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Full-Text Articles in Physical Sciences and Mathematics
Timing Of Present And Future Snowmelt From High Elevations In Northwest Montana, Bonnie Jean Gillan, Joel T. Harper, Johnnie N. Moore
Timing Of Present And Future Snowmelt From High Elevations In Northwest Montana, Bonnie Jean Gillan, Joel T. Harper, Johnnie N. Moore
Geosciences Faculty Publications
The sensitivity of snowmelt-driven water supply to climate variability and change is difficult to assess in the mountain west, where strong climatic gradients coupled with complex topography are sampled by sparse ground measurements. We developed a model which ingests daily satellite imagery and meteorological data and is suitable for areas >1000 km2, yet captures spatial variability of snow accumulation and melt in steep mountain terrain.We applied the model for the years 2000–2008 to a 2900 km2 snowmelt-dominated watershed in NW Montana. We found that >25% of the basin’s snow water equivalent (SWE) accumulates above the highest measurement station and >70% …
Apparent Seasonal Cycle In Isotopic Discrimination Of Carbon In The Atmosphere And Biosphere Due To Vapor Pressure Deficit, Ashley P. Ballantyne, J. B. Miller, P. P. Tans
Apparent Seasonal Cycle In Isotopic Discrimination Of Carbon In The Atmosphere And Biosphere Due To Vapor Pressure Deficit, Ashley P. Ballantyne, J. B. Miller, P. P. Tans
Ecosystem and Conservation Sciences Faculty Publications
We explore seasonal variability in isotopic fractionation by analyzing observational data from the atmosphere and the biosphere, as well as simulated data from a global model. Using simulated values of atmospheric CO2 and its carbon isotopic composition, we evaluated different methods for specifying background concentrations when calculating the isotopic signature of source CO2 (δs) to the atmosphere. Based on this evaluation, we determined that free troposphere measurements should be used when available as a background reference when calculating δs from boundary layer observations. We then estimate the seasonal distribution of δs from monthly …