Lake Erie Center

NSF FSML: Environmental Sensor Network for the Lake Erie Center

Scientific and Educational Merit

The project objective is to assemble and implement a real-time collaborative environmental sensor network to evaluate carbon/water cycling in the Great Lakes, providing fundamental data for understanding ecosystem and climate changes, which will be communicated to the scientific, agency, and educational communities and to the public. The southern shore of Lake Erie and particularly Maumee Bay are intensely human-impacted systems due to high human population density, industrial activity, and agricultural runoff; for which this proposed sensor system network will be invaluable. This environmental sensor system will greatly increase the capacity of the University of Toledo’s Lake Erie Center (LEC) and the entire Great Lakes region to conduct crucial research on climate change, protecting our country’s freshwater resources, maintaining productive fisheries, and alleviating pollution and harmful algal blooms. Many of our current research projects have immediate application such as tracking E. coli populations, monitoring harmful algal blooms, remediating waste disposal sites, constructing wetlands, and enhancing sportfish ecology and population structure. The sensor network will move the LEC and the Great Lakes region forward decades by establishing a state-of-the-art program in assessing carbon exchange, water quality, nutrient fluxes, climate changes, hydrological disturbances, and parameters governing their interactions with biological systems (e.g., larval fish movements, plankton distributions, algal blooms, fishery and invertebrate communities, etc.).

This environmental sensor system will consist of eddy covariance flux sensors on towers in Lake Erie along with a mobile unit, to collect and disseminate essential data on the net ecosystem exchange of green house gases (CO2, CH4), H2O, and energy, as well as the physical and chemical properties of the western Lake Erie Basin. Building on existing partnerships with agencies including EPA, NOAA, USDA, USGS, NASA, USDA, USFWS, Great Lakes Fishery Commission, the Ohio, Michigan, Pennsylvania, and New York Departments of Natural Resources, and the Ontario Ministry of Natural Resources allows for rapid dissemination of information and high potential for implementation. These agencies have joined our “Environmental Sciences Leaning Community at the Land-Lake Ecosystem Interface”, and will aid the proposed sensor network (see appended letters of collaboration). All data will be open access to promote education, research, and public awareness.

Two key areas of research will form our initial baseline: (1) Observations of Carbon and Water Fluxes on Lake Erie and (2) Improved Measurements of Harmful Algal Bloom (HAB) Biomass and Seasonal Dynamics, and are detailed below.


Research Area 1: Observations of Carbon and Water Fluxes on Lake Erie

The Great Lakes contain 18% of the earth’s surface fresh water and are among the most critical ecosystems that influence the continental carbon and water budget in North America. Yet, no acceptable conclusions have been reached in determining the carbon and water budgets and global warming potential (GWP) of any of the Great Lakes due to the extreme difficulties of collecting reliable observations over 6open water. To date, no significant scientific effort has been conducted on the lakes in regards to carbon and water budgets. These lake systems are also very complex to understand because of their interactions with the surrounding landscapes where intensive land use and human activities significantly influence the environment. For example, a recent study of the carbon cycle in Lake Superior by Urban et al. (2005) found mis-matches of carbon fluxes as large as 10 fold greater than those previously believed (McManus et al. 2003). One of our long-term goals at the LEC is to model and predict the changes of two most important resources of the ecosystem: carbon and water. Towards this goal, our team also aims to conduct integrated research on the underlying processes and controlling mechanisms so that predictions can be made with alternative future climate and management policies.

Carbon and water budgets of large lakes include four major processes: precipitation, flows between the land and lake (river and shorelines), deposition and decomposition at the lake bottom, and gas exchanges between the lake surface and the atmosphere. Within the lake, biotic processes (e.g., photosynthesis and respiration) that are influenced by chemical and physical properties play direct roles in the above four major fluxes (i.e., the underlying processes). With our advantageous location and facilities at the LEC, this sensor network will establish the essential infrastructure to measure the exchange of CO2 and H2O between the lake surface and the atmosphere, as well as the key ancillary ecosystem parameters (e.g., microclimate and water properties) to conduct mechanistic explorations of Lake Erie.

