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• 1. [Article] Occurrence of Synthetic Amino-Polycarboxylate Chelating Compounds in Oregon Surface Waters

  Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial ...

  Citation × Citation Citation Abstract Copy Title: Occurrence of Synthetic Amino-Polycarboxylate Chelating Compounds in Oregon Surface Waters Author: Hersey, Nathan A Year: 2014 Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial settings. When chelating compounds are present, the activity and transport of metal cations in the environment and the uptake of metals in natural systems can be affected. Surface water samples from across the United States were analyzed, as well as local collection and analysis of surface waters and wastewater treatment plant effluent from around Northwest Oregon. Results indicate presence of synthetic chelating compounds in areas with human activity, and absence in areas that are less populated. As a stable and water soluble compound, monitoring for chelates could have potential use as an effective indicator of further anthropogenic effects. Title: Occurrence of Synthetic Amino-Polycarboxylate Chelating Compounds in Oregon Surface Waters Author: Hersey, Nathan A Year: 2014 Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial settings. When chelating compounds are present, the activity and transport of metal cations in the environment and the uptake of metals in natural systems can be affected. Surface water samples from across the United States were analyzed, as well as local collection and analysis of surface waters and wastewater treatment plant effluent from around Northwest Oregon. Results indicate presence of synthetic chelating compounds in areas with human activity, and absence in areas that are less populated. As a stable and water soluble compound, monitoring for chelates could have potential use as an effective indicator of further anthropogenic effects. Close

• 2. [Article] Nonstationary Internal Tides Observed Using Dual-Satellite Altimetry

  Dual-satellite crossover data from the Jason-2 and Cryosat-2 altimeter missions are used in a novel approach to quantify stationary and nonstationary tides from time-lagged mean square sea surface height ...

  Citation × Citation Citation Abstract Copy Title: Nonstationary Internal Tides Observed Using Dual-Satellite Altimetry Author: Zaron, Edward D. Year: 2015 Dual-satellite crossover data from the Jason-2 and Cryosat-2 altimeter missions are used in a novel approach to quantify stationary and nonstationary tides from time-lagged mean square sea surface height (SSH) differences, computed for lags from 1 to 1440 h (60 days). The approach is made feasible by removing independent estimates of the stationary tide and mesoscale SSH variance, which greatly reduces the sampling error of the SSH statistics. For the semidiurnal tidal band, the stationary tidal variance is approximately 0.73 cm(2), and the nonstationary variance is about 0.33 cm(2), or 30% of the total. The temporal correlation of the nonstationary tide is examined by complex demodulation and found to be oscillatory with first 0 crossing at 400 h (17 days). Because a significant fraction of the time-variable mesoscale signal is resolved at time scales of roughly 150 h by the present constellation of satellite altimeters, the results suggest that it may be feasible to predict the nonstationary tide from modulations of the resolved mesoscale, thus enhancing the efficacy of tidal corrections for planned wide-swath altimeters such as the Surface Water and Ocean Topography (SWOT) mission. Title: Nonstationary Internal Tides Observed Using Dual-Satellite Altimetry Author: Zaron, Edward D. Year: 2015 Dual-satellite crossover data from the Jason-2 and Cryosat-2 altimeter missions are used in a novel approach to quantify stationary and nonstationary tides from time-lagged mean square sea surface height (SSH) differences, computed for lags from 1 to 1440 h (60 days). The approach is made feasible by removing independent estimates of the stationary tide and mesoscale SSH variance, which greatly reduces the sampling error of the SSH statistics. For the semidiurnal tidal band, the stationary tidal variance is approximately 0.73 cm(2), and the nonstationary variance is about 0.33 cm(2), or 30% of the total. The temporal correlation of the nonstationary tide is examined by complex demodulation and found to be oscillatory with first 0 crossing at 400 h (17 days). Because a significant fraction of the time-variable mesoscale signal is resolved at time scales of roughly 150 h by the present constellation of satellite altimeters, the results suggest that it may be feasible to predict the nonstationary tide from modulations of the resolved mesoscale, thus enhancing the efficacy of tidal corrections for planned wide-swath altimeters such as the Surface Water and Ocean Topography (SWOT) mission. Close

• 3. [Article] A Method for Processing Acoustic Doppler Current Profiler Velocity Data from Towed, Undulating Vehicles

  The utility of the acoustic Doppler current profiler (ADCP) for sampling small time and space scales of coastal environments can be enhanced by mounting a high-frequency (1200 kHz) ADCP on an oscillating ...

