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Articles 511 - 540 of 832

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols Jan 2014

Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols

United States Geological Survey: Staff Publications

Metapopulation ecology is a field that is richer in theory than in empirical results. Many existing empirical studies use an incidence function approach based on spatial patterns and key assumptions about extinction and colonization rates. Here we recast these assumptions as hypotheses to be tested using 18 years of historic detection survey data combined with four years of data from a new monitoring program for the Lower Keys marsh rabbit. We developed a new model to estimate probabilities of local extinction and colonization in the presence of nondetection, while accounting for estimated occupancy levels of neighboring patches. We used model …


Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification, Brett T. Mcclinktock, Larissa L. Bailey, Brian P. Dreher, William A. Link Jan 2014

Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification, Brett T. Mcclinktock, Larissa L. Bailey, Brian P. Dreher, William A. Link

United States Geological Survey: Staff Publications

As noninvasive sampling techniques for animal populations have become more popular, there has been increasing interest in the development of capture-recapture models that can accommodate both imperfect detection and misidentification of individuals (e.g., due to genotyping error). However, current methods do not allow for individual variation in parameters, such as detection or survival probability. Here we develop misidentification models for capture-recapture data that can simultaneously account for temporal variation, behavioral effects and individual heterogeneity in parameters. To facilitate Bayesian inference using our approach, we extend standard probit regression techniques to latent multinomial models where the dimension and zeros of the …


Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols Jan 2014

Testing Metapopulation Concepts: Effects Of Patch Characteristics And Neighborhood Occupancy On The Dynamics Of An Endangered Lagomorph, Mitchell J. Eaton, Phillip T. Hughes, James E. Hines, James D. Nichols

United States Geological Survey: Staff Publications

Metapopulation ecology is a field that is richer in theory than in empirical results. Many existing empirical studies use an incidence function approach based on spatial patterns and key assumptions about extinction and colonization rates. Here we recast these assumptions as hypotheses to be tested using 18 years of historic detection survey data combined with four years of data from a new monitoring program for the Lower Keys marsh rabbit. We developed a new model to estimate probabilities of local extinction and colonization in the presence of nondetection, while accounting for estimated occupancy levels of neighboring patches. We used model …


Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification1, Brett T. Mcclintock, Larissa L. Bailey, Brian P. Dreher, William A. Link Jan 2014

Probit Models For Capture-Recapture Data Subject To Imperfect Detection, Individual Heterogeneity And Misidentification1, Brett T. Mcclintock, Larissa L. Bailey, Brian P. Dreher, William A. Link

United States Geological Survey: Staff Publications

As noninvasive sampling techniques for animal populations have become more popular, there has been increasing interest in the development of capture-recapture models that can accommodate both imperfect detection and misidentification of individuals (e.g., due to genotyping error). However, current methods do not allow for individual variation in parameters, such as detection or survival probability. Here we develop misidentification models for capture-recapture data that can simultaneously account for temporal variation, behavioral effects and individual heterogeneity in parameters. To facilitate Bayesian inference using our approach, we extended standard probit regression techniques to latent multinomial models where the dimension and zeros of the …


Loess Records, Daniel R. Muhs, Stephen R. Cattle, Onn Crouvi, Denis-Didier Rousseau, Jimin Sun, Marcelo A. Zárate Jan 2014

Loess Records, Daniel R. Muhs, Stephen R. Cattle, Onn Crouvi, Denis-Didier Rousseau, Jimin Sun, Marcelo A. Zárate

United States Geological Survey: Staff Publications

Loess is aeolian sediment, dominated by silt-sized particles, that is identifiable in the field as a distinct sedimentary body. It covers a significant portion of the land surface of the Earth and as such constitutes one of the most important archives of long-term dust deposition. Large tracts of loess cover Europe, Asia, South America, and North America, and smaller loess bodies are found covering parts of Africa, the Middle East, New Zealand, and Australia. Loess thickness, particle size, and carbonate content decrease downwind from sources, trends that are powerful tools for reconstructing paleowinds. Many loess sections consist of relatively thick …


Evidence Of Repeated Wildfires Prior To Human Occupation On San Nicolas Island, California, Jeffrey S. Pigati, John P. Mcgeehin, Gary L. Skipp, Daniel R. Muhs Jan 2014

