Physical Sciences and Mathematics Commons^™

Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher

Watershed Sciences Faculty Publications

Rainbow trout (Oncorhynchus mykiss [Walbaum]) in Castle Lake, California were concentrated at certain depths during day and evening hours. A fish bioenergetics simulation model based on vertical gradients of temperature, oxygen concentration, and food availability indicated that rainbow trout selected habitats that maximized growth rate. In 1 of the 2 years of study, a strong pattern of diel vertical migration of rainbow trout was evident and was associated with vertical migrations of daphnids in the lake. The simulation model correctly predicted the occurrence and magnitude of fish migration. During the day some trout resided at depths with little potential for …

Summer Habitat Use Of Littoral-Zone Fishes In Lake Tahoe And The Effects Of Shoreline Structures, D. Beauchamp, E. Byron, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We used scuba observations to determine summer habitat use and the effects of piers on the littoral-zone fish community in Lake Tahoe, California–Nevada. Habitat complexity declined with depth. Over 50% of the littoral zone less than 2 m deep was composed of complex boulder substrates, but this substrate represented less than 10% of the habitat between 10 and 18 m deep. A severe drought lowered the surface elevation of the lake 2 m and reduced the wetted complex rocky habitat by 20% between the 0- and l0-m isobaths (referenced to the mean lake level of 1,899 m above sea level). …

A Trophic Gradient Analysis Of Lake Powell: The 1994 Utah State University Aquatic Ecology Laboratory Analyses, Wayne A. Wurtsbaugh, Megan Barker, Ron Brunson, David Fogle, Scott Hawxhurst, Chad Mellison, Lis Phillips, Felipe Queiroz, Daniel Zamecnik

Watershed Sciences Faculty Publications

From 9-11 April, 1994, the Aquatic Ecology Laboratory Class (FW462) of Utah State University sampled the upper reaches of Lake Powell to assess if a trophic gradient existed. We °ampled physical and chemical parameters (temperature, oxygen, conductivity, and total phosphorus), phytoplankton chlorophyll a, littoral and pelagic zooplankton biomass and composition, littoral and profundal benthic invertebrates, and fish abundance measured in the littoral zone (gill nets) and the pelagic zone (hydroacoustics). Data was collected along the upper 50 miles of the reservoir between Bullfrog and the Hite marina near the Colorado River inflow.

Our field trip was done just prior to …

Modelling Sun-Aligned Polar Cap Arcs, D. J. Crain, Jan Josef Sojka, Robert W. Schunk, Lie Zhu

All Physics Faculty Publications

We present results of a new model of the time-dependent ionospheric response to a generalized steady state Sun-aligned (SA) arc structure. The thermal and plasma structure of a “prototype” arc is compared to the general features of observed SA arcs. We find that the general features of electron density, N_e , electron temperature, T_e , and ion temperature, T_i , are determined by the distribution of the particle precipitation and E × B convection associated with the SA arc. The model results are extended to predict the possible variation of N_e, T_e , and …

Patches In The Polar Ionosphere: Ut And Seasonal Dependence, Jan Josef Sojka, M. D. Bowline, Robert W. Schunk

All Physics Faculty Publications

The seasonal and UT dependencies of patches in the polar ionosphere are simulated using the Utah State University time dependent ionospheric model (TDIM). Patch formation is achieved by changing the plasma convection pattern in response to temporal changes in the interplanetary magnetic field (IMF) B_y component during periods of southward IMF. This mechanism redirects the plasma flow from the dayside high-density region, which is the source of the tongue of ionization (TOI) density feature, through the throat and leads to patches, rather than a continuous TOI. The model predicts that the patches are absent at winter solstice (northern hemisphere) …

Ionospheric Response To The Sustained High Geomagnetic Activity During The March '89 Great Storm, Jan Josef Sojka, Robert W. Schunk, W. F. Denig

All Physics Faculty Publications

A simulation was conducted to model the high-latitude ionospheric response to the sustained level of high geomagnetic activity for the great magnetic storm period of March 13-14, 1989. The geomagnetic and solar activity indices and the DMSP F8 and F9 satellite data for particle precipitation and high-latitude convection were used as inputs to a time-dependent ionospheric model (TDIM). The results of the TDIM were compared to both DMSP plasma density data and ground-based total electron content (TEC) measurements for the great storm period as well as with earlier storm observations. The comparisons showed that the overall structure of the high-latitude …

Effect Of High Latitude Ionospheric Convection On Sun-Aligned Polar Caps, Jan Josef Sojka, Lie Zhu, D. J. Crain, Robert W. Schunk

