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Articles 931 - 960 of 4541

Full-Text Articles in Earth Sciences

Paid To Pump: How A Tax Credit Could Discourage Conservation Of The High Plains Aquifer, S. Polzkill,, A. Stejskal, H. Wilke, Anna Wistrom, Katherine E. B. Gibson, Mindy J. Spiehs, Nicholas Brozovic Jan 2017

Paid To Pump: How A Tax Credit Could Discourage Conservation Of The High Plains Aquifer, S. Polzkill,, A. Stejskal, H. Wilke, Anna Wistrom, Katherine E. B. Gibson, Mindy J. Spiehs, Nicholas Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

In 1965’s United States v. Shurbet case, an irrigator from Texas asserted his claim for a depletion tax deduction for groundwater pumped from the High Plains Aquifer. He argued that the unique conditions of the southern High Plains region - a plateau where the shallow aquifer is recharged only through precipitation at a slow rate - meant the groundwater resource would be depleted in time. The state argued that groundwater was not fundamentally an exhaustible natural deposit, but the Supreme Court concluded the tax deduction was appropriate given the “peculiar” conditions in the area. It was stated the decision was …


Pathways To Increasing Farmer-Led Investments In Sustainable Agricultural Water Management In Sub-Saharan Africa, Douglas J. Merrey, Peter G. Mccornick, Molly C. Nance Jan 2017

Pathways To Increasing Farmer-Led Investments In Sustainable Agricultural Water Management In Sub-Saharan Africa, Douglas J. Merrey, Peter G. Mccornick, Molly C. Nance

Daugherty Water for Food Global Institute: Faculty Publications

Without a transformative leap forward in the use of irrigation, Africa will continue falling short in the struggle to feed its growing population, improve its people’s nutrition, grow its economies, adapt to the impacts of climate change, and eliminate poverty. While Africans must lead this transformation for it to be successful, the international community can help African countries substantially increase the use of more productive and sustainable water management practices and unlock the potential of farmer-led irrigated agriculture. Achieving highly productive irrigated agricultural systems in Africa requires an enabling environment that facilitates the full engagement of farmers, public and private …


Nebraska, Usa: Wonderful Fossils, Natural History Museums And Public Art Depicting Fossils, Robert F. Diffendal Jr. Jan 2017

Nebraska, Usa: Wonderful Fossils, Natural History Museums And Public Art Depicting Fossils, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nebraska is known by vertebrate palaeontologists as the place in North America where there is a very complete Cenozoic geologic record of mammalian evolution over the last thirty-five million years or so. All you have to do is visit any of the many major natural history museums in the USA and in many countries around the world, including the UK, to see fossil skulls, articulated skeletons and large slabs of rock containing bones of fossil mammals from Nebraska to verify this assertion. Nebraska is also the site of Cretaceous rocks containing the oldest known Cretaceous fossil flower and many other …


Mono Lake Data, Larry V. Benson Jan 2017

Mono Lake Data, Larry V. Benson

United States Geological Survey: Datasets

Mono Lake Basin Data\ Depth CalAge TIC TOTC TOC 13C 18O

Mono Lake short cores.xlsx 03.03.2014 19:59:44 0.06 xlsx

Depth PSV age 18O 13C

TIC for Wilson Crk Fm.xlsx 02.03.2014 16:07:10 0.03 xlsx

Ostracode 18O and TE data Wilson Crk Fm.xlsx 10.11.2017 17:43:18 0.12 xlsx

Depth, calendar age, TIC, TOTC, TOC, 13C, and 18O of Mono Lake short cores were reported in:

Benson, L., Linsley, B., Smoot, J., Mensing, S., Lund, S., Stine, S., and Sarna-Wojcicki, A., 2003, Influence of the Pacific Decadal Oscillation on the climate of the Sierra Nevada, California and Nevada: Quaternary Research. Quaternary Research …


Summer Lake Basin Data, Larry V. Benson Jan 2017

Summer Lake Basin Data, Larry V. Benson

United States Geological Survey: Datasets

Summer Lake Basin

Name Date modified Time modified Size MB Extension

Summer Lake Basin\

Depth PSV Age 13C 18O Summer Lake B&B core.xlsx 03.03.2014 16:51:12 0.03 xlsx

In the Summer Lake Basin folder:

Depth, PSV age, 18O, 13C data for Summer Lake core B&B are reported in:

Benson, L., Lund, S., Negrini, R., Linsley, B., and Zic, M. 2003. Response of North American Great Basin lakes to Dansgaard-Oeschger oscillations. Quaternary Science Reviews 22: 2,239-2,251.

