Physical Sciences and Mathematics Commons^™

A High-Resolution Record Of Vegetation And Climate Through The Last Glacial Cycle From Caledonia Fen, Southeastern Highlands Of Australia, A Kershaw, G Mckenzie, N Porch, Richard Roberts, J Browne, H Heijnis, M Orr, Geraldine Jacobsen, P Newall

Richard G Roberts

A blocked tributary has provided a rare site of long-term sediment accumulation in montane southeastern Australia. This site has yielded a continuous, detailed pollen record through the last ca. 140 000 years and revealed marked vegetation and environmental changes at orbital to sub-millennial scales. Radiocarbon and optically stimulated luminescence (OSL, or optical) ages provide some chronological control for the last ca. 70 000 years. Most of the sediment is inorganic but with well preserved pollen that accumulated under unproductive and probably largely ice-covered lake conditions. The lake was surrounded by low-growing plants with an alpine character. Exceptions include three discrete …

Initial Speleothem Results From Western Flores And Eastern Java, Indonesia: Were Climate Changes From 47 To 5ka Responsible For The Extinction Of Homo Floresiensis?, Richard Roberts, Allan Chivas, T. Sutikna, Michael Morwood, J Zhao, Kira Westaway

Richard G Roberts

No abstract provided.

Redating The Advance Of The New Zealand Franz Josef Glacier During The Last Termination: Evidence For Asynchronous Climate Change, Richard Roberts, Christian Turney, Matt Mcglone, J Cooper, J Wilmshurst, N De Jonge, C Prior

Richard G Roberts

No abstract provided.

On The Lack Of Stratospheric Dynamical Variability In Low‐Top Versions Of The Cmip5 Models, Andrew J. Charlton-Perez, Mark P. Baldwin, Thomas Birner, Robert X. Black, Amy H. Butler, Natalia Calvo, Nicholas A. Davis, Edwin P. Gerber, Nathan Gillett, Steven Hardiman, Junsu Kim, Kirsten Krüger, Yun-Young Lee, Elisa Manzini, Brent A. Mcdaniel, Lorenzo Polvani, Thomas Reichler, Tiffany A. Shaw, Michael Sigmond, Seok-Woo Son, Matthew Toohey, Laura Wilcox, Shigeo Yoden, Bo Christiansen, François Lott, Drew Shindell, Seiji Yukimoto, Shingo Watanabe

Faculty Articles

We describe the main differences in simulations of stratospheric climate and variability by models within the fifth Coupled Model Intercomparison Project (CMIP5) that have a model top above the stratopause and relatively fine stratospheric vertical resolution (high-top), and those that have a model top below the stratopause (low-top). Although the simulation of mean stratospheric climate by the two model ensembles is similar, the low-top model ensemble has very weak stratospheric variability on daily and interannual time scales. The frequency of major sudden stratospheric warming events is strongly underestimated by the low-top models with less than half the frequency of events …

Bryophyte Species Composition Over Moisture Gradients In The Windmill Islands, East Antarctica: Development Of A Baseline For Monitoring Climate Change Impacts, J Wasley, S A. Robinson, J D. Turnbull, D H. King, W Wanek, M Popp

Sharon Robinson

Extreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves, will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic …

A Spatial Analysis Of Multivariate Output From Regional Climate Models, Stephan Sain, Reinhard Furrer, Noel A. Cressie

Professor Noel Cressie

Climate models have become an important tool in the study of climate and climate change, and ensemble experiments consisting of multiple climate-model runs are used in studying and quantifying the uncertainty in climate-model output. However, there are often only a limited number of model runs available for a particular experiment, and one of the statistical challenges is to characterize the distribution of the model output. To that end, we have developed a multivariate hierarchical approach, at the heart of which is a new representation of a multivariate Markov random field. This approach allows for flexible modeling of the multivariate spatial …

Implementation And Model To Model Intercomparison Of 12 Heat Stress Metrics, Jonathan Robert Buzan

Open Access Theses

Earth system models simulate the dynamics of the most complex systems on our planet with some success. Despite the overwhelming sophistication of these models, which include dynamical interactions of ocean, atmosphere, vegetation, ice, and land-surface properties, they fail to include the most important element. People. Humans are also a complex physical-biological system and coupling of human physiology within an Earth Systems Modeling framework is challenging. This thesis presents results that tackle one particular component of human physiological climate interaction--a representation of heat stress on human physiology. Twelve different metrics were implemented and analyzed. These metrics represent a variety of philosophical …

