This study tested the utility of a variable mixing efficiency formulation proposed by Mashayek, et al. (2017) for use in oceanographic models other than the modern, pre-industrial ocean. This formulation is used to calculate diapycnal (vertical) mixing due to unresolved subgrid-scale processes. Results from Last Glacial Maximum (LGM) simulations for...
During the Last Glacial Maximum (LGM, ∼ 21 ky before present) the atmospheric CO2 concentration was about 100 ppm lower than its pre-industrial (PI)value. The missing carbon from the atmosphere must have been stored in thedeep ocean during this period, but the mechanisms driving such re-distribution ofthe carbon cycle are...
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...
For spatial data visualization, we approach two problems and provide solutions: heat map resolution selection, and heat map confidence interval presentation. Analysts often present spatial data in gridded heat maps, at some chosen resolution. However, many data types vary in density across the domain. We develop variable-resolution heat maps to...
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...