NOAA Great Lakes Environmental Research Laboratory

The latest news and information about NOAA research in and around the Great Lakes


Leave a comment

Five decades of Great Lakes ice cover data – and where to find it

Understanding the major effects of ice on the Great Lakes is crucial. Ice cover impacts a range of societal benefits provided by the lakes, from hydropower generation to commercial shipping to the fishing industry. The amount of ice cover varies from year to year, as well as how long it remains on the lakes. With almost five full decades of ice data to look at, GLERL scientists are observing long-term changes in ice cover as a result of climate change. Studying, monitoring, and predicting ice coverage on the Great Lakes plays an important role in determining climate patterns, lake water levels, water movement patterns, water temperature structure, and spring plankton blooms.

Maximum ice cover on the Great Lakes every year from 1973 to 2018. Credit: NOAA GLERL.

NOAA GLERL has been exploring the relationships between ice cover, lake thermal structure, and regional climate for over 30 years through the use of historical model simulations and observations of ice cover, surface water temperature, and other variables. Weekly ice cover imaging products produced by the Canadian Ice Service (CIS) started in 1973. Beginning in 1989, the U.S. National Ice Center (NIC) produced Great Lakes ice cover charts that combined both Canadian and U.S. satellite imagery. Today, these products are downloaded and processed at GLERL by our CoastWatch program, a nationwide NOAA program within which GLERL functions as the Great Lakes regional node. In this capacity, GLERL uses near real-time satellite data to produce and deliver products that support environmental decision-making and ongoing research. While the Great Lakes CoastWatch Program is a great resource for near real-time ice cover data, historical data is just as important – and that’s where GLERL’s Great Lakes Ice Cover Database comes in. Originally archived by GLERL through the National Snow & Ice Data Center, the Great Lakes Ice Cover Database houses data that dates back to 1973 and continues to be updated daily during the ice season every year.

Ice caves on Lake Michigan’s Glen Haven beach in 2005. Credit: National Parks Service.

Even though the CIS and NIC are the ones who actually collect Great Lakes ice cover data, GLERL plays the important role of re-processing this ice data into more accessible file formats, making it readily usable to anyone who needs it. Agencies and organizations that have used ice cover data from GLERL in the past include the NASA Earth Observatory, U.S. Army Corps of Engineers, U.S. Coast Guard, and National Geographic. Types of data requested might include historic minimum and maximum ice coverage for certain regions or lakes, or dates of the first and last ice cover in a region from year to year. This information can be helpful for managers in industries like energy production and commercial shipping.

This graph shows annual maximum ice coverage on the Great Lakes every year from 1973 to 2020. The red dashed line marks the long-term average maximum ice cover of 53.3%. Credit: NOAA GLERL.

GLERL scientists can also use this historic ice cover data to analyze how current ice cover conditions compare with previous years. For example, here’s how the ice cover during January 2021 stacks up against data for past Januarys:

  • Lake Michigan and the five-lake average had their second lowest January ice cover (with January 2002 being the first lowest).
  • The other lakes are all in the top five lowest ice cover for the month of January.
  • Six out of ten of the Januarys with the lowest ice cover have occurred during the last decade for the five-lake average (though 2014 was fourth highest January ice cover).
This graph shows average Great Lakes ice cover for the month of January every year from 1973 to 2021, organized by lowest ice cover (far left) to highest ice cover (far right). Credit: NOAA GLERL.

GLERL is also working to make this data more user-friendly for anyone looking to utilize it. This recent paper from GLERL and the Cooperative Institute for Great Lakes Research (CIGLR) describes the scientists’ efforts to standardize two existing formats of historic ice cover data. The authors explain that “technology has improved and the needs of users have evolved, so Great Lakes ice cover datasets have been upgraded several times in both spatial and temporal resolutions.” The paper documents the steps the authors took to reprocess the data in order to make it more consistent and accessible, which ultimately makes it easier for users to study long-term trends.

Timeline of ice chart evolution and frequency, from the research paper described above (Yang et al 2020). Credit: Ting-Yi Yang, Cooperative Institute for Great Lakes Research.

Whether you’re looking for decades of Great Lakes ice data or just a few days, GLERL’s got you covered! Looking for more Great Lakes ice cover information? Visit our ice cover homepage here.

MODIS satellite image of ice cover on the Great Lakes, March 16, 2014. Credit: NOAA Great Lakes CoastWatch.


Leave a comment

New science with historic data: 15 years of Great Lakes environmental data archived in NOAA data repository

With a network of experimental buoys that are constantly recording new data every few minutes, the amount of data the NOAA Great Lakes Environmental Research Laboratory (GLERL) has collected in the past 15 years is massive – and prepping it all to be archived in an official data repository is no small task. This year, thanks to the hard work of GLERL’s data managers and engineers, the Great Lakes environmental data collected by NOAA GLERL’s real-time buoys has been archived with NOAA’s National Centers for Environmental Information (NCEI) data repository. NCEI hosts and provides public access to one of the most significant archives of oceanic, atmospheric and geophysical data in the world.

