M. Alisa Mast (Former Employee)
Science and Products
Filter Total Items: 13
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Filter Total Items: 96
Atmospheric deposition maps for the Rocky Mountains Atmospheric deposition maps for the Rocky Mountains
Variability in atmospheric deposition across the Rocky Mountains is influenced by elevation, slope, aspect, and precipitation amount and by regional and local sources of air pollution. To improve estimates of deposition in mountainous regions, maps of average annual atmospheric deposition loadings of nitrate, sulfate, and acidity were developed for the Rocky Mountains by using spatial...
Authors
L. Nanus, K. Campbell, G.P. Ingersoll, D. W. Clow, M.A. Mast
Chemistry of selected high-elevation lakes in seven national parks in the western United States Chemistry of selected high-elevation lakes in seven national parks in the western United States
A chemical survey of 69 high-altitude lakes in seven national parks in the western United States was conducted during the fallof 1999; the lakes were previously sampled during the fall of 1985, as part of the Western Lake Survey. Lakes in parks in the Sierra/southern Cascades (Lassen Volcanic, Yosemite, Sequoia/Kings Canyon National Parks) and in the southern RockyMountains (Rocky...
Authors
David W. Clow, Robert G. Striegl, Leora Nanus, M. Alisa Mast, Donald H. Campbell, David P. Krabbenhoft
Use of natural 35S to trace sulphate cycling in small lakes, Flattops Wilderness Area, Colorado, U.S.A. Use of natural 35S to trace sulphate cycling in small lakes, Flattops Wilderness Area, Colorado, U.S.A.
Measurements of the cosmogenically-produced 35S, a radioisotope of sulphur (t1/2 = 87 days), are reported for the Ned Wilson Lake watershed in Colorado. The watershed contains two small lakes and a flowing spring presumed to be representative of local ground water. The watershed is located in the Flattops Wilderness Area and the waters in the system have low alkalinity, making them...
Authors
Robert L. Michel, John T. Turk, Donald H. Campbell, M. Alisa Mast
Rocky Mountain snowpack chemistry network: History, methods, and the importance of monitoring mountain ecosystems Rocky Mountain snowpack chemistry network: History, methods, and the importance of monitoring mountain ecosystems
Because regional-scale atmospheric deposition data in the Rocky Mountains are sparse, a program was designed by the U.S. Geological Survey to more thoroughly determine the quality of precipitation and to identify sources of atmospherically deposited pollution in a network of high-elevation sites. Depth-integrated samples of seasonal snowpacks at 52 sampling sites, in a network from New...
Authors
George P. Ingersoll, John T. Turk, M. Alisa Mast, David W. Clow, Donald H. Campbell, Zelda C. Bailey
Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition
Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data...
Authors
David W. Clow, George P. Ingersoll, M. Alisa Mast, John T. Turk, Donald H. Campbell
Major-ion chemistry of the Rocky Mountain snowpack, USA Major-ion chemistry of the Rocky Mountain snowpack, USA
During 1993-97, samples of the full depth of the Rocky Mountain snowpack were collected at 52 sites from northern New Mexico to Montana and analyzed for major-ion concentrations. Concentrations of acidity, sulfate, nitrate, and calcium increased from north to south along the mountain range. In the northern part of the study area, acidity was most correlated (negatively) with calcium...
Authors
J.T. Turk, Howard E. Taylor, G.P. Ingersoll, K.A. Tonnessen, D. W. Clow, M.A. Mast, K. Campbell, J.M. Melack
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 96
Atmospheric deposition maps for the Rocky Mountains Atmospheric deposition maps for the Rocky Mountains
Variability in atmospheric deposition across the Rocky Mountains is influenced by elevation, slope, aspect, and precipitation amount and by regional and local sources of air pollution. To improve estimates of deposition in mountainous regions, maps of average annual atmospheric deposition loadings of nitrate, sulfate, and acidity were developed for the Rocky Mountains by using spatial...
Authors
L. Nanus, K. Campbell, G.P. Ingersoll, D. W. Clow, M.A. Mast
Chemistry of selected high-elevation lakes in seven national parks in the western United States Chemistry of selected high-elevation lakes in seven national parks in the western United States
A chemical survey of 69 high-altitude lakes in seven national parks in the western United States was conducted during the fallof 1999; the lakes were previously sampled during the fall of 1985, as part of the Western Lake Survey. Lakes in parks in the Sierra/southern Cascades (Lassen Volcanic, Yosemite, Sequoia/Kings Canyon National Parks) and in the southern RockyMountains (Rocky...
Authors
David W. Clow, Robert G. Striegl, Leora Nanus, M. Alisa Mast, Donald H. Campbell, David P. Krabbenhoft
Use of natural 35S to trace sulphate cycling in small lakes, Flattops Wilderness Area, Colorado, U.S.A. Use of natural 35S to trace sulphate cycling in small lakes, Flattops Wilderness Area, Colorado, U.S.A.
Measurements of the cosmogenically-produced 35S, a radioisotope of sulphur (t1/2 = 87 days), are reported for the Ned Wilson Lake watershed in Colorado. The watershed contains two small lakes and a flowing spring presumed to be representative of local ground water. The watershed is located in the Flattops Wilderness Area and the waters in the system have low alkalinity, making them...
Authors
Robert L. Michel, John T. Turk, Donald H. Campbell, M. Alisa Mast
Rocky Mountain snowpack chemistry network: History, methods, and the importance of monitoring mountain ecosystems Rocky Mountain snowpack chemistry network: History, methods, and the importance of monitoring mountain ecosystems
Because regional-scale atmospheric deposition data in the Rocky Mountains are sparse, a program was designed by the U.S. Geological Survey to more thoroughly determine the quality of precipitation and to identify sources of atmospherically deposited pollution in a network of high-elevation sites. Depth-integrated samples of seasonal snowpacks at 52 sampling sites, in a network from New...
Authors
George P. Ingersoll, John T. Turk, M. Alisa Mast, David W. Clow, Donald H. Campbell, Zelda C. Bailey
Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition
Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data...
Authors
David W. Clow, George P. Ingersoll, M. Alisa Mast, John T. Turk, Donald H. Campbell
Major-ion chemistry of the Rocky Mountain snowpack, USA Major-ion chemistry of the Rocky Mountain snowpack, USA
During 1993-97, samples of the full depth of the Rocky Mountain snowpack were collected at 52 sites from northern New Mexico to Montana and analyzed for major-ion concentrations. Concentrations of acidity, sulfate, nitrate, and calcium increased from north to south along the mountain range. In the northern part of the study area, acidity was most correlated (negatively) with calcium...
Authors
J.T. Turk, Howard E. Taylor, G.P. Ingersoll, K.A. Tonnessen, D. W. Clow, M.A. Mast, K. Campbell, J.M. Melack