In situ optical sensors are rapidly developing and emerging technologies that hold enormous promise for measurement of important biogeochemical parameters at very high temporal resolution (down to seconds) and potentially over large spatial scales. Broader use of these new instruments in watershed research is critical to advance our understanding of biogeochemical cycles. However, the productive application of sensors that were originally developed for oceanographic studies to rivers and streams remains a critical challenge. For example, how do you design deployment strategies for focused studies versus long-term monitoring studies? What are the maintenance and data processing requirements for each sensor or suites of sensors? Which sensors are the most reliable and robust to deploy in lakes and rivers? How do you evaluate and ensure data quality from sensors?

This 3-day training workshop will focus on how to successfully deploy, maintain and process data from in situ optical sensors in freshwater systems. The workshop will focus on the use of in situ fluorometers and spectrophotometers for studies of organic matter, nitrate and particulates in rivers, streams and lakes. The workshop will be led by the USGS Bay-Delta Carbon Group (California Water Science Center), which is one of the few groups conducting research with in situ optical sensors in freshwater systems. The USGS group currently owns and operates instrumentation used for direct measurements and proxies for depth profiles in reservoirs, diurnal studies in rivers and shallow wetlands, storm event sampling, long-term river deployments, and tidal wetland fluxes. This workshop should be of interest to graduate students, post-doctoral fellows, and research scientists working on watershed management, drinking water quality, ecosystem dynamics, and climate change.