Impact of disturbed desert soils on duration of mountain snow cover

• Published in: Geophysical research letters Vol. 34; no. 12
• Main Authors: Painter, Thomas H., Barrett, Andrew P., Landry, Christopher C., Neff, Jason C., Cassidy, Maureen P., Lawrence, Corey R., McBride, Kathleen E., Farmer, G. Lang
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.06.2007; American Geophysical Union
• Subjects: dust; Earth sciences; Earth, ocean, space; Exact sciences and technology; radiative forcing; snowmelt; Rocky Mountains; Colorado Plateau; United States; San Juan Mountains; U. S. Rocky Mountains; Argentina, San Juan; USA, Colorado Plateau; short period waves; mountains; projects; atmospheric precipitation; Dust fall out; ablation; Radiation balance; Perturbation; North America; Desert soils; frequency; intensity; currents; deserts; drought; Radiative transfer; Snow cover; Forcing; soils; dust
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2007GL030284

Snow cover duration in a seasonally snow covered mountain range (San Juan Mountains, USA) was found to be shortened by 18 to 35 days during ablation through surface shortwave radiative forcing by deposition of disturbed desert dust. Frequency of dust deposition and radiative forcing doubled when the Colorado Plateau, the dust source region, experienced intense drought (8 events and 39–59 Watts per square meter in 2006) versus a year with near normal precipitation (4 events and 17–34 Watts per square meter in 2005). It is likely that the current duration of snow cover and surface radiation budget represent a dramatic change from those before the widespread soil disturbance of the western US in the late 1800s that resulted in enhanced dust emission. Moreover, the projected increases in drought intensity and frequency and associated increases in dust emission from the desert southwest US may further reduce snow cover duration.