Yesterday we caught a slight break in our string of cold, windy days and researchers here from the UW- Madison Center for Limnology and Department of Atmospheric and Oceanic Sciences were able to head out onto Lake Mendota to retrieve our invaluable instrumented buoy for the winter. (It goes by David Buoy in these parts).
The bright yellow buoy spends most of the year anchored out in the middle of the lake where it is covered in scientific instruments that allow it to record everything from wind speed to water temperature to algae blooms. This fall wraps up its 11th season on the lake, which made us remember the following post from long ago. It seems like only yesterday we were putting David Buoy back into Mendota on a chilly spring day…
(Originally published April 29, 2013.) Early season boaters on Lake Mendota may have noticed a familiar sight out on the water this spring – a bright yellow beacon, bobbing right above the lake’s deepest point.
Meet “David Buoy,” the tireless floating scientific instrument that has plumbed the depths of our fair lake for five years. Luke Winslow, a graduate student in the Hanson Lab at the Center for Limnology, has been with the buoy since the beginning. Starting the project as an undergrad, Luke has helped fine-tune the instruments collecting data, dealt with random acts of vandalism, and monitored conditions in Mendota. The data collected by the buoy (some available online in real-time) will help researchers here at the CFL better understand what drives the health of Lake Mendota and how human activities affect its waters.
For example, using data in part collected by the buoy on water temperature and plankton communities, scientists at the CFL can now predict in the spring what harmful algal blooms are likely to be like in the summer.
Winslow recently worked with a team of divers and researchers to get David Buoy out onto the lake for 2013. He sent in this write up below:
We first deployed the buoy in 2008. We didn’t get the platform until late in the spring we didn’t get the everything ready until June. June 26th was a balmy summer day. The sun was shining and the water temperature was 22 C. We had almost all day to deploy the buoy and more people to help deploy than we really needed. After getting it in the water and deploying anchors, we swam around the buoy in swim suits and snorkels as we dropped sensors into the water.
Flash forward five years. Since the first deployment, the buoy has gone out every year. It has spent, sum total, over three full years out on Mendota. It has recorded wind gusts above 80 miles per hour, surface water temperatures over 30 degrees Celcius (86F), and has made 50 million individual observations of water temperature and meteorological conditions.
This year we had a late ice off and what felt like an even later spring. Despite this, we had pressing scientific questions about how phytoplankton communities (aka: algae) change over the course of the spring and wanted to get the buoy out as soon as possible. Unlike 2008, this year the water temperatures hovered around 5 degrees C (41 C). Instead of snorkels and swimsuits, the divers wore dry suits. Despite the cold water, it was still a beautiful day on the lake.
“David Buoy” is now ready for the 2013 science, sailing, and scuba season.
Video below of Ted Bier during the 2012 deployment.