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• 1. [Article] Using Transects to Understand Cyanobacterial Blooms

  Presentation focuses on Toxic algae (and cyanobacteria) and on short-term mitigation: Monitoring Possible approaches

  Citation × Citation Citation Abstract Copy Title: Using Transects to Understand Cyanobacterial Blooms Author: Rueter, John Year: 2016 Presentation focuses on Toxic algae (and cyanobacteria) and on short-term mitigation: Monitoring Possible approaches Title: Using Transects to Understand Cyanobacterial Blooms Author: Rueter, John Year: 2016 Presentation focuses on Toxic algae (and cyanobacteria) and on short-term mitigation: Monitoring Possible approaches Close

• 2. [Article] Interference suppression in HO fluorescence detection

  In this Letter we report preliminary results on a sampling method that greatly reduces the above interferences relative to hydroxyl fluorescence.

  Citation × Citation Citation Abstract Copy Title: Interference suppression in HO fluorescence detection Author: Hard, Thomas M., O'Brien, Robert J., Cook, T. B., Tsongas, G. A. Year: 1979 In this Letter we report preliminary results on a sampling method that greatly reduces the above interferences relative to hydroxyl fluorescence. Title: Interference suppression in HO fluorescence detection Author: Hard, Thomas M., O'Brien, Robert J., Cook, T. B., Tsongas, G. A. Year: 1979 In this Letter we report preliminary results on a sampling method that greatly reduces the above interferences relative to hydroxyl fluorescence. Close

• 3. [Article] A New Model For Simulating Climate Change and Carbon Dynamics in Forested Landscapes

  Journal of Ecosystems & Management vol. 13 no. 2 2012 news brief .

  Citation × Citation Citation Abstract Copy Title: A New Model For Simulating Climate Change and Carbon Dynamics in Forested Landscapes Author: Dymond, Caren C., Scheller, Robert M., Beukema, Sarah Year: 2012 Journal of Ecosystems & Management vol. 13 no. 2 2012 news brief . Title: A New Model For Simulating Climate Change and Carbon Dynamics in Forested Landscapes Author: Dymond, Caren C., Scheller, Robert M., Beukema, Sarah Year: 2012 Journal of Ecosystems & Management vol. 13 no. 2 2012 news brief . Close

• 4. [Article] Worldview-Based Scenarios Highlight Stakeholder Values and Assumptions

  In lake management, we have the privilege and responsibility to work with the public on highly visible resources. Everybody has an opinion based on his or her personal values and observations. While we ...

  Citation × Citation Citation Abstract Copy Title: Worldview-Based Scenarios Highlight Stakeholder Values and Assumptions Author: Rueter, John Year: 2016 In lake management, we have the privilege and responsibility to work with the public on highly visible resources. Everybody has an opinion based on his or her personal values and observations. While we might sometimes consider this plethora of value statements as the bane of our existence, we all realize that public engagement is crucial for the health and future of lakes. Poor lake health is often caused by many little insults that stem from a wide range of legitimate views for how the lake should be treated as a resource. We need a framework to be able to deal with these differing values and assumptions for how lakes should be managed. Title: Worldview-Based Scenarios Highlight Stakeholder Values and Assumptions Author: Rueter, John Year: 2016 In lake management, we have the privilege and responsibility to work with the public on highly visible resources. Everybody has an opinion based on his or her personal values and observations. While we might sometimes consider this plethora of value statements as the bane of our existence, we all realize that public engagement is crucial for the health and future of lakes. Poor lake health is often caused by many little insults that stem from a wide range of legitimate views for how the lake should be treated as a resource. We need a framework to be able to deal with these differing values and assumptions for how lakes should be managed. Close

• 5. [Article] Emerging Contaminants in Oregon Coastal Waters: Hotspots, Landscape Drivers and Synergistic Effects on Bivalves

  This presentation focuses on the following research questions: Types and levels of contaminants of emerging concern (CECs) in Oregon’s coastal ocean? Levels of CECs in native and commercial oysters? ...

  Citation × Citation Citation Abstract Copy Title: Emerging Contaminants in Oregon Coastal Waters: Hotspots, Landscape Drivers and Synergistic Effects on Bivalves Author: Granek, Elise F., Fish, William, Strecker, Angela L. Year: 2013 This presentation focuses on the following research questions: Types and levels of contaminants of emerging concern (CECs) in Oregon’s coastal ocean? Levels of CECs in native and commercial oysters? Ecological effects (growth, reproductive output, etc.) of these contaminants in marine bivalves? Title: Emerging Contaminants in Oregon Coastal Waters: Hotspots, Landscape Drivers and Synergistic Effects on Bivalves Author: Granek, Elise F., Fish, William, Strecker, Angela L. Year: 2013 This presentation focuses on the following research questions: Types and levels of contaminants of emerging concern (CECs) in Oregon’s coastal ocean? Levels of CECs in native and commercial oysters? Ecological effects (growth, reproductive output, etc.) of these contaminants in marine bivalves? Close

• 6. [Article] FAGE measurements of tropospheric HO with measurements and model of interferences

  Ambient HO measurements by low-pressure laser-excited fluorescence with chemical modulation, and supporting ozone and water-vapor data, are presented for periods in May and August 1987. The observed peak ...

