Measuring our air:

New eddy flux tower installed on campus

By California State University, Bakersfield

January 22^nd, 2021

California State University, Bakersfield is now home to a new Eddy Covariance Flux Tower, a tower that continuously monitors levels of carbon dioxide (CO2) and water in the air. The tower will provide students from a variety of scientific disciplines with data they can use to research climate change.

The tower was recently installed on campus in the Environmental Studies Area, part of the School of Natural Sciences, Mathematics, and Engineering. It was purchased from a “STEM Graduate Excellence” grant, co-directed by Drs. Anna Jacobsen and Debra Jackson, that seeks to grow research opportunities and resources available to graduate students and support interdisciplinary research. Climate change is a research topic rich with opportunities for collaborative research, so it quickly became a focus for the grant.

“The acquisition of an Eddy Covariance Flux Tower is a very exciting development for our campus,” said Dr. Jackson, Interim Associate Vice President for Academic Affairs and Dean of Academic Programs. “This equipment measures CO2, a greenhouse gas known to negatively affect the functioning of ecosystems as well as human health. The faculty and students who use the data produced by this equipment will now have a new opportunity to contribute toward climate change research, and hopefully improve the well-being of our planet and its people.”

Dr. Jacobsen, a biology professor in NSME, said there are countless ways students in the biology, computer science, and geology programs could use the data produced by the tower. Mathematics students could also find the information useful for processing and analyzing large datasets. One example Dr. Jacobsen gave is studying how plants function across the terrain, comparing grasses to trees and shrubs and seasonal change. Over time, student and faculty researchers will be able to evaluate long-term changes in atmospheric CO2.

Beyond the world of STEM, students interested in sustainability, economics and policy could use the data to study subjects like carbon emissions from vehicles during rush hour compared to other times of day.

“It can be particularly powerful for students, especially those from non-traditional backgrounds, to examine questions and data that are generated locally and represent ‘home,’” Dr. Jacobsen said. “There are numerous questions that could be pursued, many more than I can think of or list.”

Dr. Brandon Pratt, also a biology professor, explained how the eddy flux tower works: it rapidly measures 3D wind speeds using a sonic anemometer, along with carbon dioxide, water vapor, temperature, and pressure. In one second, it will register 10 measurements.

“These measurements can be used to calculate the amount of carbon dioxide and water vapor moving from the atmosphere into an ecosystem or moving from the ecosystem into the atmosphere,” he said. “These measurements are vital because the carbon dioxide that moves into an ecosystem represents the amount of food (plant mass) available in that ecosystem to support all other organisms. Carbon dioxide also has a profound effect on the Earth’s climate; thus, it is a research imperative to understand the factors that are controlling how ecosystems are taking it up.”

Dr. Pratt explained how scientists want to know how hotter and drier conditions around the world will affect carbon dioxide in the atmosphere. Both photosynthesis (the process through which plants and some microbes take carbon dioxide out of the air) and respiration (when organisms produce carbon dioxide by breaking down sugars into more immediately usable forms of chemical energy) are affected by climate change.

“There is a positive feedback in many hot and dry areas (think Bakersfield) where more carbon dioxide in the atmosphere leads to hotter and drier conditions, which leads to more carbon dioxide in the atmosphere in what amounts to a vicious circle,” he said. “This can occur because respiration is enhanced and photosynthesis is hindered when conditions become hotter and drier. We want to know if ecosystems in Bakersfield are producing more carbon dioxide than they are taking up under hot and dry conditions. This has implications for future carbon dioxide in the atmosphere and future climate predictions.”

Through a network of other researchers using these kinds of towers around the world, CSUB students will be able to compare local data to those of other locations. Similar systems are operated by San Diego State University, CSU East Bay, UC Irvine, and UC Berkeley as well as United States Geological Survey, National Laboratory, and USDA-run sites.

“This also opens up additional research opportunities and questions that graduate student could pursue, through the combination of data from our campus with those from other sites,” Dr. Jacobsen said. “These represent great opportunities for connections across campus, particularly for our students that may pursue PhD program opportunities within the UC, and also future employment avenues.”

Dr. Jacobsen is excited about the new addition to campus and the ideas it will spark. There are plans to hold a seminar on campus when the equipment is fully operational and its initial data has been collected.

“Once graduate students and their mentors are aware of this equipment and the freely available data that are collected and logged,” Dr. Jacobsen said, “I think that many new and exciting projects and collaborations will emerge.”