Mobilization of natural nitrate (NO3-) deposits in the subsoil by irrigation water in arid and semiarid regions has the potential to produce large groundwater NO3- concentrations. The use of isotopes to distinguish between natural and anthropogenic NO3- sources in these settings could be complicated by the wide range in δ15N values of natural NO3-. An ∼10 000 year record of paleorecharge from the regionally extensive High Plains aquifer indicates that δ15N values for NO3- derived from natural sources ranged from 1.3 to 12.3‰ and increased systematically from the northern to the southern High Plains. This collective range in δ15N values spans the range that might be interpreted as evidence for fertilizer and animal-waste sources of NO3-; however, the δ15N values for NO3- in modern recharge ( less than 50 years) under irrigated fields were, for the most part, distinctly different from those of paleorecharge when viewed in the overall regional context. An inverse relation was observed between the δ15N[NO3-] values and the NO3-/Cl- ratios in paleorecharge that is qualitatively consistent with fractionating losses of N increasing from north to south in the High Plains. N and O isotope data for NO3- are consistent with both NH3 volatilization and denitrification, having contributed to fractionating losses of N prior to recharge. The relative importance of different isotope fractionating processes may be influenced by regional climate patterns as well as by local variation in soils, vegetation, topography, and moisture conditions.
","language":"English","publisher":"ACS Publications","doi":"10.1021/es052229q","issn":"0013936X","usgsCitation":"McMahon, P., and Böhlke, J., 2006, Regional patterns in the isotopic composition of natural and anthropogenic nitrate in groundwater, High Plains, U.S.A.: Environmental Science & Technology, v. 40, no. 9, p. 2965-2970, https://doi.org/10.1021/es052229q.","productDescription":"6 p.","startPage":"2965","endPage":"2970","numberOfPages":"6","costCenters":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"links":[{"id":239521,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212099,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es052229q"}],"volume":"40","issue":"9","noUsgsAuthors":false,"publicationDate":"2006-03-31","publicationStatus":"PW","scienceBaseUri":"50e4a541e4b0e8fec6cdbdbf","contributors":{"authors":[{"text":"McMahon, P.B. 0000-0001-7452-2379","orcid":"https://orcid.org/0000-0001-7452-2379","contributorId":10762,"corporation":false,"usgs":true,"family":"McMahon","given":"P.B.","affiliations":[],"preferred":false,"id":427265,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Böhlke, J.K. 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":96696,"corporation":false,"usgs":true,"family":"Böhlke","given":"J.K.","affiliations":[],"preferred":false,"id":427266,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030471,"text":"70030471 - 2006 - Geophysical monitoring of a field-scale biostimulation pilot project","interactions":[],"lastModifiedDate":"2019-10-17T07:07:05","indexId":"70030471","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"Geophysical monitoring of a field-scale biostimulation pilot project","docAbstract":"The USGS conducted a geophysical investigation in support of a U.S. Naval Facilities Engineering Command, Southern Division field‐scale biostimulation pilot project at Anoka County Riverfront Park (ACP), downgradient of the Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota. The goal of the pilot project is to evaluate subsurface injection of vegetable oil emulsion (VOE) to stimulate microbial degradation of chlorinated hydrocarbons. To monitor the emplacement and movement of the VOE and changes in water chemistry resulting from VOE dissolution and/or enhanced biological activity, the USGS acquired cross‐hole radar zero‐offset profiles, traveltime tomograms, and borehole geophysical logs during five site visits over 1.5 years. Analysis of pre‐ and postinjection data sets using petrophysical models developed to estimate VOE saturation and changes in total dissolved solids provides insights into the spatial and temporal distribution of VOE and ground water with altered chemistry. Radar slowness‐difference tomograms and zero‐offset slowness profiles indicate that the VOE remained close to the injection wells, whereas radar attenuation profiles and electromagnetic induction logs indicate that bulk electrical conductivity increased downgradient of the injection zone, diagnostic of changing water chemistry. Geophysical logs indicate that some screened intervals were located above or below zones of elevated dissolved solids; hence, the geophysical data provide a broader context for interpretation of water samples and evaluation of the biostimulation effort. Our results include (1) demonstration of field and data analysis methods for geophysical monitoring of VOE biostimulation and (2) site‐specific insights into the spatial and temporal distributions of VOE at the ACP.