All Physics Faculty Publications

A coupled magnetospheric-ionospheric (M-I) MHD model has been used to simulate the formation of Sun-aligned polar cap arcs for a variety of interplanetary magnetic field (IMF) dependent polar cap convection fields. The formation process involves launching an Alfvén shear wave from the magnetosphere to the ionosphere where the ionospheric conductance can react self-consistently to changes in the upward currents. We assume that the initial Alfvén shear wave is the result of solar wind-magnetosphere interactions. The simulations show how the E region density is affected by the changes in the electron precipitation that are associated with the upward currents. These changes …

Uinta National Forest, Rangeland Ecosystem Forest Plan Amendment, Final Environmental Impact Statement, United States Forest Service

Final environmental Impact Statements (UT)

This Final Environmental Impact Statement describes alternatives, including a "No Action" alternative for management of National Forest Rangeland Resources on the Uinta National Forest. Alternatives range from no change from past management practices, which in some instances have resulted in less than favorable ecological conditions on National Forest Rangelands and riparian resources, to managing these resources to achieve the "Potential Natural Community" in terms of vegetative cover types and condition. The environmental consequences of all alternatives considered in detail are displayed. The alternative selected for implementation will become an amendment to the Uinta National Forest Land and Resource Management Plan. …

Photoemission Measurement Of Equilibrium Segregation At Gesi Surfaces, J. E. Rowe, D. Mark Riffe, G. K. Wertheim, J. C. Bean

All Physics Faculty Publications

Photoemission spectroscopy is used to demonstrate that Ge segregates to the first atomic layer of Ge_0.5Si_0.5(100)2×1 and that the second layer is predominantly Si. Comparison of the resolved signals from the dimer atoms of the reconstructed (100)2×1 surfaces of Ge, Si, and equiatomic Ge‐Si alloy shows that the surface layer of the alloy is extremely Ge rich and the second layer is occupied mainly by Si atoms. This result is in good agreement with theoretical predictions.

Ionospheric Response To Traveling Convection Twin Vortices, Robert W. Schunk, Lie Zhu, Jan Josef Sojka

All Physics Faculty Publications

Traveling convection twin vortices have been observed for several years. At ionospheric altitudes, the twin vortices correspond to spatially localized, transient structures embedded in a large‐scale background convection pattern. The convection vortices are typically observed in the morning and evening regions. They are aligned predominantly in the east‐west direction and have a horizontal extent of from 500–1000 km. Associated with the twin vortices are enhanced electric fields, particle precipitation, and an upward/downward field‐aligned current pair. Once formed, the twin vortex structures propagate in the tailward direction at speeds of several km/s, but they weaken as they propagate and only last …

Theoretical Study Of Polar Cap Arcs: Time-Dependent Model And Its Applications, Lie Zhu, Jan Josef Sojka, Robert W. Schunk, D. J. Crain

All Physics Faculty Publications

A time-dependent theoretical model of polar cap arcs developed during the Coupling, Energetics, and Dynamics of Atmospheric Regions/High-Latitude Plasma Structures (CEDAR/HLPS) campaigns in the past two years is briefly described. In the model the electrodynamics of the polar cap arcs are treated self-consistently in the frame of the coupled magnetosphere-ionosphere system. The preliminary simulation results of the temporal evolution and spatial structure of the polar cap arcs for both winter and summer conditions are presented. The model can be used to conduct both the model-observation study of specific features of the polar cap arcs and the quantitative theoretical study of …

Model Study Of Multiple Polar Cap Arcs: Occurrence And Spacing, Lie Zhu, Jan Josef Sojka, Robert W. Schunk, D. J. Crain

All Physics Faculty Publications

A new scenario for the formation of multiple polar cap arcs is proposed based on the results from a time‐dependent electrodynamic model of polar cap arcs developed by Zhu et al. [1993]. The results suggest that the appearance of multiple polar cap arcs may not be due to multiple structures in the magnetospheric source region, but instead, may primarily be determined by the coupled magnetosphere‐ionosphere system in which the ionosphere plays an active role. It was found that with the same magnetospheric driver, a strong ionospheric background convection and an ionospheric background Hall conductance in the range of from 0.5 …

Magnetospheric Shortcomings In Ionospheric-Magnetospheric Coupling: An Ionospheric Perspective, Jan Josef Sojka

All Physics Faculty Publications

The ionosphere, on a global scale, is reasonably well understood from a climatology perspective. However, the storm dynamics of the ionosphere are not fully understood. This partly arises from the complex response function of the Thermosphere-Ionosphere(T-I) system but also from the uncertainty in the space and time dynamics of the magnetospheric inputs to the ionosphere. In the context of M-I coupling, the ionosphere responds to magnetospheric electrodynamic forcing by altering the conductivity in the ionosphere and by plasma transport. Phenomenologically,we understand how to let the ionospheric conductivity evolve in response to local precipitation and how to transport plasma in the …

Savant Sage Final Environmental Impact Statement Maps, United States Forest Service

Final Environmental Impact Statements (ID)

Savant Sage Final Environmental Impact Statement Maps.