  Citation × Citation Citation Abstract Copy Title: A Method for Processing Acoustic Doppler Current Profiler Velocity Data from Towed, Undulating Vehicles Author: Jay, David A., Pan, Jiayi Year: 2008 The utility of the acoustic Doppler current profiler (ADCP) for sampling small time and space scales of coastal environments can be enhanced by mounting a high-frequency (1200 kHz) ADCP on an oscillating towed body. This approach requires both an external reference to convert the measured shears to velocities in the earth coordinates and a method to determine the towed body velocities. During the River Influence on the Shelf Ecosystems (RISE) project cruise, a high-frequency (1200 kHz) and narrowbeam ADCP with mode 12 sampling was mounted on a TRIAXUS oscillating towfish, which steers a 3D path behind the ship. This deployment approach extended the vertical range of the ADCP and allowed it to sample near-surface waters outside the ship?s wake. The measurements from a ship-mounted 1200-kHz narrowbeam ADCP are used as references for TRIAXUS ADCP data, and a method of overlapping bins is employed to recover the entire vertical range of the TRIAXUS ADCP. The TRIAXUS vehicle horizontal velocities are obtained by removing the derived ocean current velocity from the TRIAXUS ADCP measurements. The results show that the method is practical. Title: A Method for Processing Acoustic Doppler Current Profiler Velocity Data from Towed, Undulating Vehicles Author: Jay, David A., Pan, Jiayi Year: 2008 The utility of the acoustic Doppler current profiler (ADCP) for sampling small time and space scales of coastal environments can be enhanced by mounting a high-frequency (1200 kHz) ADCP on an oscillating towed body. This approach requires both an external reference to convert the measured shears to velocities in the earth coordinates and a method to determine the towed body velocities. During the River Influence on the Shelf Ecosystems (RISE) project cruise, a high-frequency (1200 kHz) and narrowbeam ADCP with mode 12 sampling was mounted on a TRIAXUS oscillating towfish, which steers a 3D path behind the ship. This deployment approach extended the vertical range of the ADCP and allowed it to sample near-surface waters outside the ship?s wake. The measurements from a ship-mounted 1200-kHz narrowbeam ADCP are used as references for TRIAXUS ADCP data, and a method of overlapping bins is employed to recover the entire vertical range of the TRIAXUS ADCP. The TRIAXUS vehicle horizontal velocities are obtained by removing the derived ocean current velocity from the TRIAXUS ADCP measurements. The results show that the method is practical. Close

• 4. [Article] The Small Volume Autonomous Water Sampler (SVAWS): An Innovative, Cost- Effective, Adaptable Protocol

  As of 2007, U.S. pesticide use stood at 1.1 billion pounds with 80% of all usage in agriculture. Such realities pose a potentially dangerous threat to our surface water bodies. This research provides a ...

