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Unformatted text preview: 3/24/2008 1 ESM 236: The Mountain Snowpack ESM 236: The Mountain Snowpack — Introduction Introduction Jeff Dozier Spring 2008 Worldwide importance of the mountain Worldwide importance of the mountain snowpack snowpack Barnett et al., Nature, 17 Nov 2005 1/6 of Earth’s population relies on glaciers or seasonal snow for their water supply Topics Topics • Snow accumulation and runoff • Energy balance of the snowpack • Water flow 3 • Snow metamorphism and melt • Implications for nutrient cycling in watersheds • Long-term trends Example: Merced River, Happy Isle in Example: Merced River, Happy Isle in Yosemite Valley Yosemite Valley 4 Peterson et al., USGS SWE (snow water equivalence) and mass SWE (snow water equivalence) and mass balance balance ( )-2 , (snow density depth) [kg m ] (layers) (Divide by density of water to s d n s s n n SWE d z dz d ρ ρ ρ = × = ≈ Δ ∑ ∫ 5 3 express as a depth equivalent) [m or mm] 1000kg m Mass balance: Snowfall - Sublimation - s w SWE d SWE ρ ρ − = = Δ = Runoff Water balance: Runoff = Melt Storage ± Δ Manual measurement of Manual measurement of SWE SWE 6 3/24/2008 2 Measurement of SWE and Measurement of SWE and Snowfall Snowfall 7 Automated measurement with snow pillow Automated measurement with snow pillow 8 Map of pillows in Bales et al. 2006 Snow Snow-pillow data for Dana pillow data for Dana Meadows Meadows (DAN) (DAN) and Tuolumne and Tuolumne Meadows (TUM) Meadows (TUM) 1200 1400 1600 1800 1983 TUM 1983 DAN 10/01 11/01 12/01 01/01 02/01 03/01 04/01 05/01 06/01 07/01 200 400 600 800 1000 2003 2003 2005 2005 SWE, mm 9 Accumulation and ablation inferred from snow pillow data, Accumulation and ablation inferred from snow pillow data,...
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- Spring '08
- Snow, saturation vapor pressure, Dana Meadows, UCSB Snow Hydrology Research Group