Photo by Lars Peterson
Photo by Angus Duncan
My research interests and experiences are on the topics of terrestrial hydrology, hydrometeorology, and remote sensing in mountainous and forested seasonally snow-covered environments.
The overarching goal of my research is to evaluate the availability of freshwater in these environments and the physical mechanisms and pathways responsible for its evolution.
Accurate seasonal runoff predictions in mountainous regions require a process-based representation of how snow accumulation (e.g. precipitation, wind redistribution) and ablation (e.g. melt, sublimation) vary in time and space over complex terrain. A project in the southern Sierra Nevada of California evaluates when and where meltwater is available to the soil and river systems and how these processes vary with seasonal meteorology, land cover, elevation, and climate conditions.
In alpine regions, wind plays an important role in determining snow redistribution (drift and scour) patterns, which influence the duration and spatial patterns of spring and summer meltwater availability in headwater basins. An ongoing project in the Canadian Rockies evaluates the hydrological uncertainty associated with windflow representation methods commonly used in snow models.
- Water resources
- Forest hydrology
- Snowmelt modeling
- Climate change
- Remote sensing of surface processes
- Ground-based measurements
- Forest radiation models
- Snow - forest interactions
- Data visualization
Using a process-level approach that relies upon observation and models, my work examines how forest cover alters the surface energy and mass balance. Ongoing research projects serve to build a holistic understanding of the net effect of forests and forest management on basin water yield and seasonal runoff timing - and how these processes are linked to climate, latitude and landscape properties.
In the western U.S., mountain snow accumulation provides water for tens of millions of people and multi-billion dollar agricultural industries. Water scientists and managers monitor this resource with data from remote stations like this NRCS SNOTEL site (https://www.wcc.nrcs.usda.gov/snow/snotel-data.html) on the Colorado Front Range. This timelapse of hourly (daytime) webcam images highlights the complexity of mountain snowpack during the spring melt season. Measured air temperature, precipitation, melt, and snow depth values are plotted for reference.
Click here to access a read-only version of the paper: http://rdcu.be/pDjq
In regions where snow is an important component of the annual water budget, it is vital for water and land managers to understand potential climate change impacts on snow water resources and reliant human and ecological systems. There is general consensus that projected warming will cause earlier snowmelt, but how snowmelt rates will respond is both poorly known and a critical determinant of future streamflow.
In a project conducted at the National Center for Atmospheric Research, historical observations and climate model simulations are used to develop and test a hypothesis that snowmelt will be slower in a warmer world. The results are reported in a recent paper published in Nature Climate Change.