A NOAA GLERL Real-Time Coastal Observation Network (ReCON) buoy in Lake Michigan.

An ever-growing collection of Great Lakes data

This real-time Great Lakes observational data archived in NCEI has been collected over time by sensors on coastal buoys as part of GLERL’s Real-Time Coastal Observation Network (ReCON). Each of ReCON’s 16 buoy stations collects meteorological data and provides sub-surface measurements of chemical, biological, and physical parameters (things like wave height, dissolved oxygen, chlorophyll, and water temperature). Totaling an impressive 2,055 data files, this data spans 15 years – from the inception of the first ReCON station in 2004 through the end of the 2019 field season. The data collected by GLERL’s ReCON buoys in the past 15 years are unique and valuable, and now that they are properly processed and easily accessible in the NCEI archive, they can be used in a variety of ways.

Using historic data to improve scientific models

While the near real-time info that our experimental ReCON buoys provide is great for helping you decide whether to hit the water for a day of boating or fishing, their usefulness doesn’t stop there. This Great Lakes ReCON data – both old and new – is incredibly useful to state and federal resource managers, educators, and researchers. For example, scientists can use the historic datasets to test the accuracy of their models, a process known as ‘hindcasting.’ When using archived data for hindcasting, researchers enter data for past events into their model to see how well the model’s output matches the known results. One cool example of hindcasting is the animation below that shows the Lake Superior wind and wave conditions that led to the sinking of the Edmund Fitzgerald in 1975.

Animation created with hindcasting that shows significant wave height and wind field, final voyage of the Edmund Fitzgerald, Nov 9-11, 1975.

As for the fact that ReCON data is collected in near real-time, these convenient same-day measurements can help determine whether or not a hypoxic (low oxygen) event will occur, detect nutrients contributing to harmful algal blooms, and even provide crucial data to the NOAA National Weather Service for coastal forecasting.

Water intake crib off the coast of Lake Erie in Cleveland, Ohio. Real-time data collected by NOAA GLERL’s ReCON buoys can help warn water intake managers of potential hypoxic events, which can affect drinking water quality.

Putting our data to the test

NOAA GLERL data manager Lacey Mason and marine engineer Ron Muzzi are in charge of preparing and submitting the data to NOAA’s NCEI data repository. Preparing the data to be archived involves performing quality assurance checks to ensure that it meets the Integrated Ocean Observing System’s (IOOS) standards set specifically for real-time oceanographic data. All of the data undergoes multiple quality tests before being archived, and each data point is flagged to indicate its reliability – whether it passed all tests, is suspect, or failed one or more tests.

In addition to being available on NOAA GLERL’s website and now the NOAA NCEI data repository, GLERL’s real-time buoy data can also be found on NOAA’s National Data Buoy Center website. The NCEI archive is fully updated with all of GLERL’s real-time data through 2019, and GLERL will continue to add new data to the archive on a yearly basis. The archived data can be accessed from the link here: https://doi.org/10.25921/jvks-b587.


1 Comment

Sinkhole Science: Groundwater in the Great Lakes

If you followed our fieldwork last summer, you probably remember hearing about our research on the fascinating sinkholes and microbial communities that lie at the bottom of northern Lake Huron off the coast of Alpena, MI. Now you can experience this research as a short film!

NOAA GLERL has partnered with Great Lakes Outreach Media to create a short film entitled Sinkhole Science: Groundwater in the Great Lakes. It was recently featured on Detroit Public Television’s Great Lakes Now program as well as the Thunder Bay National Marine Sanctuary’s International Film Festival. 

In the film, you’ll learn how NOAA GLERL’s Observation Systems and Advanced Technology (OSAT) branch studies how these sinkholes impact the water levels and ecosystems of the Great Lakes. GLERL’s OSAT Program Leader Steve Ruberg explains the high-tech gadgets involved in this research, including a remotely operated vehicle (ROV), a tilt-based current sensor, and temperature strings to determine vertical movement of groundwater entering the lakes through the sinkholes.

Hit “play” to dive into the exciting world of GLERL’s sinkhole science!

Researchers from NOAA GLERL’s Observation Systems and Advanced Technology team set out on the R/V Storm to study sinkholes on the floor of northern Lake Huron off the coast of Alpena, MI. Photo: Great Lakes Outreach Media
Researchers on NOAA GLERL’s R/V Storm deploy a remotely operated vehicle (ROV) to observe sinkholes at the bottom of Lake Huron off the coast of Alpena, MI. Photo: Great Lakes Outreach Media
NOAA GLERL’s OSAT Program Lead Steve Ruberg and Instrument Specialist Steven Constant observe a sinkhole via live video feed from the ROV. Photo: Great Lakes Outreach Media
NOAA GLERL Marine Engineer Kyle Beadle controls the ROV in order to observe sinkholes from the R/V Storm. Photo: Great Lakes Outreach Media
NOAA GLERL Instrument Specialist Steven Constant and Vessel Captain Travis Smith monitor the ROV as it dives beneath the surface to observe a sinkhole. Photo: Great Lakes Outreach Media


2 Comments

Millions of Microbes: The Unexpected Inhabitants of Lake Huron’s Underwater Sinkholes

When most people think of sinkholes, a massive cavity in the ground opening up and swallowing a car is what usually comes to mind. But when scientists at the NOAA Great Lakes Environmental Research Laboratory (GLERL) hear “sinkholes,” their minds jump to an unusual place — the bottom of a Great Lake.