Long-term exposure to elevated nitrate levels in community drinking water supplies has been associated with an elevated risk of several cancers including non-Hodgkin's lymphoma, colon cancer, and bladder cancer. To estimate human exposure to nitrate, specific crop type information is needed as fertilizer application rates vary widely by crop type. Corn requires the highest application of nitrogen fertilizer of crops grown in the Midwest US. We developed a method to refine the US Geological Survey National Land Cover Dataset (NLCD) (including map and original Landsat images) to distinguish corn from other crops. Overall average agreement between the resulting corn and other row crops class and ground reference data was 0.79 kappa coefficient with individual Landsat images ranging from 0.46 to 0.93 kappa. The highest accuracies occurred in Regions where corn was the single dominant crop (greater than 80.0%) and the crop vegetation conditions at the time of image acquisition were optimum for separation of corn from all other crops. Factors that resulted in lower accuracies included the accuracy of the NLCD map, accuracy of corn areal estimates, crop mixture, crop condition at the time of Landsat overpass, and Landsat scene anomalies.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.compag.2005.11.003","issn":"01681699","usgsCitation":"Maxwell, S., Nuckols, J., and Ward, M., 2006, A method for mapping corn using the US Geological Survey 1992 National Land Cover Dataset: Computers and Electronics in Agriculture, v. 51, no. 1-2, p. 54-65, https://doi.org/10.1016/j.compag.2005.11.003.","productDescription":"12 p.","startPage":"54","endPage":"65","numberOfPages":"12","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":239100,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211750,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.compag.2005.11.003"}],"volume":"51","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e455e4b0c8380cd465b4","contributors":{"authors":[{"text":"Maxwell, S.K.","contributorId":36665,"corporation":false,"usgs":true,"family":"Maxwell","given":"S.K.","email":"","affiliations":[],"preferred":false,"id":427166,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nuckols, J.R.","contributorId":85385,"corporation":false,"usgs":true,"family":"Nuckols","given":"J.R.","affiliations":[],"preferred":false,"id":427167,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ward, M.H.","contributorId":35939,"corporation":false,"usgs":true,"family":"Ward","given":"M.H.","email":"","affiliations":[],"preferred":false,"id":427165,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030440,"text":"70030440 - 2006 - Response of surface water chemistry to reduced levels of acid precipitation: Comparison of trends in two regions of New York, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:03","indexId":"70030440","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Response of surface water chemistry to reduced levels of acid precipitation: Comparison of trends in two regions of New York, USA","docAbstract":"In light of recent reductions in sulphur (S) and nitrogen (N) emissions mandated by Title IV of the Clean Air Act Amendments of 1990, temporal trends and trend coherence in precipitation (1984-2001 and 1992-2001) and surface water chemistry (1992-2001) were determined in two of the most acid-sensitive regions of North America, i.e. the Catskill and Adirondack Mountains of New York. Precipitation chemistry data from six sites located near these regions showed decreasing sulphate (SO42-), nitrate (NO3-), and base cation (CB) concentrations and increasing pH during 1984-2001, but few significant trends during 1992-2001. Data from five Catskill streams and 12 Adirondack lakes showed decreasing trends in SO42- concentrations at all sites, and decreasing trends in NO3-, CB, and H+ concentrations and increasing trends in dissolved organic carbon at most sites. In contrast, acid-neutralizing capacity (ANC increased significantly at only about half the Adirondack lakes and in one of the Catskill streams. Flow correction prior to trend analysis did not change any trend directions and had little effect on SO42- trends, but it caused several significant non-flow-corrected trends in NO3- and ANC to become non-significant, suggesting that trend results for flow-sensitive constituents are affected by flow-related climate variation. SO42- concentrations showed high temporal coherence in precipitation, surface waters, and in precipitation-surface water comparisons, reflecting a strong link between S emissions, precipitation SO42- concentrations, and the processes that affect S cycling within these regions. NO3- and H+ concentrations and ANC generally showed weak coherence, especially in surface waters and in precipitation-surface water comparisons, indicating that variation in local-scale processes driven by factors such as climate are affecting trends in acid-base chemistry in these two regions. Copyright ?? 