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

Physical Sciences and Mathematics Commons

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

Earth Sciences

University of Nebraska - Lincoln

2012

Keyword
Publication

Articles 1 - 30 of 141

Full-Text Articles in Physical Sciences and Mathematics

U.S. Drought Monitor, December 25, 2012, Richard R. Heim Jr. Dec 2012

U.S. Drought Monitor, December 25, 2012, Richard R. Heim Jr.

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 25, 2012 (12/25/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


U.S. Drought Monitor, December 18, 2012, David Simeral Dec 2012

U.S. Drought Monitor, December 18, 2012, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 18, 2012 (12/18/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


Seasonal Dimorphism In The Horny Bills Of Sparrows, Russell Greenberg, Matthew Etterson, Raymond M. Danner Dec 2012

Seasonal Dimorphism In The Horny Bills Of Sparrows, Russell Greenberg, Matthew Etterson, Raymond M. Danner

United States Environmental Protection Agency: Staff Publications

Bill size is often viewed as a species-specific adaptation for feeding, but it sometimes varies between sexes, suggesting that sexual selection or intersexual competition may also be important. Hypotheses to explain sexual dimorphism in avian bill size include divergence in feeding niche or thermoregulatory demands, intrasexual selection based on increased competition among males, or female preference. Birds also show seasonal changes in bill size due to shifts in the balance between growth rate and wear, which may be due to diet or endogenous rhythms in growth. Insight into the function of dimorphism can be gained using the novel approach of …


U.S. Drought Monitor, December 11, 2012, Rich Tinker Dec 2012

U.S. Drought Monitor, December 11, 2012, Rich Tinker

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 11, 2012 (12/11/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


Spatial Filter Approach To Evaluating The Role Of Convection On The Evolution Of A Mesoscale Vortex, Glenn A. Creighton, Robert E. Hart, Philip Cunningham Dec 2012

Spatial Filter Approach To Evaluating The Role Of Convection On The Evolution Of A Mesoscale Vortex, Glenn A. Creighton, Robert E. Hart, Philip Cunningham

Department of Earth and Atmospheric Sciences: Faculty Publications

A new spatial filter is proposed that exploits a spectral gap in power between the convective scale and the system (‘‘vortex’’) scale during tropical cyclone (TC) genesis simulations. Using this spatial separation, this study analyzes idealized three-dimensional numerical simulations of deep moist convection in the presence of a symmetric midlevel vortex to quantify and understand the energy cascade between the objectively defined convective scale and system scale during the early stages of tropical cyclogenesis. The simulations neglect surface momentum, heat, and moisture fluxes to focus on generation and enhancement of vorticity within the interior to more completely close off the …


U.S. Drought Monitor, December 4, 2012, Rich Tinker Dec 2012

U.S. Drought Monitor, December 4, 2012, Rich Tinker

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 4, 2012 (12/4/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


Interactions Of Zooplankton And Phytoplankton With Cyanobacteria, Rebecca Alexander Dec 2012

Interactions Of Zooplankton And Phytoplankton With Cyanobacteria, Rebecca Alexander

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

Cyanobacteria are a major concern in Nebraska reservoirs and are capable of producing toxins that can cause skin irritations and gastrointestinal problems, as well as affect the nervous system. It is important to determine the mechanisms that can cause cyanobacteria blooms due to the effect they can have on human health. The interaction of zooplankton and other phytoplankton groups with cyanobacteria is important because there is a biological component in surface waters that should be taken into consideration along with the physical and chemical parameters that have been noted to promote cyanobacteria. For example, zooplankton have the ability to alter …


Interactions Of Zoo Plankton And Phytoplankton With Cyanobacteria, Rebecca J. Alexander Dec 2012

Interactions Of Zoo Plankton And Phytoplankton With Cyanobacteria, Rebecca J. Alexander

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

Cyanobacteria are a major concern in Nebraska reservoirs and are capable of producing toxins that can cause skin irritations and gastrointestinal problems, as well as affect the nervous system. It is important to determine the mechanisms that can cause cyanobacteria blooms due to the effect they can have on human health. The interaction of zooplankton and other phytoplankton groups with cyanobacteria is important because there is a biological component in surface waters that should be taken into consideration along with the physical and chemical parameters that have been noted to promote cyanobacteria. For example, zooplankton have the ability to alter …


Autumn Migration Of Mississippi Flyway Mallards As Determined By Satellite Telemetry, David George G. Krementz, Kwasi Asante, Luke W. Naylor Dec 2012

Autumn Migration Of Mississippi Flyway Mallards As Determined By Satellite Telemetry, David George G. Krementz, Kwasi Asante, Luke W. Naylor

United States Geological Survey: Staff Publications

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17–December 7). For those mallards that stopped for .1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The …


U.S. Drought Monitor, November 27, 2012, Eric Luebehusen Nov 2012

U.S. Drought Monitor, November 27, 2012, Eric Luebehusen

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 27, 2012 (11/27/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


