Physical Sciences and Mathematics Commons^™

Climate Change In The Dead Heart Of Australia, Joshua Larsen, Gerald C. Nanson, Timothy J. Cohen, Brian G. Jones, John D. Jansen, Jan-Hendrik May

Timothy Cohen

Despite the absence of large-scale glaciation, the Australian continent has experienced substantial environmental change throughout the Quaternary period. This is especially pronounced in central Australia, where one seventh of the continent is drained internally to the depocentre, and lowest point in Australia, Lake Eyre (Figure 1). Research has shown that at one time, large sandy braided and meandering rivers carried water through dunefields to a large freshwater lake system. Today, the rivers are hostage to the dunefield, and floodwaters might only reach Lake Eyre once every ten years or so. In order to understand the development of this arid desert …

Slides: Natural Gas: Game Changer Or Runner Left On Base? Working To Get It Right In Co!, Gary Graham

Drawing the Blueprint for a Sustainable Natural Gas Future (January 18)

Presenter: Dr. Gary Graham, Director, Lands Program, Western Resource Advocates

21 slides

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

Faculty of Informatics - Papers (Archive)

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 …

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

Faculty of Science - Papers (Archive)

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 …

Seasonal Zooplankton Dynamics In Lake Michigan: Disentangling Impacts Of Resource Limitation, Ecosystem Engineering, And Predation During A Critical Ecosystem Transition, Henry A. Vanderploeg, Steven A. Pothoven, Gary L. Fahnenstiel, Joann F. Cavaletto, James R. Liebig, Craig A. Stow, Thomas F. Nalepa, Charles P. Madenjian, David B. Bunnell

United States Department of Commerce: Staff Publications

We examined seasonal dynamics of zooplankton at an offshore station in Lake Michigan from 1994 to 2003 and 2007 to 2008. This period saw variable weather, declines in planktivorous fish abundance, the introduction and expansion of dreissenid mussels, and a slow decline in total phosphorus concentrations. After the major expansion of mussels into deep water (2007–2008), chlorophyll in spring declined sharply, Secchi depth increased markedly in all seasons, and planktivorous fish biomass declined to record-low levels. Overlaying these dramatic ecosystem-level changes, the zooplankton community exhibited complex seasonal dynamics between 1994–2003 and 2007–2008. Phenology of the zooplankton maximum was affected by …

Climate Change, Fuel And Fire Behaviour In A Eucalypt Forest, Stuart Matthews, Andrew L. Sullivan, Penny Watson, Richard J. Williams

Faculty of Science - Papers (Archive)

A suite of models was used to examine the links between climate, fuels and fire behaviour in dry eucalypt forests in south-eastern Australia. Predictions from a downscaled climate model were used to drive models of fuel amount, the moisture content of fuels and two models of forest fire behaviour at a location in western Sydney in New South Wales, Australia. We found that a warming and drying climate produced lower fine fuel amounts, but greater availability of this fuel to burn due to lower moisture contents. Changing fuel load had only a small effect on fuel moisture. A warmer, drier …

Manipulating Thermal Stress On Rocky Shores To Predict Patterns Of Recruitment Of Marine Invertebrates Under A Changing Climate, Justin A. Lathlean, Todd E. Minchinton

Faculty of Science - Papers (Archive)

For rocky intertidal organisms, temperature is often considered the most influential factor governing early survival and growth. Nevertheless, our review of the literature revealed that few studies have manipulated temperatures in the field to test for effects on these critical early life history processes. Here, we present the results from a novel manipulation of substratum temperature using settlement plates of different colour (black, grey and white) and infrared measurements of temperature to test hypotheses that temperature influences the early survival and growth of recent settlers of the intertidal barnacle Tesseropora rosea. Mean surface temperatures of black and grey plates …

Meteorological Modes Of Variability For Fine Particulate Matter (Pm2.5) Air Quality In The United States: Implications For Pm2.5 Sensitivity To Climate Change, A. P K. Tai, L J. Mickley, D J. Jacob, E M. Leibensperger, L Zhang, J A. Fisher, H. O T. Pye

Faculty of Science - Papers (Archive)

We applied a multiple linear regression model to understand the relationships of PM_2.5 with meteorological variables in the contiguous US and from there to infer the sensitivity of PM_2.5 to climate change. We used 2004–2008 PM_2.5 observations from ~1000 sites (~200 sites for PM_2.5 components) and compared to results from the GEOS-Chem chemical transport model (CTM). All data were deseasonalized to focus on synoptic-scale correlations. We find strong positive correlations of PM_2.5 components with temperature in most of the US, except for nitrate in the Southeast where the correlation is negative. Relative humidity (RH) is …