General Comment: In most cases an age model based on 14C analyses is not included with the datasets although ones were created for …


Greater Sage-Grouse Population Trends Across Wyoming, David R. Edmunds, Cameron L. Aldridge, Michael S. O'Donnell, Adrian P. Monroe Jan 2017

Greater Sage-Grouse Population Trends Across Wyoming, David R. Edmunds, Cameron L. Aldridge, Michael S. O'Donnell, Adrian P. Monroe

United States Geological Survey: Staff Publications

The scale at which analyses are performed can have an effect on model results and often one scale does not accurately describe the ecological phenomena of interest (e.g., population trends) for wide-ranging species: yet, most ecological studies are performed at a single, arbitrary scale. To best determine local and regional trends for greater sage-grouse (Centrocercus urophasianus) in Wyoming, USA, we modeled density-independent and -dependent population growth across multiple spatial scales relevant to management and conservation (Core Areas [habitat encompassing approximately 83% of the sage-grouse population on ~24% of surface area in Wyoming], local Working Groups [7 regional areas for …


A Photosynthesis-Based Two-Leaf Canopy Stomatal Conductance Model For Meteorology And Air Quality Modeling With Wrf/Cmaq Px Lsm, Limei Ran, Jonathan Pleim, Conghe Song, Larry Band, John T. Walker, Francis S. Binkowski Jan 2017

A Photosynthesis-Based Two-Leaf Canopy Stomatal Conductance Model For Meteorology And Air Quality Modeling With Wrf/Cmaq Px Lsm, Limei Ran, Jonathan Pleim, Conghe Song, Larry Band, John T. Walker, Francis S. Binkowski

United States Environmental Protection Agency: Publications

A coupled photosynthesis-stomatal conductance model with single-layer sunlit and shaded leaf canopy scaling is implemented and evaluated in a diagnostic box model with the Pleim-Xiu land surface model (PX LSM) and ozone deposition model components taken directly from the meteorology and air quality modeling system—WRF/CMAQ (Weather Research and Forecast model and Community Multiscale Air Quality model). The photosynthesis-based model for PX LSM (PX PSN) is evaluated at a FLUXNET site for implementation against different parameterizations and the current PX LSM approach with a simple Jarvis function (PX Jarvis). Latent heat flux (LH) from PX PSN is further evaluated at five …


Why Do Different Drought Indices Show Distinct Future Drought Risk Outcomes In The U.S. Great Plains?, Song Feng, Miroslav Trnka, Michael Hayes, Yongjun Zheng Jan 2017

Why Do Different Drought Indices Show Distinct Future Drought Risk Outcomes In The U.S. Great Plains?, Song Feng, Miroslav Trnka, Michael Hayes, Yongjun Zheng

National Drought Mitigation Center: Faculty Publications

Vigorous discussions and disagreements about the future changes in drought intensity in the U.S. Great Plains have been taking place recently within the literature. These discussions have involved widely varying estimates based on drought indices and model-based projections of the future. To investigate and understand the causes for such a disparity between these previous estimates, the authors analyzed the soil moisture at the near-surface soil layer and the entire soil column, as well as the Palmer drought severity index, the Palmer Z index, and the standardized precipitation and evaporation index using the output from the Community Climate System Model, version …


Upper Blue Nile Basin Water Budget From A Multi-Model Perspective, Hahn Chul Jung, Augusto Getirana, Frederick Policelli, Amy Mcnally, Kristi R. Arsenault, Sujay Kumar, Tsegaye Tadesse, Christa D. Peters-Lidard Jan 2017

Upper Blue Nile Basin Water Budget From A Multi-Model Perspective, Hahn Chul Jung, Augusto Getirana, Frederick Policelli, Amy Mcnally, Kristi R. Arsenault, Sujay Kumar, Tsegaye Tadesse, Christa D. Peters-Lidard