We will install two permanent monitoring stations (PermS1, PermS2) on permanent structures in Lake Erie and a shipboard station on the LEC’s research vessel (BoatS). PermS1 will be mounted on a permanent navigational structure located about 16 km offshore in western Lake Erie, complementing existing NOAA GLERL sensors at the same location PermS2 will be mounted on the City of Toledo water intake (crib) ~3 km from shore. These stations will provide continuous data on offshore and nearshore atmospheric and water quality conditions, while BoatS will be used to measure the fluxes across the lake (i.e., spatial coverage). Each station will include an open-path eddy covariance system (Noormets et al. 2008) for measuring net exchange of CO2, H2O and energy, a full microclimatic station and sensors (Chen et al. 2004), and a submersible multiple-probe sonde including optical chlorophyll a and phycocyanin (cyanobacteria pigment) and turbidity sensors, an absorption spectrometer, and backscatter meter. Measurements at these stations will be complemented by satellite-derived measurements to examine spatial variability within the lake. Water surface temperature from the MODIS, AVHRR and chlorophyll measurements from SEAWiFS, MODIS- Aqua and MERIS will be used to interpolate results between the towers.

This sensor network will join our other existing and to-be-constructed flux towers on adjacent land and wetland sites to form an array, thus scaling up the flux measurements at broader spatial scales. All towers are equipped with the same flux sensors to assure comparability. Due to the large amount of CH4 fluxes from the coastal wetlands and agricultural fields, we propose to add a CH4 gas analyzer (LI7700 and LI7550) at these sites. Our data will be archived and displayed at a central server, available to the public and other researchers.

Research Area 2: Improved Measurements of Harmful Algal Bloom (HAB) Biomass and Seasonal Dynamics

Recent harmful algal blooms in western Lake Erie create serious problems for the ecology of the lake and local human populations. Summer blooms of the cyanobacteria Microcystis produce levels of algal toxins that exceed limits set by the WHO (Rinta-Kanto et al. 2005) and force municipal water utilities to spend large sums ($3,000-4,000/day) in additional filtration costs to ensure a safe water supply. Toxins also are transferred through the food web to sportfish that may be consumed by humans. The decomposition of algae following a bloom may contribute to the increasing problem of hypoxia in some bottom regions of Lake Erie. Efforts to remediate blooms will depend on a thorough understanding of their causes and the environmental factors that influence their magnitude. Understanding bloom dynamics, in turn, depends on accurate and frequent measurements of bloom size and density. These measurements are best made by remote sensing and several advances have been made in determining bloom biomass using satellite data (Wynne et al. 2008, Becker et al. 2009). HAB algorithms, however, are limited by the availability of ground-truth data. Algal pigment sensors (chlorophyll a, phycocyanin) are already deployed each summer at PermS1 (NOAA GLERL), and we propose to add similar sensors at PermS2 and on the mobile boat platform. These sensors would be deployed in bloom areas to provide phytoplankton data at a much higher temporal resolution (1-30 minutes) than previously available from boat-based surveys (1-2 weeks). The combination of newly acquired algal pigment sensors, an absorption spectrometer and backscatter meter, combined with existing reflectance spectrometers will provide excellent ground supporting data for improving satellite algorithms in the optically complex western basin. These data will be used to evaluate and improve atmospheric corrections necessary for utilizing satellite and airborne data to accurately map the HAB biomass. They will also be used in the development of algorithms for satellite and airborne sensors.

In addition to producing advances in remote sensing algorithms, the data generated by our sensors will be incorporated into Linked Hydrodynamic –Sediment Transport –Eutrophication Models that are presently being developed to link watershed processes to HAB development (more information, PDF). Lake Erie Center data have already contributed to the development of these models and the higher resolution data provided by the additional sensors would lead to significant improvements in modeling, especially in capturing the episodic changes caused by storm and flooding events.  The new sensor data will also be used in the development and calibration of Ecological Forecasting models for Lake Erie (ECOFORE) that link watershed processes to lake eutrophication and hypoxia (more information, PDF). Finally, the location of phycocyanin sensors at PermS2 may provide the City of Toledo Water Utility with an early warning of increasing HAB species concentration and the potential for toxins that would need to be filtered from the water supply.

Key Scientific Questions

Based on the sensor network, we anticipate a wide range of collaborative effort with scientists from academic institutions and applied research groups. Some initial questions include:

  • How much water is evaporated from the Lake Erie Basin and what are the driving forces for its dynamics at various temporal scales? Would changes in water chemistry, physical properties, and hydrological cycle affect (and be affected) the water loss?
  • How does changing climate and increasing extreme climate affect the fluxes of CO2, CH4, water, and energy within the western Lake Erie Basin, including water and adjacent landscapes?
  • How do human activities (e.g., alternative land uses, urbanization) influence the overall functions of the basin?
  • Will the basin respond the changing climate similarly to other ecosystems worldwide? If not, why and how?
  • How large are HAB blooms in the western basin at any given time?
  • What factors affect algal bloom size and dynamics?
  • What portion of the carbon fluxes in the western basin is related to algal blooms?

