We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...
Over the last 150 years, Oregon white oak habitat in the Willamette Valley has been converted to support grass crops, orchards and vineyards, cities, and conifer forests, nearly extirpating it from the Willamette Valley. Yet Oregon white oak offers many ecosystem services to the Willamette Valley and its residents. Recent...
The El Niño/Southern Oscillation (ENSO) affects millions of people via global teleconnections in the form of drought and torrential rainfall that impact agriculture and food production in many countries. Yet how ENSO will respond to a warming world is uncertain and a greatly debated topic. The Intergovernmental Panel on Climate...
As climate change and its associated environmental and socioeconomic impacts become increasingly severe and imminent across the United States, it has become imperative for the public to be aware of and actively engaged with this issue. Although scientists generally perceive outreach in a positive light, a critical barrier that tends...
In the 1954 John Nash [1] showed, through use of an iterative scheme of approximate embedding maps, that the sphere S² could be isometrically embedded into a ball of any radius by a C¹ map. In the 1980's M. Gromov [2] generalized Nash's work to the h-principal and convex integration....
In this work, we consider a convexity splitting scheme for a coupled phase field and energy equation, a modification of Stefan problem. The Stefan problem is a free boundary value problem that models the temperature in a homogeneous multiphase medium. Each phase is modeled using a heat diffusion parabolic partial...
In this work, we provide a detailed analysis of a discrete time regime switching financial market model with jumps. We consider the model under two different scenarios: known and unknown initial regime. For each scenario we investigated conditions that guarantee the model's completeness. We find that the model under consideration...
This thesis presents the results of an investigation into the measured and modeled
mass balance of the Collier Glacier, a small (0.70 km²), valley glacier located in the
Oregon Cascade Range (44° 10' N, 121° 47' W). Here we present mass-balance
measurements conducted for the 2009 and 2010 balance years...
Water is one of the most biologically and economically important substances on Earth. A significant portion of Earth's water subsists in the subsurface. Our ability to monitor the flow and transport of water and other fluids through this unseen environment is crucial for a myriad of reasons.
One difficulty we...
Understanding how the latitudinal distribution of methane sources changed between stadial and interstadial climate states during the last glacial period can provide important clues about how terrestrial hydroclimate and ecosystems evolved between these different states. The punctuation of the millennial-scale structure by Heinrich events is also of interest in this...