National Drought Mitigation Center: Faculty Publications

Improved understanding of the water balance in the Blue Nile is of critical importance because of increasingly frequent hydroclimatic extremes under a changing climate. The intercomparison and evaluation of multiple land surface models (LSMs) associated with different meteorological forcing and precipitation datasets can offer a moderate range of water budget variable estimates. In this context, two LSMs, Noah version 3.3 (Noah3.3) and Catchment LSM version Fortuna 2.5 (CLSMF2.5) coupled with the Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme are used to produce hydrological estimates over the region. The two LSMs were forced with different combinations of two reanalysis-based …


Climate Change And Population Growth Impacts On Surface Water Supply And Demand Of Addis Ababa, Ethiopia, Bisrat Kifle Arsiso, Gizaw Mengistu Tsidu, Gerrit Hendrik Stoffberg, Tsegaye Tadesse Jan 2017

Climate Change And Population Growth Impacts On Surface Water Supply And Demand Of Addis Ababa, Ethiopia, Bisrat Kifle Arsiso, Gizaw Mengistu Tsidu, Gerrit Hendrik Stoffberg, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

Addis Ababa is expected to experience water supply stress as a result of complex interaction of urbanization and climate change. The aim of this study is to investigate water demand and supply prospects for the City of Addis Ababa by applying the Water Evaluation and Planning (WEAP) hydrological model and using scenarios of population growth trends and climate change. The study includes analysis of water consumption, hydrological information and climate data which is statistically downscaled using approach used to generate climate data available at the Worldclim data center. Bias corrected climate model data of NIMR-HadGEM2-AO under a midrange RCP 4.5 …


Agricultural Trade Publications And The 2012 Midwestern U.S. Drought: A Missed Opportunity For Climate Risk Communication, Sarah P. Church, Tonya Haigh, Melissa Widhalm, Silvestre Garcia De Jalon, Nicholas Babin, J. Stuart Carlton, Michael Dunn, Katie Fagan, Cody L. Knutson, Linda Stalker Prokopy Jan 2017

Agricultural Trade Publications And The 2012 Midwestern U.S. Drought: A Missed Opportunity For Climate Risk Communication, Sarah P. Church, Tonya Haigh, Melissa Widhalm, Silvestre Garcia De Jalon, Nicholas Babin, J. Stuart Carlton, Michael Dunn, Katie Fagan, Cody L. Knutson, Linda Stalker Prokopy

National Drought Mitigation Center: Faculty Publications

The Midwestern United States experienced a devastating drought in 2012, leading to reduced corn and soybean yields and increased instances of pests and disease. Climate change induced weather variability and extremes are expected to increase in the future, and have and will continue to impact the agricultural sector. This study investigated how agricultural trade publications portrayed the 2012 U.S. Midwestern drought, whether climate change was associated with drought, and whether these publications laid out transformative adaptation measures farmers could undertake in order to increase their adaptive capacity for future climate uncertainty. We performed a content analysis of 1000 media reports …


Information Mining From Heterogeneous Data Sources: A Case Study On Drought Predictions, Getachew B. Demisse, Tsegaye Tadesse, Solomon Atnafu, Shawndra Hill, Brian D. Wardlow, Yared Bayissa, Andualem Shiferaw Jan 2017

Information Mining From Heterogeneous Data Sources: A Case Study On Drought Predictions, Getachew B. Demisse, Tsegaye Tadesse, Solomon Atnafu, Shawndra Hill, Brian D. Wardlow, Yared Bayissa, Andualem Shiferaw

National Drought Mitigation Center: Faculty Publications

The objective of this study was to develop information mining methodology for drought modeling and predictions using historical records of climate, satellite, environmental, and oceanic data. The classification and regression tree (CART) approach was used for extracting drought episodes at different time-lag prediction intervals. Using the CART approach, a number of successful model trees were constructed, which can easily be interpreted and used by decision makers in their drought management decisions. The regression rules produced by CART were found to have correlation coefficients from 0.71–0.95 in rules-alone modeling. The accuracies of the models were found to be higher in the …


