Joellen Russell's research investigates the ocean's role in the carbon cycle in the past, present and future. Her early research forged a new paradigm in climate science by describing the mechanism responsible for transferring one-third of the carbon dioxide in the atmosphere into the ocean and then back out again. She now focuses on the Southern Ocean, which accounts for nearly half of the annual oceanic uptake of human-released carbon dioxide from the atmosphere and about 70% of the excess heat transferred from the atmosphere to the ocean yearly. She is one of the authors of the climate scientists' amicus brief cited in the landmark 2007 Massachusetts vs. the EPA Supreme Court decision that ruled that carbon dioxide is a pollutant covered under the Clean Air Act and must be regulated.

Russell leads the modeling theme of the Southern Ocean Carbon and Climate Observations and Modeling project, including its Southern Ocean Model Intercomparison Project. She is co-chair of the National Oceanic and Atmospheric AdministrationScience Advisory Board Climate Working Group and is on the National Center for Atmospheric Research's Community Earth System Model Advisory Board. She also acts as an objective leader for the Scientific Committee on Antarctic Research's AntarcticClimate21.

Russell, aThomas R. Brown Distinguished Chair of Integrative Science, has joint appointments in the Departments of Lunar and Planetary Sciences, Hydrology and Atmospheric Sciences, and Mathematics. She has served on theFaculty Senate since 2015 and on the Honors Faculty Advisory Council for the Honors College. Russell isa cofounder of the College of Science's Women in STEM Leadership group. She also is an executive committee member of the University of Arizona Space Institute and the Applied Math Graduate Interdisciplinary Program, and is a faculty member in the Global Change Graduate Interdisciplinary Program.