About the Experimental Lake Erie Harmful Algal Bloom (HAB) Tracker
The NOAA Experimental Lake Erie Harmful Algal Bloom (HAB) Tracker is a forecast model in development that shows where the blooms are, how big they are, and where they are likely headed in Lake Erie. Similar to a weather forecast, this new tool provides a daily HAB update and a five day outlook. This forecast is based on satellite imagery, weather forecast information, and modeled currents in Lake Erie during the bloom season. The HAB Tracker is updated daily with forecast currents, and the position of the bloom is updated when a cloud-free satellite image is available. The HAB Tracker also predicts the vertical distribution of buoyant Microcystis colonies, which provides information on when the bloom is likely to form surface scums versus mixing from surface to bottom.
How does the Lake Erie HAB Tracker work?
The NOAA Experimental Lake Erie Harmful Algal Bloom (HAB) Tracker uses the latest satellite imagery of Lake Erie to produce an up-to-date estimate of the present location and 5-day forecast of HABs in western Lake Erie. This forecast is based on satellite images, weather forecast information, and modeled currents in Lake Erie during the HAB season.
Satellite images are processed by the NOAA HAB Operational Forecast System to obtain the “cyanobacterial index”, a measure of HAB intensity. HABs in Lake Erie are mostly composed of Microcystis—a type of cyanobacteria that produces the family of toxic compounds called, microcystins (additional information about Great Lakes HABs and related research). The position of the bloom is updated within the HAB Tracker forecast when a cloud-free satellite image is available.
Modeled currents are produced by the Great Lakes Coastal Forecasting System (GLCFS), which is driven by observed and forecast weather information. Modeled currents inform the HAB Tracker predictions for where the bloom will travel and the depth to which the bloom may mix into the water column. The HAB Tracker is updated daily with the latest weather forecast and modeled currents.
For more, see the HAB Tracker FAQ section below.
Who uses the Lake Erie HAB Tracker?
The HAB Tracker provides public water systems, anglers, beach-goers, and others with timely information about the blooms, so that they may avoid the negative impacts of HABs and continue to use and enjoy Lake Erie.
The HAB Tracker can provide users with useful predictions about the concentration and location of blooms in Western Lake Erie. If users intend to travel to an area where high concentrations of HABs are predicted to occur, precautions can be taken to avoid skin contact and seek clearer water. When HABs are present, they usually affect isolated areas, so users may choose to visit part of Lake Erie that is less affected by HABs. The HAB forecasts help members of the public make informed decisions when a bloom is affecting their area.
What’s next for the Lake Erie HAB Tracker?
Advances made to our HAB forecasting capabilities through this research program are on a fast track to be transitioned into operations. The research to operations (R20) is the pathway by which research is developed into a useful tool or product and implemented into an automated or operational environment accessible for use by the public—in this case the operational product is the NOAA Lake Erie Harmful Bloom Forecast.
Because the HAB Tracker is an experimental model, improvements are actively being made to the model. Research has lead to improved understanding of variables affecting Microcystis buoyancy and growth, which will be incorporated into future versions of the HAB Tracker. In 2015, NOAA GLERL & CIGLR began a weekly airborne campaign to conduct hyperspectral monitoring of Lake Erie’s blooms in coordination with NASA Glenn. When incorporated into the HAB Tracker, these hyperspectral images will improve the precision of nearshore monitoring while providing clearer, more reliable weekly images of HABs in the western basin of Lake Erie by flying sensors under the clouds.
Who can I contact for additional information?
Info Services Branch Chief
|General HABs information:
Assistant Research Scientist
|General HABs and ESP:
|HAB sampling / monitoring:|
Associate Research Scientist
HAB Product Coordinator
HAB Tracker FAQ
How do I use the HAB Tracker?
The HAB Tracker is a forecast model in development that shows where the blooms are, how big they are, and where they are likely headed in Lake Erie. Similar to a weather forecast, this new tool provides a daily HAB update and a five day outlook. The information provided by the HAB Tracker web page can help users prepare for the likely occurrence of a HAB event, so that negative impacts may be avoided when possible, for example by avoiding visible scums or by choosing to visit part of Lake Erie that is less affected by HABs.
On the HAB Tracker web page, the HAB Tracker forecast is presented as a surface-view animated forecast of the Western Basin, and as a graphical forecast showing the vertical profile of HABs in the water column at specific stations.
Other information is included on the web page to provide users with context for understanding the HAB Tracker forecast. When viewed together, these data allow users to gain a more complete picture of predicted conditions on Lake Erie. This information includes the 5-day wave height and wind speed forecasts provided by the
Great Lakes Coastal Forecasting System (GLCFS), as well as the latest reported microcystins concentrations measured at NOAA monitoring stations in the Western Basin. The latest relatively cloud-free satellite image of Lake Erie used to initialize the HAB Tracker model is also included on this page for your reference.