  Citation × Citation Citation Abstract Copy Title: The Small Volume Autonomous Water Sampler (SVAWS): An Innovative, Cost- Effective, Adaptable Protocol Author: Fitzgerald, Nicholas B Year: 2014 As of 2007, U.S. pesticide use stood at 1.1 billion pounds with 80% of all usage in agriculture. Such realities pose a potentially dangerous threat to our surface water bodies. This research provides a detailed analysis of the design, operation and field testing of a prototype water sampler, the Small Volume Autonomous Water Sampler (SVAWS). The research includes a discussion of the design and construction of the SVAWS. Seven USGS employees operated the SVAWS in a number of different states and conditions in order to collect samples for pesticide analysis. Field-testing outcomes of the SVAWS were measured through a Participant Survey Request and a Likert-Scale Assessment. Overall, survey data proved the SVAWS to be an effective device for collecting water samples in different locations and conditions. Users also understood the SVAWS has significant potential for applications other than pesticide studies. While feedback did show a number of alterations or modifications could improve the design, the device proved to be effective across many of its goals, from valid water sampling to reducing costs of sample acquisition. Recommendations for future research include these and other avenues of research. A conclusion addresses the potential future of the SVAWS with respect to water sampling applications. Title: The Small Volume Autonomous Water Sampler (SVAWS): An Innovative, Cost- Effective, Adaptable Protocol Author: Fitzgerald, Nicholas B Year: 2014 As of 2007, U.S. pesticide use stood at 1.1 billion pounds with 80% of all usage in agriculture. Such realities pose a potentially dangerous threat to our surface water bodies. This research provides a detailed analysis of the design, operation and field testing of a prototype water sampler, the Small Volume Autonomous Water Sampler (SVAWS). The research includes a discussion of the design and construction of the SVAWS. Seven USGS employees operated the SVAWS in a number of different states and conditions in order to collect samples for pesticide analysis. Field-testing outcomes of the SVAWS were measured through a Participant Survey Request and a Likert-Scale Assessment. Overall, survey data proved the SVAWS to be an effective device for collecting water samples in different locations and conditions. Users also understood the SVAWS has significant potential for applications other than pesticide studies. While feedback did show a number of alterations or modifications could improve the design, the device proved to be effective across many of its goals, from valid water sampling to reducing costs of sample acquisition. Recommendations for future research include these and other avenues of research. A conclusion addresses the potential future of the SVAWS with respect to water sampling applications. Close

• 5. [Article] Non-Stationary Internal Tides Observed with Satellite Altimetry

  Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra ...

  Citation × Citation Citation Abstract Copy Title: Non-Stationary Internal Tides Observed with Satellite Altimetry Author: Ray, R. D., Zaron, Edward D. Year: 2011 Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-1 tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 cm2. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions shows only one region of noteworthy seasonal changes, the northern South China Sea. Implications for the anticipated SWOT altimeter mission are briefly discussed. Title: Non-Stationary Internal Tides Observed with Satellite Altimetry Author: Ray, R. D., Zaron, Edward D. Year: 2011 Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-1 tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 cm2. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions shows only one region of noteworthy seasonal changes, the northern South China Sea. Implications for the anticipated SWOT altimeter mission are briefly discussed. Close

• 6. [Article] Regional Models of Internal Tides

  Internal tides are ubiquitous in the ocean, and they play an important role in a range of ocean processes, for example, particle dispersal, acoustics, and vertical buoyancy flux. The wavelength of internal ...

  Citation × Citation Citation Abstract Copy Title: Regional Models of Internal Tides Author: Carter, Glenn S., Fringer, Oliver B., Zaron, Edward D. Year: 2012 Internal tides are ubiquitous in the ocean, and they play an important role in a range of ocean processes, for example, particle dispersal, acoustics, and vertical buoyancy flux. The wavelength of internal tides can be as much as 250 km in the open ocean, but as the generation of these tides depends on the angle between the depth-averaged current and the topography, there can be considerable local spatial variability. This range of scales makes it difficult to develop a comprehensive understanding of the processes involved from observations alone. Regional numerical modeling provides a way to study the generation and early propagation of internal tides at high resolution. Here, we review the role that regional internal tide models, primarily hydrostatic models, can play in increasing our understanding. Title: Regional Models of Internal Tides Author: Carter, Glenn S., Fringer, Oliver B., Zaron, Edward D. Year: 2012 Internal tides are ubiquitous in the ocean, and they play an important role in a range of ocean processes, for example, particle dispersal, acoustics, and vertical buoyancy flux. The wavelength of internal tides can be as much as 250 km in the open ocean, but as the generation of these tides depends on the angle between the depth-averaged current and the topography, there can be considerable local spatial variability. This range of scales makes it difficult to develop a comprehensive understanding of the processes involved from observations alone. Regional numerical modeling provides a way to study the generation and early propagation of internal tides at high resolution. Here, we review the role that regional internal tide models, primarily hydrostatic models, can play in increasing our understanding. Close

• 7. [Article] Potential Impacts of Climate Change on Flood-Induced Travel Disruptions: A Case Study of Portland, Oregon, USA

  This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate ...

