USGS Seminar

November 27, 3:00pm - 4:15pm
Mānoa Campus, St. John 11

Seeing the light: Applications of in-situ optical sensors for high frequency water quality monitoring and research

Dr. Brian A. Pellerin, USGS California Water Science Center

A challenge for accurately measuring the sources, loads and cycling of dissolved organic matter (DOM) and nutrients is making measurements at the time scales in which changes occur in aquatic systems. Traditional approaches for data collection (daily to monthly discrete samples) are often limited by high analytical and field costs, difficult site access, and logistical challenges, particularly for long-term sampling at a large number of sites. The ability to make optical measurements (absorbance and fluorescence) in-situ has been known for more than 50 years, but much of the work using commercially-available sensors in rivers and streams has taken place in only the last few years. Relatively simple optical measurements made in-situ are being incorporated into several USGS research and monitoring programs, resulting in advanced understanding of constituent loads, sources, and cycling in freshwater systems. This talk will present several examples from rivers and streams that highlight the application of continuous optical measurements for understanding DOM and nutrient dynamics at intervals of minutes to hours, as well as proxy measurements for constituents that are significantly more difficult and expensive to measure at high frequencies such as methylmercury and trihalomethane.

Short bio: Received B.S. (1998) and Ph.D. (2004) from the University of New Hampshire, M.S. (2000) from the University of Maine. Ph.D. was in the interdisciplinary Natural Resources and Earth Systems Science program and focused on the hydrology and nutrient biogeochemistry of small urban watersheds. I have been at the USGS CA Water Science Center since 2004 as an NRC Post-Doc (2004-2007) and Soil Scientist/Research Soil Scientist (2007-present). Most of my current work is on the use of in situ optical sensors for carbon and nutrients in small watersheds and large coastal rivers across the country.

Event Sponsor
Water Resources Research Center, Mānoa Campus

More Information
Philip Moravcik, 956-3097,

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Tuesday, November 27

7:30am Maui Campus, Pilina Bldg., Wellness Center
8:00am Mānoa Campus, Tokioka Room (Moore Hall 319)
10:00am Mānoa Campus, Campus Center Dining Room 203 E
10:30am Mānoa Campus, Legacy Path
11:30am Mānoa Campus, Law School CR3
11:45am Mānoa Campus, Law School, CR 4
12:00pm Mānoa Campus, St. John Auditiorium (St. John, Room 011)
12:00pm Mānoa Campus, Law School, Moot Court Room
1:30pm Mānoa Campus, Orvis Auditorium
3:00pm Mānoa Campus, St. John 11
5:30pm Mānoa Campus, Law School, Classroom 2
5:30pm Mānoa Campus, Classroom 2
6:00pm Windward Campus, Hale Kuhina 115
6:30pm Mānoa Campus, Biomed B103
7:30pm Mānoa Campus, Orvis Auditorium