Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1651 - 1680 of 3985

Full-Text Articles in Entire DC Network

Highway Construction Or Stream Destruction: A Water Quality Analysis In The Black Warrior Basin, Walker County, Alabama, Cayla Baughn Feb 2018

Highway Construction Or Stream Destruction: A Water Quality Analysis In The Black Warrior Basin, Walker County, Alabama, Cayla Baughn

Mahurin Honors College Capstone Experience/Thesis Projects

In 2012, residents along Freeman Branch Creek in Eldridge, Alabama observed unusual orange discoloration along the stream and on stream vegetation; an unprecendented black veneer coating pebbles along the streambed; and life in the stream seemed to have vanished. Freeman Branch Creek is located in Walker County, Alabama, which is known for its production of coal and natural gas from the underlying Pennsylvanian-aged Pottsville Formation, which is the uppermost geologic layer within the the Black Warrior Basin. Concerns for environmental safety related to intensive mining operations include the concern that shallow aquifers will be contaminated by mining in deep reservoir …


Spatiotemporal Change Patterns Of Coastlines In Zhejiang Province, China, Over The Last Twenty-Five Years, Jialin Li, Mengyao Ye, Ruiliang Pu, Yongchao Liu, Qiandong Guo, Baixiang Feng, Ripeng Huang, Gaili He Feb 2018

Spatiotemporal Change Patterns Of Coastlines In Zhejiang Province, China, Over The Last Twenty-Five Years, Jialin Li, Mengyao Ye, Ruiliang Pu, Yongchao Liu, Qiandong Guo, Baixiang Feng, Ripeng Huang, Gaili He

School of Geosciences Faculty and Staff Publications

Spatiotemporal analysis of coastline land utilization is important for strengthening coastline resource management and promoting sustainable development in coastal zones. In this study, basic spatiotemporal characteristics of coastline land utilization in Zhejiang Province, China, were analyzed using remote sensing (RS) and GIS techniques. For this case, Landsat Thematic Mapper and Operational Land Imager remote-sensing image data acquired from 1990 to 2015 were collected and processed. Several indices and metrics used for quantifying and analyzing the coastline utilization in Zhejiang Province were defined and calculated through processing remote sensing data and using GIS tools. They included the intensity index of coastline …


Investigation Of The Fire Radiative Energy Biomass Combustion Coefficient - A Comparison Of Polar And Geostationary Satellite Retrievals Over The Conterminous United States, Fangjun Li, Xiaoyang Zhang Feb 2018

Investigation Of The Fire Radiative Energy Biomass Combustion Coefficient - A Comparison Of Polar And Geostationary Satellite Retrievals Over The Conterminous United States, Fangjun Li, Xiaoyang Zhang

Global Land Surface Season Data Sets

The data is for the article "Investigation of the Fire Radiative Energy Biomass Combustion Coefficient - A Comparison of Polar and Geostationary Satellite Retrievals Over the Conterminous United States", which has been submitted to the Journal of Geophysical Research: Biogeosciences.

The data file contains a total of 20 files in 10 folders that are associated to the figures and tables in the article. General instruction for viewing output data for the paper can be found in the "Readme" text file.


Visualization For Spatial Comprehension, Gabriel Judkins Jan 2018

Visualization For Spatial Comprehension, Gabriel Judkins

UNLV Best Teaching Practices Expo

Mapping and understanding spatial data are fundamental necessities for geographers, yet challenging for many students (Rapp et al. 2007)


Genuine Faculty-Mentored Research Experiences For In-Service Science Teachers: Increases In Science Knowledge, Perception, And Confidence Levels, Christine E. Cutucache, Heather D. Leas, Neal F. Grandgenett, Kari L. Nelson, Steven N. Rodie, Robert Duncan Shuster, Chris Schaben, William E. Tapprich Jan 2018