  Citation × Citation Citation Abstract Copy Title: Potential Impacts of Climate Change on Flood-Induced Travel Disruptions: A Case Study of Portland, Oregon, USA Author: Chang, Heejun, Lafrenz, Martin, Jung, Il-won, Figliozzi, Miguel, Platman, Deena, Pederson, Cindy Year: 2010 This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate change scenarios, a hydrologic model, a stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the historical period of 1988 and 2006 and simulated for determining the probability of floods for 2020 through 2049. We surveyed stream cross-sections at five road crossings for stream channel geometry and determined flood water surface elevations using the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year flood water surface elevation, leading to relatively frequent nuisance flooding. These roadway flooding events will become more frequent under some climate change scenarios in the future, but climate change impacts will depend on local geomorphic conditions. Whereas vehicle miles traveled was not significantly affected by road closure, vehicle hours delay demonstrated a greater impact from road closures, increasing by 10 percent in the Fanno Creek area. Our research demonstrated the usefulness of the integration of top-down and bottom-up approaches in climate change impact assessment and the need for spatially explicit modeling and participatory planning in flood management and transportation planning under increasing climate uncertainty. Title: Potential Impacts of Climate Change on Flood-Induced Travel Disruptions: A Case Study of Portland, Oregon, USA Author: Chang, Heejun, Lafrenz, Martin, Jung, Il-won, Figliozzi, Miguel, Platman, Deena, Pederson, Cindy Year: 2010 This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate change scenarios, a hydrologic model, a stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the historical period of 1988 and 2006 and simulated for determining the probability of floods for 2020 through 2049. We surveyed stream cross-sections at five road crossings for stream channel geometry and determined flood water surface elevations using the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year flood water surface elevation, leading to relatively frequent nuisance flooding. These roadway flooding events will become more frequent under some climate change scenarios in the future, but climate change impacts will depend on local geomorphic conditions. Whereas vehicle miles traveled was not significantly affected by road closure, vehicle hours delay demonstrated a greater impact from road closures, increasing by 10 percent in the Fanno Creek area. Our research demonstrated the usefulness of the integration of top-down and bottom-up approaches in climate change impact assessment and the need for spatially explicit modeling and participatory planning in flood management and transportation planning under increasing climate uncertainty. Close

• 8. [Article] Bottom Topography Mapping via Nonlinear Data Assimilation

  A variational data assimilation method is described for bottom topography mapping in rivers and estuaries using remotely sensed observations of water surface currents. The velocity field and bottom topography ...

  Citation × Citation Citation Abstract Copy Title: Bottom Topography Mapping via Nonlinear Data Assimilation Author: Zaron, Edward D., Pradal, Marie-Aude, Miller, Patrick D., Blumberg, Alan F., Georgas, Nickitas, Li, Wei, Cornuelle, Julia Muccino Year: 2011 A variational data assimilation method is described for bottom topography mapping in rivers and estuaries using remotely sensed observations of water surface currents. The velocity field and bottom topography are related by the vertically integrated momentum and continuity equations, leading to a nonlinear inverse problem for bottom topography, which is solved using a Picard iteration strategy combined with a nonlinear line search. An illustration of the method is shown for Haverstraw Bay, in the Hudson River, where the known bottom topography is well reconstructed. Once the topography has been estimated, currents and water levels may be forecast. The method makes feasible 1) the estimation of bottom topography in regions where in situ data collection may be impossible, dangerous, or expensive, and 2) the calibration of barotropic shallow-water models via control of the bottom topography. Title: Bottom Topography Mapping via Nonlinear Data Assimilation Author: Zaron, Edward D., Pradal, Marie-Aude, Miller, Patrick D., Blumberg, Alan F., Georgas, Nickitas, Li, Wei, Cornuelle, Julia Muccino Year: 2011 A variational data assimilation method is described for bottom topography mapping in rivers and estuaries using remotely sensed observations of water surface currents. The velocity field and bottom topography are related by the vertically integrated momentum and continuity equations, leading to a nonlinear inverse problem for bottom topography, which is solved using a Picard iteration strategy combined with a nonlinear line search. An illustration of the method is shown for Haverstraw Bay, in the Hudson River, where the known bottom topography is well reconstructed. Once the topography has been estimated, currents and water levels may be forecast. The method makes feasible 1) the estimation of bottom topography in regions where in situ data collection may be impossible, dangerous, or expensive, and 2) the calibration of barotropic shallow-water models via control of the bottom topography. Close

• 9. [Article] A Comparison of Five Models for Estimating Clear-Sky Solar Radiation

  Many agencies in the USA are developing management approaches to address water quality concerns and threatened and endangered species habitat requirements in water bodies. Many of these water bodies are ...

