Deuterium to hydrogen (D/H) ratios in Earth’s hydrologic cycle have long served as important tracers of climate processes, yet the global HDO budget remains poorly constrained because of uncertainties in the isotopic compositions of continental evapotranspiration and runoff. Here bias-corrected satellite retrievals of HDO and H₂O concentrations from the Tropospheric...
With water vapor and clouds expected to effect significant feedbacks on climate, moisture transport through convective processes has important implications for future temperature change. The precipitation efficiency—the ratio of the rates at which precipitation and condensation form (e = P/C)—is useful for characterizing how much boundary layer moisture recycles through precipitation versus...
A new matrix operator framework is developed to analyze results from climate modeling studies that employ numerical water tracers (WTs), which track the movement of water in the aerial hydrological cycle from evaporation to precipitation. Model WT output is related to the fundamental equation of hydrology, and the moisture flux...
With the recent advent of commercial laser absorption spectrometers, field studies measuring stable isotope ratios of hydrogen and oxygen in water vapor have proliferated. These pioneering analyses have provided invaluable feedback about best strategies for optimizing instrumental accuracy, yet questions still remain about instrument performance and calibration approaches for multi-year...
With the recent advent of commercial laser absorption spectrometers, field studies measuring stable isotope ratios of hydrogen and oxygen in water vapor have proliferated. These pioneering analyses have provided invaluable feedback about best strategies for optimizing instrumental accuracy, yet questions still remain about instrument performance and calibration approaches for multi-year...
This research examines the effect of recent landownership changes and new management stewardship mechanisms (e.g., forest certification and working forest conservation easements) on disturbance rates in Maine forests. We quantify forest disturbance rates between 2000 and 2007 and forest cover type composition in 2007, as detected by Landsat Thematic Mapper...
Understanding the processes that control the terrestrial exchange of carbon is critical for
assessing atmospheric CO₂ budgets. Carbonyl sulfide (COS) is taken up by vegetation during
photosynthesis following a pathway that mirrors CO₂ but has a small or nonexistent emission component,
providing a possible tracer for gross primary production. Field...
The delta O-18 signal preserved in paleoarchives is widely used to reconstruct past climate conditions. In many speleothems, this signal is classically interpreted via the amount effect. However, recent work has shown that precipitation delta O-18 (delta O-18(p)) is greatly influenced by convective processes distinct from precipitation amount, and new...
This study investigates the response of the global mean and spatial variations of the δ¹⁸O value of atmospheric CO₂ (δCₐ) to changes in soil CO₂ hydration rates, relative humidity, the δ¹⁸O value of precipitation and water vapor, visible radiation, temperature, and ecosystem flux partitioning. A three-dimensional global transport model was...
Understanding controls on the stable isotopic composition of precipitation and vapor in the West Pacific Warm Pool is vital for accurate representation of convective processes in models and correct interpretation of isotope-based paleoclimate proxies, yet a lack of direct observational evidence precludes the utility of these isotopic tracers. Results from...