Formaldehyde Sources in the Remote Upper Troposphere

The NASA Atmospheric Tomography (ATom) mission provided a unique opportunity to sample the remote UT with an instrument payload that included HCHO and many of its oxidative precursors. Upper tropospheric HCHO plays a central role in UT HO_x and O₃ chemistry, and quantifying the HCHO sources in the remote UT will improve our understanding of the HO_x budget and O₃ production in regions with very limited in situ sampling. We will focus on the importance of convective transport of HCHO and its precursors to the UT HCHO budget during ATom 1 and 2, both investigating individual case studies of convective influence and looking more broadly at campaign-wide UT HCHO. We will utilize a back trajectory derived measure of convective influence to identify air masses affected by recent vertical transport for both approaches. The chemistry of the individually identifiable, convectively influenced air masses will be explored using a 0-D box model to evaluate the completeness of our representation of the oxidative environment using the available measurements.