2005 John Wiley & Sons, Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrological Processes","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1002/hyp.5961","issn":"08856087","usgsCitation":"Burns, D.A., McHale, M., Driscoll, C.T., and Roy, K.M., 2006, Response of surface water chemistry to reduced levels of acid precipitation: Comparison of trends in two regions of New York, USA: Hydrological Processes, v. 20, no. 7, p. 1611-1627, https://doi.org/10.1002/hyp.5961.","startPage":"1611","endPage":"1627","numberOfPages":"17","costCenters":[],"links":[{"id":211722,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.5961"},{"id":239066,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"20","issue":"7","noUsgsAuthors":false,"publicationDate":"2005-12-23","publicationStatus":"PW","scienceBaseUri":"505aaa6ee4b0c8380cd86322","contributors":{"authors":[{"text":"Burns, Douglas A. 0000-0001-6516-2869","orcid":"https://orcid.org/0000-0001-6516-2869","contributorId":29450,"corporation":false,"usgs":true,"family":"Burns","given":"Douglas","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":427159,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McHale, M.R.","contributorId":66442,"corporation":false,"usgs":true,"family":"McHale","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":427162,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Driscoll, C. T.","contributorId":47530,"corporation":false,"usgs":false,"family":"Driscoll","given":"C.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":427160,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Roy, K. M.","contributorId":52710,"corporation":false,"usgs":false,"family":"Roy","given":"K.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":427161,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70030435,"text":"70030435 - 2006 - Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates","interactions":[],"lastModifiedDate":"2012-03-12T17:21:12","indexId":"70030435","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2316,"text":"Journal of Geophysical Research D: Atmospheres","active":true,"publicationSubtype":{"id":10}},"title":"Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates","docAbstract":"Desert dust simulations generated by the National Center for Atmospheric Research's Community Climate System Model for the current climate are shown to be consistent with present day satellite and deposition data. The response of the dust cycle to last glacial maximum, preindustrial, modern, and doubled-carbon dioxide climates is analyzed. Only natural (non-land use related) dust sources are included in this simulation. Similar to some previous studies, dust production mainly responds to changes in the source areas from vegetation changes, not from winds or soil moisture changes alone. This model simulates a +92%, +33%, and -60% change in dust loading for the last glacial maximum, preindustrial, and doubled-carbon dioxide climate, respectively, when impacts of carbon dioxide fertilization on vegetation are included in the model. Terrestrial sediment records from the last glacial maximum compiled here indicate a large underestimate of deposition in continental regions, probably due to the lack of simulation of glaciogenic dust sources. In order to include the glaciogenic dust sources as a first approximation, we designate the location of these sources, and infer the size of the sources using an inversion method that best matches the available data. The inclusion of these inferred glaciogenic dust sources increases our dust flux in the last glacial maximum from 2.1 to 3.3 times current deposition. Copyright 2006 by the American Geophysical Union.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research D: Atmospheres","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/2005JD006653","issn":"01480227","usgsCitation":"Mahowald, N., Muhs, D., Levis, S., Rasch, P., Yoshioka, M., Zender, C., and Luo, C., 2006, Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates: Journal of Geophysical Research D: Atmospheres, v. 111, no. 10, https://doi.org/10.1029/2005JD006653.","costCenters":[],"links":[{"id":477488,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://escholarship.org/uc/item/8q3815jn","text":"Publisher Index Page"},{"id":212126,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2005JD006653"},{"id":239552,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"111","issue":"10","noUsgsAuthors":false,"publicationDate":"2006-05-31","publicationStatus":"PW","scienceBaseUri":"5059f400e4b0c8380cd4ba9a","contributors":{"authors":[{"text":"Mahowald, N. M.","contributorId":22964,"corporation":false,"usgs":false,"family":"Mahowald","given":"N. M.","affiliations":[],"preferred":false,"id":427142,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Muhs, D.R. 