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

Faculty of Science - Papers (Archive)

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 …

The First Climate Refugees? Contesting Global Narratives Of Climate Change In Tuvalu, Carol Farbotko, Heather Lazrus

Faculty of Science - Papers (Archive)

Climate change effects such as sea-level rise are almost certain. What these outcomes mean for different populations, however, is far less certain. Climate change is both a narrative and material phenomenon. In so being, understanding climate change requires broad conceptualisations that incorporate multiple voices and recognise the agency of vulnerable populations. In climate change discourse, climate mobility is often characterised as the production of 'refugees', with a tendency to discount long histories of ordinary mobility among affected populations. The case of Tuvalu in the Pacific juxtaposes migration as everyday practice with climate refugee narratives. This climate-exposed population is being problematically …

Late Miocene Palaeoclimate And Ecosystem Dynamics In Southwestern Bulgaria − A Study Based On Pollen Data From The Gotse-Delchev Basin, Dimiter A. Ivanov, Torsten Utescher, A. Rahman Ashraf, Volker Mosbrugger, Vladimir Bozukov, Nadezhda Djorgova, Evgenia Slavomirova

Turkish Journal of Earth Sciences

A profile 63 m thick in the Late Miocene in the Gotse-Dechev Basin (SW Bulgaria) was sampled for pollen analysis in the Kanina opencast mine. The exposed sequence comprises a basal unit with brown coal-clay cycles and clayey/siliciclastic cover layers partly representing a lacustrine facies. A total of 60 pollen samples were analysed, but quantitative data are confined to 30 polleniferous samples. The palynological analysis carried out provides data about the composition and structure of the fossil vegetation. The main vegetation type was a mixed mesophytic forest dominated by Carya, Fagus, Betula, Quercus, and Ulmus. Accessory elements included Magnolia, Corylopsis, …

Changing Land Use On Unproductive Soils, Andrew Blake, Mike Clarke, Angela Stuart-Street

Resource management technical reports

A three year study completed in 2010 examined farming systems in the north-eastern agricultural region and eastern wheatbelt of Western Australia which experienced a succession of variable seasons from 2000. This culminated in severe drought in 2006 and 2007. At that time, farmers experienced labour shortages and declining terms of trade triggered by cost inflation outpacing growth in commodity prices. As a result, farm business equity was eroded as farm debt escalated. This left many farm businesses in a highly vulnerable state. At the time of the study many farmers were facing an uncertain future.

These experiences, coupled with a …

The Effects Of Hydrologic Modifications On Floodplain Forest Tree Recruitment And Growth In The Mississippi River Alluvial Valley, Usa, Hugo Gee

LSU Doctoral Dissertations

Floodplains forests are productive and diverse ecosystems characterized by frequent riverine flooding. Levees and dams have eliminated or altered riverine flooding which can potentially affect floodplain tree recruitment and growth. Increased light availability from canopy disturbances may increase photosynthesis given sufficient soil moisture, but information on the combined effect of canopy disturbances and hydrologic modifications on tree recruitment and growth is lacking. I used dendrochronological techniques to reconstruct tree recruitment, growth (Quercus lyrata, Fraxinus pennsylvanica), and canopy disturbance patterns over a 90-year period at several floodplains in the Mississippi River Alluvial Valley, USA: an unleveed site below dams and two …

Cora – A Dedicated Device For Carbon Dioxide Monitoring In Cave Environments, Marc Luetscher, Felix Ziegler

International Journal of Speleology

High resolution time-series of cave CO₂ fluctuations are increasingly demanded to quantify calcite precipitation processes. CORA, an energy-efficient NDIR-device, has been specifically developed for the long-term monitoring of carbon dioxide in remote cave environments. To allow comparison between different cave sites, changes in air pressure and temperature are compensated for using dedicated probes. Laboratory experiments demonstrate that CORA’s precision is adapted to the analysis of spatially and temporally variable CO₂ regimes and therefore suitable for a large number of applications. Data obtained with 12 independently calibrated instruments are reproducible within 3% (1σ). The two-point calibration function is validated …

An Evaluation Of Disturbance-Induced Nutrient Changes And Climate Responses Of Loblolly Pine Xylem, Rebecca Lynne Stratton

Doctoral Dissertations

Dendrochronological techniques are currently limited to the identification of visible fire scars. However, through the development of new dendrochemical techniques, the potential exists to provide insight into a broader array of pyric ecosystems. In addition, the ability to identify historic climate-growth responses provides a better understanding of the conditions under which historic fire regimes occurred.

