Browsing by Author "Thames, Alexander"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
Item Mapping hydroxyl variability throughout the global remote troposphere via synthesis of airborne and satellite formaldehyde observations(PNAS, 2019-05-20) Wolfe, Glenn M.; Nicely, Julie M.; St. Clair, Jason; Hanisco, Thomas F.; Liao, Jin; Oman, Luke D.; Brune, William B.; Miller, David; Thames, Alexander; Abad, Gonzalo González; Ryerson, Thomas B.; Thompson, Chelsea R.; Peischl, Jeff; McKain, Kathryn; Sweeney, Colm; Wennberg, Paul O.; Kim, Michelle; Crounse, John D.; Hall, Samuel R.; Ullmann, Kirk; Diskin, Glenn; Bui, Paul; Chang, Cecilia; Dean-Day, JonathanThe hydroxyl radical (OH) fuels tropospheric ozone production and governs the lifetime of methane and many other gases. Existing methods to quantify global OH are limited to annual and global-to-hemispheric averages. Finer resolution is essential for isolating model deficiencies and building process-level understanding. In situ observations from the Atmospheric Tomography (ATom) mission demonstrate that remote tropospheric OH is tightly coupled to the production and loss of formaldehyde (HCHO), a major hydrocarbon oxidation product. Synthesis of this relationship with satellite-based HCHO retrievals and model-derived HCHO loss frequencies yields a map of total-column OH abundance throughout the remote troposphere (up to 70% of tropospheric mass) over the first two ATom missions (August 2016 and February 2017). This dataset offers unique insights on near-global oxidizing capacity. OH exhibits significant seasonality within individual hemispheres, but the domain mean concentration is nearly identical for both seasons (1.03 ± 0.25 × 10⁶ cm⁻³), and the biseasonal average North/South Hemisphere ratio is 0.89 ± 0.06, consistent with a balance of OH sources and sinks across the remote troposphere. Regional phenomena are also highlighted, such as a 10-fold OH depression in the Tropical West Pacific and enhancements in the East Pacific and South Atlantic. This method is complementary to budget-based global OH constraints and can help elucidate the spatial and temporal variability of OH production and methane loss