Socio-Environmental Drought Response In A Mixed Urban-Agricultural Setting: Synthesizing Biophysical And Governance Responses In The Platte River Watershed, Nebraska, Usa, Samuel C. Zipper, Kelly Helm Smith, Betsy Breyer, Jianxiao Qui, Anthony Kung, Dustin Herrmann Jan 2017

Socio-Environmental Drought Response In A Mixed Urban-Agricultural Setting: Synthesizing Biophysical And Governance Responses In The Platte River Watershed, Nebraska, Usa, Samuel C. Zipper, Kelly Helm Smith, Betsy Breyer, Jianxiao Qui, Anthony Kung, Dustin Herrmann

National Drought Mitigation Center: Faculty Publications

Ensuring global food and water security requires a detailed understanding of how coupled socio-environmental systems respond to drought. Using the Platte River Watershed in Nebraska (USA) as an exemplar mixed urban-agricultural watershed, we quantify biophysical response to drought in urban (Lincoln NE) and agricultural systems alongside a qualitative analysis of governance response and adaptive capacity of both sectors. Synthesis of results highlights parallels and discontinuities between urban and agricultural preparations for and response to drought. Whereas drought prompted an increase in well installations and expansion of water-intensive crops, e.g., corn, in the agricultural sector, outdoor water use restrictions rapidly curtailed …


Cocorahs Observers Contribute To “Condition Monitoring” In The Carolinas: A New Initiative Addresses Needs For Drought Impacts Information, Kirsten Lackstrom, Amanda Farris, David Eckhardt, Nolan Doesken, Henry Reges, Julian Turner, Kelly Helm Smith, Rebecca Ward Jan 2017

Cocorahs Observers Contribute To “Condition Monitoring” In The Carolinas: A New Initiative Addresses Needs For Drought Impacts Information, Kirsten Lackstrom, Amanda Farris, David Eckhardt, Nolan Doesken, Henry Reges, Julian Turner, Kelly Helm Smith, Rebecca Ward

National Drought Mitigation Center: Faculty Publications

No abstract provided.


Great Basin Surface Water And Precipitation Isotope Data, Larry V. Benson Jan 2017

Great Basin Surface Water And Precipitation Isotope Data, Larry V. Benson

United States Geological Survey: Datasets

In the Great Basin Surface Water and Precipitation Isotope Data folder:

Farad, Nixon, and Pyramid Lake 18O data were reported in:

Benson, L.V., 1994, Stable isotopes of oxygen and hydrogen in the Truckee River-Pyramid Lake surface-water system. 1. Data analysis and extraction of paleoclimatic information: Limnology and Oceanography, vol. 39, p. 344-355. https://digitalcommons.unl.edu/usgsstaffpub/1015

Spring chemistry around Pyramid Lake data were reported in:

Benson, L.V., 1994, Carbonate deposition, Pyramid Lake subbasin, Nevada: 1. Sequence of formation and elevational distribution of carbonate deposits (tufas): Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 109, p. 55-87.

Benson, L.V., Kashgarian M., and Rubin, M., 1995, Carbonate deposition, …


High Plains Regional Climate Center (Poster) Jan 2017

High Plains Regional Climate Center (Poster)

High Plains Regional Climate Center: Staff Publications

The HPRCC provides the public with several ways to access climate data and information. Whether via direct contact, website access, or through a subscription to one of HPRCC’s online services, users can acquire a variety of climate data products, such as: • Near Real-Time and Historical Climate Data • National and Regional Climate Data Maps • Agricultural Climate Products • Monthly, Quarterly, and Annual Regional Climate Summaries


Statistical Survey Of Persistent Organic Pollutants: Risk Estimations To Humans And Wildlife Through Consumption Of Fish From U.S. Rivers, Angela L. Batt, John B. Wathen, James M. Lazorchak, Anthony R. Olsen, Thomas M. Kincaid Jan 2017

Statistical Survey Of Persistent Organic Pollutants: Risk Estimations To Humans And Wildlife Through Consumption Of Fish From U.S. Rivers, Angela L. Batt, John B. Wathen, James M. Lazorchak, Anthony R. Olsen, Thomas M. Kincaid

