Photo of Noah Molotch

Noah Molotch

We are primarily focused on the processes controlling hydrologic fluxes in cold regions and within the greater Earth system. Improved understanding of these processes is essential for sustainable management of natural resources and for making informed environmental policy decisions.

Learn about the Mountain Hydrology Group 

Institute News

Color coded US map of how rain-on-snow events can create potential nitrogen sources. Northern areas of the northeast, midwest, and northwest coast have high potential.

As winters warm, nutrient pollution threatens 40% of U.S. (U Vermont)

As climate changes, previously frozen chemical runoff from farms and fields puts water quality at risk in over 40 states, research says. Keith Musselman part of team looking at winter nutrient pollution, a new problem caused by climate change. Read more
A multidisciplinary team walks through an open forest to survey the future site of an EcoTram, a moving monitoring platform

Persistent places update: Groups come together to define and map climate change in Colorado’s public lands

A convergence research project is uniting land managers, local residents, and scientists to jointly understand how Colorado Front Range ecosystems and public lands are responding to pressures from people and climate change. Read more
Narrow canyon in Lake Powell showing lowered water level

Climate change will make it hard to predict the amount of snow and water that will be available (ABC News)

A new study that included Will Wieder and Keith Musselman finds that snow-free seasons are expected to last longer, putting Northern Hemisphere water supplies at risk. Read more
More institute news for Mountain Hydrology


Group news


Noah Molotch about "Studying the snowpack in a changing climate", new Water Desk podcast

October 28, 2020.   An interesting and in-depth look at snowpack as it relates to water in the west by our very own CWEST and Mountain Hydrology Group director Noah Molotch. From the Water Desk podcast page:  The snowpack is crucial to the West’s water supply, ecosystems and economy. But climate change threatens to make the region’s snowpack thinner and less reliable. We talk to a leading snowpack researcher about how scientists are analyzing the past, present and future of the West’s snow. Water Desk Director Mitch Tobin talks to Noah Molotch, Director of the Center for Water Earth Science & Technology (CWEST) at the University of Colorado Boulder, about the importance of snow to our water supply and what the future may hold for the American West’s snowpack.

Visit the podcast > 

Welcome to Eric Kennedy our newest group member

August 17, 2020.   We are pleased to welcome our newest member to the Mountain Hydrology Group, Eric Kennedy. Eric is an incoming MA student in the Geography program. His current research focuses on the impacts of changing snowmelt patterns on forest ecosystem processes with the goal of improving understanding of mountainous areas' vulnerability to climate change. Eric's research is motivated by previous work as a wildland firefighter and ski patroller in the Pacific Northwest and his avid mountain recreation habit.

Rain-on-Snow Flooding in the Feather River Basin, California

 Kevin Grow/Calif. Dept. of Water Resources

The repaired main spillway of Oroville Dam in April 2019. Photo credit: Kevin Grow/Calif. Dept. of Water Resources

July 23, 2020.  "We know that climate change is expected to increase the intensity of storm events in the Sierra Nevada, including extreme melt of deep mountain snowpack,” said Mountain Hydrology Group co-author Keith Musselman. “With our Oroville Dam case study, we highlight an example of potential threats to public safety and infrastructure associated with a warmer and more variable climate". A new paper analyzes the factors behind the February 2017 Oroville Dam spillways incident in California. The lead author, Brian Henn a former researcher at the Center for Western Weather and Water Extremes (CW3E) at Scripps Institution of Oceanography at the University of California San Diego put together a research team consisting of Keith Musselman, Leanne Lestak and Noah Molotch from the Mountain Hydrology group here at INSTAAR, and F. Martin Ralph director of the CW3E. The press release by Robert Monroe from Scripps News states that "Heavy snowmelt [from a series of atmospheric rivers] delivered a surge of runoff to Feather River and Lake Oroville". To read more about the research visit the press release and the paper.

Visit the press release > 

Snow Cover in the Sierra Nevada

March 16, 2020.   Our regression modeled SWE estimates for the Sierra Nevada were used for the NASA Image of the Day. The winter of 2019-2020 brought a range of extreme weather to the mid-latitudes of the Northern Hemisphere, with some areas receiving a deluge of moisture and others staying much drier than usual. California experienced the latter, as evidenced by the thin snowpack in the Sierra Nevada near the start of spring. Snow-covered areas, as seen in natural-color satellite imagery, make for an interesting visual, but such imagery does not tell a complete story because it does not account for the depth or density of the snow. A more meaningful indicator of the quality of the snowpack is snow-water equivalent—an estimate of how much water you would get if all of the snow melted at once. The maps (left) show snow-water equivalents across the Sierra Nevada in early March for each year between 2015 and 2020. Data for the maps, developed by the University of Colorado’s Center for Water, Earth Science, and Technology, are derived from ground-based data, computer models, and satellite imagery. They incorporate a data set from the Jet Propulsion Laboratory (JPL)  called the MODIS Snow Covered Area and Grain-size (MODSCAG), which uses data from NASA’s Terra satellite to determine properties of the snow —- things like the area covered, grain size, and albedo —- that are useful for deriving accurate estimates of snow-water equivalent.

Visit link > 

Opening Reception: INSTAAR's Boulder Creek Watershed Exhibit at the Museum of Boulder

January 13, 2020.   We are excited to announce our opening of the educational exhibit "Our Living Landscape: Exploring Boulder's Watershed." The exhibit is at the Museum of Boulder from January 31st to March 31st, 2020. Come join us for an evening of celebration at the Open Reception (free to the public) Friday, January 31st, from 5:30 – 7:30 pm!  

The Boulder Creek watershed exhibit is a collaboration between INSTAAR’s Boulder Creek Critical Zone ObservatoryNiwot Ridge Long-term Ecological Research programCenter for Water Earth Science and Technology, and many partners including Boulder County Parks & Open SpaceCity of Boulder, United States Geological Survey, and more. It shares what we’ve discovered about the land, plants, animals, water, and climate of the place we all call home, over the course of decades of research in the watershed, with the community.

This exhibit was funded by the University of Colorado’s Office of Outreach and Engagement. In-kind contributions were provided by INSTAAR, BcCZO, NWT LTER, CWEST, CU Mountain Research Station, and the City of Boulder.

Visit link >