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Is Desertification in the Southwest Affecting the Colorado Snowpack? Chris Landry CSAS – Silverton Tom Painter, Andy Barrett NSIDC Jason Neff CU Geosciences. Colorado Plateau. Desert Dust Emission. Possible sources: ‘natural’ processes drought
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Is Desertification in the Southwest Affecting the Colorado Snowpack? Chris Landry CSAS – Silverton Tom Painter, Andy Barrett NSIDC Jason Neff CU Geosciences Colorado Plateau
Desert Dust Emission • Possible sources: • ‘natural’ processes • drought • dryland farming • recreation • overgrazing March 25, 2006 near Shiprock
1999 2003 Dust Deposition in Colorado Mtns. March 31, 1999 2004
Trajectory Analyses NOAA Hysplit Model 48 hour back-trajectories
Radiative effects of desert dust deposits in alpine snow CSAS TH Painter1, C Landry2, J Neff3, AP Barrett1 1National Snow and Ice Data Center, 2Center for Snow and Avalanche Studies, 3CU-Boulder, Dept of Geological Sciences Collaborative Research funded by the National Science Foundation Atmospheric Sciences, Geography, and Hydrologic Sciences Grants #ATM-0432327 to NSIDC and ATM-0431955 to the CSAS
Study Site – Senator Beck Basin Operated by Center for Snow and Avalanche Studies, Silverton, CO
May 21, 2004 Photo courtesy JPL (Ian McCubbin)
Swamp Angel Study Plot 11,050’ Senator Beck Study Plot 12,200’
Measurements • Snowpack: depth, SWE (density), stratigraphy, grain size & type, temperature, wetness, coverage • Climatology: air temp, RH, wind speed & direction, precipitation, pressure, dust event trajectories • Radiation: incoming LW, SW; reflected SW; IR ‘skin’ temperature, snow surface albedo • Sediment & Dust: mineralogy, concentrations • Hydrological: temperature, EC, streamflow
Snow Albedo April 4, 2003 - San Juan Mountains 0.78 126 w/m2 0.60 224 w/m2
May 2005 May 2004
Observed SnowmeltSwamp Angel Study Plot, Red Mountain Pass, CO • 15 inches SWE May 20, 2003 • 0 inches SWE May 28, 2003
Spectral albedo Snowmelt flux SWE
Preliminary Findings … • Dust deposition appears to significantly decrease snow albedo on a regional scale ... • The ‘doubling’ of absorbed solar radiation appears to increase snowmelt rates and likely results in a higher amplitude and shorter duration snowmelt hydrograph …
Next Steps … • Formalize findings on albedo effects ... • Develop modeling of ‘dust-on-snow’ effects on basin-scale snowmelt timing, intensity, and duration …