United States Environmental Protection Agency: Publications

U.S. EPA conducted a national statistical survey of fish tissue contamination at 540 river sites (representing 82 954 river km) in 2008−2009, and analyzed samples for 50 persistent organic pollutants (POPs), including 21 PCB congeners, 8 PBDE congeners, and 21 organochlorine pesticides. The survey results were used to provide national estimates of contamination for these POPs. PCBs were the most abundant, being measured in 93.5% of samples. Summed concentrations of the 21 PCB congeners had a national weighted mean of 32.7 μg/kg and a maximum concentration of 857 μg/kg, and exceeded the human health cancer screening value of 12 μg/kg …


Taphonomic Problems In Reconstructing Sea-Level History From The Late Quaternary Marine Terraces Of Barbados, Daniel R. Muhs, Kathleen R. Simmons Jan 2017

Taphonomic Problems In Reconstructing Sea-Level History From The Late Quaternary Marine Terraces Of Barbados, Daniel R. Muhs, Kathleen R. Simmons

United States Geological Survey: Staff Publications

Although uranium series (U-series) ages of growth-position fossil corals are important to Quaternary sea-level history, coral clast reworking from storms can yield ages on a terrace dating to more than one high-sea stand, confounding interpretations of sea-level history. On northern Barbados, U-series ages corals from a thick storm deposit are not always younger with successively higher stratigraphic positions, but all date to the last interglacial period (~127 ka to ~112 ka), Marine Isotope Substage (MIS) 5.5. The storm deposit ages are consistent with the ages of growth-position corals found at the base of the section and at landward localities on …


Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Hannah Birge, Daniel A. Decaro, Alexander K. Fremier, Alexander K. Fremier, Hannah Gosnell, Edella C. Schlager Jan 2017

Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Hannah Birge, Daniel A. Decaro, Alexander K. Fremier, Alexander K. Fremier, Hannah Gosnell, Edella C. Schlager

United States Geological Survey: Staff Publications

Adaptive governance must work “on the ground,” that is, it must operate through structures and procedures that the people it governs perceive to be legitimate and fair, as well as incorporating processes and substantive goals that are effective in allowing social-ecological systems (SESs) to adapt to climate change and other impacts. To address the continuing and accelerating alterations that climate change is bringing to SESs, adaptive governance generally will require more flexibility than prior governance institutions have often allowed. However, to function as good governance, adaptive governance must pay real attention to the problem of how to balance this increased …


Smartphone Technologies And Bayesian Networks To Assess Shorebird Habitat Selection, Sara L. Zeigler, E. Robert Thieler, Benjamin T. Gutierrez, Nathaniel G. Plant, Megan Hines, James D. Fraser, Daniel H. Catlin Jan 2017

Smartphone Technologies And Bayesian Networks To Assess Shorebird Habitat Selection, Sara L. Zeigler, E. Robert Thieler, Benjamin T. Gutierrez, Nathaniel G. Plant, Megan Hines, James D. Fraser, Daniel H. Catlin

United States Geological Survey: Staff Publications

Understanding patterns of habitat selection across a species’ geographic distribution can be critical for adequately managing populations and planning for habitat loss and related threats. However, studies of habitat selection can be time consuming and expensive over broad spatial scales, and a lack of standardized monitoring targets or methods can impede the generalization of site-based studies. Our objective was to collaborate with natural resource managers to define available nesting habitat for piping plovers (Charadrius melodus) throughout their U.S. Atlantic coast distribution from Maine to North Carolina, with a goal of providing science that could inform habitat management in …


Camera System Considerations For Geomorphic Applications Of Sfm Photogrammetry, Adam R. Mosbrucker, Jon J. Major, Kurt R. Spicer, John Pitlick Jan 2017

Camera System Considerations For Geomorphic Applications Of Sfm Photogrammetry, Adam R. Mosbrucker, Jon J. Major, Kurt R. Spicer, John Pitlick

United States Geological Survey: Staff Publications

The availability of high-resolution, multi-temporal, remotely sensed topographic data is revolutionizing geomorphic analysis. Three-dimensional topographic point measurements acquired from structure-from-motion (SfM) photogrammetry have been shown to be highly accurate and cost-effective compared to laser-based alternatives in some environments. Use of consumer-grade digital cameras to generate terrain models and derivatives is becoming prevalent within the geomorphic community despite the details of these instruments being largely overlooked in current SfM literature.