Evidence Of Repeated Wildfires Prior To Human Occupation On San Nicolas Island, California, Jeffrey S. Pigati, John P. Mcgeehin, Gary L. Skipp, Daniel R. Muhs

United States Geological Survey: Staff Publications

Understanding how early humans on the California Channel Islands might have changed local fire regimes requires a baseline knowledge of the frequency of natural wildfires on the islands prior to human occupation. A sedimentary sequence that was recently discovered in a small canyon on San Nicolas Island contains evidence of at least 24 burn events that date to between ~37 and 25 ka (thousands of calibrated 14C years before present), well before humans entered North America. The evidence includes abundant macroscopic charcoal, blackened sediments, and discrete packages of oxidized, reddish-brown sediments that are similar in appearance to sedimentary features …


Assessing Optimal Set Of Implemental Physical Parameterization Schemes In A Multi-Physics Land Surface Model Using Genetic Algorithm, S. Hong, X. Yu, S. K. Park, Y.-S. Choi, Boksoon Myoung Jan 2014

Assessing Optimal Set Of Implemental Physical Parameterization Schemes In A Multi-Physics Land Surface Model Using Genetic Algorithm, S. Hong, X. Yu, S. K. Park, Y.-S. Choi, Boksoon Myoung

Mathematics, Physics, and Computer Science Faculty Articles and Research

Optimization of land surface models has been challenging due to the model complexity and uncertainty. In this study, we performed scheme-based model optimizations by designing a framework for coupling "the micro-genetic algorithm" (micro-GA) and "the Noah land surface model with multiple physics options" (Noah-MP). Micro-GA controls the scheme selections among eight different land surface parameterization categories, each containing 2–4 schemes, in Noah-MP in order to extract the optimal scheme combination that achieves the best skill score. This coupling framework was successfully applied to the optimizations of evapotranspiration and runoff simulations in terms of surface water balance over the Han River …


Examining The Relationship Between Drought Development And Rapid Changes In The Evaporative Stress Index, Jason A. Otkin, Martha C. Anderson, Christopher Hain, Mark D. Svoboda Oct 2013

Examining The Relationship Between Drought Development And Rapid Changes In The Evaporative Stress Index, Jason A. Otkin, Martha C. Anderson, Christopher Hain, Mark D. Svoboda

National Drought Mitigation Center: Faculty Publications

In this study, the ability of a new drought metric based on thermal infrared remote sensing imagery to provide early warning of an elevated risk for drought intensification is assessed. This new metric, called the rapid change index (RCI), is designed to highlight areas undergoing rapid changes in moisture stress as inferred from weekly changes in the evaporative stress index (ESI) generated using the Atmosphere–Land Exchange Inverse (ALEXI) surface energy balance model. Two case study analyses across the central United States revealed that the initial appearance of negative RCI values indicative of rapid increases in moisture stress preceded the introduction …


Environmental Factors Influencing Diatom Communities In Antarctic Cryoconite Holes, Lee F. Stanish, Elizabeth A. Bagshaw, Diane M. Mcknight, Andrew G. Fountain, Martyn Tranter Oct 2013

Environmental Factors Influencing Diatom Communities In Antarctic Cryoconite Holes, Lee F. Stanish, Elizabeth A. Bagshaw, Diane M. Mcknight, Andrew G. Fountain, Martyn Tranter

Geology Faculty Publications and Presentations

Cryoconite holes are ice-bound habitats that can act as refuges for aquatic and terrestrial microorganisms on glacier surfaces. In the McMurdo Dry Valleys of Antarctica, these holes are often capped by an ice lid that prevents the exchange of material and gases with the surrounding atmosphere and aquatic environment. Diatoms have been documented in cryoconite holes, and recent findings suggest that these habitats may harbour a distinctive diatom flora compared to the surrounding aquatic environments. In this study, we examined diatom community composition in cryoconite holes and environmental correlates across three glaciers in Taylor Valley, Antarctica. The diatom communities were …


A Detailed Seabed Signature From Hurricane Sandy Revealed In Bedforms And Scour, Arthur Trembanis, Carter Duval, Jonathan Beaudoin, Val E. Schmidt, Doug Miller, Larry A. Mayer Oct 2013