0000-0001-7449-251X","orcid":"https://orcid.org/0000-0001-7449-251X","contributorId":61460,"corporation":false,"usgs":true,"family":"Muhs","given":"D.R.","affiliations":[],"preferred":false,"id":427147,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Levis, S.","contributorId":24172,"corporation":false,"usgs":true,"family":"Levis","given":"S.","email":"","affiliations":[],"preferred":false,"id":427143,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Rasch, P.J.","contributorId":33919,"corporation":false,"usgs":true,"family":"Rasch","given":"P.J.","email":"","affiliations":[],"preferred":false,"id":427145,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Yoshioka, M.","contributorId":22579,"corporation":false,"usgs":true,"family":"Yoshioka","given":"M.","email":"","affiliations":[],"preferred":false,"id":427141,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Zender, C.S.","contributorId":30443,"corporation":false,"usgs":true,"family":"Zender","given":"C.S.","email":"","affiliations":[],"preferred":false,"id":427144,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Luo, C.","contributorId":52697,"corporation":false,"usgs":true,"family":"Luo","given":"C.","email":"","affiliations":[],"preferred":false,"id":427146,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70030432,"text":"70030432 - 2006 - Sensitivity of Last Glacial Maximum climate to uncertainties in tropical and subtropical ocean temperatures","interactions":[],"lastModifiedDate":"2012-03-12T17:21:12","indexId":"70030432","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3219,"text":"Quaternary Science Reviews","active":true,"publicationSubtype":{"id":10}},"title":"Sensitivity of Last Glacial Maximum climate to uncertainties in tropical and subtropical ocean temperatures","docAbstract":"The faunal and floral gradients that underlie the CLIMAP (1981) sea-surface temperature (SST) reconstructions for the Last Glacial Maximum (LGM) reflect ocean temperature gradients and frontal positions. The transfer functions used to reconstruct SSTs from biologic gradients are biased, however, because at the warmest sites they display inherently low sensitivity in translating fauna to SST and they underestimate SST within the euphotic zones where the pycnocline is strong. Here we assemble available data and apply a statistical approach to adjust for hypothetical biases in the faunal-based SST estimates of LGM temperature. The largest bias adjustments are distributed in the tropics (to address low sensitivity) and subtropics (to address underestimation in the euphotic zones). The resulting SSTs are generally in better agreement than CLIMAP with recent geochemical estimates of glacial-interglacial temperature changes. We conducted a series of model experiments using the GENESIS general atmospheric circulation model to assess the sensitivity of the climate system to our bias-adjusted SSTs. Globally, the new SST field results in a modeled LGM surface-air cooling relative to present of 6.4 ??C (1.9 ??C cooler than that of CLIMAP). Relative to the simulation with CLIMAP SSTs, modeled precipitation over the oceans is reduced by 0.4 mm d-1 (an anomaly -0.4 versus 0.0 mm d-1 for CLIMAP) and increased over land (an anomaly -0.2 versus -0.5 mm d-1 for CLIMAP). Regionally strong responses are induced by changes in SST gradients. Data-model comparisons indicate improvement in agreement relative to CLIMAP, but differences among terrestrial data inferences and simulated moisture and temperature remain. Our SSTs result in positive mass balance over the northern hemisphere ice sheets (primarily through reduced summer ablation), supporting the hypothesis that tropical and subtropical ocean temperatures may have played a role in triggering glacial changes at higher latitudes.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary Science Reviews","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.quascirev.2005.12.010","issn":"02773791","usgsCitation":"Hostetler, S., Pisias, N., and Mix, A., 2006, Sensitivity of Last Glacial Maximum climate to uncertainties in tropical and subtropical ocean temperatures: Quaternary Science Reviews, v. 25, no. 11-12, p. 1168-1185, https://doi.org/10.1016/j.quascirev.2005.12.010.","startPage":"1168","endPage":"1185","numberOfPages":"18","costCenters":[],"links":[{"id":212096,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.quascirev.2005.12.010"},{"id":239517,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"25","issue":"11-12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8d27e4b08c986b3182a0","contributors":{"authors":[{"text":"Hostetler, S. 0000-0003-2272-8302","orcid":"https://orcid.org/0000-0003-2272-8302","contributorId":30336,"corporation":false,"usgs":true,"family":"Hostetler","given":"S.","affiliations":[],"preferred":false,"id":427134,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pisias, N.","contributorId":25290,"corporation":false,"usgs":true,"family":"Pisias","given":"N.","affiliations":[],"preferred":false,"id":427133,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mix, A.","contributorId":39363,"corporation":false,"usgs":true,"family":"Mix","given":"A.","email":"","affiliations":[],"preferred":false,"id":427135,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70028993,"text":"70028993 - 2006 - Mourning dove hunting regulation strategy based on annual harvest statistics and banding data","interactions":[],"lastModifiedDate":"2012-03-12T17:20:42","indexId":"70028993","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2508,"text":"Journal of Wildlife Management","active":true,"publicationSubtype":{"id":10}},"title":"Mourning dove hunting regulation strategy based on annual harvest statistics and banding data","docAbstract":"Although managers should strive to base game bird harvest management strategies on mechanistic population models, monitoring programs required to build and continuously update these models may not be in place. Alternatively, If estimates of total harvest and harvest rates are available, then population estimates derived from these harvest data can serve as the basis for making hunting regulation decisions based on population growth rates derived from these estimates. I present a statistically rigorous approach for regulation decision-making using a hypothesis-testing framework and an assumed framework of 3 hunting regulation alternatives. I illustrate and evaluate the technique with historical data on the mid-continent mallard (Anas platyrhynchos) population. I evaluate the statistical properties of the hypothesis-testing framework using the best available data on mourning doves (Zenaida macroura). I use these results to discuss practical implementation of the technique as an interim harvest strategy for mourning doves until reliable mechanistic population models and associated monitoring programs are developed.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Wildlife Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2193/0022-541X(2006)70[1302:MDHRSB]2.0.CO;2","issn":"0022541X","usgsCitation":"Otis, D.L., 2006, Mourning dove hunting regulation strategy based on annual harvest statistics and banding data: Journal of Wildlife Management, v. 70, no. 5, p. 1302-1307, https://doi.org/10.2193/0022-541X(2006)70[1302:MDHRSB]2.0.CO;2.","startPage":"1302","endPage":"1307","numberOfPages":"6","costCenters":[],"links":[{"id":209912,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2193/0022-541X(2006)70[1302:MDHRSB]2.0.CO;2"},{"id":236664,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"70","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5ec2e4b0c8380cd70c61","contributors":{"authors":[{"text":"Otis, David L.","contributorId":64396,"corporation":false,"usgs":true,"family":"Otis","given":"David","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":420865,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70030954,"text":"70030954 - 2006 - Analysis of environmental variation in a Great Plains reservoir using principal components analysis and geographic information systems","interactions":[],"lastModifiedDate":"2012-03-12T17:21:04","indexId":"70030954","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2592,"text":"Lake and Reservoir Management","active":true,"publicationSubtype":{"id":10}},"title":"Analysis of environmental variation in a Great Plains reservoir using principal components analysis and geographic information systems","docAbstract":"We present a method for spatial interpretation of environmental variation in a reservoir that integrates principal components analysis (PCA) of environmental data with geographic information systems (GIS). To illustrate our method, we used data from a Great Plains reservoir (Skiatook Lake, Oklahoma) with longitudinal variation in physicochemical conditions. We measured 18 physicochemical features, mapped them using GIS, and then calculated and interpreted four principal components. Principal component 1 (PC1) was readily interpreted as longitudinal variation in water chemistry, but the other principal components (PC2-4) were difficult to interpret. Site scores for PC1-4 were calculated in GIS by summing weighted overlays of the 18 measured environmental variables, with the factor loadings from the PCA as the weights. PC1-4 were then ordered into a landscape hierarchy, an emergent property of this technique, which enabled their interpretation. PC1 was interpreted as a reservoir scale change in water chemistry, PC2 was a microhabitat variable of rip-rap substrate, PC3 identified coves/embayments and PC4 consisted of shoreline microhabitats related to slope. The use of GIS improved our ability to interpret the more obscure principal components (PC2-4), which made the spatial variability of the reservoir environment more apparent. This method is applicable to a variety of aquatic systems, can be accomplished using commercially available software programs, and allows for improved interpretation of the geographic environmental variability of a system compared to using typical PCA plots. ?? Copyright by the North American Lake Management Society 2006.