Metr 200: Weather And Climate—A Peer Review Of Teaching Project Benchmark Portfolio, Matthew S. Van Den Broeke

UNL Faculty Course Portfolios

This benchmark portfolio is meant to be an assessment of how well the objectives of METR 200 (Weather and Climate) are being attained by students in several classifications of academic major. Students from a wide range of backgrounds enroll in this course as a general science elective, and for many, it will be the only science course taken in college. Thus, it is important that course material be sufficiently accessible for all students, while providing meaningful information which will be applicable by students of all backgrounds once they leave the course. In this portfolio, an analysis will be presented showing …

An Analysis Of Surface Air Temperature Trends And Variability Along The Andes, Eric Franquist

Legacy Theses & Dissertations (2009 - 2024)

Climate change is difficult to study in mountainous regions such as the Andes since steep changes in elevation cannot always be resolved by climate models. However, it is important to examine temperature trends in this region as rises in surface air temperature are leading to the melting of tropical glaciers. Local communities rely on the glacier-fed streamflow to get their water for drinking, irrigation, and livestock. Moreover, communities also rely on the tourism of hikers who come to the region to view the glaciers. As the temperatures increase, these glaciers are no longer in equilibrium with their current climate and …

Synoptic To Interannual Variability In Volumetric Flushing In Tampa Bay, Fl Using Observational Data And A Numerical Model, Monica Wilson

USF Tampa Graduate Theses and Dissertations

This research provides insight into changes in volumetric flushing of the Tampa Bay estuary caused by synoptic scale wind events. The two main studies of this dissertation involve 1) using wavelet analysis to investigate the link between the El Niño-Southern Oscillation (ENSO) and the frequency and strength of volumetric flushing driven by synoptic variability and 2) using a multi-decadal model simulation to examine how extratropical/winter storms and hurricanes affect the overall flushing rates for Tampa Bay, FL.

In the first study, two analyses are performed on 55 years of observational data to investigate the effect of multiple small wind events …

The Roles Of Humans And Climatic Variation On The Fire History Of Subalpine Meadows - Mount Rainer National Park (Washington), Michael Louis Lukens

All Master's Theses

With the creation of Mount Rainier National Park (MORA) in 1899 came the active management of the park's landscapes and a heavy emphasis on fire suppression. Today managers at MORA have made returning fire to the park's landscapes a top priority. In order to achieve this goal, and to make more informed decisions in regard to the application of fire, land managers at MORA need to better understand past fire occurrences and the drivers of fire activity on the mountain. To address this problem, analysis of macroscopic charcoal preserved in lake sediments was used to reconstruct the fire history for …

Initial Conditions For A Post-Flood Rapid Ice Age, Steven M. Gollmer

Science and Mathematics Faculty Publications

In the early years of the modern creationist movement questions were raised as to the role of ice ages in explaining geological data. Beginning with Whitcomb and Morris (1961) and formalized by Oard (1979), a proposed scenario of warm oceans and volcanic activity would provide the needed conditions to initiate a post-flood ice age. During the 1990’s Vardiman used the Community Climate Model (CCM) to study the impact of warm oceans on global air circulation and precipitation patterns. Following Vardiman’s lead this study uses the Goddard Institute of Space Studies (GISS) Model E climate model. The first part of the …

Resilience In Quaking Aspen: Recent Advances And Future Needs, Paul C. Rogers, C. Eisenberg, S. Clair

Wildland Resources Faculty Publications

Quaking Aspen (Populus tremuloides) sustainability is a topic of intense interest in forest ecology. Reports range from declines to persisting or increasing coverage in some areas. Moreover, there is little agreement on ultimate factors driving changes. Low aspen recruitment has been attributed to climate patterns, past management, herbivore increases, competitive interactions with conifers, predator and beaver extirpation, and livestock grazing. Several of these potential causes result from direct or indirect actions of human agency. On June 27–28, 2012 a group of leading aspen ecologists from diverse backgrounds convened at the High Lonesome Ranch in western Colorado to address the state …

Controlling Factors On Bedrock River Sinuosity In The Eastern Tibetan Plateau, Lydia Curliss