A Detailed Seabed Signature From Hurricane Sandy Revealed In Bedforms And Scour, Arthur Trembanis, Carter Duval, Jonathan Beaudoin, Val E. Schmidt, Doug Miller, Larry A. Mayer

Center for Coastal and Ocean Mapping

On 30 October 2012, Hurricane Sandy made landfall near Brigantine New Jersey bringing widespread erosion and damage to the coastline. We have obtained a unique set of high-resolution before and after storm measurements of seabed morphology and in situhydrodynamic conditions (waves and currents) capturing the impact of the storm at an inner continental shelf field site known as the “Redbird reef”. Understanding the signature of this storm event is important for identifying the impacts of such events and for understanding the role that such events have in the transport of sediment and marine debris on the inner continental shelf. …


Droughtscape, Fall 2013, National Drought Mitigation Center Oct 2013

Droughtscape, Fall 2013, National Drought Mitigation Center

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

Contents

Director’s report

Kansas community drought planning workshop November 5

Drought impacts webinars

Drought outlook and summary

Late summer drought brings more agricultural impacts

Plans help ranchers weather drought

NDMC contributions to U2U project

Drought Management Database archives strategies

QuickDRI will help spot flash droughts

NDMC Co-Hosts NASA workshop

Wilhite leads Integrated Drought Management Program work

Speaking of drought

Managing #Drought tweet chat transcript

Updated USDM website


The Influence Of Soil Organic Matter Stabilization Mechanisms On Carbon Mean Residence Time Within Various Ecosystems In The United States, Vicky Lynn Giese, Kate Heckman Phd Aug 2013

The Influence Of Soil Organic Matter Stabilization Mechanisms On Carbon Mean Residence Time Within Various Ecosystems In The United States, Vicky Lynn Giese, Kate Heckman Phd

STAR Program Research Presentations

Some terrestrial ecosystems and soils serve as carbon sinks, partially offsetting rising atmospheric CO2 levels. Physiochemical mechanisms of soil organic matter (SOM) stabilization affect how carbon stocks respond to global warming. In order to clarify the variance in SOM stabilization mechanisms across different soil types, SOM abundance, distribution and mean residence time (MRT) were compared for thirty-two soil samples from six ecosystems across the United States. Soils were previously described, collected and archived by the United States Geological Survey. Samples were processed by LLNL at the Center for Accelerator Mass Spectrometry (CAMS) using density fractionation to separate particulate organics …


Droughtscape, Summer 2013, National Drought Mitigation Center Jul 2013

Droughtscape, Summer 2013, National Drought Mitigation Center

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

Contents

Director’s report

July 25 webinar: Drought management database, NIDIS update

Republican River Basin workshops July 31, August 1

Summer climate outlook, spring summary

Spring impacts: wildfire, water, agriculture and business

Data help managers assess Nebraska groundwater declines after drought of 2012

Tadesse helps Mexico with Veg-DRI concept

Visiting scholar explores remote sensing of drought in forests

U.S. Drought Monitor Forum photo recap, details online

Workshop helps New Mexico ranchers cope with drought

Alabama’s new drought plan

National Drought Forum report

Drought Impacts Community of Practice report


Toward Global Drought Early Warning Capability: Expanding International Cooperation For The Development Of A Framework For Monitoring And Forecasting, Will Pozzi, Justin Sheffield, Robert Stefanski, Douglas Cripe, Roger Pulwarty, Jürgen V. Vogt, Richard R. Heim Jr., Michael J. Brewer, Mark Svoboda, Rogier Westerhoff, Albert I. J. M. Van Dijk, Benjamin Lloyd-Hughes, Florian Pappenberger, Micha Werner, Emanuel Dutra, Fredrik Wetterhall, Wolfgang Wagner, Siegfried Schubert, Kingtse Mo, Margaret Nicholson, Lynette Bettio, Liliana Nunez, Rens Van Beek, Marc Bierkens, Luis Gustavo Goncalves De Goncalves, João Gerd Zell De Mattos, Richard Lawford Jun 2013

