Paul Wennberg

Paul O. Wennberg is the R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering at the California Institute of Technology (Caltech). Until 2023, he was the director of the Ronald and Maxine Linde Center for Global Environmental Science. He served as the first chair of the Total Carbon Column Observing Network and a founding member of the Orbiting Carbon Observatory project, which created NASA's first spacecraft for analysis of carbon dioxide in the atmosphere.

Wennberg's research focuses on the atmospheric chemistry of planets, including air quality, photochemistry, and the carbon cycle. At Harvard, he worked with James G. Anderson, professor of atmospheric chemistry. His doctoral thesis was In Situ Measurements of Stratospheric Hydroxyl and Hydroperoxyl Radicals.

Career Wennberg joined Caltech in 1998. He was an associate professor of atmospheric chemistry and environmental engineering science from 1998 to 2001, becoming a full professor in 2001. In 2004, he was appointed as the R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering. He served as the director from 2008 to 2011, acting director from 2012 to 2014 and director from 2014 onwards. The laser-induced fluorescence instrument that he developed was placed in the nose of a NASA ER-2 aircraft to measure radicals during flight. It has been used to measure radicals in both the troposphere and the stratosphere.

Wennberg's sensor was used in several NASA missions, beginning with the SPADE mission in 1993. NASA's ASHOE/MAESA mission (1994) took measurements of HOx from latitudes of -70°S to 70°N, reaching nearly from the south pole to the north pole. The STRAT mission (1995–1996) was the first to record measurements of HOx in the upper troposphere, and demonstrated that the concentration of HOx considerably exceeded expected levels. The POLARIS mission in 1997 obtained measurements all the way to 90° N latitude, the North pole. The Total Carbon Column Observing Network is a group of about 20 ground-based sites worldwide that host Fourier transform spectrometers. The spectrometers examine near-infrared (NIR) solar absorption spectra and measure atmospheric column abundances of CO2, CH4, CO, N2O and other molecules in terrestrial ecosystems. Methane emissions from the Aliso Canyon gas leak were detected by TCCON within a day of the start of the leak. "TCCON has pioneered a key element of the ground segment measurements required to provide the evidence base for policy making for the next 100 years." Spectrometers on the satellite can map the distribution of CO2 particles across the planet by measuring the average amount of CO2 above specific locations. He was named a MacArthur Foundation Fellow in 2002. Wennberg is a member of the US National Academy of Sciences and a Fellow of the American Geophysical Union and the American Academy of Arts and Sciences.