Genuine Faculty-Mentored Research Experiences For In-Service Science Teachers: Increases In Science Knowledge, Perception, And Confidence Levels, Christine E. Cutucache, Heather D. Leas, Neal F. Grandgenett, Kari L. Nelson, Steven N. Rodie, Robert Duncan Shuster, Chris Schaben, William E. Tapprich

Biology Faculty Publications

The overall purpose of this multifocused study was to explore how participation in genuine mentored scientific research experiences impacts in-service science teachers and the knowledge and skills needed for their own science teaching. The research experiences resulted from a partnership between the University of Nebraska at Omaha and the Omaha Public School District. This Teacher- Researcher Partnership Program facilitated opportunities in inquiry, science content, interaction with laboratory instrumentation and technologies, critical discussion of literature, and dissemination of findings for participating in-service science teacher professional development utilizing an inquiry-based theoretical framework wherein we examined science teacher preparation via inquiry-based methods in …


Quantitative Map Literacy: A Cross Between Map Literacy And Quantitative Literacy, Ming Xie, H. L. Vacher, Steven Reader, Elizabeth Walton Jan 2018

Quantitative Map Literacy: A Cross Between Map Literacy And Quantitative Literacy, Ming Xie, H. L. Vacher, Steven Reader, Elizabeth Walton

Numeracy

We define quantitative map literacy (QML), a cross between map literacy and quantitative literacy (QL), as the concepts and skills required to accurately read, use, interpret, and understand the quantitative information embedded in a geospatial representation of data on a geographic background. Long used as tools in technical geographic fields, maps are now a common vehicle for communicating quantitative information to the public. As such, QML has potential to stand alongside health numeracy and financial literacy as an identifiable subdomain of transdisciplinary QL.

What concepts and skills are crucial for QML? The obvious answer is, “It depends on the type …


Data On Aeolian Sand Dune Activity In The White River Badlands, South Dakota, Northern Great Plains, Usa, Paul Baldauf, Patrick Burkhart, Paul Hanson, Maraina Miles, Ashley Larsen Jan 2018

Data On Aeolian Sand Dune Activity In The White River Badlands, South Dakota, Northern Great Plains, Usa, Paul Baldauf, Patrick Burkhart, Paul Hanson, Maraina Miles, Ashley Larsen

Marine & Environmental Sciences Faculty Datasets

This data paper reports on optically stimulated luminescence (OSL) data from samples collected in the White River Badlands, South Dakota, northern Great Plains. Sand samples were collected from the crests of parabolic dune heads and arms, as well as blowout exposures, on three tables located on private land in the Buffalo Gap National Grasslands. Using hand augers, samples were collected at depths of 1 and 2m below ground surface to minimize potential effects of bioturbation. An improvised split-spoon sampler was used at selected sites to ensure collection from laminated sediments. At auger and exposure localities, sediment was collected by inserting …


Mapping The Yearly Extent Of Surface Coal Mining In Central Appalachia Using Landsat And Google Earth Engine, Andrew A. Pericak, Christian J. Thomas, David A. Kroodsma, Matthew F. Wasson, Matthew R.V. Ross, Nicolas E. Clinton, David J. Campagna, Yolandita Franklin, Emily S. Bernhardt, John F. Amos Jan 2018

Mapping The Yearly Extent Of Surface Coal Mining In Central Appalachia Using Landsat And Google Earth Engine, Andrew A. Pericak, Christian J. Thomas, David A. Kroodsma, Matthew F. Wasson, Matthew R.V. Ross, Nicolas E. Clinton, David J. Campagna, Yolandita Franklin, Emily S. Bernhardt, John F. Amos

Faculty & Staff Scholarship

Surface mining for coal has taken place in the Central Appalachian region of the United States for well over a century, with a notable increase since the 1970s. Researchers have quantified the ecosystem and health impacts stemming from mining, relying in part on a geospatial dataset defining surface mining’s extent at a decadal interval. This dataset, how- ever, does not deliver the temporal resolution necessary to support research that could establish causal links between mining activity and environmental or public health and safety outcomes, nor has it been updated since 2005. Here we use Google Earth Engine and Landsat imagery …


