Black Carbon in the Eastern Sierra Nevada
Abstract
Black carbon (BC) aerosols emitted during combustion and deposited on snow decrease reflectance, leading to enhanced snowpack warming, sublimation and melt. The Sierra Nevada supplies roughly 55% of California’s developed water, and more than 85% of Nevada’s water supply originates as mountain snow in higher elevations. Although the sources and impacts of BC are poorly understood, local emissions are significant. Abatement efforts in Nevada and California could help reduce early melting of snow and runoff. From January through April 2009 at three-week intervals, we dug five snow pits and sampled them at 10 cm intervals from the ground to the snow surface on Mammoth Mountain, CA. After the onset of melt, we dug four more snow pits in May at one-week intervals, and we retrieved water samples from lysimeters at the snow-soil interface. Average concentrations from snow pits were 5 ppb, with surface measurements as high as 429 ppb. Data analyses and interpretation of results suggests that deposition of BC remains stable as the snow accumulates. During the melt season, the properties of BC (hydrophilic vs. hydrophobic) influence the fate and transport through the snowpack.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.H33E0933S
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 1863 HYDROLOGY / Snow and ice