Agricultural Advisors: A Receptive Audience For Weather And Climate Information?, Linda Stalker Prokopy, Tonya Haigh, Amber Saylor Mase, Jim Angel, Chad Hart, Cody Knutson, Maria Carmen Lemos, Yun Jia Lo, Jean Mcguire, Lois Wright Morton, Jennifer Perron, Dennis Todey, Melissa Widhalm Nov 2012

Agricultural Advisors: A Receptive Audience For Weather And Climate Information?, Linda Stalker Prokopy, Tonya Haigh, Amber Saylor Mase, Jim Angel, Chad Hart, Cody Knutson, Maria Carmen Lemos, Yun Jia Lo, Jean Mcguire, Lois Wright Morton, Jennifer Perron, Dennis Todey, Melissa Widhalm

Drought Mitigation Center: Faculty Publications

As the climate in the midwestern United States becomes increasingly variable because of global climate change, it is critical to provide tools to the agricultural community to ensure adaptability and profitability of agricultural cropping systems. When used by farmers and their advisors, agricultural decision support tools can reduce uncertainty and risks in the planning, operation, and management decisions of the farm enterprise. Agricultural advisors have historically played a key role in providing information and guidance in these decisions. However, little is known about what these advisors know or think about weather and climate information and their willingness to incorporate this …


U.S. Drought Monitor, November 20, 2012, Eric Luebehusen Nov 2012

U.S. Drought Monitor, November 20, 2012, Eric Luebehusen

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 20, 2012 (11/20/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


U.S. Drought Monitor, November 13, 2012, David Miskus Nov 2012

U.S. Drought Monitor, November 13, 2012, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 13, 2012 (11/13/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


U.S. Drought Monitor, November 6, 2012, David Miskus Nov 2012

U.S. Drought Monitor, November 6, 2012, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 6, 2012 (11/6/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


U.S. Drought Monitor, October 30, 2012, Michael J. Brewer, Liz Love-Brotak Oct 2012

U.S. Drought Monitor, October 30, 2012, Michael J. Brewer, Liz Love-Brotak

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for October 30, 2012 (10/30/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


Applicability And Estimation Of Error For Determination Of Hydraulic Conductivity Values Based Upon Traditional Aquifer Test Methods For 2-D Groundwater Modeling, Timothy W. Freed Sr. Oct 2012

Applicability And Estimation Of Error For Determination Of Hydraulic Conductivity Values Based Upon Traditional Aquifer Test Methods For 2-D Groundwater Modeling, Timothy W. Freed Sr.

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

The Theis method and its derivative Cooper-Jacob method are commonly used for determining hydraulic conductivity (K) for aquifer studies using two-dimensional (2-D) groundwater modeling. Theis and derivative equations assume isotropic, homogeneous aquifers and horizontal flow. In nature, saturated permeable layers of an aquifer are often separated by less permeable layers or lenses, which commonly have K's that are lower by several orders of magnitude. The presence of such geologic features induces vertical flow during aquifer tests violating assumptions for Theis based methods. This study assesses the appropriateness and error of using Theis based equations to determine K for use in …


Geologic Observations Along The Steamboat Trace Trail, Markers 16-20, In The Vicinity Of Peru, Nemaha County, Nebraska (Including On The Indian Cave Sandstone), Robert F. Diffendal Jr. Oct 2012

Geologic Observations Along The Steamboat Trace Trail, Markers 16-20, In The Vicinity Of Peru, Nemaha County, Nebraska (Including On The Indian Cave Sandstone), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

This section of the Steamboat Trace Trail from markers 16 through 20 (Figure 1) offers especially good examples of geologic features in this part of Nebraska (Figure 2). These include: The Missouri River, its valley, river cuts into the valley side, tributaries to the river, and flood control structures; Sites of active and potential landslides; Wind-deposited silts (called loess by geologists and soil scientists); Glacial deposits; Bedrock exposures of ancient sandstone, shale, conglomerate, and limestone; Fossils of ocean- and land-dwelling plants and animals; Coal deposits.


U.S. Drought Monitor, October 16, 2012, Matthew Rosencrans Oct 2012

U.S. Drought Monitor, October 16, 2012, Matthew Rosencrans

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for October 16, 2012 (10/16/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


U.S. Drought Monitor, October 9, 2012, Matthew Rosencrans Oct 2012

U.S. Drought Monitor, October 9, 2012, Matthew Rosencrans

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for October 9, 2012 (10/9/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


U.S. Drought Monitor, October 2, 2012, Anthony Artusa Oct 2012

U.S. Drought Monitor, October 2, 2012, Anthony Artusa

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for October 2, 2012 (10/2/2012) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.