Paleoflood Hydrology And Basin Morphometric Characteristics Related To Flooding In The Colorado Front Range, Natalie Trivino Jan 2018

Paleoflood Hydrology And Basin Morphometric Characteristics Related To Flooding In The Colorado Front Range, Natalie Trivino

Electronic Theses and Dissertations

Flooding hazards are common in the Colorado Front Range due to the steep, complex terrain of the mountains where waters quickly spill out onto the most populated region of Colorado. This region has experienced numerous catastrophic floods, such as the 2013 Front Range Floods, the Fort Collins Flood of 1997, and the Big Thompson Canyon Flood of 1976 to name a few. The objective of this study was to analyze basin morphometric characteristics of several drainage basins throughout the Colorado Front Range South Platte River tributaries and determine how these characteristics relate to extreme flooding. This was done through three …


Power Scaling Of The Mainland Shoreline Of The Contiguous United States, Erik S. Vasko Jan 2018

Power Scaling Of The Mainland Shoreline Of The Contiguous United States, Erik S. Vasko

Browse all Theses and Dissertations

Previous fractal analyses of shoreline roughness have measured the fractal dimension of long segments of shoreline, e.g. Mandelbrot (1983) quantified the shoreline of the west coast of Britain and Feder (1988) quantified the shoreline of Norway. Consequently, changes in roughness along short segments are not captured by the analysis. In this study, the fractal dimension of the mainland shoreline of the contiguous United States has been measured in 125, 250, and 375 km segments using the box-counting method. The box counting method is based on the equation N = c x b where N is number of occupied boxes, C …


Flume Tests On Fluvial Erosion Mechanisms In Tillbed Channels, L Pike, Peter Ashmore, S Gaskin Jan 2018

Flume Tests On Fluvial Erosion Mechanisms In Tillbed Channels, L Pike, Peter Ashmore, S Gaskin

Geography & Environment Publications

Semi-alluvial stream channels eroded into till and other glacial sediments are common in areas of extensive glacial deposition such as the Great Lakes region and northern interior plains of North America. The mechanics of erosion and erosional weakness of till results in the dominance of fluvial scour and mass erosion due to spontaneous fracture at planes of weakness under shearing flow. There have been few controlled tests looking at erosional mechanisms and resistance of till in river channels.We subjected small blocks of till to unidirectional flows in a laboratory flume to measure the threshold shear stress for erosion and observed …


Transforming Toronto's Rivers: A Socio-Geomorphic Perspective, Peter Ashmore Jan 2018

Transforming Toronto's Rivers: A Socio-Geomorphic Perspective, Peter Ashmore

Geography & Environment Publications

No abstract provided.


The Flathead Catfish Invasion Of The Great Lakes, Pam L. Fuller, Gary E. Whelan Jan 2018

The Flathead Catfish Invasion Of The Great Lakes, Pam L. Fuller, Gary E. Whelan

United States Geological Survey: Staff Publications

A detailed review of historical literature andmuseumdata revealed that flathead catfish were not historically native in the Great Lakes Basin, with the possible exception of a relict population in Lake Erie. The species has invaded Lake Erie, Lake St. Clair, Lake Huron, nearly all drainages in Michigan, and the Fox/Wolf and Milwaukee drainages in Wisconsin. They have not been collected from Lake Superior yet, and the temperature suitability of that lake is questionable. Flathead catfish have been stocked sparingly in the Great Lakes and is not the mechanism responsible for their spread. A stocking in 1968 in Ohio may be …


Droughtscape, Winter 2018, National Drought Mitigation Center Jan 2018

Droughtscape, Winter 2018, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Year in review: Drought eased in California, developed in Northern Plains

