Judith L. Lean, Ph.D., is a Research Physicist with the Space Science Division, Naval Research Laboratory, in Washington, D.C. Her research focuses primarily on mechanisms, measurements, and modeling of variations in the Sun's radiative output at all wavelengths, and on effects of this variability on Earth's global climate and space weather.

A member of the National Academy of Sciences and of the American Geophysical Union, Lean earned her doctorate in atmospheric sciences from the University of Adelaide and her B.S. in physics from the Australian National University. She has been a U.S. citizen since 1992. Lean has testified before the U.S. Senate's Committee on Energy and Natural Resources and before the U.S. Senate Committee on Commerce, Science. She is a member of the National Research Council's Committee on Radiative Forcings Effects on Climate and a member of the National Science Foundation's Advisory Committee for Geosciences. She has authored or co-authored more than 80 refereed journal papers, more than half of them as the first or sole author, and she has dealt extensively with general circulation and specialized news organizations.