Aerial view of research boat on green water
Researchers on GLERL’s R/V Storm study sinkholes in northern Lake Huron off the coast of Alpena, Michigan. (Credit: David J Ruck/Great Lakes Outreach Media)

Thousands of years ago, off the coast of Alpena, Michigan, patches of ground beneath Lake Huron collapsed to form a series of underwater sinkholes — some measuring hundreds of feet across and up to 60 feet deep. You may have read this NOAA.gov article about how these sinkholes are contributing water to Lake Huron, but did you know they also support a huge kingdom of microorganisms?

Microbes might be tiny, but they’re one of the biggest research topics in the Great Lakes. They thrive near the sinkholes because the groundwater seeping in has the perfect chemistry for their survival: low oxygen levels and lots of chloride and sulfate, which come from the dissolved limestone underlying the lake. These factors make the sinkholes inhospitable for fish and other wildlife normally found in the Great Lakes, which means these microbes have a much easier time surviving there than other creatures. With perfect living conditions and little competition, they’re so abundant that they form purple, green, and white microbial mats that cover the lake floor like a colorful carpet.

Floor of Lake Huron covered by purple and white microbial mats with bubbles in them.
Purple microbial mats in the Middle Island Sinkhole in Lake Huron, June 2019. Small hills and “fingers” like this one in the mats are caused by gases like methane and hydrogen sulfide bubbling up beneath them. (Credit: Phil Hartmeyer, NOAA Thunder Bay National Marine Sanctuary)

Scientists at GLERL are collaborating with partners from the University of Michigan and Grand Valley State University to see just what these microscopic lake dwellers can teach us. This video by Great Lakes Outreach Media highlights how they can even give us a deeper insight into the history of Earth itself.

Associate Professor Greg Dick from the University of Michigan discusses cyanobacteria’s important role in Earth science. This clip is from Great Lakes Outreach Media’s upcoming documentary, “The Erie Situation.”

Some sinkholes are so deep that sunlight can’t reach them, but that doesn’t stop some microbes from calling them home. They’re able to live their entire lives in complete darkness, because they get their energy from the added minerals in the water rather than from sunlight — a process called chemosynthesis. But whether they need sunlight or not, several of the microbial species present have proven to be full of surprises.

“In the near-shore systems, the cyanobacteria we found have DNA signatures that come closest to comparing to the cyanobacteria found at the bottom of a lake in Antarctica. So that’s a strange coincidence,” said Steve Ruberg, the scientist in charge of sinkhole research at GLERL. “Some of the other bacteria we’ve found in the deeper systems have only been found off the coast of Africa.”

Fish sitting on a rock, which is covered by purple and white microbes
A burbot resting on rocks covered in purple and white microbial mats inside the Middle Island sinkhole in Lake Huron. (Credit: Phil Hartmeyer, NOAA Thunder Bay National Marine Sanctuary)

The particular sinkholes we’re studying are located within NOAA’s Thunder Bay National Marine Sanctuary, an area of Lake Huron that’s federally protected for the purpose of preserving nearly 200 shipwrecks. In fact, the only reason we know about these sinkholes is because they were discovered by accident only 18 years ago, on a research cruise documenting the shipwrecks.

Close up of rocks covered in  purple, white and green microbes on the bottom of Lake Huron, with a diver in the background.
A diver observes the purple, white and green microbes covering rocks in Lake Huron’s Middle Island Sinkhole (Credit: Phil Hartmeyer, NOAA Thunder Bay National Marine Sanctuary)

So why did this microbial paradise come into existence in the first place? The story goes back much further than the sinkholes’ discovery in 2001. About 400 million years ago, before the Great Lakes even existed, a layer of limestone bedrock formed beneath what is now Lake Huron. Then around 10,000 years ago, underground caves were created when a chemical reaction between the limestone and acidic groundwater dissolved away holes in the bedrock. All that was left were weakly supported “ceilings” that eventually collapsed into the sinkholes we — and the microbes — know and love today.

Close up of rocks covered in purple, white and green microbes on the floor of Lake Huron
Purple cyanobacteria and white chemosynthetic mats on the floor of Lake Huron with Lowell Instruments current meter. (Credit: Phil Hartmeyer, NOAA Thunder Bay National Marine Sanctuary)

Since Lakes Michigan and Erie have the same limestone bedrock as Lake Huron, GLERL scientists think these lakes could be home to more of these fascinating underwater features. So while the excitement of this fieldwork has died down for the year, our research on Great Lakes sinkholes and their tiny inhabitants is far from over.