Quarterly Summary: Drought creeps across the country

Annual impact summary: A year of wildfires

Quarterly impact summary: Drought expands in Texas, Colorado

Drought and water crisis book updated

U.S. Drought Monitor available in Spanish

Study shows cities step up when drought occurs

New staff at the NDMC

Drought Summit in photos


Preparing For A Northwest Passage: A Workshop On The Role Of New England In Navigating The New Arctic, Katharine A. Duderstadt, Catherine M. Ashcraft, Jennifer F. Brewer, Elizabeth Burakowski, Jaed M. Coffin, Jack E. Dibb, Lawrence C. Hamilton, Nancy E. Kinner, Larry A. Mayer, Jennifer L. Miksis-Olds, Joseph Salisbury, Kerri D. Seger, Ruth K. Varner, Cameron P. Wake Jan 2018

Preparing For A Northwest Passage: A Workshop On The Role Of New England In Navigating The New Arctic, Katharine A. Duderstadt, Catherine M. Ashcraft, Jennifer F. Brewer, Elizabeth Burakowski, Jaed M. Coffin, Jack E. Dibb, Lawrence C. Hamilton, Nancy E. Kinner, Larry A. Mayer, Jennifer L. Miksis-Olds, Joseph Salisbury, Kerri D. Seger, Ruth K. Varner, Cameron P. Wake

All Materials

Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic (March 25 - 27, 2018 -- The University of New Hampshire) paired two of NSF's 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this event, participants assessed economic, environmental, and social impacts of Arctic change on New England and established convergence research initiatives to prepare for, adapt to, and respond to these effects. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt …


Sustainability At Sit: A Look At The Past, A Plan For The Future, Taliesin Haugh Jan 2018

Sustainability At Sit: A Look At The Past, A Plan For The Future, Taliesin Haugh

Capstone Collection

Climate change threatens our world and way of life. Intelligent development and investment could mitigate the worst threats of climate change, while simultaneously providing continuous growth for the global economy. The New Climate Economy proposes efforts to combat this ecological collapse that would result in $30 trillion in new annual economic growth by 2030. Stockholm Resilience Center agrees, giving a framework based on global ecological systems that calls for five critical tasks that can bring growth and stability: Renewable energy

Sustainable local food production

New development models, based on what has worked globally

Reduction of wealth inequity

Education, health, and …


Disaster Risk In The Lake Nyos Area, Cameroon: Effects Of The Gas Hazard And Socially Produced Vulnerability, Mary Witucki Jan 2018

Disaster Risk In The Lake Nyos Area, Cameroon: Effects Of The Gas Hazard And Socially Produced Vulnerability, Mary Witucki

Dissertations, Master's Theses and Master's Reports

Effective disaster risk reduction (DRR) efforts depend on comprehensive risk assessments that consider potential hazard events and social vulnerability. The Lake Nyos Disaster (LND) caused the deaths of about 1,700 people, forced another 4,000 people from their homes, and left survivors more vulnerable to future hazards. There is considerable research on the gas hazard and some work on local vulnerability; however studies rarely consider both aspects of disaster risk (DR). This study addresses both the hazard and vulnerability and uses several qualitative and quantitative methods which have never been applied to LND survivor vulnerability or gas hazard. Interviews, participant observation, …


40ar-39ar Geochronology And Petrogenesis Of Postcollisional Trachytic Volcanism Along The İzmir-Ankara-Erzincan Suture Zone (Ne, Turkey), Gönenç Göçmengi̇l, Zeki̇ye Karacik, Şengül Can Genç, Mehmet Zeki̇ Bi̇llor Jan 2018

40ar-39ar Geochronology And Petrogenesis Of Postcollisional Trachytic Volcanism Along The İzmir-Ankara-Erzincan Suture Zone (Ne, Turkey), Gönenç Göçmengi̇l, Zeki̇ye Karacik, Şengül Can Genç, Mehmet Zeki̇ Bi̇llor

