Tim J Baxter

Fluorescence sensor measurements in sediment suspensions to evaluate turbidity corrections

The use of field-deployable fluorescence sensors to better understand dissolved organic matter concentrations and composition has grown immensely in recent years. Applications of these sensors to critical monitoring efforts have also grown to encompass post-fire monitoring, wastewater tracking, and use as a proxy for various contaminants. Despite the growth, it is well known that these sensors are subject to various interferences and require corrections for temperature, turbidity, and concentration effects. Although temperature corrections are widely applicable across sensors, the turbidity and concentration corrections can be site-specific and/or sensor-specific. The corrections can even be subject to changes in...

Categories: Data; Tags: DOC, USGS California Water Science Center, USGS Science Data Catalog (SDC), Water Quality, biota, All tags... continuous monitoring, dissolved organic carbon, fDOM, fluorescence, high frequency, in situ, optical sensor, organic matter, standard solution, turbidity, water quality, Fewer tags

Laboratory fluorescence and total dissolved nitrogen measurements for surface water samples collected from the Rio Grande during a 24-hr time period near Albuquerque, New Mexico

Here, we present data supporting temporal variability and sources of PFAS in the Rio Grande through an arid urban area using high-frequency sampling and novel samplers. Data are compiled into two tables: 1) full fluorescence spectra in vectorized format, and 2) summary file of concentrations of total dissolved nitrogen and commonly extracted field-based sensor arrays. Data are reported from two sites at Rio Grande, New Mexico during a 24-hour collection period. Two field blanks, one field replicate, and two laboratory replicates are reported for 26 environmental samples.

Categories: Data; Tags: California, Organic Matter Research Lab, Sacramento, TDN, USGS Science Data Catalog (SDC), All tags... Water Quality, continuous monitoring, environment, fDOM, fluorescence, high frequency, in situ, optical sensor, organic matter, total dissolved nitrogen, water quality, Fewer tags

Above-water hyperspectral field spectroscopy measurements at Franks Tract in the Sacramento-San Joaquin Delta, California

Hand-held hyperspectral spectroscopy data were collected in 2022 in Franks Tract, a flooded area located in the central Sacramento-San Joaquin Delta of California. The data were collected from a boat and co-located within pixels from the Ocean Land Color Imaging (OLCI) sensor on the Sentinel-3A and 3-B satellites. Data from 16 sites within 7 OLCI pixels were collected on three days: July 14, August 3, and November 3, 2022. Radiance measurements from the water, sky, and a reflectance plaque were collected to enable calculation of water-leaving radiance (Mobley 1999, Ruddick et al. 2019). At the location of each spectroscopy site, discrete water samples were also collected and analyzed for chlorophyll a, dissolved...

Categories: Data; Tags: Central Valley, Chlorophyll, Cyanobacteria, Franks Tract, Harmful algal blooms, All tags... Hyperspectral, Phytoplankton, Remote Sensing, Sacramento-San Joaquin Delta, San Joaquin, USGS Science Data Catalog (SDC), Water Quality, Water Quality, biota, Fewer tags