Carbon is the basic building block of life, of our food, and of most of our energy. Our dependency on carbon causes one of the biggest challenges we face today: global climate change. Knowing how and why carbon flows through different “pools” on Earth is key to understanding how and how fast climate will change. I study how carbon moves between different pools (e.g., air, water, rock, soil, living organisms), and how it cycles between its two main forms: organic carbon and inorganic carbon (e.g., carbon dioxide, a greenhouse gas).
For example, much of my research is in the Arctic, which is warming ~ 4 times faster than the rest of the Earth. Current estimates are that 5–15% of the tremendous pool of organic carbon stored in permafrost soils could be emitted as greenhouse gases by 2100 given the current trajectory of climate change, resulting in an additional one third degree Celsius of warming everywhere on Earth (i.e., Arctic amplification of climate change). My research has shown that these estimates are too low by at least 14% because they do not consider how sunlight oxidizes dissolved organic carbon to carbon dioxide in inland waters of the Arctic.
Closer to home here at the University of Michigan, I study how carbon cycling influences water quality in Lake Erie, a drinking water source to millions of people. Water quality in the western basin of Lake Erie is threatened by toxin-forming cyanobacterial harmful algal blooms. My research tests ideas on how transformations and cycling of dissolved organic carbon influences toxin-forming algal blooms in Lake Erie. For instance, dissolved organic carbon delivered from rivers to Lake Erie is a source of energy and nutrients, and it controls the light field and oxidative stress burden in the water column, all of which may influence toxin-forming algal blooms in Lake Erie.
Field work is the foundation of all my research. With the data collected in the field, we use mathematical and statistical models to identify specific compounds within the organic carbon pool and to understand the processes transforming these compounds to greenhouse gases. In addition, we are very interested in how we may couple our extensive field monitoring datasets of dissolved organic carbon, which strongly influences or controls the apparent optical properties of natural waters, with satellite products, to understand and predict changes in carbon cycling and water quality.
What is the most significant scientific contribution you would like to make?
I have 2 goals:
- Predict how and how fast carbon dioxide will be released to the atmosphere from thawing permafrost soils in the Arctic.
- Understand how and why organic carbon export from rivers to lakes may be changing, and quantify the impacts of such changes on water quality and greenhouse gas emissions from lakes.
What makes you excited about your data science and AI research?
Improvements in instrumentation, protocols and knowledge in my field has resulted in fairly long-term datasets that are highly resolved in space and time. These datasets are ripe for modeling, synthesis, and integration with other kinds of products (e.g., satellite or other remote sensing). And it is urgent do so. E.g., North American and European freshwaters are changing color (due to increased dissolved organic carbon concentrations over the past ~ 40 years), and we don’t really know why or what the implications will be for climate or water quality.
As a faculty member and associate chair for our undergraduate curriculum in Earth and Environmental Sciences, I am immersed earth systems and geospatial science. I led the development of a new Geospatial Sciences minor in our department, and am very excited to engage others in geospatial science especially those with expertise in data science and AI.
What are 1-3 interesting facts about yourself?
I love running. If I could run to collect all my soil and water samples, I would! However, mostly running is my time to think about a paper or proposal I’m working on, and to notice the changing of seasons and how everything is interconnected.