Principle Investigators

Paul Hanson
Robert Holz
Trina McMahon
Chin Wu


Faculty and Staff

Dave Balsiger
Barbara Benson
Fred Best
Ted Bier
Steve Carpenter
Dave Harring
Tim Kratz
Richard Lathrop
Tim Meinke
Steven Sendelbach
Jonathan Thom


Graduate Students

Lucas Beversdorf
Luke Winslow


Undergraduates

Erika Phillips


Principle Investigators

Paul Hanson

Science Question

Paul is the head Principal Investigator of the GLEON Research Coordination Network. He is a Research Scientist at UW-Madison’s Center for Limnology. His research interests include environmental sensor networks, ecosystems modeling, landscape carbon cycling, and biological and hydrological interactions.

Robert Holz

Robert Holz grew up in Ann Arbor, Michigan before attending UW–Madison to receive B.S. and M.S. (2001) degrees from the Department of Atmospheric and Oceanic Science with Professor Steven Ackerman. Working with pioneering lidar scientist Edwin Eloranta on his research thesis, he measured the optical properties of cirrus clouds (those made of ice) using a High Spectral Resolution Lidar (HSRL) developed at UW–Madison. An important result from his research was deducing the climatology of cirrus backscatter phase functions from the measurements.

Trina McMahon

Science Question

Trina is the lead Principal Investigator of the North Temperate Lakes Microbial Observatory (NTL-MO). She is an Associate Professor in the Civil and Environmental Engineering Department and the Bacteriology Department at UW-Madison. Her research interests include microbial ecology, environmental biotechnology, environmental engineering, water quality, environmental genomics, and freshwater microbiology.

Chin Wu

Fundamental understanding of physical processes in air-sea interactions is one of critical components for accurately predicting climate change. We are specifically interested in the role of three-dimensional breaking waves and waves breaking due to wave-current interactions. To elucidate these processes, experimental, theoretical, and numerical approaches are used. Work is underway to study kinematic and dynamic effects of sheared currents on extreme and breaking waves in the laboratory and field. Further we are examining the occurence of freak wave and its characteristics. Our ultimate goal is to develop a temporal form of physics-based parameterizations for momentum, heat, and humidity fluxes of the coupled atmospheric-ocean models to better predict wave and climate evolution.

Contaminated sediments in rivers or estuaries can cause serious water quality problems. A fundamental understanding of interaction of hydrodynamic, sediment, and chemical processes is critical. To quantify the fate and transport of the contaminated sediments under current/wave dominated flows, we are developing an innovative in-situ instrument package to measure waves, current and sediment profiles, sediment resuspension rates, depositions, and particle size distributions. In addition, a well-controlled automated image sediment erosion test flume system is developed to further quantify bottom sediment characteristics. Our ultimate goal is to understand the coastal processes responsible for the resuspension, transport, and deposition of contaminated sediments, the cycling of pollutants, and biological productivity in the Great Lakes, inland lakes, streams, or rivers.

The effects of hydrologic and hydrodynamic characteristics on environmental impacts of many lakes such as bloom formation, water quality and shoreline erosion have been great concerns to the local communities as well as national agencies. We are developing a three-dimensional non-hydrostatic and stratified flow model (3DNHYS) to examine general circulation pattern, surface and internal waves and their breaking over shoaling bathymetry. In addition, the 3DNYHS model will be coupled with a cohesive sediment transport model, a water quality model, and an ecosystem model to examine the interactions of physical, chemical, and biological processes in lakes response to anthropogenic pollution and weather or climate changes. An interdisciplinary approach is undertaken to further address their environmental and social impacts.


Faculty and Staff

Steve Carpenter

Science Question

My limnological research focuses on the interaction of biogeochemistry and food web processes in lakes. I am especially interested in prediction of lake characteristics from land-water interactions and food web processes, including human effects such as fishing and introduction of exotic species. My research on these topics is connected to the LTER, BioComplexity, and Trophic Cascade projects.

I am also studying resilience of linked social-ecological systems. This work involves theoretical studies as well as case studies in selected regions of the world. Work at Wisconsin is affiliated with the LTER and BioComplexity projects. Additional collaborators are affiliated with the Resilience Alliance and the Millennium Ecosystem Assessment: Resilience Studies in Wisconsin, Resilience Alliance, Millennium Ecosystem Assessment.

I am a Fellow of the Beijer Institute of Ecological Economics and Chairman of the Board of the Cary Institute of Ecosystem Studies

Jonathan E. Thom

I am an assistant researcher at the Space Science and Engineering Center at the University of Wisconsin-Madison. My current responsibilities are with the Antarctic Automatic Weather Station (AWS) group. This involves processing of AWS data received from our stations and field maintenance of our stations. I have also been involved with a project that has installed AWS stations with Global Positioning System (GPS) receivers on icebergs to track their motions.

I received a bachelor’s degree from the University of Minnesota-Twin Cities in Mathematics. I then ended up in Madison, Wisconsin working in insurance. I soon realized that was a misguided career choice. I longed for the hallowed halls of academia. I then decided to enter the University of Wisconsin-Madison Graduate School in Atmospheric and Oceanic Science. I had no experience in the field, but was undeterred. After an initial disorientation I ended up in the Antarctic AWS group. I received a master’s degree in Atmospheric Science. My thesis was studying the surface heat budget of the snow on the Greenland crest. I left the Antarctic sciences for a year or two before I found myself back with the AWS group.

I am married to Kristi and we have a super dog, Nick. I enjoy backpacking, hiking, camping, canoeing, tinkering with my bicycles, riding my bicycles, running, cooking (and eating), and hanging out with Kristi and Nick.


Graduate Students

Lucas Beversdorf

Lucas received his B.S. in Biology and Chemistry from Marian University, Fond du Lac, Wisconsin and his M.S. in Oceanography from the University of Hawaii. He is currently a graduate student in the McMahon Laboratory at the University of Wisconsin’s Civil and Environmental Engineering Department. Lucas’ research interests include phosphorus speciation and cycling, phosphorus uptake by Cyanobacteria, and the formation of toxic Cyanobacteria blooms.