Turkish Journal of Earth Sciences

The obliteration of the Neo-Tethyan Ocean and collision of the microplates along the northern part of Turkey led to the development of the İzmir-Ankara-Erzincan suture zone (IAESZ). After the collision of Pontides with the Central-Anatolian Crystalline Complex (CACC) in the Paleocene, a new phase of extension and volcanism concomitantly developed along the northern (Almus; Pontides) and southern (Yıldızeli; CACC) sides and along the IAESZ during the Middle Eocene time interval. The first products of the Middle Eocene volcanism in these areas are represented by calc-alkaline to alkaline (basic-intermediate) volcanic and volcanoclastic units together with late-stage trachytic dikes, plugs, and stocks. …


Reconstructing The Sedimentary Evolution Of The Miocene Aksu Basin Based On Fan Delta Development (Eastern Mediterranean-Turkey), Serkan Üner, Erman Özsayin, Ramazan Kadi̇r Di̇ri̇k, Tahsi̇n Atti̇la Çi̇ner, Mustafa Karabiyikoğlu Jan 2018

Reconstructing The Sedimentary Evolution Of The Miocene Aksu Basin Based On Fan Delta Development (Eastern Mediterranean-Turkey), Serkan Üner, Erman Özsayin, Ramazan Kadi̇r Di̇ri̇k, Tahsi̇n Atti̇la Çi̇ner, Mustafa Karabiyikoğlu

Turkish Journal of Earth Sciences

The Aksu Basin in southern Turkey is dominantly represented by an alluvial fan and five fan deltas (FDs) developed along the tectonically controlled margins of the basin during the Miocene. Four alternating compressional and tensional tectonic phases have influenced the basin since its formation. Strong tectonic movements caused high sedimentation rates and progradation of large debris-flow and mass-flow dominated FDs. Here we describe two FDs (the Karadağ and Kargı FDs) in detail. The Karadağ FD began to develop under the control of a compressional regime and continued the evolution under a tensional regime. The same tensional regime caused the separation …


Watered Down: The Challenges Of Managing Water Resources In Montana, Beau E. Baker Jan 2018

Watered Down: The Challenges Of Managing Water Resources In Montana, Beau E. Baker

Graduate Student Theses, Dissertations, & Professional Papers

Like much of the American West, Montana sits in the cross hairs of climate change. State drought resiliency projects and cooperative watershed management are on the rise in the face of decreased snowpack, early runoff, precipitation variability and lower seasonal stream flows. Population growth, land use practices, recreation and tourism all contribute to pressures on state water supplies.

Montana is faced with the arrival of invasive species that threaten the ecological health of its lakes, rivers and streams. State budget constraints and depressed agency capacity are hurting our ability to fend off these threats. There’s a lack of public education …


The Origin Of Dark Mats At The Sunrise Ridge Borrow Pit Site (45pi408) Mount Rainier National Park, Washington, Sean Stcherbinine Jan 2018

The Origin Of Dark Mats At The Sunrise Ridge Borrow Pit Site (45pi408) Mount Rainier National Park, Washington, Sean Stcherbinine

All Master's Theses

The Sunrise Ridge Borrow Pit Site is a precontact archaeological site located in the upland forest soils of Mount Rainier National Park. Site stratigraphy is complicated, consisting of tephra deposits from mostly known origins that are intercalated with dark sediments of unknown origin, referred to here as dark mats. Precontact occupation has been split previously into two components based on the ambiguous depositional history of the dark mats, notably their unknown parent material, depositional environment, and relationship with adjacent tephra strata. Stratigraphic samples from excavation units, features, and one off-site excavation unit was used to investigate these data gaps. Grain …


Accounting For Spatial Autocorrelation In Modeling The Distribution Of Water Quality Variables, Lorrayne Miralha Jan 2018

Accounting For Spatial Autocorrelation In Modeling The Distribution Of Water Quality Variables, Lorrayne Miralha