Toward Global Drought Early Warning Capability: Expanding International Cooperation For The Development Of A Framework For Monitoring And Forecasting, Will Pozzi, Justin Sheffield, Robert Stefanski, Douglas Cripe, Roger Pulwarty, Jürgen V. Vogt, Richard R. Heim Jr., Michael J. Brewer, Mark Svoboda, Rogier Westerhoff, Albert I. J. M. Van Dijk, Benjamin Lloyd-Hughes, Florian Pappenberger, Micha Werner, Emanuel Dutra, Fredrik Wetterhall, Wolfgang Wagner, Siegfried Schubert, Kingtse Mo, Margaret Nicholson, Lynette Bettio, Liliana Nunez, Rens Van Beek, Marc Bierkens, Luis Gustavo Goncalves De Goncalves, João Gerd Zell De Mattos, Richard Lawford

National Drought Mitigation Center: Faculty Publications

The need for a global drought early warning framework. Drought has had a significant impact on civilization throughout history in terms of reductions in agricultural productivity, potable water supply, and economic activity, and in extreme cases this has led to famine. Every continent has semiarid areas, which are especially vulnerable to drought. The Intergovernmental Panel on Climate Change has noted that average annual river runoff and water availability are projected to decrease by 10%–13% over some dry and semiarid regions in mid and low latitudes, increasing the frequency, intensity, and duration of drought, along with its associated impacts. The sheer …


Evidence Of Songbird Intoxication From Rozol Application At A Black-Tailed Prairie Dog Colony, Nimish B. Vyas, Craig S. Hulse, Carol U. Meteyer, Clifford P. Rice Jun 2013

Evidence Of Songbird Intoxication From Rozol Application At A Black-Tailed Prairie Dog Colony, Nimish B. Vyas, Craig S. Hulse, Carol U. Meteyer, Clifford P. Rice

United States Geological Survey: Staff Publications

Concerns about avian poisonings from anticoagulant rodenticides have traditionally focused on secondary poisoning of raptors exposed by feeding on contaminated mammalian prey. However, ground foraging songbirds can be directly poisoned from operational applications of the anticoagulant rodenticide RozolH (0.005% chlorophacinone, active ingredient) applied as a grain bait, at black-tailed prairie dog Cynomys ludovicianus colonies. A dead western meadowlark Sturnella neglecta recovered from the study prairie dog colony displayed hemorrhaging in brain and pectoral muscle tissue, and it contained chlorophacinone residue concentrations of 0.59 and 0.49 mg/g (wet weight) in the liver and intestinal contents, respectively. Chlorophacinone residues from two Rozol-colored …


The Missing Piece: Drought Impacts Monitoring Report From A Workshop In Tucson, Az March 5-6, 2013, Kirsten Lackstrom, Amanda Brennan, Daniel Ferguson, Mike Crimmins, Lisa Darby, Kirstin Dow, Keith Ingram, Alison Meadow, Henry Reges, Mark Shafer, Kelly Helm Smith Jun 2013

The Missing Piece: Drought Impacts Monitoring Report From A Workshop In Tucson, Az March 5-6, 2013, Kirsten Lackstrom, Amanda Brennan, Daniel Ferguson, Mike Crimmins, Lisa Darby, Kirstin Dow, Keith Ingram, Alison Meadow, Henry Reges, Mark Shafer, Kelly Helm Smith

National Drought Mitigation Center: Faculty Publications

Based on a shared interest to better understand the impacts of drought and the potential utility of using drought impacts reporting as a tool for monitoring conditions, researchers from the Carolinas RISA (Dow, Lackstrom, and Brennan), the Climate Assessment for the Southwest (Crimmins and Ferguson), and the Southwest Climate Science Center (Meadow) decided to convene a workshop in Tucson in March 2013. The primary goal was to assemble a small group of university and agency scientists involved with drought impacts monitoring to discuss opportunities and barriers associated with drought impacts reporting, recommend best practices for implementing a drought impacts reporting …


Examining Rapid Onset Drought Development Using The Thermal Infrared–Based Evaporative Stress Index, Jason A. Otkin, Martha C. Anderson, Christopher Hain, Iliana E. Mladenova, Jeffrey B. Basara, Mark Svoboda Apr 2013

Examining Rapid Onset Drought Development Using The Thermal Infrared–Based Evaporative Stress Index, Jason A. Otkin, Martha C. Anderson, Christopher Hain, Iliana E. Mladenova, Jeffrey B. Basara, Mark Svoboda

