Physical Sciences and Mathematics Commons^™

Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Garry D. Wilson

School of Natural Resources: Faculty Publications

The purpose of this study is to improve our understanding of temperature and precipitation effects on the Palmer Drought Severity Index (PDSI). Both theoretical and observational analyses were applied to separate and compare temperature and precipitation effects on PDSI. The results showed that because of the dependence of PDSI on the ‘climatologically appropriate rainfall’, which is a function of time and varies with surface air temperature, the PDSI can be equally affected by temperature and precipitation, when both have similar magnitudes of anomalies. Calculations using observational data further illustrated the temperature influence on PDSI in different climate regions in the …

The Effectiveness Of The Asos, Mmts, Gill, And Crs Air Temperature Radiation Shields*, K. G. Hubbard, X. Lin, E.A. Walter-Shea

School of Natural Resources: Faculty Publications

Periodic upgrades of air temperature measurement systems in surface weather station networks cause data discontinuities. From a climatological viewpoint, it is necessary to evaluate the air temperature data discontinuities when air temperature radiation shields are upgraded. This study was undertaken to investigate the effectiveness of four common air temperature radiation shields including the Automated Surface Observing System (ASOS), the Maximum–Minimum Temperature System (MMTS), the Gill, and the Cotton Region Shelter (CRS) shields. The solar radiation shielding effectiveness for each shield under typical grass ground surface and different artificial surfaces (black, white, and aluminum) were investigated. The shield effectiveness was evaluated …

Correlations Between Burrowing Owl And Black-Tailed Prairie Dog Declines: A 7-Year Analysis, Martha J. Desmond, Julie A. Savidge, Kent M. Eskridge

School of Natural Resources: Faculty Publications

Concern over the status of species associated with prairie dog colonies has increased with the recent proposed listing of black-tailed prairie dogs (Cynomys ludovicianus). We monitored burrowing owl (Athene cunicularia) populations and prairie dog densities in 17 black-tailed prairie dog colonies in the Nebraska panhandle between 1990 and 1996. All prairie dog colonies were controlled at least once during the study. We observed a 63% decline in nesting pairs of burrowing owls and significant declines in burrow densities. Results indicated a time lag in owl response to changes in active burrow densities. However, in the later …

A Flexible K-12 Weather Data Collection And Education Program, Mark A. Mesarch, S. J. Meyer, David C. Gosselin

School of Natural Resources: Faculty Publications

The Nebraska Earth Science Education Network (NESEN) is an organization within the University of Nebraska-Lincoln whose objectives are to: 1) promote and enhance K-12 earth science education in Nebraska, 2) improve teacher knowledge and understanding so that students become better informed about the complexities of environmental and natural resources issues and 3) enhance the transfer of earth science information to the K-12 teaching community (Gosselin, Mohlman, Mesarch & Meyer, 1996; Gosselin et al., 1999). To achieve this last objective NESEN developed the Students and Teachers Exchanging Data, Information and Ideas (STEDII) program with the help of support from the National …

Evaluation And Assessment Of Agrichemical Contaminants In The Creighton, Ne Area, Mark E. Burbach, Roy F. Spalding

School of Natural Resources: Faculty Publications

The Lewis and Clark Natural Resources District (LCNRD) has reported elevated nitrate- nitrogen (NO3-N) concentrations in ground water near Creighton, NE. The U.S. Environmental Protection Agency has set a maximum contaminant level (MCL) of 10 mg/L for NO3-N in public water supplies. NO3-N in the city of Creighton municipal drinking water wells and several rural domestic and irrigation wells have exceeded the MCL. The city of Creighton has constructed a reverse-osmosis water treatment system at a cost of $1.1 million to reduce the NO3-N concentration below the MCL in its water supply. In response to this NO3-N contamination problem the …

The Eos Prototype Validation Exercise (Prove) At Jornada: Overview And Lessons Learned, J. L. Privette, G. P. Asner, J. Conel, K. F. Huemmrich, R. Olson, A. Rango, A. F. Rahman, K. Thome, Elizabeth A. Walter-Shea

School of Natural Resources: Faculty Publications

The Earth Observing System (EOS) instrument teams must validate the operational products they produce from the Terra spacecraft data. As a pilot for future validation activities, four EOS teams (MODIS, MISR, ASTER, and Landsat-7) and community experts conducted an 11-day field campaign in May 1997 near Las Cruces, NM. The goals of the Prototype Validation Exercise (PROVE) included (1) gaining experience in the collection and use of field data for EOS product validation; (2) developing coordination, measurement, and data-archiving protocols; and (3) compiling a synoptic land and atmospheric data set for testing algorithms. PROVE was held at the USDA-Agricultural Research …

Airflow Characteristics Of Commonly Used Temperature Radiation Shields*, X. Lin, Kenneth G. Hubbard, George E. Meyer

School of Natural Resources: Faculty Publications

The air temperature radiation shield is a key component in air temperature measurement in weather station networks; however, it is widely recognized that significant errors in the measured air temperature exist due to insufficient airflow past the air temperature sensor housed inside the shield. During the last several decades, the U.S. National Weather Service has employed a number of different shields in air temperature measurements. This paper focuses on the airflow characteristics inside air temperature shields including the Maximum–Minimum Temperature System (MMTS), the Gill shields, and the Cotton Region Shelter (CRS).