This study provides the groundwork for the identification of a dendrochemical nutrient fire signature in xylem and identifies the climate-radial growth responses of loblolly pine (Pinus taeda L.) on five sites in the Piedmont of South Carolina. Changes in N, P, K, Ca, Mg, …

Atlantic Multidecadal Oscillation-Forced Regional Summertime Precipitation Variations In The Central United States, Michael C. Veres

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The purpose of this research is to identify the regional mechanisms by which the Atlantic Multidecadal Oscillation (AMO) influences summer (June-August) precipitation in the central U.S. This was accomplished by running two different sets of simulations using the Weather Research and Forecasting (WRF) regional climate model, one forced by observations and the other forced only by variations in the AMO as obtained via a global climate model (GCM). The results reveal a complex set of mechanisms active in the lower and middle troposphere by which the AMO influences summer circulation and precipitation in the central U.S. During the cold phase …

Spatial Accuracy Of Climate Networks In Nebraska, Andrea J. Coop

School of Natural Resources: Dissertations, Theses, and Student Research

Climate data has become increasingly scrutinized for its accuracy because of the need for reliable predictions about climate change. The U.S. has taken great strides to keep up with the demand for accurate climate data. Over the last thirty years, vast improvements to instrumentation, data collection, and station siting have created more accurate data records. This study is to explore the accuracy of existing networks. This study analyzes three climate networks used in Nebraska: the U.S. Historical Climatology Network (HCN), the Automated Weather Data Network (AWDN), and the newest network, the U.S. Climate Reference Network (CRN). Each of these networks …

The Use Of Large-Scale Climate Data To Predict Drought, River Flows, And Vegetation Over Central-Southwest Asia, Matthew Barlow

2011 Symposium on Data-Driven Approaches to Droughts

Central-Southwest Asia is a semi-arid, economically stressed region where droughts have severe societal impacts in terms of agriculture, farming, access to fresh water for drinking, and sanitation. There are two sources of drought predictability for this area: the influence of predictable modes of large-scale climate variability at both seasonal and intraseasonal timescales, and the importance of the snow pack to warm season river flows and vegetation. Local data scarcity is a critical problem for the region, both for historical analysis and for real-time monitoring. However, analysis shows that satellite data can be used to provide a considerable amount of high-resolution …

Monitoring Drought Across Many Scales, Chris Funk

2011 Symposium on Data-Driven Approaches to Droughts

Monitoring drought across many scales Chris Funk As gas and food prices increase while per capita harvested area decreases, drought and disruptions in food availability exert more and more pressure on the political and economic stability of ‘frailed’ states. Improved drought monitoring across many spatial and temporal time scales has therefore become increasingly important. As this need mounts, so have our capacities to observe and understand the earth’s climate. Relatively new satellite systems, such as the Moderate Resolution Imaging Spectrometer, allow us to watch the earth at scales of ~100 meters. Improved rainfall retrievals give us more timely and accurate …

Slides: Who Should Be At The Table, And What Should They Be Talking About?, Robert W. Adler

Navigating the Future of the Colorado River (Martz Summer Conference, June 8-10)

Presenter: Robert W. Adler, James I. Farr Chair in Law, University of Utah, S.J. Quinney College of Law

9 slides

Slides: Introduction To Large-Scale Planning And The Intermountain Bmp Project, Kathryn Mutz

Best Management Practices (BMPs): What? How? And Why? (May 26)

Presenter: Kathryn Mutz, Natural Resources Law Center, University of Colorado School of Law

18 slides

Holocene Climate And Environmental History Of Laguna Saladilla, Dominican Republic, Maria Anne Caffrey

Doctoral Dissertations

Stratigraphic analyses of lacustrine sediments provide powerful tools for reconstructing past environments. The records that result from these analyses are key to understanding present-day climate mechanisms and how the natural environment may respond to anthropogenic climate change in the future. This doctoral dissertation research investigates climate and environmental history at Laguna Saladilla (19° [degrees] 39' N, 71° [degrees] 42' W; ca. 2 masl), a large (220 ha) lake along the north coast of Hispaniola. I reconstructed changes in vegetation and environmental conditions over the mid to late Holocene based on pollen, microscopic charcoal, and diatoms in an 8.51 m sediment …

Carbon And Sulfur Cycling In Early Paleozoic Oceans, Cara Kim Thompson

Doctoral Dissertations

Here, I evaluate biospheric evolution during the Ordovician using high-resolution inorganic carbon and sulfur (carbonate-associated sulfate and pyrite) isotope profiles for Early Ordovician to early Late Ordovician strata from geographically distant sections in Western Newfoundland and the Argentine Precordillera. Additionally, I present new, high-resolution U-Pb ages for volcanic ash beds within strata of the Argentine Precordillera. Carbon isotope data record subdued variation that is typical of Early- to Middle Ordovician strata worldwide. By contrast, sulfur-isotopic compositions of carbonate-associated sulfate reveal a complex signal of short-term, rhythmic variation superimposed over a longer-term signal. This short-term, rhythmic variation occurs in all sections …