Impacts Of Climate Change On The Surface Water Balance Of The Central United States, 1984-2007, Bo Dong Oct 2012

Impacts Of Climate Change On The Surface Water Balance Of The Central United States, 1984-2007, Bo Dong

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

The climate system and the hydrologic cycle are strongly connected with each other. Understanding the interactions between these two systems is important, since variations in climate can trigger extensive changes in the hydrologic cycle, with significant impacts on agriculture, ecosystems, and society. Observations over the central U.S. in recent decades show numerous changes in climatic variables. This includes decreases in cloud cover and wind speed, increases in air temperature, and seasonal shifts in precipitation rate and rain/snow fraction. To assess the impacts of these variations in climate on the regional water cycle, a terrestrial ecosystem/land surface hydrologic model (Agro-IBIS) is …


Droughtscape- Fall 2012, National Drought Mitigation Center Oct 2012

Droughtscape- Fall 2012, National Drought Mitigation Center

Droughtscape, Quarterly Newsletter of NDMC, 2007-

CONTENTS

Director’s report ....................... 1

Updated resources ................... 1

Drought outlook and review... 2

2012 and past droughters..... 4

Summer impacts summary.... 6

Urban planners and drought..... 9

USDM wins CLEAN seal... 10

Meixiu Yu's Chinese SPEI... 11

Ethiopian project..... 12

Mexican VegDRI.... 13

Drought monitor sculpture.... 14


Documenting Change At Upper Hamburg Bend: Nebraska's First Side-Channel Restoration, Brandon L. Eder, Gerald Mestl Oct 2012

Documenting Change At Upper Hamburg Bend: Nebraska's First Side-Channel Restoration, Brandon L. Eder, Gerald Mestl

Great Plains Research: A Journal of Natural and Social Sciences

In 1996 a side channel was excavated on 629 hectares of former agricultural land at Upper Hamburg Bend on the Missouri River in Otoe County, NE. This was the first side channel constructed on the Missouri River in an attempt to restore lost aquatic habitat. The initial design was for an approximately 4,200 m long side channel to be constructed with a 3 m bottom width. Development ofthe site was to be dependent on flows diverted from the main channel of the river with a final projected top width of 61 m. The side channel was completed in the spring, …


Catching Air - Those Magnificent Jumping Suwannee Sturgeons, Ken Sulak Oct 2012

Catching Air - Those Magnificent Jumping Suwannee Sturgeons, Ken Sulak

United States Geological Survey: Staff Publications

It starts deep at the bottom of the dark silent river, three to four powerful tail beats and three sharp acoustic clicks. Then, a sudden upturn of the body and the fish explodes upward, 100 pounds going vertical, catching air, lots of air. A good jump can power a big fish, six to nine feet into the air. You have to be quick to get a photo, hang time is only about a second, but an accomplished jump by a big old Suwannee River Gulf Sturgeon is impressive; a magnificent display of power. The exit is almost vertical. The tail …


The Geologic Records Of Dust In The Quaternary, Daniel R. Muhs Sep 2012

The Geologic Records Of Dust In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Study of geologic records of dust composition, sources and deposition rates is important for understanding the role of dust in the overall planetary radiation balance, fertilization of organisms in the world’s oceans, nutrient additions to the terrestrial biosphere and soils, and for paleoclimatic reconstructions. Both glacial and non-glacial processes produce fine-grained particles that can be transported by the wind. Geologic records of dust flux occur in a number of depositional archives for sediments: (1) loess deposits; (2) lake sediments; (3) soils; (4) deep-ocean basins; and (5) ice sheets and smaller glaciers. These archives have several characteristics that make them highly …


U.S. Drought Monitor, September 25, 2012, Anthony Artusa Sep 2012

U.S. Drought Monitor, September 25, 2012, Anthony Artusa

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for September 25, 2012 (9/25/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


U.S. Drought Monitor, September 18, 2012, David Simeral Sep 2012

U.S. Drought Monitor, September 18, 2012, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for September 18, 2012 (9/18/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


U.S. Drought Monitor, September 11, 2012, David Simeral Sep 2012

U.S. Drought Monitor, September 11, 2012, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for September 11, 2012 (9/11/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


U.S. Drought Monitor, September 4, 2012, Brian Fuchs Sep 2012

U.S. Drought Monitor, September 4, 2012, Brian Fuchs

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for September 4, 2012 (9/4/12) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle.


Analytical Modeling Of Irrigation And Land Use Effects On Streamflow In Semi-Arid Conditions: Frenchman Creek, Nebraska, Jonathan P. Traylor Sep 2012

Analytical Modeling Of Irrigation And Land Use Effects On Streamflow In Semi-Arid Conditions: Frenchman Creek, Nebraska, Jonathan P. Traylor

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

With proliferation of various numerical models, water budget studies commonly resort to numerical modeling techniques. However, availability and uncertainty in input data limit advantages of this approach. Often, analytical models capture the major traits of the watersheds and can assimilate important data. We developed a model for baseflow-dominated watersheds and apply it to Frenchman Creek in southwestern Nebraska. Frenchman Creek has experienced large streamflow reductions since the 1950s. The cause of these reductions is a combination of irrigation, conservation terrace construction, and other land use changes. However, the influence of each factor has not been well quantified. The objective of …