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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #407327
Research Project: Science and Technologies for the Sustainable Management of Western Rangeland Systems

Location: Range Management Research

Title: Understanding impacts of Dust-on-Snow on Regional Hydrology Dynamics in the Upper Colorado River Basin for the past 20 years

Author
item CAI, JIAXUAN - Duke University
item NAPLE, PATRICK - University Of Utah
item MCKENZIE, SKILES - University Of Utah
item DHITAL, SAROJ - New Mexico State University
item Webb, Nicholas - Nick
item NAUMAN, TRAVIS - Natural Resources Conservation Service (NRCS, USDA)
item DUNIWAY, MICHAEL - Us Geological Survey (USGS)
item TYREE, GAYLE - Us Geological Survey (USGS)
item CHANEY, NATHANIEL - Duke University

Submitted to: American Geophysical Union Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2023
Publication Date: 12/11/2023
Citation: Cai, J., Naple, P., S. McKenzie, S., Dhital, S., Webb, N.P., Nauman, T., Duniway, M., Tyree, G., Chaney, N. 2023. Understanding impacts of Dust-on-Snow on Regional Hydrology Dynamics in the Upper Colorado River Basin for the past 20 years. American Geophysical Union Meeting Abstract. Abstract.

Interpretive Summary: Mountain snowpacks are a vital resource in arid and semi-arid regions, and the Upper Colorado River Basin (UCRB), where seasonal mountain snowmelt contributes 70%–90% of streamflow. However, the water capacity of the UCRB is declining due to climate change and human influence. Deposition of dust prduced by wind erosion upwind of the Colorado mountains can drastically reduce snow albedo, which affects net solar radiation primarily. Consequently, this accelerates snowmelt, alters the timing of peak streamflow, and reduces the overall annual runoff. In this study, we use the Community Terrestrial System Model (CTSM) with satellite remote sensing data to examine the effects of dust on snow in the UCRB for the past 20 years. We use in-situ measurements available from over 100 SNOTEL sites and about 600 USGS stream stations to validate the model. The findings of this study offer insights into the dynamic changes in the UCRB water cycle and the varying impacts of dust deposition on snow over the past two decades, crucial for land and water management in the region.

Technical Abstract: Mountain snowpacks are a vital resource in arid and semi-arid regions, and the Upper Colorado River Basin (UCRB), where seasonal mountain snowmelt contributing to 70%–90% of streamflow is no exception. However, the water capacity of the UCRB is declining due to climate change and human influence. Previous research has demonstrated that dust deposition on the Colorado mountains can drastically reduce snow albedo, which affects net solar radiation primarily. Consequently, this accelerates snowmelt, changes the energy balance, alters the timing of peak streamflow, and reduces the overall annual runoff. There has been a lack of long-term analysis of trends and extremes regarding the effects of dust-on-snow across the entire basin. To address this, the Community Terrestrial System Model (CTSM) with the MERRA-2 dataset is employed to develop a hydrologic response analysis in the UCRB for the past 20 years. The CTSM, featuring the enhanced Snow, Ice, and Aerosol Radiative model (SNICAR), offers a more accurate representation of snow albedo. For meteorological input, we incorporated the Princeton CONUS Forcing dataset and the Analysis of Record for Calibration. CTSM simulations were conducted hourly at a spatial resolution of 3-km from the water years 2002 to 2022. Two scenarios are explored: (1) clean snow (NODUST), where dust deposition was manually set to zero, and (2) dust on snow (DUST), using MERRA-2 hourly dust deposition fluxes. Given the coarse spatial resolution of the MERRA-2 dataset, the daily MODIS Dust Radiative Forcing in Snow (STC-MODDRFS) dataset was applied to correct the simulation. To ensure a robust assessment of the hydrologic response, in-situ measurements, as available from over 100 SNOTEL sites and about 600 USGS stream stations, were used to validate the model. The findings of this study offer insights into the dynamic changes in the UCRB water cycle and the varying impacts of dust deposition on snow over the past two decades, crucial for land and water management in the region.