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Lake and Reservoir Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"10402381","usgsCitation":"Long, J., and Fisher, W., 2006, Analysis of environmental variation in a Great Plains reservoir using principal components analysis and geographic information systems: Lake and Reservoir Management, v. 22, no. 2, p. 132-140.","startPage":"132","endPage":"140","numberOfPages":"9","costCenters":[],"links":[{"id":239036,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"22","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eb11e4b0c8380cd48bcb","contributors":{"authors":[{"text":"Long, J.M.","contributorId":88944,"corporation":false,"usgs":true,"family":"Long","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":429380,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fisher, W.L.","contributorId":87713,"corporation":false,"usgs":true,"family":"Fisher","given":"W.L.","email":"","affiliations":[],"preferred":false,"id":429379,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70028975,"text":"70028975 - 2006 - Long-term dynamics of production, respiration, and net CO2 exchange in two sagebrush-steppe ecosystems","interactions":[],"lastModifiedDate":"2017-04-11T15:53:45","indexId":"70028975","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3228,"text":"Rangeland Ecology and Management","onlineIssn":"1551-5028","printIssn":"1550-7424","active":true,"publicationSubtype":{"id":10}},"title":"Long-term dynamics of production, respiration, and net CO2 exchange in two sagebrush-steppe ecosystems","docAbstract":"We present a synthesis of long-term measurements of CO2 exchange in 2 US Intermountain West sagebrush-steppe ecosystems. The locations near Burns, Oregon (1995–2001), and Dubois, Idaho (1996–2001), are part of the AgriFlux Network of the Agricultural Research Service, United States Department of Agriculture. Measurements of net ecosystem CO2 exchange (Fc) during the growing season were continuously recorded at flux towers using the Bowen ratio-energy balance technique. Data were partitioned into gross primary productivity (Pg) and ecosystem respiration (Re) using the light-response function method. Wintertime fluxes were measured during 1999/2000 and 2000/2001 and used to model fluxes in other winters. Comparison of daytime respiration derived from light-response analysis with nighttime tower measurements showed close correlation, with daytime respiration being on the average higher than nighttime respiration. Maxima of Pg and Re at Burns were both 20 g CO2·m−2·d−1 in 1998. Maxima of Pg and Re at Dubois were 37 and 35 g CO2·m−2·d−1, respectively, in 1997. Mean annual gross primary production at Burns was 1 111 (range 475–1 715) g CO2·m−2·y−1 or about 30% lower than that at Dubois (1 602, range 963–2 162 g CO2·m−2·y−1). Across the years, both ecosystems were net sinks for atmospheric CO2 with a mean net ecosystem CO2 exchange of 82 g CO2·m−2·y−1 at Burns and 253 g CO2·m−2·y−1 at Dubois, but on a yearly basis either site could be a C sink or source, mostly depending on precipitation timing and amount. Total annual precipitation is not a good predictor of carbon sequestration across sites. Our results suggest that Fc should be partitioned into Pg and Re components to allow prediction of seasonal and yearly dynamics of CO2fluxes.
","language":"English","publisher":"Elsevier","doi":"10.2111/05-198R1.1","issn":"15507424","usgsCitation":"Gilmanov, T., Svejcar, T., Johnson, D., Angell, R., Saliendra, N.Z., and Wylie, B., 2006, Long-term dynamics of production, respiration, and net CO2 exchange in two sagebrush-steppe ecosystems: Rangeland Ecology and Management, v. 59, no. 6, p. 585-599, https://doi.org/10.2111/05-198R1.1.","productDescription":"15 p.","startPage":"585","endPage":"599","numberOfPages":"15","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":491482,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://hdl.handle.net/10150/643112","text":"External Repository"},{"id":209834,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2111/05-198R1.1"},{"id":236563,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"59","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4984e4b0c8380cd6869b","contributors":{"authors":[{"text":"Gilmanov, T.G.","contributorId":44716,"corporation":false,"usgs":true,"family":"Gilmanov","given":"T.G.","email":"","affiliations":[],"preferred":false,"id":420806,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Svejcar, T.J.","contributorId":29087,"corporation":false,"usgs":true,"family":"Svejcar","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":420804,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Johnson, D.A.","contributorId":61370,"corporation":false,"usgs":true,"family":"Johnson","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":420807,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Angell, R.F.","contributorId":30019,"corporation":false,"usgs":true,"family":"Angell","given":"R.F.","email":"","affiliations":[],"preferred":false,"id":420805,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Saliendra, Nicanor