Halogens are primarily located within surface reservoirs of the Earth; as such they have proven to be effective tracers for the identification of subducted volatiles within the mantle. Subducting lithologies exhibit a wide variety of halogen compositions, yet the mantle maintains a fairly uniform signature, suggesting halogens may be homogenized...
An improved understanding of ecohydrologic connections is critical for improving land management decisions in water-scarce regions of the western United States. For this study, conducted in a semiarid (358 mm) rangeland location in central Oregon, we evaluated precipitation-interception-soil moisture dynamics at the plot scale and characterized surface water and groundwater...
Observations of turbulence, internal waves, and subinertial flow were made over a steep, corrugated continental slope off Virginia during May–June 1998. At semidiurnal frequencies, a convergence of low-mode, onshore energy flux is approximately balanced by a divergence of high-wavenumber offshore energy flux. This conversion occurs in a region where the...
Parasites and pathogens influence the size and stability of wildlife populations, yet many population models ignore
the population-level effects of pathogens. Standard survival analysis methods (e.g., accelerated failure time models)
are used to assess how survival rates are influenced by disease. However, they assume that each individual is equally
susceptible...
Identification of heterotic groups and patterns among breeding populations provides fundamental information to help plant breeders more knowledgeably manipulate heterosis. A diallel analysis was conducted among nine alfalfa (Medicago sativa L.) germplasms, commonly referred to as African, Chilean, Flemish, Indian, Ladak, M. falcata, M. varia, Peruvian, and Turkistan, which represent...
Although climate acts as a fundamental constraint on the distribution of
organisms, understanding how this relationship between climate and distribution varies over a
species’ range is critical for addressing the potential impacts of accelerated climate change on
biodiversity. Bioclimatic niche models provide compelling evidence that many species will
experience range...
Ecological niche theory holds that species distributions are shaped by a large and complex suite of interacting factors. Species distribution models (SDMs) are increasingly used to describe species’ niches and predict the effects of future environmental change, including climate change. Currently, SDMs often fail to capture the complexity of species’...
Air passing upward through the tropical tropopause is “marked” by an annually varying water vapor mixing ratio much as a tape recorder marks a magnetic tape; as the air ascends in the tropical stratosphere, these marks are effaced by a combination of vertical diffusion within the tropics and dilution of...
Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu’u seamount. Nafanua grew from the 1,000-m-deep crater floor in <4 years and could reach the sea surface within decades. Vents fill Vailulu’u crater with a thick suspension of particulates and...
The accuracy of state-of-the-art global barotropic tide models is assessed using bottom
pressure data, coastal tide gauges, satellite altimetry, various geodetic data on Antarctic ice shelves, and
independent tracked satellite orbit perturbations. Tide models under review include empirical, purely
hydrodynamic (“forward”), and assimilative dynamical, i.e., constrained by observations. Ten dominant...