How Can Data Buoys Prepare Lake Champlain for the Impacts of Climate Change?
Eric Leibensperger, assistant professor of physics at Ithaca College, has used data buoys on Lake Champlain to collect weather and lake observations since 2016. The first data buoy, launched with SUNY Plattsburgh’s Lake Champlain Research Institute, is located near Valcour Island in the main lake. Since 2016, Middlebury College and SUNY Plattsburgh have deployed other data buoys throughout the lake, some of which are still collecting data.
The buoys collect subsurface temperature data every 1-2 meters in depth and wind velocity, air temperature, and pressure readings every fifteen minutes each day throughout the summer.
In 2019, Lake Champlain Sea Grant provided funding to Eric and his team to determine the impact of events on water quality, specifically chlorophyll, turbidity, and plankton abundance in surface and deep waters in the South Main Lake and at the Valcour data buoy site. Now with seven years of buoy data, we asked Eric a few questions about his research and initial findings.
LCSG: First, can you explain what physical characteristics of Lake Champlain most significantly impact the overall lake system?
Eric: I like to think of the lake as having three systems: chemical, biological, and physical. Each of these has experts that work directly in their realm, for example by studying nutrients, ecosystem dynamics, or weather. But the systems couple together to create the complex, interdependent ecosystem in Lake Champlain. As one system changes, it impacts others. Therefore, you must address any problem in the lake holistically.
Lake Champlain is a large, long lake that has sporadic, intense weather events. There are a few characteristics of the lake that have a large influence on the data we collect. The first is called a seiche. Seiches exist in long lakes like Champlain, where strong wind blows from one end towards the other, pushing the water to the downwind side. When the wind stops, the water level rebounds to the other side, and so on, creating a kind of seesaw motion until it eventually calms down. The other principal characteristic of Lake Champlain is stratification. Stratification occurs in deep lakes where the water is separated into layers of cold water at the bottom and warmer surface water in summer.
Lakes that stratify usually mix, or “turn over,” twice per year—once in spring as ice melts and surface temperatures warm, and again in fall as surface temperatures cool, when the colder, denser water sinks. However, we are finding that Lake Champlain turns over more than semi-annually, and this process influences many other lake processes such as cyanobacteria blooms and oxygen levels.
LCSG: What questions does your buoy data try to answer?
Eric: Through conversations with colleagues, we realized there was a gap in long-term physical data collection on Lake Champlain. We want to know if the lake is warming, by how much, and, if possible, use present day observations to better predict future lake conditions. Neighboring lakes have been recording this kind of information for decades and can now look back at their records to understand their lake better. In Lake Champlain, we do not have this data, and we are finding that we know less about the physical aspects of Lake Champlain than we thought.
For example, Tom Manley, professor emeritus at Middlebury College and one of the partners on the Lake Champlain Sea Grant project, began taking observations about a quarter mile away from our Valcour Island site in the 1990s, and this data was used as a model for our research. The focus of his earlier project only required two years of monitoring, but we aren’t able to use such a short-term record to determine how much Lake Champlain has been warming or identify other trends, so we needed to create a record for future researchers to look back on.
LCSG: What’s the most important information to gather to understand trends?
Eric: The more information we can gather the better! We should prioritize continuing long-term monitoring projects so that we can compare the future with previous records. This consistency helps us understand daily, seasonal, and annual variations and patterns in weather on Lake Champlain.
We have expanded our data buoy network for a short period and found that more locations throughout the lake provides complementary information. We have not fully analyzed much of this data but having the data spatially dispersed with different physical characteristics will further help identify long-term trends versus seasonal or daily variations.
LCSG: How does this research help us understand climate change in Lake Champlain?
Eric: With our data, we are now able to go back and look for trends of warming in the lake. Our data suggests the largest trend of warming is in the fall and the winter, but due to storm and weather events, this time is also the most variable year-to-year, which would make it hard to recognize trends if not for this consistent data.
Now that we have seven years of data collected on water temperature, air temperature, and other factors in the lake, we can extrapolate to estimate how much climate change—global warming in specific—will impact lake temperature and the biological and chemical processes that are temperature-sensitive.
In our data, we found for every degree increase in air temperature, the surface water temperature of Lake Champlain increases 0.83 degrees. With this information, we can predict what Lake Champlain will look like at different levels of warming in the future. At a global warming of two degrees, the Champlain Valley air temperature will increase three degrees, which means the lake surface temperature will increase more than two and a half degrees, causing significant impacts to lake ecology and chemistry.
LCSG: How does this research contribute to our understanding of weather on Lake Champlain?
Eric: It’s not just long-term change that we’re interested in; shorter time scale weather changes are important in understanding the conditions that cause things like algae blooms and affect zooplankton and other aquatic species. Since these weather patterns impact ecology and water quality, we get a better picture of what is actually happening in the lake if we examine data simultaneously. With the data we have, we have been able to cross examine our weather data with biological and chemical trends in the water.
LCSG: What’s the biggest challenge you have had with collecting data on Lake Champlain?
Eric: In general, it’s hard to find funding for long-term monitoring projects because there are not new, applicable findings after one, or even five, years of research. But without monitoring, we cannot fully understand lake dynamics, year-to-year variations, or any climate trends.
The logistical challenge of the data buoys themselves has also been challenging. The buoys do not fare well with ice, so we are not able to keep them out on the water if there is any risk of ice. This limits our study to only summer monitoring.
LCSG: What are the future research plans with this project?
Eric: Lake Champlain is now included in the State of the Climate Report by the America Meteorological Society. This report summarizes conditions around the world, and our data buoy contributes the record for Lake Champlain. The buoy will continue collecting data each year for as long as it can.
We have two years of observations collected from six data buoys and five acoustic doppler current profilers in the South Main Lake. We are analyzing this information to better understand the impact of storms on lake conditions. With this new dataset, as well as the longer record from the Valcour data buoy, we hope to learn how weather itself impacts the lake and connects to changes occurring as the climate warms.
Learn More
Check out the recordings of Eric's research webinars or look at the data yourself.