Theses and Dissertations--Geography

Several studies in hydrology have reported differences in outcomes between models in which spatial autocorrelation (SAC) is accounted for and those in which SAC is not. However, the capacity to predict the magnitude of such differences is still ambiguous. In this thesis, I hypothesized that SAC, inherently possessed by a response variable, influences spatial modeling outcomes. I selected ten watersheds in the USA and analyzed them to determine whether water quality variables with higher Moran’s I values undergo greater increases in the coefficient of determination (R²) and greater decreases in residual SAC (rSAC) after spatial modeling. I compared non-spatial ordinary …


Heavy Minerals And Exotic Pebbles From The Eocene Flysch Deposits Of The Magura Nappe (Outer Western Carpathians, Eastern Slovakia): Their Composition And Implications On The Provenance, Katarína Bónová, Ján Bóna, Martin Kovácik, Tomás Mikus Jan 2018

Heavy Minerals And Exotic Pebbles From The Eocene Flysch Deposits Of The Magura Nappe (Outer Western Carpathians, Eastern Slovakia): Their Composition And Implications On The Provenance, Katarína Bónová, Ján Bóna, Martin Kovácik, Tomás Mikus

Turkish Journal of Earth Sciences

The study aims to reconstruct the crystalline parent rock assemblages of the Eocene Strihovce Formation (Krynica Unit) and Mrazovce Member (Raca Unit) deposits, based on the heavy mineral suites, their corrosive features, geochemistry of garnet and tourmaline, zircon cathodoluminescence (CL) images, and exotic pebble composition. Both units are an integral part of the Magura Nappe belonging to the Flysch Belt (Outer Western Carpathians). Corrosion signs observable on heavy minerals point to different burial conditions and/or diverse sources. The compositions of the detrital garnets and tourmalines as well as the CL study of zircons indicate their origin in gneisses, mica schists, …


Land Use Change Sustainability And Carbon Turnover Rate In The Northern Great Plains Soil, Deepak Raj Joshi Jan 2018

Land Use Change Sustainability And Carbon Turnover Rate In The Northern Great Plains Soil, Deepak Raj Joshi

Electronic Theses and Dissertations

Sustainable land management involves the management of land, water, biodiversity and other resources that meet human requirements while maintaining ecosystem services. In the northern Great Plains (NGP), the combined impacts of landuse and climate variability have placed many soils at the tipping point of sustainability. The objectives of this study were to: 1) calculate land-use changes from 2006 to 2012 and from 2012 to 2014 in South Dakota and Nebraska; 2) assess if land use changes had impacted on soil sustainability; 3) calculate variation in total carbon budget and turnover due to seasonal climate variability, biomass quality and soil properties; …


Land Use, Microclimate, And Surface Runoff Linkages: Space-Time Modeling From Rockel-Seli River Basin, Sierra Leone, C. Wilson, B. Liang, S. Wilson, Fenda A. Akiwumi Jan 2018

Land Use, Microclimate, And Surface Runoff Linkages: Space-Time Modeling From Rockel-Seli River Basin, Sierra Leone, C. Wilson, B. Liang, S. Wilson, Fenda A. Akiwumi

School of Geosciences Faculty and Staff Publications

This study mainly utilized the Soil and Water Assessment Tool (SWAT) together with SWAT-CUP, both free and open source software (FOSS), to construct a distributed hydrologic flow model for the Rokel-Seli River basin, Sierra Leone, in a bid to spatiotemporally evaluate the role of changes in land use/land cover (LULC) and microclimate on streamflow regimes. The model was informed by LULC data derived from three Landsat satellite images collected in 2002, 2010, and 2016. The LULC data was generated with the aid of several python libraries accessed through the FOSS Anaconda Navigator. LULC change analysis demonstrated that between 2002 and …


Quantifying The Offset Of Greenhouse Gas Emissions At The University Of North Alabama, Paul Dunn Graham Jan 2018

Quantifying The Offset Of Greenhouse Gas Emissions At The University Of North Alabama, Paul Dunn Graham

Theses

No abstract provided.


