Search Results - "Esser, Bradley K."

Volatile fluxes through the Big Bend section of the San Andreas Fault, California: Helium and carbon-dioxide systematics by Kulongoski, Justin T., Hilton, David R., Barry, Peter H., Esser, Bradley K., Hillegonds, Darren, Belitz, Kenneth

“…To investigate the source of volatiles and their relationship to the San Andreas Fault System (SAFS), 18 groundwater samples were collected from wells near the…”
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Nitrate vulnerability projections from Bayesian inference of multiple groundwater age tracers by Alikhani, Jamal, Deinhart, Amanda L., Visser, Ate, Bibby, Richard K., Purtschert, Roland, Moran, Jean E., Massoudieh, Arash, Esser, Bradley K.

“…•Nitrate level and isotopes were used to infer the residence time distributions.•Residence time distribution was used to project nitrate confidence…”
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Tracers Reveal Recharge Elevations, Groundwater Flow Paths and Travel Times on Mount Shasta, California by Peters, Elizabeth, Visser, Ate, Esser, Bradley, Moran, Jean

“…Mount Shasta (4322 m) is famous for its spring water. Water for municipal, domestic and industrial use is obtained from local springs and wells, fed by annual…”
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Sources of groundwater nitrate revealed using residence time and isotope methods by Moore, Keara B., Ekwurzel, Brenda, Esser, Bradley K., Hudson, G. Bryant, Moran, Jean E.

“…Nitrate concentrations approaching and greater than the maximum contaminant level are impairing the viability of many groundwater basins as drinking water…”
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Quantifying Apparent Groundwater Ages near Managed Aquifer Recharge Operations Using Radio-Sulfur (35S) as an Intrinsic Tracer by Clark, Jordan, Urióstegui, Stephanie, Bibby, Richard, Esser, Bradley, Tredoux, Gideon

“…The application of the cosmogenic radioisotope sulfur-35 (35S) as a chronometer near spreading basins is evaluated at two well-established Managed Aquifer…”
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Quantifying Reaeration Rates in Alpine Streams Using Deliberate Gas Tracer Experiments by Benson, Andrew, Zane, Matthew, Becker, Timothy E, Visser, Ate, Uriostegui, Stephanie H, DeRubeis, Elizabeth, Moran, Jean E, Esser, Bradley K, Clark, Jordan F

“…Gas exchange across the air-water interface is a critical process that maintains adequate dissolved oxygen (DO) in the water column to support life. Oxygen…”
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Importance of river water recharge to the San Joaquin Valley groundwater system by Visser, Ate, Moran, Jean E., Singleton, Michael J., Esser, Bradley K.

“…Groundwater is not a sustainable resource, unless ion is balanced by recharge. Identifying the sources of recharge in a groundwater basin is critical for…”
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A partial exponential lumped parameter model to evaluate groundwater age distributions and nitrate trends in long-screened wells by Jurgens, Bryant C., Böhlke, J.K., Kauffman, Leon J., Belitz, Kenneth, Esser, Bradley K.

“…•A partial exponential lumped parameter model (PEM) was derived.•PEMs were parameterized using well construction and water level data.•PEMs revealed age…”
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Dissolved atmospheric gas in xylem sap measured with membrane inlet mass spectrometry by Schenk, H. Jochen, Espino, Susana, Visser, Ate, Esser, Bradley K.

“…A new method is described for measuring dissolved gas concentrations in small volumes of xylem sap using membrane inlet mass spectrometry. The technique can be…”
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Regional oxygen reduction and denitrification rates in groundwater from multi-model residence time distributions, San Joaquin Valley, USA by Green, Christopher T., Jurgens, Bryant C., Zhang, Yong, Starn, J. Jeffrey, Singleton, Michael J., Esser, Bradley K.

“…•Multi-model residence time distribution (RTD) approach for multiple tracers.•Regional O2 reduction and denitrification rates are estimated in RTD…”
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Isotope Effect of Mercury Diffusion in Air by Koster van Groos, Paul G, Esser, Bradley K, Williams, Ross W, Hunt, James R

“…Identifying and reducing impacts from mercury sources in the environment remains a considerable challenge and requires process based models to quantify mercury…”
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Analytical Method for Measuring Cosmogenic (35)S in Natural Waters by Urióstegui, Stephanie H, Bibby, Richard K, Esser, Bradley K, Clark, Jordan F

“…Cosmogenic sulfur-35 in water as dissolved sulfate ((35)SO4) has successfully been used as an intrinsic hydrologic tracer in low-SO4, high-elevation basins…”
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Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA by Landon, Matthew K., Green, Christopher T., Belitz, Kenneth, Singleton, Michael J., Esser, Bradley K.

“…In a 2,700-km 2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic…”
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Seasonal variation of high elevation groundwater recharge as indicator of climate response by Segal, Daniel C., Moran, Jean E., Visser, Ate, Singleton, Michael J., Esser, Bradley K.

“…•Aquifer recharge is occurring primarily in the lower elevations of Martis Valley.•Wells exhibit seasonal variations in recharge conditions and groundwater…”
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Quantifying groundwater travel time near managed recharge operations using 35S as an intrinsic tracer by Urióstegui, Stephanie H., Bibby, Richard K., Esser, Bradley K., Clark, Jordan F.

“…•Developed sulfur-35 (35S) method for dating managed aquifer recharge (MAR).•35S successfully measured in MAR source waters and groundwater.•35S travel times…”
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Quantifying annual groundwater recharge and storage in the central Sierra Nevada using naturally occurring 35S by Urióstegui, Stephanie H., Bibby, Richard K., Esser, Bradley K., Clark, Jordan F.

“…Identifying aquifer vulnerability to climate change is of vital importance in the Sierra Nevada and other snow‐dominated basins where groundwater systems are…”
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Submarine Groundwater Discharge-Derived Nutrient Loads to San Francisco Bay: Implications to Future Ecosystem Changes by Null, Kimberly A., Dimova, Natasha T., Knee, Karen L., Esser, Bradley K., Swarzenski, Peter W., Singleton, Michael J., Stacey, Mark, Paytan, Adina

“…Submarine groundwater discharge (SGD) was quantified at select sites in San Francisco Bay (SFB) from radium ( 223 Ra and 224 Ra) and radon ( 222 Rn) activities…”
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A membrane inlet mass spectrometry system for noble gases at natural abundances in gas and water samples by Visser, Ate, Singleton, Michael J., Hillegonds, Darren J., Velsko, Carol A., Moran, Jean E., Esser, Bradley K.

“…RATIONALE Noble gases dissolved in groundwater can reveal paleotemperatures, recharge conditions, and precise travel times. The collection and analysis of…”
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Evaluation of historical beryllium abundance in soils, airborne particulates and facilities at Lawrence Livermore National Laboratory by Sutton, Mark, Bibby, Richard K., Eppich, Gary R., Lee, Steven, Lindvall, Rachel E., Wilson, Kent, Esser, Bradley K.

“…Beryllium has been historically machined, handled and stored in facilities at Lawrence Livermore National Laboratory (LLNL) since the 1950s. Additionally,…”
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Ion exchange and trace element surface complexation reactions associated with applied recharge of low-TDS water in the San Joaquin Valley, California by McNab, Walt W., Singleton, Michael J., Moran, Jean E., Esser, Bradley K.

“…Stable isotope data, a dissolved gas tracer study, groundwater age dating, and geochemical modeling were used to identify and characterize the effects of…”
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