Origin and Influence of Background Ozone in the Western United States (U.S.) from Observations at the Mount Bachelor Observatory

This project supports continued atmospheric chemistry measurements at Mt. Bachelor Observatory, a high elevation atmospheric science research station that has been operating for 20 years. The project includes plans for a combination of continuous measurements of trace gases (including ozone, carbon monoxide, nitrogen oxide, and carbon dioxide), aerosol mass, scattering and absorption coefficients and meteorological variables, plus the development of a variety of machine learning/statistical analyses. The goal of this research is to investigate the causes of variability in background/free tropospheric ozone and how this variability impacts surface ozone at downwind locations. It also includes a study of sources and variability of ozone in wildfire smoke plumes detected at the Mt Bachelor research station. Atmospheric ozone at the Earth’s surface is a pollutant with adverse health consequences for both humans and ecosystems. Data from this project will be used to assess the following scientific questions: (1) What controls background ozone (O3) in the lower free troposphere? How well can background O3 be predicted using statistical/machine learning methods? (2) What is the relationship between background and downwind O3 at surface sites? How well can downwind surface O3 be predicted using Mt. Bachelor Observatory (MBO), meteorology, fire information, satellite data and other observations with statistical/machine learning methods? (3) What factors control O3 in isolated smoke plumes (as opposed to urban smoke plumes)? How well can O3 in smoke plumes be predicted using statistical/machine learning methods? This project also includes the use of satellite measurements from TEMPO. This project facilitates the transition of operations at MBO from the University of Washington to Reed College, ensuring the continuation of the 20-year measurement record. Reed College is primarily an undergraduate institution, and the continued operation of MBO by Reed faculty and staff will ensure that the site will continue to be used for scientific training for both undergraduate and graduate students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.