Nursery Pest Management Final Environmental Impact Statement Record Of Decision, United States Forest Service

Record of Decisions (ID)

The Final Environmental Impact Statement (FEIS) documents results of the analysis of alternatives for pest management at the USDA Forest Service, Lucky Peak Nursery in the Intermountain Region. I have reviewed the FEIS and related materials, including responses to the Draft Environmental Impact Statement (DEIS) published in December 1991. My decision is based upon that review.

Grade/Dukes Timber Sale Final Supplemental Environmental Impact Statement, United States Forest Service

Final Environmental Impact Statements (ID)

This Final Supplemental Environmental Impact Statement (FSEIS) documents the analysis of the modifications made to the original Record of Decision Alternative for the proposed Grade/Dukes timber sale, which the Regional Forester sent back to the Payette National Forest on remand. The Proposed Alternative responds to the additional analysis required from the appeals and remand points and new concerns received during public scoping. This document is tiered to the original Grade/Dukes Final Environmental Impact Statement (FEIS) and Record of Decision (ROD).

Nursery Pest Management Final Environmental Impact Statement, United States Forest Service

Final Environmental Impact Statements (ID)

The Forest Service, in compliance with the National Environmental Policy Act of 1969, is presenting three alternative ways of managing pests (weeds, diseases, insects, and animals) at the Lucky Peak Nursery in the Intermountain Region.

Flood Insurance Study, City Of South Salt Lake, Utah, Salt Lake County, Federal Emergency Management Agency

All U.S. Government Documents (Utah Regional Depository)

This Flood Insurance Study investigates the existence and severity of flood hazards in the City of South Salt Lake, Salt Lake County, Utah, and aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study has developed flood risk data for various areas of the community that will be used to establish actuarial flood insurance rates and assist the community in its efforts to promote sound flood plain management. Minimum flood plain management requirements for participation in the National Flood Insurance Program are set forth in the Code of …

Managing Coarse Woody Debris In Forests Of The Rocky Mountains, U.S. Forest Service

All U.S. Government Documents (Utah Regional Depository)

Fourteen habitat types were examined. Coarse woody debris management recommendations were developed by using ectomycorrhizae as a bioindicator of healthy, productive forest soils.

Status, Biology, And Management Of Ferruginous Hawks: A Review, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

The purpose of this paper is to promote the wise management of ferruginous hawk habitat to enable the species to maintain or increase its population levels. Twenty-seven recommendations are presented, supported by reviews of population status, nesting chronology, nest site characteristics, food habits, and spatial considerations. This is followed by discussion of the impacts of human activities on the ferruginous hawk, such as urbanization, cultivation, grazing, land conversion, poisoning and small mammal control, mining, fire and fire management, and other activities.

Long-Term Flow Test #1, Roosevelt Hot Springs, Utah, D. D. Faulder

All U.S. Government Documents (Utah Regional Depository)

The Roosevelt Hot Springs, Utah geothermal field has been the site of numerous investigations into the behavior of a geothermal system. However, a detailed description of the reservoir is lacking. This paper presents the results of the 237 day Long-Term Flow Test #1, conducted in 1977 and 1978, followed by a 100 day pressure buildup. The responses from one production well and three pressure observation wells, ranging 600 to 12,000 feet from the production well, were used. This study illustrates the utility of a reevaluation of a geothermal system using old, pre-exploitation data and is part of an ongoing case …

Blm, Utah State Office Hazardous Substances Contingency Plan, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

This document is the Utah BLM hazardous substances release contingency plan or what to do when hazardous substances are discovered on public lands.

Questar Pipeline Company, Environmental Assessment For The Birch Creek Natural Gas Pipeline, United States Department Of The Interior Bureau Of Land Management

Environmental Assessments (WY)

Questar Pipeline Company (Questar) is a natural gas pipeline transportation company that operates more than 2,400 miles of transmission and gathering pipelines in northwestern Colorado, southwestern Wyoming, and northern and central Utah and who, through its interconnections with other major pipeline, provides customers with gas gathering, transportation, and storage services. Questar has applied to the Bureau of Land Management (BLM), Rock Springs District, for approval to construct the Birch Creek Pipeline in southwestern Sublette County, eastern Lincoln County, and northwestern Sweetwater County, Wyoming (Figure 1.1). The proposed pipeline would be a gathering line for existing and future natural gas fields …

Mcmurry Oil Company Jonah Prospect Field Natural Gas Development Environmental Assessment, United States Department Of The Interior Bureau Of Land Management

Environmental Assessments (WY)

The U.S. Department of Interior, Bureau of Land Management (BLM), prepared this Environmental Assessment (EA) to evaluate and disclose potential environmental impacts of development of a new natural gas field known as the Jonah Prospect Field (Jonah Field, project area). McMurry Oil Company (McMurry) proposes to drill 40 natural gas wells and construct associated well pads, access roads, gathering and sales pipeline systems; expand an existing compressor station; and include a wareyard at their existing office site.