Ground Deformation Studies And Evacuation Behavior During Eruptions At Guatemalan Volcanoes, Hans Lechner Jan 2018

Ground Deformation Studies And Evacuation Behavior During Eruptions At Guatemalan Volcanoes, Hans Lechner

Dissertations, Master's Theses and Master's Reports

Volcanic eruptions can be an especially problematic hazard when considering the uncertainty in eruption timing and magnitude coupled with challenges associated with delivering warnings to remote areas and facilitating effective evacuations. The hazards presented by Guatemala’s active volcanoes demand enhanced monitoring capabilities and instrumentation infrastructure. Strengthening the link between the physical and social sciences should lead to more accurate, reliable, and timely hazard information to the people living in proximity to the volcano and facilitate rational decisions and actions that reduce their level of risk. While there is no one single technique that can provide unambiguous diagnostics about the timing, …


Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar Jan 2018

Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar

Dissertations, Master's Theses and Master's Reports

Wildfires are episodic disturbances that exert a significant influence on the Earth system. They emit substantial amounts of atmospheric pollutants, which can impact atmospheric chemistry/composition and the Earth’s climate at the global and regional scales. This work presents a collection of studies aimed at better estimating wildfire emissions of atmospheric pollutants, quantifying their impacts on remote ecosystems and determining the implications of 2000s-2050s global environmental change (land use/land cover, climate) for wildfire emissions following the Intergovernmental Panel on Climate Change (IPCC) A1B socioeconomic scenario.

A global fire emissions model is developed to compile global wildfire emission inventories for major atmospheric …


Lake Regionalization And Diatom Metacommunity Structuring In Tropical South America, Xavier Benito, Sherilyn C. Fritz, Miriam Steinitz-Kannan, Maria I. Velez, Michael M. Mcglue Jan 2018

Lake Regionalization And Diatom Metacommunity Structuring In Tropical South America, Xavier Benito, Sherilyn C. Fritz, Miriam Steinitz-Kannan, Maria I. Velez, Michael M. Mcglue

Department of Earth and Atmospheric Sciences: Faculty Publications

Lakes and their topological distribution across Earth’s surface impose ecological and evolutionary constraints on aquatic metacommunities. In this study, we group similar lake ecosystems as metacommunity units influencing diatom community structure. We assembled a database of 195 lakes from the tropical Andes and adjacent lowlands (8°N–30°S and 58–79°W) with associated environmental predictors to examine diatom metacommunity patterns at two different levels: taxon and functional (deconstructed species matrix by ecological guilds). We also derived spatial variables that inherently assessed the relative role of dispersal. Using complementary multivariate statistical techniques (principal component analysis, cluster analysis, nonmetric multidimensional scaling, Procrustes, variance partitioning), we …


Spectral Signatures Of Submicron Scale Light-Absorbing Impurities In Snow And Ice Using Hyperspectral Microscopy, Farra Dal Anna, Susan Kaspari, James Beach, Thomas D. Bucheli, Michael Schaepman, Margit Schwikowski Jan 2018

Spectral Signatures Of Submicron Scale Light-Absorbing Impurities In Snow And Ice Using Hyperspectral Microscopy, Farra Dal Anna, Susan Kaspari, James Beach, Thomas D. Bucheli, Michael Schaepman, Margit Schwikowski

Geological Sciences Faculty Scholarship

Light-absorbing impurities (LAI) can darken snow and ice surfaces, reduce snow/ice albedo and accelerate melt. Efforts to allocate the relative contribution of different LAI to snow/ice albedo reductions have been limited by uncertainties in the optical properties of LAI. We developed a new method to measure LAI spectral reflectance at the submicron scale by modifying a Hyperspectral Imaging Microscope Spectrometer (HIMS). We present the instrument’s internal calibration, and the overall small influence of a particle’s orientation on its measured reflectance spectrum. We validated this new method through the comparison with a field spectroradiometer by measuring different standard materials. Measurements with …