  Citation × Citation Citation Abstract Copy Title: A Comparison of Five Models for Estimating Clear-Sky Solar Radiation Author: Annear, Robert Leslie, Wells, Scott A. Year: 2007 Many agencies in the USA are developing management approaches to address water quality concerns and threatened and endangered species habitat requirements in water bodies. Many of these water bodies are water quality limited for temperature. Factors influencing stream temperature include: streamside vegetation, topographic shading, inflows and outflows, stream width, stream depth, light extinction and solar radiation. One of the key driving factors in estimating a water body heat budget is calculating the amount of solar radiation incident on the water surface. Even though it is preferable to measure clear-sky solar radiation, many temperature models rely on theoretical estimates of clear-sky solar radiation. The literature on estimating short-wave solar radiation by calculating the position of the sun and attenuating the radiation through the atmosphere was reviewed. As a first step in relating water temperature to solar radiation, several empirical solar radiation models were calibrated to data at seventeen sites around the United States for clear-sky days. Sensitivity analyses were conducted and differences between the models were examined. Results indicated that the more complex models for calculating solar radiation resulted in better estimates of clear-sky solar radiation once they were calibrated to data. When no data were available, models with one or no calibration parameters did reasonably well at estimating clear-sky solar radiation. Title: A Comparison of Five Models for Estimating Clear-Sky Solar Radiation Author: Annear, Robert Leslie, Wells, Scott A. Year: 2007 Many agencies in the USA are developing management approaches to address water quality concerns and threatened and endangered species habitat requirements in water bodies. Many of these water bodies are water quality limited for temperature. Factors influencing stream temperature include: streamside vegetation, topographic shading, inflows and outflows, stream width, stream depth, light extinction and solar radiation. One of the key driving factors in estimating a water body heat budget is calculating the amount of solar radiation incident on the water surface. Even though it is preferable to measure clear-sky solar radiation, many temperature models rely on theoretical estimates of clear-sky solar radiation. The literature on estimating short-wave solar radiation by calculating the position of the sun and attenuating the radiation through the atmosphere was reviewed. As a first step in relating water temperature to solar radiation, several empirical solar radiation models were calibrated to data at seventeen sites around the United States for clear-sky days. Sensitivity analyses were conducted and differences between the models were examined. Results indicated that the more complex models for calculating solar radiation resulted in better estimates of clear-sky solar radiation once they were calibrated to data. When no data were available, models with one or no calibration parameters did reasonably well at estimating clear-sky solar radiation. Close

• 10. [Article] Idaho Pend Oreille River Model: Model Development and Calibration

  The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during ...

  Citation × Citation Citation Abstract Copy Title: Idaho Pend Oreille River Model: Model Development and Calibration Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2006 The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables: flow, water surface elevation, and velocity temperature o dissolved oxygen nutrients (NO3-N+NO2-N, NH4-N, PO4-P) algae – chlorophyll a BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae periphyton The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic and water quality model that includes typical eutrophication constituents (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). Portland State University’s Water Quality Research Group is a center for development of this modeling tool (see http://www.cee.pdx.edu/w2). The model simulation was run from January 1st, 2004 to September 25th, 2005. The calibration period focused on the summers during each year when water quality data were obtained. Title: Idaho Pend Oreille River Model: Model Development and Calibration Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2006 The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables: flow, water surface elevation, and velocity temperature o dissolved oxygen nutrients (NO3-N+NO2-N, NH4-N, PO4-P) algae – chlorophyll a BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae periphyton The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic and water quality model that includes typical eutrophication constituents (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). Portland State University’s Water Quality Research Group is a center for development of this modeling tool (see http://www.cee.pdx.edu/w2). The model simulation was run from January 1st, 2004 to September 25th, 2005. The calibration period focused on the summers during each year when water quality data were obtained. Close