The Combined Impact of Canopy Stability and Soil NO_x Exchange on Ozone Removal in a Temperate Deciduous Forest

Abstract

Removal of ozone at the land surface (ozone dry deposition) is an important component of the tropospheric ozone budget, accounting for 15%-20% of the total tropospheric ozone sink (Bates & Jacob, 2020;Hu et al., 2017;Young et al., 2018). Ozone dry deposition occurs when air masses, transported downward by turbulent motions in the atmospheric boundary layer, come in contact with the land surface. Forests are particularly efficient ozone sinks (e.g., Hardacre et al., 2015): removal processes include plant uptake through stomata and various non-stomatal sinks such as external leaf surfaces and soils, and chemical removal in the canopy airspace (Fowler et al., 2009). Upon stomatal uptake, ozone may impact stomatal conductance and photosynthesis, reducing ecosystem carbon assimilation on large spatial scales (Ainsworth et al., 2012). Better quantitative estimates