Average airspeed profiles and airflow efficiency inside the shields …

Extralimital Records Of The Mexican Free-Tailed Bat (Tadarida Brasilensis Mexicana) In The Central United States And Their Biological Significance, Hugh H. Genoways, Patricia W. Freeman, Cary Grell

School of Natural Resources: Faculty Publications

Two new records of Tadarida brasiliensis mexicana are reported from Nebraska. The literature records of this taxon from the central United States are summarized. In this region of North America, these bats occupy a “natal range” where the species carries on regular reproductive activities and the populations are relatively stable, including California, Arizona, New Mexico, Texas, and Oklahoma. To the north of the natal range of T. b. mexicana is a “pioneering zone” where, under favorable conditions, the species is capable of reproducing and conducting its normal activities. The pioneering zone of the Mexican free-tailed bat includes Barber and Comanche …

Shifting Distributional Patterns Of Mammals In Nebraska, Russell A. Benedict, Hugh H. Genoways, Patricia W. Freeman

School of Natural Resources: Faculty Publications

New distributional records are presented for 20 species of mammals in Nebraska. The majority of these records appear to represent changes in geographic distribution rather than just better sampling in poorly known areas. One group of mammals, including the opossum, northern myotis, evening bat, red bat, woodchuck, white-footed mouse, and gray fox, is expanding westward, probably in response to increasing woodlands along river systems. Another group, including the meadow vole, masked shrew, and least weasel, is expanding southward, possibly in response to new prey species and changing microclimates. The eastern woodrat appears to be expanding northward in eastern Nebraska. The …

The Eos Prototype Validation Exercise (Prove) At Jornada: Overview And Lessons Learned, J. L. Privette, G. P. Asner, J. Conel, K. R. Huemmrich, R. Olson, A. Rango, A. F. Rahman, K. Thome, Elizabeth A. Walter-Shea

School of Natural Resources: Faculty Publications

The Earth Observing System (EOS) instrument teams must validate the operational products they produce from the Terra spacecraft data. As a pilot for future validation activities, four EOS teams (MODIS, MISR, ASTER, and Landsat-7) and community experts conducted an 11-day field campaign in May 1997 near Las Cruces, NM. The goals of the Prototype Validation Exercise (PROVE) included (1) gaining experience in the collection and use of field data for EOS product validation; (2) developing coordination, measurement, and data-archiving protocols; and (3) compiling a synoptic land and atmospheric data set for testing algorithms. PROVE was held at the USDA-Agricultural Research …

Forestry's Role In Sustainable Agriculture, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Determination Of Drag Properties Of A Shelterbelt From Measurements And A Numerical Model, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Pressure Perturbations Around Shelterbelts: Measurements And Model Results, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreaks An Old System With A New Look, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreaks: Are They Effective?, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Silvopastoral Systems In The Pine Ridge Of Nebraska, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

The Effect Of Structure On The Drag Force Of A Windbreak, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Windbreak Practices, James R. Brandle

School of Natural Resources: Faculty Publications

No abstract provided.

Oxygen Budget For Lake Ogallala, Kyle D. Hoagland, John C. Holz, Tadd M. Barrow, Richard J. Ruane

School of Natural Resources: Faculty Publications

Lake Ogallala, located below Kingsley Dam which impounds Lake McConaughy in Keith County, Nebraska, is a 260-surface hectare lake with an average depth of approximately eight meters. The lake provides mUltiple uses including a sport fishery and a hydropower and irrigation regulation basin. Since the installation of the hydroelectric generating plant in 1984 (Kingsley Dam was constructed in 1942) and the continued eutrophication of Lake McConaughy, dissolved oxygen concentrations have generally declined in Lake Ogallala. Hypolimnetic withdrawal from Lake McConaughy results in depressed oxygen levels in Lake Ogallala during the mid to latter part of the summer, particularly in certain …

Late Albian Kiowa-Skull Creek Marine Transgression, Lower Dakota Formation, Eastern Margin Of Western Interior Seaway, R.L. Brenner, G.A. Ludvigson, B.J. Witzke, A.N. Zawistoski, E.P. Kvale, R.L. Ravn, R.M. Joeckel

School of Natural Resources: Faculty Publications

No abstract provided.