Physiographic Factors Defining The Snake River Valley Ava; Beyond "Vin De Idaho", David Wilkins, Virginia Gillerman, Krista Shellie, Ron Bitner, Gregory Jones

David E. Wilkins

Beginning in 1971 with the first plantings of wine grapes, the wine and wine grape industry in southwest Idaho have grown to become significant contributors to the state economy with an annual impact of $75 million (Bierle et al., 2008). With around 1600 acres under cultivation in 50 vineyards producing at least 24 varietals (as of 2007), wine grapes are the state's second largest fruit crop in acreage, with the majority of the crop (USDA, 2008) being produced in the western Snake River Plain of southwestern Idaho and eastern Oregon. In April, 2007, a 21,400 sq. km area in this …

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

Geography Faculty Research

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.

Crop Updates 2011 - Farming Systems, Janette Drew, Rob Grima, Bob French, Raj Malik, Mark Seymour, Christine Zaicou-Kunesch, Glenn Mcdonald, Brendon Nicholas, Dennis Van Gool, James Fisher, Peter Tozer, Doug Abrecht, Michael Robertson, Cameron Weeks, Michael O'Conner, Peter Newman, Mike Clarke, Andrew Blake, Gordon Macaulay, Vijay Jayasena, Syed M. Nasar-Abbas, Larisa Cato, Robert Loughman, Ken Quail

Crop Updates

This session covers twelve papers from different authors:

1. Fallowing 50% of the farm each year – does it pay? Janette Drew and Rob Grima

Department of Agriculture and Food

2. How crop sequences affect the productivity and resilience of cropping systems in two Western Australian environments, Bob French, Raj Malik, Mark Seymour, Department of Agriculture and Food

3. When is continuous wheat or barley sustainable? Christine Zaicou-Kunesch and Rob Grima Department of Agriculture and Food

4. Identifying constraints to bridging the yield gap, Glenn McDonald, Department of Agriculture and Food

5. Land constraints limiting wheat yields in …

Multidecadal Otolith Growth Histories For Red And Gray Snapper (Lutjanus Spp.) In The Northern Gulf Of Mexico, Usa, Bryan A. Black, Robert J. Allman, Isaac D. Schroeder, Michael J. Schirripa

United States Department of Commerce: Staff Publications

Dendrochronology (tree-ring analysis) techniques were applied to develop chronologies from the annual growth-increment widths of red snapper (Lutjanus campechanus) and gray snapper (Lutjanus griseus) otoliths sampled from the northern Gulf of Mexico, USA. Growth increment widths showed considerable synchrony within and across species, indicating that some component of environmental variability influenced growth. The final, exactly dated red snapper chronology continuously spanned 1975 through 2003, while the gray snapper chronology continuously spanned 1975 through 2006. To determine baseline climategrowth relationships, chronologies were compared to monthly averages of sea surface temperatures, U winds (west to east), V winds …

Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf

School of Natural Resources: Faculty Publications

Social factors, such as farming methods, have an impact on farm vulnerability to drought, but have received little research or policy attention. Some researchers and advocates have argued that sustainable agriculture systems are less vulnerable to climate risk than conventional systems because sustainable agriculture requires producers to have skills promoting adaptability. In this paper, we investigate producers’ perceptions on the use of sustainable agriculture in reducing drought risk, and what they believe would help them better adapt to drought. We surveyed and interviewed farmer members of two sustainable agriculture organizations in Nebraska, USA, during a multi-year drought period from 1999 …

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

Faculty of Informatics - Papers (Archive)

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 …

How Well Do Predators Adjust To Climate-Mediated Shifts In Prey Distribution? A Study On Australian Water Pythons, Beata Ujvari, Rick Shine, Thomas Madsen

Faculty of Science - Papers (Archive)

Climate change can move the spatial location of resources critical for population viability, and a species resilience to such changes will depend upon its ability to flexibly shift its activities away from no-longer-suitable sites to exploit new opportunities. Intuition suggests that vagile predators should be able to track spatial shifts in prey availability, but our data on water pythons (Liasis fuscus) in tropical Australia suggest a less encouraging scenario. These pythons undergo regular long-range (to .10 km) seasonal migrations to follow flooding-induced migrations by their prey (native dusky rats, Rattus colletti ). However, when an extreme flooding event virtually eliminated …