A practical discussion of camera system selection, configuration, and image acquisition is presented. The hypothesis that optimizing source imagery can increase digital terrain model (DTM) accuracy is tested by evaluating accuracies …


Channel-Planform Evolution In Four Rivers Of Olympic National Park, Washington, Usa: The Roles Of Physical Drivers And Trophic Cascades, Amy E. East, Kurt J. Jenkins, Patricia J. Happe, Jennifer A. Bountry, Timothy J. Beechie, Mark C. Mastin, Joel B. Sankey, Timothy J. Randle Jan 2017

Channel-Planform Evolution In Four Rivers Of Olympic National Park, Washington, Usa: The Roles Of Physical Drivers And Trophic Cascades, Amy E. East, Kurt J. Jenkins, Patricia J. Happe, Jennifer A. Bountry, Timothy J. Beechie, Mark C. Mastin, Joel B. Sankey, Timothy J. Randle

United States Geological Survey: Staff Publications

Identifying the relative contributions of physical and ecological processes to channel evolution remains a substantial challenge in fluvial geomorphology. We use a 74-year aerial photographic record of the Hoh, Queets, Quinault, and Elwha Rivers, Olympic National Park, Washington, USA, to investigate whether physical or trophic-cascade-driven ecological factors – excessive elk impacts after wolves were extirpated a century ago – are the dominant drivers of channel planform in these gravel-bed rivers.We find that channel width and braiding show strong relationships with recent flood history. All four rivers widened significantly after having been relatively narrow in the 1970s, consistent with increased flood …


Semi-Arid Grassland Bird Responses To Patch-Burn Grazing And Drought, Susan K. Skagen, David J. Augustine, Justin D. Derner Jan 2017

Semi-Arid Grassland Bird Responses To Patch-Burn Grazing And Drought, Susan K. Skagen, David J. Augustine, Justin D. Derner

United States Geological Survey: Staff Publications

As grassland birds of central North America experience steep population declines with changes in land use, management of remaining tracts becomes increasingly important for population viability. The integrated use of fire and grazing may enhance vegetation heterogeneity and diversity in breeding birds, but the subsequent effects on reproduction are unknown. We examined the influence of patch-burn grazing management in shortgrass steppe in eastern Colorado on habitat use and reproductive success of 3 grassland bird species, horned lark (Eremophila alpestris), lark bunting (Calamospiza melanocorys), and McCown’s longspur (Rhynchophanes mccownii), at several spatial scales during 2011 …


Effects Of Industrial And Investigator Disturbance On Arctic-Nesting Geese, Brandt W. Meixell, Paul L. Flint Jan 2017

Effects Of Industrial And Investigator Disturbance On Arctic-Nesting Geese, Brandt W. Meixell, Paul L. Flint

United States Geological Survey: Staff Publications

Oil and gas development on the Arctic Coastal Plain (ACP) of Alaska, USA may have effects on Arctic-nesting birds. To estimate effects of industrial activity and investigator disturbance on avian productivity, we monitored nests of greater white-fronted geese (Anser albifrons) with digital cameras and periodic nest visits during 2013–2014 at 2 sites on the ACP. A disturbed site was adjacent to human-made infrastructure and industrial clean-up activities initiated at the onset of the study and a control site was >2 km from sources of industrial disturbance. We assessed variation in estimates of incubation constancy, nest survival, and predator …


Simulating The Effects Of Management Practices On Cropland Soilorganic Carbon Changes In The Temperate Prairies Ecoregion Of Theunited States From 1980 To 2012, Zhengpeng Li, Shuguang Liu, Zhengxi Tan, Terry L. Sohl, Yiping Wu Jan 2017

Simulating The Effects Of Management Practices On Cropland Soilorganic Carbon Changes In The Temperate Prairies Ecoregion Of Theunited States From 1980 To 2012, Zhengpeng Li, Shuguang Liu, Zhengxi Tan, Terry L. Sohl, Yiping Wu

United States Geological Survey: Staff Publications

Understanding the effects of management practices on soil organic carbon (SOC) is important for design-ing effective policies to mitigate greenhouse gas emissions in agriculture. In the Midwest United States,management practices in the croplands have been improved to increase crop production and reduce SOCloss since the 1980s. Many studies of SOC dynamics in croplands have been performed to understandthe effects of management, but the results are still not conclusive. This study quantified SOC dynam-ics in the Midwest croplands from 1980 to 2012 with the General Ensemble Biogeochemical ModellingSystem (GEMS) and available management data. Our results showed that the total SOC in …