Honors Papers

Average sinuosity of bedrock rivers across the eastern Tibetan Plateau (including the Yangtze, Mekong, Salween, Irrawaddy, and Tsang Po) ranges from 1.20-1.41. From 25°-30°N, sinuosity marginally increases east to west; over the entire distance of each river, sinuosity increases north to south. Increases in sinuosity parallel a regional tectonic gradient in an area with a marginal climate gradient. Several past studies correlate sinuous bedrock rivers in mountainous regions with gradients in climate, arguing that landslides are the main mechanism by which bedrock rivers increase sinuosity. Other studies find correlations between tectonics and increasing landslide frequency. To investigate the role of …

Becoming Differently Modern: Geographic Contributions To A Generative Climate Politics, Lesley M. Head, Christopher R. Gibson

Chris Gibson

Anthropogenic climate change is a quintessentially modern problem in its historical origins and discursive framing, but how well does modernist thinking provide us with the tools to solve the problems it created? On one hand even though anthropogenic climate change is argued to be a problem of human origins, solutions to which will require human actions and engagements, modernity separates people from climate change in a number of ways. On the other, while amodern or more-than-human concepts of multiple and relational agency are more consistent with the empirical evidence of humans being deeply embedded in earth surface processes, these approaches …

Co2 Injection Into A Deep Saline Aquifer: Porosity Measurements, Numerical Modeling, And Costs Associated With Uncertainty Of Petrophysical Parameters, Michael John Gragg

Masters Theses

Anthropogenic levels of atmospheric greenhouse gases, particularly carbon dioxide (CO₂) have increased rapidly over the last several decades and coincide with rising temperatures globally. One possible solution is to capture CO₂ before it is released into the atmosphere by large point sources, such as fossil fuel power plants. Once captured, the CO₂ can be condensed and transported to a storage facility. Of the available options for storage of condensed CO₂, geologic sequestration in deep saline aquifers is considered the most viable option.

Porosity measurements were obtained for nearly 100 core samples of the Knox …

A Spatial Agent-Based Model To Explore Scenarios Of Adaptation To Climate Change In An Alpine Tourism Destination, Stefano Balbi, Pascal Perez, Carlo Giupponi

Professor Pascal Perez

A vast body of literature suggests that the European Alpine region may be one of the most sensitive to climate change impacts. Adaptation to climate change of Alpine socioecosystems is increasingly becoming an issue of interest for the scientific community while the people of the Alps are often unaware of or simply ignore the problem. ClimAlpTour is a European research project of the Alpine Space Programme, bringing together institutions and scholars from all countries of the Alpine arch, in view of dealing with the expected decrease in snow and ice cover, which may lead to a rethinking of tourism development …

Simkat: A Virtual Laboratory To Explore The Impact Of Climate Change Scenarios On The Western Australian Wheat-Belt, A Dray, S Asseng, Pascal Perez, S Charles, B Bates

Professor Pascal Perez

The northernmost part of the Mesoamerican Barrier Reef (MBR) runs along the eastern Yucatan peninsula (Mexico). Over two decades, sprawling coastal tourism development and over-exploitation of marine resources have considerably reduced fringing reef's ecological functions. SimReef is an interactive model designed to better understand the interactions between regional and local drivers strongly influencing the health of coral reefs. SimReef's development follows a collective design approach and an inductive process whereby dynamics are represented by data-driven relationships. Experts and stakeholders participate to the designing phase in order to help calibrating the model and to support a consensual validation of the results.

Combining Outputs From The North American Regional Climate Change Assessment Program By Using A Bayesian Hierarchical Model, Emily L. Kang, Noel Cressie, Stephan R. Sain

Professor Noel Cressie

We investigate the 20-year-average boreal winter temperatures generated by an ensemble of six regional climate models (RCMs) in phase I of the North American Regional Climate Change Assessment Program. We use the long-run average (20-year integration) to smooth out variability and to capture the climate properties from the RCM outputs. We find that, although the RCMs capture the large-scale climate variation from coast to coast and from south to north similarly, their outputs can differ substantially in some regions. We propose a Bayesian hierarchical model to synthesize information from the ensemble of RCMs, and we construct a consensus climate signal …

Episodic Recruitment And Climate Analysis Of Ponderosa Pine On The Palmer Divide, Eastern Colorado, William Henry Brenton Jr.

