earlier than expected, and this can have real world impacts—for example if the ground is still frozen it’s too early for farmers to use. A reservoir manager can store early snowmelt, but they need the information to plan for that. If we can start to build dust into the snowmelt forecast models, it will make water management decision-making more informed.”
Going forward, the team aspires to collect more data with the goal of being able to forecast future snowmelt patterns, thus alleviating the burden of local communities to forecast it independently and suffering the risks, as well.
How will dust-covered snowmelt influence the Colorado River in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Geophysical Research Letters, EurekAlert!, The University of Utah
Featured Image: Rocky Mountain dust storm in 2009. (Credit: McKenzie Skiles)