The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- January 2017, Natalie Umphlett, Jamie Lahowetz, Bill Sorensen, Crystal J. Stiles Jan 2017

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- January 2017, Natalie Umphlett, Jamie Lahowetz, Bill Sorensen, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the interim director........................................1

30th anniversary......................1

Stakeholder engagement activities......................................2

Product highlights..................3

AWDN information.................4

Update on regional climate conditions..................................4

Services update........................5

Recent and upcoming travel and activities.............................6


Local To Global: Developing Solutions And Creating Impacts. Annual Report Fy 2017, Robert B. Daugherty Water For Food Global Institute Jan 2017

Local To Global: Developing Solutions And Creating Impacts. Annual Report Fy 2017, Robert B. Daugherty Water For Food Global Institute

Daugherty Water for Food Global Institute: Administrative Materials

FOREWORD - Hank M. Bounds, President, University of Nebraska

PREFACE - Peter G. McCornick, Executive Director

Focus Areas: Where we are headed We are committed to helping the world efficiently use its limited freshwater resources to ensure food security for current and future generations. The diversity of projects and activities in this report reflects the complexity of the challenges we face in achieving this goal through technical and policy research, education and communication. Our research and policy development efforts are focused within five areas to maximize the expertise of DWFI staff, our colleagues at the National Drought Mitigation Center (NDMC) …


Weathering And Erosion Of Fractured Bedrock Systems, Marina I. Lebedeva, Susan L. Brantley Jan 2017

Weathering And Erosion Of Fractured Bedrock Systems, Marina I. Lebedeva, Susan L. Brantley

United States Geological Survey: Staff Publications

We explore the contribution of fractures (joints) in controlling the rate of weathering advance for a low-porosity rock by using methods of homogenization to create averaged weathering equations. The rate of advance of the weathering front can be expressed as the same rate observed in non-fractured media (or in an individual block) divided by the volume fraction of nonfractured blocks in the fractured parent material. In the model, the parent has fractures that are filled with a more porous material that contains only inert or completely weathered material. The low-porosity rock weathers by reaction-transport processes. As observed in field systems, …


Dynamics Of Cloud-Top Generating Cells In Winter Cyclones. Part Iii: Shear And Convective Organization, Jason M. Keeler, Robert M. Rauber, Brian F. Jewett, Greg M. Mcfarquhar, Roy M. Rasmussen, Lulin Xue, Changhai Liu, Gregory Thompson Jan 2017

Dynamics Of Cloud-Top Generating Cells In Winter Cyclones. Part Iii: Shear And Convective Organization, Jason M. Keeler, Robert M. Rauber, Brian F. Jewett, Greg M. Mcfarquhar, Roy M. Rasmussen, Lulin Xue, Changhai Liu, Gregory Thompson

Department of Earth and Atmospheric Sciences: Faculty Publications

Cloud-top generating cells (GCs) are a common feature atop stratiform clouds within the comma head of winter cyclones. The dynamics of cloud-top GCs are investigated using very high-resolution idealized WRF Model simulations to examine the role of shear in modulating the structure and intensity of GCs. Simulations were run for the same combinations of radiative forcing and instability as in Part II of this series, but with six different shear profiles ranging from 0 to 10ms21 km21 within the layer encompassing the GCs.

The primary role of shear was to modulate the organization of GCs, which organized as closed convective …


Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko Jan 2017

Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this study was to explore the relationships between stand-level photochemical reflectance index (PRI) and canopy structure/ pigment pools, as well as light use efficiency (LUE) of photosynthetically active vegetation focusing on seasonal or ontogenetic time frames. PRI was originally designed as a means of assessing the xanthophyll cycle and LUE over short (e.g. diurnal) time frames, and few studies have explored the drivers of PRI over longer, seasonal time frames, particularly in crops having different photosynthetic pathways or canopy structures. Consequently, our purpose was to understand and quantify the drivers of PRI responses over seasonal time scales …