Z.","contributorId":16623,"corporation":false,"usgs":true,"family":"Saliendra","given":"Nicanor","email":"","middleInitial":"Z.","affiliations":[],"preferred":false,"id":420802,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Wylie, B.K. 0000-0002-7374-1083","orcid":"https://orcid.org/0000-0002-7374-1083","contributorId":24877,"corporation":false,"usgs":true,"family":"Wylie","given":"B.K.","affiliations":[],"preferred":false,"id":420803,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70028953,"text":"70028953 - 2006 - Use of the moon to support on-orbit sensor calibration for climate change measurements","interactions":[],"lastModifiedDate":"2012-03-12T17:20:58","indexId":"70028953","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Use of the moon to support on-orbit sensor calibration for climate change measurements","docAbstract":"Production of reliable climate datasets from multiple observational measurements acquired by remote sensing satellite systems available now and in the future places stringent requirements on the stability of sensors and consistency among the instruments and platforms. Detecting trends in environmental parameters measured at solar reflectance wavelengths (0.3 to 2.5 microns) requires on-orbit instrument stability at a level of 1% over a decade. This benchmark can be attained using the Moon as a radiometric reference. The lunar calibration program at the U.S. Geological Survey has an operational model to predict the lunar spectral irradiance with precision ???1%, explicitly accounting for the effects of phase, lunar librations, and the lunar surface photometric function. A system for utilization of the Moon by on-orbit instruments has been established. With multiple lunar views taken by a spacecraft instrument, sensor response characterization with sub-percent precision over several years has been achieved. Meteorological satellites in geostationary orbit (GEO) capture the Moon in operational images; applying lunar calibration to GEO visible-channel image archives has the potential to develop a climate record extending decades into the past. The USGS model and system can provide reliable transfer of calibration among instruments that have viewed the Moon as a common source. This capability will be enhanced with improvements to the USGS model absolute scale. Lunar calibration may prove essential to the critical calibration needs to cover a potential gap in observational capabilities prior to deployment of NPP/NPOESS. A key requirement is that current and future instruments observe the Moon.","largerWorkTitle":"Proceedings of SPIE - The International Society for Optical Engineering","conferenceTitle":"Earth Observing Systems XI","conferenceDate":"14 August 2006 through 16 August 2006","conferenceLocation":"San Diego, CA","language":"English","doi":"10.1117/12.678605","issn":"0277786X","isbn":"0819463752; 9780819463753","usgsCitation":"Stone, T., and Kieffer, H.H., 2006, Use of the moon to support on-orbit sensor calibration for climate change measurements, in Proceedings of SPIE - The International Society for Optical Engineering, v. 6296, San Diego, CA, 14 August 2006 through 16 August 2006, https://doi.org/10.1117/12.678605.","costCenters":[],"links":[{"id":209728,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1117/12.678605"},{"id":236423,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6296","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbf9ee4b08c986b329c7a","contributors":{"authors":[{"text":"Stone, T.C.","contributorId":74874,"corporation":false,"usgs":true,"family":"Stone","given":"T.C.","email":"","affiliations":[],"preferred":false,"id":420698,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kieffer, H. H.","contributorId":40725,"corporation":false,"usgs":false,"family":"Kieffer","given":"H.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":420697,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030797,"text":"70030797 - 2006 - Sampling strategies for volatile organic compounds at three karst springs in Tennessee","interactions":[],"lastModifiedDate":"2012-03-12T17:21:19","indexId":"70030797","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1864,"text":"Ground Water Monitoring and Remediation","active":true,"publicationSubtype":{"id":10}},"title":"Sampling strategies for volatile organic compounds at three karst springs in Tennessee","docAbstract":"The influence of different sampling strategies on characterizing volatile organic compound (VOC) concentrations and estimating VOC loads was evaluated at three karst springs in Tennessee. During a 6-month period, water samples for VOC analyses were collected weekly at all three springs and as frequently as every 