Potential Production And Environmental Effects Of Switchgrass And Traditional Crops Under Current And Greenhouse-Altered Climate In The Central United States: A Simulation Study, R.A. Brown, N.J. Rosenberg, Cynthia J. Hays, W.E. Easterling, L.O. Mearns

School of Natural Resources: Faculty Publications

If, as many climate change analysts _ speculate, industrial and other emissions of CO₂ can be offset by substitution of biofuels, large areas of land, including agricultural land, may be converted to the production of biomass feedstocks. This paper explores the feasibility for the Missouri–Iowa–Nebraska–Kansas (MINK) region of the US of converting some agricultural land to the production of switchgrass (Panicum virgatum L.), a perennial warm season grass, as a biomass energy crop. The erosion productivity impact calculator (EPIC) crop growth model simulated production of corn (Zea mays L.), sorghum (Sorghum bicolor (L.) Moench), soybean ( …

Observed Climate Variability And Change Of Relevance To The Biosphere, David R. Easterling, Thomas R. Karl, Kevin P. Gallo, David A. Robinson, Kevin E. Trenberth, Aiguo Dai

School of Natural Resources: Faculty Publications

In this paper we review the current instrumental evidence regarding climate variations and change during the 20th century emphasizing those changes that are likely to have direct interactions with the biosphere.

The Spectral Contribution Of Carotenoids To Light Absorption And Reflectance In Green Leaves, Y. Zur, A. A. Gitelson, O. B. Chivkunova, M. N. Merzlyak

School of Natural Resources: Faculty Publications

Absorbance and reflectance spectra in the visible and near infrared range of the spectrum, acquired for maple (Acer platanoides L.) leaves were studied. Standard deviation of absorbance spectra showed that in yellow to green leaves, with chlorophyll content at least up to 30 nmol/cm2, there is a spectral feature at 520 nm attributable to carotenoids. Reflectance around 520 nm also correlates closely with carotenoids content in yellow to green leaves. Thus, this spectral feature at 520 nm could be used as a measure of carotenoids content in green leaves and plants.

Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell

School of Natural Resources: Faculty Publications

The Eastern Towhee (Pipilo erythrophthalmus) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the …

Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Gary D. Willson

School of Natural Resources: Faculty Publications

The purpose of this study is to improve our understanding of temperature and precipitation effects on the Palmer Drought Severity Index (PDSI). Both theoretical and observational analyses were applied to separate and compare temperature and precipitation effects on PDSI. The results showed that because of the dependence of PDSI on the ‘climatologically appropriate rainfall’, which is a function of time and varies with surface air temperature, the PDSI can be equally affected by temperature and precipitation, when both have similar magnitudes of anomalies. Calculations using observational data further illustrated the temperature influence on PDSI in different climate regions in the …

Remote Monitoring Of Selected Ground-Water Dominated Lakes In The Nebraska Sand Hills, David C. Gosselin, Donald C. Rundquist, Stuart K. Mcfeeters

School of Natural Resources: Faculty Publications

The Landsat-Multispectral Scanner (MSS) data were used to measure lake area fluctuations (1972-1989) for 130 groundwater dominated lakes in the Western Lakes Region of the Nebraska Sand Hills. In general, the pattern shown in lake area hydrographs was similar to that for in-situ lake elevations. In-situ lake-elevation data verify that remote monitoring of surface- area fluctuations, even at relatively coarse spatial resolution, is not only practical and useful, but also it elucidates the hydrologic characteristics of groundwater-dominated lakes of the Sand Hills. The apparent differences in behavior between lakes in the northern and southern portions of the study area may …

Process-Oriented Environmental Change Curriculum-Development Workshops, David C. Gosselin, Sherri Lowrey, Steven John Meyer

School of Natural Resources: Faculty Publications

To improve scientific literacy, K-12 educators need to: develop the ability to use and analyze data, incorporate data into their curriculum, and interact with teachers from other disciplines to create interdisciplinary units. A Process-Oriented Environmental Change Education workshop was conducted for eleven interdisciplinary teams, consisting of 21 teachers, in 1997 and 1998. The National Science Standards provided the criteria for the organization of the workshop. Inquiry and interpretation exercises helped to expand scientific knowledge and skills as well as the teachers’ use of technology. We explicitly discussed the uncertainty of science through group discussions and problem-solving activities. More than 85% …

Geochemical Evidence For An Eolian Sand Dam Across The North And South Platte Rivers In Nebraska, Daniel R. Muhs, James B. Swinehart, David B. Loope, Josh Been, Shannon A. Mahan, Charles A. Bush

School of Natural Resources: Faculty Publications

Geochemical and geomorphic data from dune fields in southwestern Nebraska provide new evidence that the Nebraska Sand Hills once migrated across the North and South Platte rivers and dammed the largest tributary system to the Missouri River. The Lincoln County and Imperial dune fields, which lie downwind of the South Platte River, have compositions intermediate between the Nebraska Sand Hills (quartz-rich) and northeastern Colorado dunes (K-feldspar-rich). The most likely explanation for the intermediate composition is that the Lincoln County and Imperial dunes are derived in part from the Nebraska Sand Hills and in part from the South Platte River. The …