National Drought Mitigation Center: Faculty Publications

Reliable indicators of rapid drought onset can help to improve the effectiveness of drought early warning systems. In this study, the evaporative stress index (ESI), which uses remotely sensed thermal infrared imagery to estimate evapotranspiration (ET), is compared to drought classifications in the U.S. Drought Monitor (USDM) and standard precipitation-based drought indicators for several cases of rapid drought development that have occurred across the United States in recent years. Analysis of meteorological time series from the North American Regional Reanalysis indicates that these events are typically characterized by warm air temperature and low cloud cover anomalies, often with high winds …


Droughtscape, Spring 2013, National Drought Mitigation Center Apr 2013

Droughtscape, Spring 2013, National Drought Mitigation Center

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

Contents

Director’s report

First quarter climate summary and outlook

Impacts: Crop indemnities set records in 2012; water conflicts escalating

International meeting recommends countries have drought policies

NDMC plays key role in international drought policy meeting

EDEN and VOAD guide helps build community drought capacity

Svoboda, other experts and policymakers focus on food and water security

New Mexico ranching workshop set for May 29 in Socorro

Ranch planning updates: archived webinars, new publications

Tune in to the US Drought Monitor Forum, April 16-18

Archived webinar looks at using drought simulations in planning

CoCoRaHS WxTalk on drought


Exploration Of Eratosthenes Seamount – A Continental Fragment Being Forced Down An Oceanic Trench, Garrett Mitchell, Larry A. Mayer, Katherine L.C. Bell, Nicole A. Raineault, Chris Roman, Robert D. Ballard, Kelsey Cornwell, Al Hine, Eugene Shinn, Iordanis Dimitriadis, Onac Bogdan Mar 2013

Exploration Of Eratosthenes Seamount – A Continental Fragment Being Forced Down An Oceanic Trench, Garrett Mitchell, Larry A. Mayer, Katherine L.C. Bell, Nicole A. Raineault, Chris Roman, Robert D. Ballard, Kelsey Cornwell, Al Hine, Eugene Shinn, Iordanis Dimitriadis, Onac Bogdan

Center for Coastal and Ocean Mapping

No abstract provided.


An Intercomparison Of Drought Indicators Based On Thermal Remote Sensing And Nldas-2 Simulations With U.S. Drought Monitor Classifications, Martha C. Anderson, Christopher Hain, Jason Otkin, Xiwu Zhan, Kingtse Mo, Mark Svoboda, Brian Wardlow, Agustin Pimstein Jan 2013

An Intercomparison Of Drought Indicators Based On Thermal Remote Sensing And Nldas-2 Simulations With U.S. Drought Monitor Classifications, Martha C. Anderson, Christopher Hain, Jason Otkin, Xiwu Zhan, Kingtse Mo, Mark Svoboda, Brian Wardlow, Agustin Pimstein

National Drought Mitigation Center: Faculty Publications

Comparison of multiple hydrologic indicators, derived from independent data sources and modeling approaches, may improve confidence in signals of emerging drought, particularly during periods of rapid onset. This paper compares the evaporative stress index (ESI)—a diagnostic fast-response indicator describing evapotranspiration (ET) deficits derived within a thermal remote sensing energy balance framework—with prognostic estimates of soil moisture (SM), ET, and runoff anomalies generated with the North American Land Data Assimilation System (NLDAS). Widely used empirical indices based on thermal remote sensing [vegetation health index (VHI)] and precipitation percentiles [standardized precipitation index (SPI)] were also included to assess relative performance. Spatial and …


Influence Of Management And Precipitation On Carbon Fluxes In Great Plains Grasslands, Matthew Rigge, Bruce K. Wylie, Li Zhang, Stephen P. Boyte Jan 2013

Influence Of Management And Precipitation On Carbon Fluxes In Great Plains Grasslands, Matthew Rigge, Bruce K. Wylie, Li Zhang, Stephen P. Boyte

United States Geological Survey: Staff Publications

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data …


Modeling Rain-Fed Maize Vulnerability To Droughts Using The Standardized Precipitation Index From Satellite Estimated Rainfall-Southern Malawi Case Study, Harikishan Jayanthi, Gregory J. Husak, Chris Funk, Tamuka Magadzire, Adams Chavula, James P. Verdin Jan 2013