20 min during storms at the two springs with variable water quality conditions. Total 6-month loads for selected VOCs were calculated, and VOC data were systematically subsampled to simulate and evaluate several potential sampling strategies. Results from the study indicate that sampling strategies for karst springs need to be developed on a site-specific basis. The use of fixed sampling intervals (as infrequently as quarterly or semiannually) produced accurate concentration and load estimates at one of the springs; however, additional sampling was needed to detect storm-related changes at a second spring located in a similar hydrogeologic setting. Continuous discharge data and high-frequency or flow-controlled sampling were needed at the third spring, which had the most variable flow and water quality conditions. The lack of continuous discharge data at the third spring would substantially affect load calculations, and the use of fixed sampling intervals would affect load calculations and the ability to detect pulses of high contaminant concentrations that might exceed toxicity levels for aquatic organisms. ?? 2006 National Ground Water Association.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ground Water Monitoring and Remediation","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1745-6592.2006.00044.x","issn":"10693629","usgsCitation":"Williams, S., Wolfe, W., and Farmer, J., 2006, Sampling strategies for volatile organic compounds at three karst springs in Tennessee: Ground Water Monitoring and Remediation, v. 26, no. 1, p. 53-62, https://doi.org/10.1111/j.1745-6592.2006.00044.x.","startPage":"53","endPage":"62","numberOfPages":"10","costCenters":[],"links":[{"id":506173,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1745-6592.2006.00044.x","text":"Publisher Index Page"},{"id":238696,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211412,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1745-6592.2006.00044.x"}],"volume":"26","issue":"1","noUsgsAuthors":false,"publicationDate":"2006-02-13","publicationStatus":"PW","scienceBaseUri":"505ab093e4b0c8380cd87b9f","contributors":{"authors":[{"text":"Williams, S.D.","contributorId":92706,"corporation":false,"usgs":true,"family":"Williams","given":"S.D.","email":"","affiliations":[],"preferred":false,"id":428730,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wolfe, W.J.","contributorId":10069,"corporation":false,"usgs":true,"family":"Wolfe","given":"W.J.","email":"","affiliations":[],"preferred":false,"id":428728,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Farmer, J.J.","contributorId":69358,"corporation":false,"usgs":true,"family":"Farmer","given":"J.J.","email":"","affiliations":[],"preferred":false,"id":428729,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030769,"text":"70030769 - 2006 - On the absence of InSAR-detected volcano deformation spanning the 1995-1996 and 1999 eruptions of Shishaldin Volcano, Alaska","interactions":[],"lastModifiedDate":"2019-04-15T09:41:49","indexId":"70030769","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"On the absence of InSAR-detected volcano deformation spanning the 1995-1996 and 1999 eruptions of Shishaldin Volcano, Alaska","docAbstract":"Shishaldin Volcano, a large, frequently active basaltic-andesite volcano located on Unimak Island in the Aleutian Arc of Alaska, had a minor eruption in 1995–1996 and a VEI 3 sub-Plinian basaltic eruption in 1999. We used 21 synthetic aperture radar images acquired by ERS-1, ERS-2, JERS-1, and RADARSAT-1 satellites to construct 12 coherent interferograms that span most of the 1993–2003 time interval. All interferograms lack coherence within ∼5 km of the summit, primarily due to persistent snow and ice cover on the edifice. Remarkably, in the 5–15 km distance range where interferograms are coherent, the InSAR images show no intrusion- or withdrawal-related deformation at Shishaldin during this entire time period. However, several InSAR images do show deformation associated with a shallow ML 5.2 earthquake located ∼14 km west of Shishaldin that occurred 6 weeks before the 1999 eruption. We use a theoretical model to predict deformation magnitudes due to a volumetric expansion source having a volume equivalent to the 1999 erupted volume, and find that deformation magnitudes for sources shallower than 10 km are within the expected detection capabilities for interferograms generated from C-band ERS 1/2 and RADARSAT-1 synthetic aperture radar images. We also find that InSAR images cannot resolve relatively shallow deformation sources (1–2 km below sea level) due to spatial gaps in the InSAR images caused by lost coherence. The lack of any deformation, particularly for the 1999 eruption, leads us to speculate that magma feeding eruptions at the summit moves rapidly (at least 80m/day) from > 10 km depth, and that the intrusion–eruption cycle at Shishaldin does not produce significant permanent deformation at the surface.