How accurate is the HAB Tracker forecast?
To evaluate the accuracy of the model, researchers apply the model to HAB events that occurred in the past and compared model predictions to subsequent satellite-observed HAB events that describe what actually occurred on the lake. This process is known as skill assessment. On average over a six-day period, the HAB Tracker model was found to be more accurate than a previous version of the model, and more accurate than assuming no change in the bloom from the most recent satellite image, which represents the best available alternative to using the model (Rowe et al., 2016). There is some uncertainty in the speed and direction of bloom movement. Model accuracy at making predictions for specific locations was improved when model output was averaged over a 3-km square surrounding the location. Therefore, when looking at model predictions for a specific location, it is informative to look at nearby locations as well.
The HAB Tracker is an experimental forecast model, which means that researchers are actively working to increase the model’s accuracy every year by improving the quality of input data, and of physical and biological processes represented in the model (such as wind speed, currents, Microcystis movement in the water column, etc.). Since the launching of the HAB Tracker in 2014, improvements to the model have been incorporated each year.
Rowe, M.D., Anderson, E. J., Wynne, T. T., Stumpf, R. P., Fanslow, D. L., Kijanka, K., Vanderploeg, H. A., Strickler, J. R., Davis, T. W. (2016), Vertical distribution of buoyant Microcystis blooms in a Lagrangian particle tracking model for short-term forecasts in Lake Erie. Journal of Geophysical Research:Oceans, 121: 5296-5314.
Is the growth of Microcystis represented in the model?
The HAB Tracker forecast model doesn’t consider growth or decay of Microcystis. The HAB Tracker assumes that changes in the bloom over a relatively short period of time (~ 5 days) are mainly due to physical processes such as transport by currents, vertical mixing, and buoyancy.
How does the model predict formation of surface scums?
Microcystis colonies often float to the surface under calm conditions and form surface scums. The highest concentrations of Microcystis biomass, chlorophyll-a, and potentially toxins are often associated with these scums. Under windy conditions, turbulent mixing in the water column overcomes buoyancy, resulting in a uniform concentration of Microcystis colonies from surface to bottom. The HAB Tracker receives information on the intensity of vertical mixing from the LEOFS model, which is driven by wind data. The HAB Tracker assumes that Microcystis colonies are floating, based on measurements conducted by CIGLR and GLERL (Rowe et al., 2016). Microcystis colonies also sink under some conditions, which is not presently represented in the HAB Tracker model. Researchers are exploring updates to the model to consider the effects of light and nutrients on the buoyancy and growth of Microcystis.
Where does funding come from for the HAB Tracker?
The development of the HAB Tracker is funded by Great Lakes Restoration Initiative support along with additional contributions from NOAA GLERL.
NOAA is authorized by the Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA 1998, 2004) to help communities counter this increasing threat through research in its labs and centers and to augment our expertise by funding research by our extramural partners.
How should the color scale of the HAB Tracker be interpreted?
The animated 5-day forecast predicts the intensity of the bloom, which means that yellow or red areas on the HAB Tracker forecast indicate a high concentration of Microcystis on the lake surface (scum) is likely. However, the presence of scum does not necessarily mean that the bloom is toxic, because not all blooms produce microcystins. A highly concentrated bloom does have greater potential to produce higher concentrations of algal toxins than a less concentrated bloom. Researchers are currently working on ways to forecast toxin concentrations. The HAB Tracker does not predict toxin concentrations. For the latest toxin measurements taken at our monitoring stations in the western basin, see the Microcystins Concentrations Map. For more information about public health warnings associated with levels of microcystins, visit the Ohio Environmental Protection Agency’s webpage.
How does NOAA & CIGLR’s HAB work support the prevention of future HABs emergencies, like the 2014 Toledo Water Crisis?
HAB monitoring and forecasts help public water systems managers and other Lake Erie users to prepare and take actions to avoid the potential negative impacts of HABs in Lake Erie. Weekly and real-time data from field monitoring, buoys, and sensors provide managers with the latest available information on the location, extent, and toxicity of HABs. These data also assist in the development of tools that predict the magnitude and movement of algal blooms.
HAB forecasts alert coastal managers to blooms before they cause serious damage, helping users like public water systems managers to prepare to treat their raw water for removal of microcystins. Researchers with NOAA GLERL & CIGLR also seek to communicate with stakeholders, such as public water systems managers, beachgoers, anglers, etc., throughout the research process to ensure that research products meet the needs of the public.
It is also important to note that substantial improvements have been made to the water treatment infrastructure and regulatory framework since 2014, which makes it much less likely that toxins would enter the water supply even if water plant intakes are affected by HABs. See the Ohio EPA website, for more.
Additional NOAA HAB Forecast Products