Modeling Rain-Fed Maize Vulnerability To Droughts Using The Standardized Precipitation Index From Satellite Estimated Rainfall-Southern Malawi Case Study, Harikishan Jayanthi, Gregory J. Husak, Chris Funk, Tamuka Magadzire, Adams Chavula, James P. Verdin

United States Geological Survey: Staff Publications

During 1990s, disaster risk reduction emerged as a novel, proactive approach to managing risks from natural hazards. The World Bank, USAlD, and other international donor agencies began making efforts to mainstream disaster risk reduction in countries whose population and economies were heavily dependent on rain-fed agriculture. This approach has more significance in light of the increasing climatic hazard patterns and the climate scenarios projected for different hazard prone countries in the world. The Famine Early Warning System Network (FEWS NET) has been monitoring the food security issues in the sub-Saharan Africa, Asia and in Haiti. FEWS NET monitors the rainfall …


Characterizing Ledaps Surface Reflectance Products By Comparisons With Aeronet, Field Spectrometer, And Modis Data, T.K. Maiersperger, P.L. Scaramuzza, L. Leigh, S. Shrestha, K.P. Gallo, C.B. Jenkerson, J.L. Dwyer Jan 2013

Characterizing Ledaps Surface Reflectance Products By Comparisons With Aeronet, Field Spectrometer, And Modis Data, T.K. Maiersperger, P.L. Scaramuzza, L. Leigh, S. Shrestha, K.P. Gallo, C.B. Jenkerson, J.L. Dwyer

United States Geological Survey: Staff Publications

This study provides a baseline quality check on provisional Landsat Surface Reflectance (SR) products as generated by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center using Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software. Characterization of the Landsat SR products leveraged comparisons between aerosol optical thickness derived from LEDAPS and measured by Aerosol Robotic Network (AERONET), as well as reflectance correlations with field spectrometer and Moderate Resolution Imaging Spectroradiometer (MODIS) data. Results consistently indicated similarity between LEDAPS and alternative data products in longer wavelengths over vegetated areas with no adjacent water, while less reliable performance was …


Radiocarbon Dating Late Quaternary Loess Deposits Using Small Terrestrial Gastropod Shells, Jeffrey S. Pigati, John Mcgeehin, Daniel R. Muhs, E. Arthur Bettis Iii Jan 2013

Radiocarbon Dating Late Quaternary Loess Deposits Using Small Terrestrial Gastropod Shells, Jeffrey S. Pigati, John Mcgeehin, Daniel R. Muhs, E. Arthur Bettis Iii

United States Geological Survey: Staff Publications

No abstract provided.


Droughtscape, Winter 2013, Kelly Smith Jan 2013

Droughtscape, Winter 2013, Kelly Smith

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

Contents

Director’s report

Climatological overview of drought in 2012

Climatological overview of drought, October-December 2012

Impacts of drought in 2012

Drought planning webinars scheduled for ranch advisors

UNL honors NDMC for exceptional service

Report from the emerging community of drought planners

Feb. 6 webinar on drought simulations

Climate Masters course starting

Climate Change in the Midwest book includes drought

Video highlights from coverage of drought of 2012

U.S. Drought Monitor Forum 2013

UN’s High Level Meeting on National Drought Policy

NDMC collaboration with India, Czech Republic


Impacts Of Migratory Sandhill Cranes (Grus Canadensis) On Microbial Water Quality In The Central Platte River, Nebraska, Usa, Jason R. Vogel, Dale W. Griffin, Hon S. Ip, Nicholas J. Ashbolt, Matthew T. Moser, Jingrang Lu, Mary K. Beitz, Hodon Ryu, Jorge W. Santo Domingo Jan 2013

Impacts Of Migratory Sandhill Cranes (Grus Canadensis) On Microbial Water Quality In The Central Platte River, Nebraska, Usa, Jason R. Vogel, Dale W. Griffin, Hon S. Ip, Nicholas J. Ashbolt, Matthew T. Moser, Jingrang Lu, Mary K. Beitz, Hodon Ryu, Jorge W. Santo Domingo

