M. Alisa Mast (Former Employee)
Science and Products
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Long‐term trends in stream water and precipitation chemistry at five headwater basins in the northeastern United States Long‐term trends in stream water and precipitation chemistry at five headwater basins in the northeastern United States
Stream water data from five headwater basins in the northeastern United States covering water years 1968–1996 and precipitation data from eight nearby precipitation monitoring sites covering water years 1984‐1996 were analyzed for temporal trends in chemistry using the nonparametric seasonal Kendall test. Concentrations of SO4declined at three of five streams during 1968–1996 (p 0.1)...
Authors
David W. Clow, M. Alisa Mast
Trends in precipitation and stream-water chemistry in the northeastern United States, water years 1984-96 Trends in precipitation and stream-water chemistry in the northeastern United States, water years 1984-96
Trends in precipitation and stream-water chemistry during water years 1984-96 were examined at eight precipitation monitoring sites and five nearby streams operated by the U.S. Geological Survey in the northeastern United States. The statistical analyses indicate the following: 1)Stream-water sulfate (SO4) concentrations decreased at seven of eight precipitation monitoring sites and in...
Authors
D. W. Clow, M. Alisa Mast
Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains
Methane exchange between the atmosphere and subalpine wetland and unsaturated soils was evaluated over a 15-month period during 1995-1996. Four vegetation community types along a moisture gradient (wetland, moist-grassy, moist-mossy, and dry) were included in a 100 m sampling transect situated at 3200 m elevation in Rocky Mountain National Park, Colorado. Methane fluxes and soil...
Authors
K.P. Wickland, Robert G. Striegl, S.K. Schmidt, M.A. Mast
Winter fluxes of CO2 and CH4 from subalpine soils in Rocky Mountain National Park, Colorado Winter fluxes of CO2 and CH4 from subalpine soils in Rocky Mountain National Park, Colorado
Fluxes of CO2 and CH4 through a seasonal snowpack were measured in and adjacent to a subalpine wetland in Rocky Mountain National Park, Colorado. Gas diffusion through the snow was controlled by gas production or consumption in the soil and by physical snowpack properties. The snowpack insulated soils from cold midwinter air temperatures allowing microbial activity to continue through...
Authors
M. Alisa Mast, Kimberly P. Wickland, Robert G. Striegl, David W. Clow
Strontium 87/strontium 86 as a tracer of mineral weathering reactions and calcium sources in an alpine/subalpine watershed, Loch Vale, Colorado Strontium 87/strontium 86 as a tracer of mineral weathering reactions and calcium sources in an alpine/subalpine watershed, Loch Vale, Colorado
Sr isotopic ratios of atmospheric deposition, surface and subsurface water, and geologic materials were measured in an alpine/subalpine watershed to characterize weathering reactions and identify sources of dissolved Ca in stream water. Previous studies have noted an excess of Ca in stream water above that expected from stoichiometric weathering of the dominant bedrock minerals. Mixing
Authors
David W. Clow, M. Alisa Mast, Thomas D. Bullen, John T. Turk
Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California
Surface water draining granitic bedrock in Yosemite National Park exhibits considerable variability in chemical composition, despite the relative homogeneity of bedrock chemistry. Other geological factors, including the jointing and distribution of glacial till, appear to exert strong controls on water composition. Chemical data from three surface water surveys in the upper Merced River...
Authors
D. W. Clow, M.A. Mast, K. Campbell
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 96
Long‐term trends in stream water and precipitation chemistry at five headwater basins in the northeastern United States Long‐term trends in stream water and precipitation chemistry at five headwater basins in the northeastern United States
Stream water data from five headwater basins in the northeastern United States covering water years 1968–1996 and precipitation data from eight nearby precipitation monitoring sites covering water years 1984‐1996 were analyzed for temporal trends in chemistry using the nonparametric seasonal Kendall test. Concentrations of SO4declined at three of five streams during 1968–1996 (p 0.1)...
Authors
David W. Clow, M. Alisa Mast
Trends in precipitation and stream-water chemistry in the northeastern United States, water years 1984-96 Trends in precipitation and stream-water chemistry in the northeastern United States, water years 1984-96
Trends in precipitation and stream-water chemistry during water years 1984-96 were examined at eight precipitation monitoring sites and five nearby streams operated by the U.S. Geological Survey in the northeastern United States. The statistical analyses indicate the following: 1)Stream-water sulfate (SO4) concentrations decreased at seven of eight precipitation monitoring sites and in...
Authors
D. W. Clow, M. Alisa Mast
Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains Methane flux in subalpine wetland and unsaturated soils in the southern Rocky Mountains
Methane exchange between the atmosphere and subalpine wetland and unsaturated soils was evaluated over a 15-month period during 1995-1996. Four vegetation community types along a moisture gradient (wetland, moist-grassy, moist-mossy, and dry) were included in a 100 m sampling transect situated at 3200 m elevation in Rocky Mountain National Park, Colorado. Methane fluxes and soil...
Authors
K.P. Wickland, Robert G. Striegl, S.K. Schmidt, M.A. Mast
Winter fluxes of CO2 and CH4 from subalpine soils in Rocky Mountain National Park, Colorado Winter fluxes of CO2 and CH4 from subalpine soils in Rocky Mountain National Park, Colorado
Fluxes of CO2 and CH4 through a seasonal snowpack were measured in and adjacent to a subalpine wetland in Rocky Mountain National Park, Colorado. Gas diffusion through the snow was controlled by gas production or consumption in the soil and by physical snowpack properties. The snowpack insulated soils from cold midwinter air temperatures allowing microbial activity to continue through...
Authors
M. Alisa Mast, Kimberly P. Wickland, Robert G. Striegl, David W. Clow
Strontium 87/strontium 86 as a tracer of mineral weathering reactions and calcium sources in an alpine/subalpine watershed, Loch Vale, Colorado Strontium 87/strontium 86 as a tracer of mineral weathering reactions and calcium sources in an alpine/subalpine watershed, Loch Vale, Colorado
Sr isotopic ratios of atmospheric deposition, surface and subsurface water, and geologic materials were measured in an alpine/subalpine watershed to characterize weathering reactions and identify sources of dissolved Ca in stream water. Previous studies have noted an excess of Ca in stream water above that expected from stoichiometric weathering of the dominant bedrock minerals. Mixing
Authors
David W. Clow, M. Alisa Mast, Thomas D. Bullen, John T. Turk
Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California
Surface water draining granitic bedrock in Yosemite National Park exhibits considerable variability in chemical composition, despite the relative homogeneity of bedrock chemistry. Other geological factors, including the jointing and distribution of glacial till, appear to exert strong controls on water composition. Chemical data from three surface water surveys in the upper Merced River...
Authors
D. W. Clow, M.A. Mast, K. Campbell