Electronic Theses and Dissertations

Previous recruitment studies on populations of ponderosa pine (Pinus ponderosa P. & C. Lawson) in Colorado have been limited to the western mountains and the Front Range. In this research I used tree-ring data to reconstruct recruitment for ponderosa pine near the eastern limits of its distribution at two sites on the Palmer Divide, Eastern Colorado, to determine the relative climate sensitivity of the two sites, and the extent to which climate or other factors may have influenced recruitment at the sites. The results of the tree-ring analysis suggest that ponderosa pines in more the easterly site lower elevation …

Bryophyte Species Composition Over Moisture Gradients In The Windmill Islands, East Antarctica: Development Of A Baseline For Monitoring Climate Change Impacts, J Wasley, S A. Robinson, J D. Turnbull, D H. King, W Wanek, M Popp

Faculty of Science - Papers (Archive)

Extreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves, will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic …

Slides: Session 3: Decision-Making And The Energy Poor, Andrew Yager

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Andrew Yager, United Nations Department of Economic and Social Affairs, Division for Sustainable Development

33 slides

Age And Origin Of Alluvial Sediments Within And Flanking The Mt Lofty Ranges, Southern South Australia: A Late Quaternary Archive Of Climate And Environmental Change, D Banerjee, N F. Alley, R P. Bourman, S Buckman, J R. Prescott

Solomon Buckman Dr.

No abstract provided.

The Weather And Climate Of West Virginia, Kevin Law, H. Michael Mogil

Kevin Law

West Virginia is a geographically small state with a distinctive climate. The article describes the climatological patterns of the state plus describes some historical weather events.

Radiocarbon Bomb Spike Reveals Biological Effects Of Antarctic Climate Change, Laurence J Clarke, Sharon A. Robinson, Quan Hua, David J. Ayre, David Fink

Sharon Robinson

The Antarctic has experienced major changes in temperature, wind speed and stratospheric ozone levels during thelast 50 years. However, until recently continental Antarctica appeared to be little impacted by climate warming, thusbiological changes were predicted to be relatively slow. Detecting the biological effects of Antarctic climate changehas been hindered by the paucity of long-term data sets, particularly for organisms that have been exposed to thesechanges throughout their lives. We show that radiocarbon signals are preserved along shoots of the dominant Antarcticmoss flora and use these to determine accurate growth rates over a period of several decades, allowing us toexplore the …

Climate And Culture, Gordon R. Waitt, Andrew W. Gorman-Murray

Gordon Waitt

No abstract provided.

Modeling Glacial Termination, Michael Murphy

Natural Resources Management and Environmental Sciences

Examines possible cause of the glacial termination or ice age cycle using a numerical model created by Tziperman et al. Also explores possible physical mechanisms causing the observed cycle of slow cooling followed by rapid warming.

Investigating Three Decades Of Vegetation Change In A Mojave Desert Mountain Range, Chris Lee Roberts

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project is a vegetation change study spanning 29 years in the Newberry Mountains of Southern Nevada. Long term monitoring data are crucial for understanding the effects of climate change on vegetation dynamics. Successful management intervention in vegetation change will require identification of early indicator plant species and their responses to climatic cues. This project is one of the oldest comparisons of resurveyed Mojave vegetation community plots with repeatable methodology and the longest survey interval reported for the southeastern Mojave Desert. 103 plots were relocated and resurveyed based on data methods in Jim Holland's thesis titled "A Vegetative Analysis of …

Tracking Lateglacial And Early Holocene Environmental Change: A Palaeolimnological Study Of Sediment At Preluca Tiganului, Nw Romania, Angelica Feurdean

Studia UBB Geologia

Palaeoecological, palaeohydrological, and paleoenvironmental reconstruction of the Late Glacial and the early Holocene have been performed from sediment accumulated in a small former crater lake, in the GutâI Mountains, NW Romania. Pollen, lithology, mineral magnetic, and loss-on-ignition analyses in conjunction to radiocarbon dating have been use for this purpose. The data indicates that during the Late Glacial period, vegetation dynamics were likely driven by climatic fluctuations. The climate events during the Late Glacial are well mirrored in local vegetation assemblage development, and past lake level fluctuations. These climatic events recorded in south-eastern Europe, are well correlated with the climate events …

Seed Bank Persistence And Climate Change, Mark K. J Ooi

Faculty of Science - Papers (Archive)

"The strong mechanistic relationship between climatic factors and seed dormancy and germination suggests that forecast climatic changes will significantly affect seed bank persistence. This review focuses on the potential impact of changing temperature, rainfall and fire regimes on the longevity of long-term persistent seed-banks. Currently, there are few studies investigating the mechanistic responses of demographic processes, such as seed-bank dynamics, to forecast climate change. However, from the work that has been published, several key points have been highlighted. First, increased air temperatures will produce significantly higher soil temperatures in open and sparsely vegetated habitats. Some evidence shows that this could …