  Citation × Citation Citation Abstract Copy Title: FAGE measurements of tropospheric HO with measurements and model of interferences Author: Hard, Thomas M., Mehrabzadeh, A. A., Chan, C. Y., O'Brien, Robert J. Year: 1992 Ambient HO measurements by low-pressure laser-excited fluorescence with chemical modulation, and supporting ozone and water-vapor data, are presented for periods in May and August 1987. The observed peak daytime ambient HO concentrations in Oregon are in the range (2.5 to 8) times106 molecules cm⁻³ and show small negative offsets due to photochemical interference. Direct measurements of the interference at fixed [O₃] give the dependence on ambient [H₂O] and on the modulating reagent [isobutane]. At ambient [O₃]=30 p.p.b. and 10 torr H₂O, with excitation and detection at a total pressure of 4 torr, the net interference is equal to [HO]=-1.3times10⁶ molecule cm⁻³. Title: FAGE measurements of tropospheric HO with measurements and model of interferences Author: Hard, Thomas M., Mehrabzadeh, A. A., Chan, C. Y., O'Brien, Robert J. Year: 1992 Ambient HO measurements by low-pressure laser-excited fluorescence with chemical modulation, and supporting ozone and water-vapor data, are presented for periods in May and August 1987. The observed peak daytime ambient HO concentrations in Oregon are in the range (2.5 to 8) times106 molecules cm⁻³ and show small negative offsets due to photochemical interference. Direct measurements of the interference at fixed [O₃] give the dependence on ambient [H₂O] and on the modulating reagent [isobutane]. At ambient [O₃]=30 p.p.b. and 10 torr H₂O, with excitation and detection at a total pressure of 4 torr, the net interference is equal to [HO]=-1.3times10⁶ molecule cm⁻³. Close

• 7. [Article] Third-generation FAGE instrument for tropospheric hydroxyl radical measurement

  The authors have constructed a single-stage, frequency-doubled, copper vapor laser-pumped dye laser to be used in the measurement of atmospheric hydroxyl radical concentrations. This laser can be tuned ...

  Citation × Citation Citation Abstract Copy Title: Third-generation FAGE instrument for tropospheric hydroxyl radical measurement Author: Chan, C. Y., Hard, Thomas M., Mehrabzadeh, A. A., O'Brien, Robert J. Year: 1990 The authors have constructed a single-stage, frequency-doubled, copper vapor laser-pumped dye laser to be used in the measurement of atmospheric hydroxyl radical concentrations. This laser can be tuned to either the 1← 0 or 0← 0 vibrational transition in the electronic transition ²Sigmalarr²Pi. A new photon counting instrument is used for HO fluorescence detection. Theoretical and experimental studies of instrument performance show better sensitivities and reduced photolytic interferences than have been possible with previous systems based upon Nd:YAG pumping. Title: Third-generation FAGE instrument for tropospheric hydroxyl radical measurement Author: Chan, C. Y., Hard, Thomas M., Mehrabzadeh, A. A., O'Brien, Robert J. Year: 1990 The authors have constructed a single-stage, frequency-doubled, copper vapor laser-pumped dye laser to be used in the measurement of atmospheric hydroxyl radical concentrations. This laser can be tuned to either the 1← 0 or 0← 0 vibrational transition in the electronic transition ²Sigmalarr²Pi. A new photon counting instrument is used for HO fluorescence detection. Theoretical and experimental studies of instrument performance show better sensitivities and reduced photolytic interferences than have been possible with previous systems based upon Nd:YAG pumping. Close

• 8. [Article] Diurnal HO₂ cycles at clean air and urban sites in the troposphere

  HO₂ concentrations have been determined at two Oregon sites for continuous periods of 36 to 48 hours, using fluorescence assay with gas expansion. At the sea level coastal site (45degN 124degW), NNW winds ...