Data Open Use, Access, and Collaborators

All data will be processed using the EC_Processor developed at the LEES Lab (Noormet et al. 2008). Additional programming codes will be jointly developed with support of Dr. C. Fairall of NOAA to address the motion effect of turbulent water. All of our data (raw and processed) will be openly posted at the project server via the LEES Lab and the Lake Erie Center’s website for broader uses by the scientific community (i.e., promoting future scientific investigations), public agencies, and general public (e.g., forecasting and monitoring). Our data collected in B5 (fluxes of CO2, CH4, water and energy) will be constructed following current protocols (more information). No password will be applied to promote the broadest use. We will adopt NOAA/GLERL’s current protocols to allow the public to visually explore the changes of fluxes at each station. In addition, we expect the data will be submitted to two major networks -- AmeriFlux/FLUXNET and GLEON.

  • AmeriFflux/USCCC of the FLUXNET: The FLUXNET is a "network of regional networks," coordinates regional and global analysis of observations from micrometeorological tower sites. The flux tower sites use eddy covariance methods to measure the exchanges of carbon dioxide (CO2), water vapor, and energy between terrestrial ecosystems and the atmosphere ( fluxnet/index.cfm). It has been funded by the National Science Foundation and DOE to promote data sharing among interested parties. Globally, there are over 500 sites. One of the efforts (aka, the LaHuile Dataset) has generated over 1500 site-years of data for sharing among the scientific community. Since 2007, dozens of scientific publications have been made with this database. The AmeriFlux is the core member of FLUXNET. The US-China Carbon Consortium (USCCC) where COI J. Chen serves as the chief scientist, is another flux network and member of FLUXNET that has 12 institutions from China and seven from USA (see institution list). So far, USCCC has served as a platform for more than 50 graduate students to conduct their thesis research. All of the data from this study will be incorporated into FLUXNET and USCCC. We anticipate the data from this new sensor network will play a major role in supporting research fluxes along the gradients of water-land and/or urban-rural landscapes. Additionally, the flux data collected through our sensors network will be the only site with cluster towers that allow the scientists to invest within-region spatiotemporal variation (i.e., a knowledge gap).
  • GLEON (Great Lakes Ecosystem Observation Network) aims to facilitate interaction and build collaborations among an international, multidisciplinary community of researchers focused on understanding, predicting, and communicating the impact of natural and anthropogenic influences on lake ecosystems by developing, deploying, and using networks of emerging observational system technologies and associated cyberinfrastructure ( It is developed around network science questions. It recognizes that technology is providing data at spatial and temporal scales that outstrip current models and theory/questions—thus providing opportunities for generating new scientific understanding and developing a multidisciplinary community.  The proposed sensor network fits GLEON’s mission well.  Our site will be a new member of GLEON (already supported by its executive committee), with unique contribution to fill the gap on fluxes, for which we expect to be implemented by other GLEON members.
  • NEON (National Ecological Observation Network). The GLACEO committee of NEON has proposed the Lake Erie Center (LEC) as a candidate site.  The NEON team at the University of Toledo – a founding member of NEON, Inc -- will continue our collaborative effort in hope that broader impact will be generated.   The data from this sensor network are considered as the core information for any NEON site; and we will organize them in alignment of NEON protocols.
  • NASA Glenn Research Center Ecosystem Monitoring Program. NASA Glenn Research Center in Cleveland, Ohio in collaboration with Bowling Green State University are working with the University of Toledo to utilize remote sensing to link the tower observations to the lake and surrounding area.  Dr. John Lekki from NASA Glenn is the lead scientist developing their aircraft remote sensing initiative. Dr. Lekki will lead a group of scientists including Gary Hunter, Frank Vergilii, Lawrence Greer, Roger Tokars, Aaron Swank, Robert Romanofsky, Laura Evans, Obadiah Kegege, James Scott developing aerial remote sensing with aircraft and unmanned aircraft system called the Aerial Investigation of the Great Lakes Ecosystems (AIGLE) project to study the Lake Erie ecosystem. NASA Glenn’s assets include an advanced hyperspectral imaging (HIS) system, Microelectrome-chanical Systems (MEMS)-based Chemical Sensor Array and four manned aircraft. The sensors sniff out trace gas species as the aircraft flies. These observations will be linked to the University of Toledo’s in situ tower observations and remote sensing imagery. The aircraft have the capability to observe carbon dioxide, carbon monoxide, methane, nitrogen oxides and sulfur dioxide. The sensors at NASA Glenn complement the sensors that will set up in this proposal to allow simultaneous measurements at individual locations both in the water and directly above the water, and at a larger scale from aircraft. This allows for a ground truth data at the sensor locations to be scaled regionally. 

