Autonomous Underwater Glider Observations in Southern Lake Ontario and Niagara Plume

Session: State of Lake Ontario: 2003-2018 CSMI Overview (2)

Paul McKinney, EPA Mid Continent Ecology Division, [email protected]
Tom Hollenhorst, EPA Mid Continent Ecology Division, [email protected]
Terry Brown, USEPA, [email protected]
Joel Hoffman, US EPA Office of Research and Development, [email protected]

Abstract

High resolution, continuous observations of water quality are required to improve understanding of the rates and mechanisms of mixing between nearshore and offshore areas in the Great Lakes, however obtaining observations required for this understanding is difficult using traditional sampling methods. To address this challenge, USEPA, assisted by partner agencies, deployed an autonomous Slocum Glider in southern Lake Ontario and the Niagara River plume as part of the 2018 CSMI. The glider was outfitted with sensors that continuously measured temperature, conductivity, dissolved oxygen as well as optical backscatter (a proxy for Total Suspended Matter) and chlorophyll-a and CDOM concentrations during two 3 week missions. Results reveal differences in the scales of variability between nearshore and offshore areas in early summer prior to lake-wide stratification versus late summer.