  Citation × Citation Citation Abstract Copy Title: Diurnal HO₂ cycles at clean air and urban sites in the troposphere Author: Hard, Thomas M., Chan, C. Y., Mehrabzadeh, A. A., O'Brien, Robert J. Year: 1992 HO₂ concentrations have been determined at two Oregon sites for continuous periods of 36 to 48 hours, using fluorescence assay with gas expansion. At the sea level coastal site (45degN 124degW), NNW winds prevailed during daytime, and a point measurement of very low total nonmethane hydrocarbon concentration indicated the presence of remote tropospheric air of oceanic origin. At the urban site, HO₂ was determined during moderately low ozone pollution levels. At both sites, maximum daily [HO₂] was in the range of 1-2times10⁸ cm⁻³ under clear-sky conditions, with an estimated overall uncertainty of 40%. Title: Diurnal HO₂ cycles at clean air and urban sites in the troposphere Author: Hard, Thomas M., Chan, C. Y., Mehrabzadeh, A. A., O'Brien, Robert J. Year: 1992 HO₂ concentrations have been determined at two Oregon sites for continuous periods of 36 to 48 hours, using fluorescence assay with gas expansion. At the sea level coastal site (45degN 124degW), NNW winds prevailed during daytime, and a point measurement of very low total nonmethane hydrocarbon concentration indicated the presence of remote tropospheric air of oceanic origin. At the urban site, HO₂ was determined during moderately low ozone pollution levels. At both sites, maximum daily [HO₂] was in the range of 1-2times10⁸ cm⁻³ under clear-sky conditions, with an estimated overall uncertainty of 40%. Close

• 9. [Article] Carbon monoxide in the antarctic atmosphere: Observations of decreasing concentrations

  Hydroxyl radicals remove hundreds, perhaps thousands, of organic gases from the atmosphere and are often regarded as am index of the oxidizing capacity of the Earth's atmosphere (Thompson 1992). In recent ...

  Citation × Citation Citation Abstract Copy Title: Carbon monoxide in the antarctic atmosphere: Observations of decreasing concentrations Author: Khalil, M. A., Rasmussen, R. A. Year: 1994 Hydroxyl radicals remove hundreds, perhaps thousands, of organic gases from the atmosphere and are often regarded as am index of the oxidizing capacity of the Earth's atmosphere (Thompson 1992). In recent years, there have been growing concerns that, over the past century and now, human activities may be depleting hydroxyl concentrations by adding huge amounts of carbon monoxide and methane to the atmosphere. Reduction in the hydroxyl concentrations can then indirectly lead to more global warming, stratospheric ozone depletion, and other disturbances in atmospheric chemistry. Carbon monoxide (CO) is a key component in the determination of hydroxyl radical (OH) concentrations: increases of CO would lead to a decline of OH. Global increases of CO had been observed in the 1980s (Khalil and Rasmussen 1985, 1988, 1990), but now it appears that the atmospheric concentrations of CO are falling. Here we will report data from Antarctica that suggest recent decreases in the concentration of CO. Title: Carbon monoxide in the antarctic atmosphere: Observations of decreasing concentrations Author: Khalil, M. A., Rasmussen, R. A. Year: 1994 Hydroxyl radicals remove hundreds, perhaps thousands, of organic gases from the atmosphere and are often regarded as am index of the oxidizing capacity of the Earth's atmosphere (Thompson 1992). In recent years, there have been growing concerns that, over the past century and now, human activities may be depleting hydroxyl concentrations by adding huge amounts of carbon monoxide and methane to the atmosphere. Reduction in the hydroxyl concentrations can then indirectly lead to more global warming, stratospheric ozone depletion, and other disturbances in atmospheric chemistry. Carbon monoxide (CO) is a key component in the determination of hydroxyl radical (OH) concentrations: increases of CO would lead to a decline of OH. Global increases of CO had been observed in the 1980s (Khalil and Rasmussen 1985, 1988, 1990), but now it appears that the atmospheric concentrations of CO are falling. Here we will report data from Antarctica that suggest recent decreases in the concentration of CO. Close

• 10. [Article] Intercomparison of Local Hydroxyl Measurements by Radiocarbon and FAGE Techniques

  A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere ...

  Citation × Citation Citation Abstract Copy Title: Intercomparison of Local Hydroxyl Measurements by Radiocarbon and FAGE Techniques Author: Campbell, Malcolm J., Hall, Brad D., Sheppard, John C., Utley, Philip L., O'Brien, Robert J., Hard, Thomas M., George, Linda Acha Year: 1995 A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere at the site is believed to contain low levels of anthropogenic pollution. The instruments' inlets were located at the same height (3.5 m) above the ground and were separated by 10 m along a line normal to the prevailing wind. Readings of the FAGE3 and radiocarbon instruments showed a high correlation (r² = 0.74) despite HO concentrations that were frequently near the detection limit of the instruments. An unweighted least squares regression shows a slope significantly different from unity, indicating different calibration scales of the two instruments Title: Intercomparison of Local Hydroxyl Measurements by Radiocarbon and FAGE Techniques Author: Campbell, Malcolm J., Hall, Brad D., Sheppard, John C., Utley, Philip L., O'Brien, Robert J., Hard, Thomas M., George, Linda Acha Year: 1995 A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere at the site is believed to contain low levels of anthropogenic pollution. The instruments' inlets were located at the same height (3.5 m) above the ground and were separated by 10 m along a line normal to the prevailing wind. Readings of the FAGE3 and radiocarbon instruments showed a high correlation (r² = 0.74) despite HO concentrations that were frequently near the detection limit of the instruments. An unweighted least squares regression shows a slope significantly different from unity, indicating different calibration scales of the two instruments Close