Education Plan and Public Dissemination of Data and Results

  • Real Time Data Dissemination: Data acquired by this sensor system will be archived in a database at the LEC and will be maintained by the LEC communications specialist. Duplicates of all raw and QA/QC’d sensor data will be stored at an off site location. Real time data will be displayed on a web interface for users (on this, the LEC's website). Data will be formatted for inclusion in the GLEON database. Dr. Chen will lead the effort in developing an open-to-the-public effort for managing and archiving the data from these sensors for broader uses by GLEON, FLUXNET, etc.
  • Sensor Network Project Focus for 2012-13 NSF GK-12 Program at the Lake Erie Center: Utilization of the real-time data and results from the proposed sensor network will be the emphasis of our Gk-12 program in 2012-13, featuring a summer course training program for high school teachers and graduate fellows, year-round learning-community seminars in our monthly evening seminar series, high school classroom exercises, and science fair projects. Graduate Fellows in High School STEM Research: An Environmental Science Learning Community at the Land-Lake Ecosystem Interface, partners advanced graduate students in STEM disciplines with high school teachers and their minority students to: (1) Generate student enthusiasm for STEM careers by engaging them in hands-on research into environmental problems; (2) Exchange STEM knowledge and pedagogies between graduate students and high school teachers resulting in cutting-edge environmental science content and increased teaching and communication skills; and (3) Develop hands-on solutions to environmental problems along schoolyard stream ecosystems feeding the Great Lakes. Partners include federal, state, and local environmental agencies.  High school classroom activities will be developed and disseminated that use the real-time sensor network.
  • Undergraduate Research Focus on Sensor Network Projects through our NSF URM Program at the Lake Erie Center and main Campus:  Undergraduate Research Students and Mentoring in Land-Lake Environmental Science. The goal of this URM program is to prepare 30 young minority scientists for graduate school in biology through hands-on sustained independent environmental research, effective mentorship, and active engagement in a research learning community. Independent research by our URM students will analyze and develop solutions for urban, industrial, and agricultural impacts on our local terrestrial and aquatic ecosystem continuum. Several URM students and projects will focus on the proposed sensor network program.
  • Sensor Network Training through GLOBE program: GLOBE is a K-12 outreach program engaging students and scientists in real-world research supported by NASA and NSF. Seminars and workshops train teachers and education students in GLOBE protocols, focusing on authentic research, collaboration with scientists, and inquiry-based research projects (Ault et al. 2006). Over 14,000 schools in 100 countries take observations on atmosphere/climate, hydrology (water quality), soils, land cover/biology and phenology. The LEC hosted a GLOBE train-the-trainer 2-week workshop that trained scientists from UT, Bowling Green State University, the Toledo Zoo, WGTE (Toledo’s PBS TV station) and Imagination Station (a hands-on science museum) to host GLOBE teacher workshops. Subsequently, 350+ teachers have been GLOBE trained at the LEC and at other sites in NW Ohio (Drs. Czajkowski & Spongberg). This program will be integrated with proposed sensor network.

  • Sensor Network Training through Inquiry Masters Program for Advancing Content for Teachers (IMPACT), U. S. Depart. Education through the Teachers for a Competitive Tomorrow program pays for M.S. degrees in Environmental Sciences for 10 teachers in 2 cohorts at the University of Toledo’s Department of Environmental Sciences. Teachers will help pilot use of the sensor data network in the classroom.

  • Undergraduate/Graduate Course in Remote Sensing of the Environment: The data generated by the sensors will be used in the University of Toledo Department of Environmental Science Course EEES 4490/5490/ GEPL 4490/5490 (Remote Sensing of the Environment). In this class students will use the data from these sensors for a lab exercise on aquatic remote sensing, where they will learn how to integrate these types of data into remote sensing analysis.

Last Updated: 3/23/15