Publications
The following list of California Water Science Center publications includes both official USGS publications and journal articles authored by our scientists.
Filter Total Items: 1734
Using nitrate dual isotopic composition (δ15N and δ18O) as a tool for exploring sources and cycling of nitrate in an estuarine system: Elkhorn Slough, California
Nitrate (NO3−) concentrations and dual isotopic composition (δ15N and δ18O) were measured during various seasons and tidal conditions in Elkhorn Slough to evaluate mixing of sources of NO3− within this California estuary. We found the isotopic composition of NO3− was influenced most heavily by mixing of two primary sources with unique isotopic signatures, a marine (Monterey Bay) and terrestrial ag
Authors
Scott D. Wankel, Carol Kendall, Adina Paytan
GRS evidence and the possibility of paleooceans on Mars
The Gamma Ray Spectrometer (Mars Odyssey spacecraft) has revealed elemental distributions of potassium (K), thorium (Th), and iron (Fe) on Mars that require fractionation of K (and possibly Th and Fe) consistent with aqueous activity. This includes weathering, evolution of soils, and transport, sorting, and deposition, as well as with the location of first-order geomorphological demarcations ident
Authors
J. M. Dohm, V.R. Baker, W. V. Boynton, A.G. Fairen, J.C. Ferris, M. Finch, R. Furfaro, T.M. Hare, D.M. Janes, J.S. Kargel, S. Karunatillake, J. Keller, K. Kerry, K.J. Kim, G. Komatsu, W.C. Mahaney, D. Schulze-Makuch, L. Marinangeli, G.G. Ori, J. Ruiz, S.J. Wheelock
Assigning land use to supply wells for the statistical characterization of regional groundwater quality: Correlating urban land use and VOC occurrence
Many national and regional groundwater studies have correlated land use "near" a well, often using a 500 m radius circle, with water quality. However, the use of a 500 m circle may seem counterintuitive given that contributing areas are expected to extend up-gradient from wells, and not be circular in shape. The objective of this study was to evaluate if a 500 m circle is adequate for assigning la
Authors
T.D. Johnson, K. Belitz
Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed sediment and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and sediment transport models used for this purpose typically are calibrated to water level, currents, and/or suspended-sediment concentratio
Authors
N. K. Ganju, D. H. Schoellhamer
Transport of viruses through saturated and unsaturated columns packed with sand
Laboratory-scale virus transport experiments were conducted in columns packed with sand under saturated and unsaturated conditions. The viruses employed were the male-specific RNA coliphage, MS2, and the Salmonella typhimurium phage, PRD1. The mathematical model developed by Sim and Chrysikopoulos (Water Resour Res 36:173–179, 2000) that accounts for processes responsible for removal of viruses du
Authors
R. Anders, C.V. Chrysikopoulos
Managing water to protect fish: A review of California's environmental water account, 2001-2005
The Sacramento-San Joaquin Delta, the landward reach of the San Francisco Estuary, provides habitat for threatened delta smelt, endangered winter-run Chinook salmon, and other species of concern. It is also the location of huge freshwater diversion facilities that entrain large numbers of fish. Reducing the entrainment of listed fishes into these facilities has required curtailment of pumping, red
Authors
L. R. Brown, W. Kimmerer, R. Brown
Coastal groundwater dynamics off Santa Barbara, California: combining geochemical tracers, electromagnetic seepmeters, and electrical resistivity
This paper presents repeat field measurements of 222Rn and 223,224,226,228Ra, electromagnetic seepage meter-derived advective fluxes, and multi-electrode, stationary and continuous marine resistivity surveys collected between November 2005 and April 2007 to study coastal groundwater dynamics within a marine beach in Santa Barbara, California. The study provides insight into magnitude and dynamics
Authors
Peter W. Swarzenski, John A. Izbicki
Metals and trace elements in giant garter snakes (Thamnophis gigas) from the Sacramento Valley, California, USA
The giant garter snake (GGS; Thamnophis gigas) is a federally listed threatened species endemic to wetlands of the Central Valley of California. Habitat destruction has been the main factor in the decline of GGS populations, but the effects of contaminants on this species are unknown. To contribute to the recovery of these snakes, the U.S. Geological Survey (USGS) began studies of the life history
Authors
Glenn D. Wylie, Roger L. Hothem, D.R. Bergen, Lisa L. Martin, Robert J. Taylor, Brianne E. Brussee
Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay
Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wet
Authors
John Y. Takekawa, A.K. Miles, D. C. Tsao-Melcer, D. H. Schoellhamer, S. Fregien, N.D. Athearn
Assessing the sources and magnitude of diurnal nitrate variability in the San Joaquin River (California) with an in situ optical nitrate sensor and dual nitrate isotopes
1. We investigated diurnal nitrate (NO3−) concentration variability in the San Joaquin River using an in situ optical NO3− sensor and discrete sampling during a 5‐day summer period characterized by high algal productivity. Dual NO3− isotopes (δ15NNO3 and δ18ONO3) and dissolved oxygen isotopes (δ18ODO) were measured over 2 days to assess NO3− sources and biogeochemical controls over diurnal time‐sc
Authors
Brian A. Pellerin, Bryan D. Downing, Carol Kendall, Randy A. Dahlgren, Tamara E.C. Kraus, John Franco Saraceno, Robert G. M. Spencer, Brian A. Bergamaschi
User Manual for the Data-Series Interface of the Gr Application Software
This manual describes the data-series interface for the Gr Application software. Basic tasks such as plotting, editing, manipulating, and printing data series are presented. The properties of the various types of data objects and graphical objects used within the application, and the relationships between them also are presented. Descriptions of compatible data-series file formats are provided.
Authors
John M. Donovan
Hindcasting of decadal‐timescale estuarine bathymetric change with a tidal‐timescale model
Hindcasting decadal-timescale bathymetric change in estuaries is prone to error due to limited data for initial conditions, boundary forcing, and calibration; computational limitations further hinder efforts. We developed and calibrated a tidal-timescale model to bathymetric change in Suisun Bay, California, over the 1867–1887 period. A general, multiple-timescale calibration ensured robustness ov
Authors
Neil K. Ganju, David H. Schoellhamer, Bruce E. Jaffe