Environmental Assessment Animal Damage Control On Public Lands Administered By The U.S. Department Of The Interior, Bureau Of Land Management, Casper District, Wyoming, United States Department Of The Interior Bureau Of Land Management

Environmental Assessments (WY)

The Bureau of Land Management (BLM) and the Animal and Plant Health Inspection Service (APHIS) recognize that native animals are resources of value and interest to the American people. Animal damage control (ADC) management may be required to minimize depredations to livestock and wildlife species; to protect threatened and endangered species; to maintain viable populations of native wildlife species; to preserve ecologically unique areas; to minimize rodent and other wildlife damage to cropland, grassland, and forestland; and, to suppress animal-borne diseases. ADC functions as a supplement to, not a substitute for, standard husbandry practices and techniques.

Decision Record And Finding Of No Significant Impact For The Environmental Assessment Predatory Animal Damage Control On Public Lands Campbell, Converse, Crook, Goshen, Johnson, Natrona, Niobrara, Platte, Sheridan, And Weston Counties, Wyoming, United States Department Of The Interior Bureau Of Land Management

Record of Decisions (WY)

The enclosed Decision Record/Finding of No Significant Impact approves a Predatory Animal Damage Control Plan for the Casper District of the Bureau of Land Management (BLM). The decision is based on the review comments from eight individuals and organizations on the Environmental Assessment (EA) released in February 1994. As a result of those comments the EA has been rewritten and a copy of the revised EA is attached.

Efficient Timestamp Input And Output, Curtis Dyreson, Richard T. Snodgrass

Curtis Dyreson

In this paper we provide efficient algorithms for converting between the internal form of a timestamp, and various external forms, principally character strings specifying Gregorian dates. We give several algorithms that explore a range of time and space tradeoffs. Unlike previous algorithms that explore a range of time and space tradeoffs. Unlike previous algorithms, those discussed here have a constant time cost over a greatly extended range of timestamp values. These algorithms are especially useful in operating systems and in database management systems.

Comparison Between Calculatedand Observed F-Region Density Profiles At Jicamarca, Peru, A. J. Preble, D. N. Anderson, Bela G. Fejer, P. H. Doherty

Bela G. Fejer

Electron density profiles and isodensity contours derived from Jicamarca incoherent scatter radar observations in Peru for October 1–2, 1970, are compared in detail with results from the Phillips Laboratory global theoretical ionospheric model. This model solves the ion continuity equation for O+ concentration through production, loss, and transport of ionization. The primary factor controlling the peak plasma density at Jicamarca is the vertical E×B drift, which drives the ionization upward during the day and downward at night. When we use the measured drift in the model, we achieve excellent results with the measured electron density profiles. We illustrate the sensitivity …

Nanoscale Patterning And Oxidation Of H-Passivated Si(100)-2x1 Surfaces With An Ultrahigh Vacuum Scanning Tunneling Microscope, J. W. Lyding, T. -C. Shen, J. S. Hubaceck, J. R. Tucker, G. C. Abeln

T. -C. Shen

Nanoscale patterning of the hydrogen terminated Si(100)‐2×1 surface has been achieved with an ultrahigh vacuum scanning tunneling microscope.Patterning occurs when electrons field emitted from the probe locally desorb hydrogen, converting the surface into clean silicon. Linewidths of 1 nm on a 3 nm pitch are achieved by this technique. Local chemistry is also demonstrated by the selective oxidation of the patterned areas. During oxidation, the linewidth is preserved and the surrounding H‐passivated regions remain unaffected, indicating the potential use of this technique in multistep lithography processes.

Diamond Mountain Resource Area Resource Management Plan And Record Of Decision, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

The Diamond Mountain Resource Management Plan is approved. The plan was prepared under the regulations for implementing the Federal Land Policy and Management Act (FLPMA) of 1976 (43 CFR 1600). An environmental impact statement was prepared for this plan in compliance with the National Environmental Policy Act (NEPA) of 1969. The plan is identical/nearly idential to the one set forth in the proposed plan and associated final environmental impact statement published in August 1993. Specific areawide management decisions are presented in Chapter 2 of the RMP.