United States Geological Survey: Staff Publications

Wild birds have been shown to be significant sources of numerous types of pathogens that are relevant to humans and agriculture. The presence of large numbers of migratory birds in such a sensitive and important ecosystem as the Platte River in central Nebraska, USA, could potentially serve a significant source of birdderived pathogens in the water/sediment and riverine environment. In 2009 and 2010, a study was completed to investigate the potential water-quality impacts of Sandhill Cranes and Snow Geese on the microbial water quality of the central Platte River during their spring migration period. Fecal material, river-bottom sediment, and water …


Controls On Recent Alaskan Lake Changes Identified From Water Isotopes And Remote Sensing, Lesleigh Anderson, Jennifer Rover, Nikki Gaulager, Jean Birks Jan 2013

Controls On Recent Alaskan Lake Changes Identified From Water Isotopes And Remote Sensing, Lesleigh Anderson, Jennifer Rover, Nikki Gaulager, Jean Birks

United States Geological Survey: Staff Publications

High-latitude lakes are important for terrestrial carbon dynamics and waterfowl habitat driving a need to better understand controls on lake area changes. To identify the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous permafrost in north central Alaska, we evaluate remotely sensed imagery with lake water isotope compositions and hydroclimatic parameters. Isotope compositions indicate that mixtures of precipitation, river water, and groundwater source ~95% of the studied lakes. The remaining minority are more dominantly sourced by snowmelt and/or permafrost thaw. Isotope-based water balance estimates indicate 58% of lakes lose more than half …


Ice-Age Megafauna In Arctic Alaska: Extinction, Invasion, Survival, Daniel H. Mann, Pamela Groves, Michael L. Kunz, Richard E. Reanier, Benjamin V. Gaglioti Jan 2013

Ice-Age Megafauna In Arctic Alaska: Extinction, Invasion, Survival, Daniel H. Mann, Pamela Groves, Michael L. Kunz, Richard E. Reanier, Benjamin V. Gaglioti

United States Geological Survey: Staff Publications

Radical restructuring of the terrestrial, large mammal fauna living in arctic Alaska occurred between 14,000 and 10,000 years ago at the end of the last ice age. Steppe bison, horse, and woolly mammoth became extinct, moose and humans invaded, while muskox and caribou persisted. The ice age mega fauna was more diverse in species and possibly contained 6x more individual animals than live in the region today. Mega faunal biomass during the last ice age may have been 30x greater than present. Horse was the dominant species in terms of number of individuals. Lions, short-faced bears, wolves, and possibly grizzly …


Loess And Its Geomorphic, Stratigraphic, And Paleoclimatic Significance In The Quaternary, Daniel R. Muhs Jan 2013

Loess And Its Geomorphic, Stratigraphic, And Paleoclimatic Significance In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is aeolian silt visible in the field as a sedimentary body. It covers a significant portion of the land surface of the Earth. Loess thickness, particle size, and carbonate content decrease downwind from sources, useful trends for paleowinds. Many loess sections consist of relatively thick deposits of mostly unaltered sediment with intercalated paleosols. Paleosols represent periods of landscape stability when loess deposition slowed significantly. Loess in most regions was deposited during glacial periods and paleosols formed during interglacial periods. Loess has the potential to record the timing and environment of glacial–interglacial cycles of the Quaternary on many continents.


The Floodplain Food Web Mosaic: A Study Of Its Importance To Salmon And Steelhead With Implications For Their Recovery, J. Ryan Bellmore, Colden V. Baxter, Kyle Martens, Patrick J. Connolly Jan 2013

The Floodplain Food Web Mosaic: A Study Of Its Importance To Salmon And Steelhead With Implications For Their Recovery, J. Ryan Bellmore, Colden V. Baxter, Kyle Martens, Patrick J. Connolly

United States Geological Survey: Staff Publications

Although numerous studies have attempted to place species of interest within the context of food webs, such efforts have generally occurred at small scales or disregard potentially important spatial heterogeneity. If food web approaches are to be employed to manage species, studies are needed that evaluate the multiple habitats and associated webs of interactions in which these species participate. Here, we quantify the food webs that sustain rearing salmon and steelhead within a floodplain landscape of the Methow River, Washington, USA, a location where restoration has been proposed to restore side channels in an attempt to recover anadromous fishes. We …