FORCAsT?gs: Importance of Stomatal Conductance Parameterization to Estimated Ozone Deposition Velocity

The role of stomata in regulating photosynthesis and transpiration, hence governing global biogeochemical cycles climate, is well-known. Less well-understood, however, the importance stomatal control to exchange other trace gases between terrestrial vegetation atmosphere. Yet these determine atmospheric composition, air quality on scales ranging from local global, seconds decades. Vegetation a major sink for ground-level ozone via process dry deposition primary source many biogenic volatile organic compounds (BVOCs). rate largely controlled by diffusion gas through stomata, this also governs emission some key BVOCs. It critical therefore that canopy-atmosphere models capture physiological processes controlling conductance transfer than carbon dioxide water vapor. We incorporate three most widely used coupled conductance-photosynthesis into one-dimensional multi-layer FORest Canopy-Atmosphere Transfer (FORCAsT1.0) model assess choice parameterization simulated rates. Modeled GPP across broad range ecosystems differ up factor two best worst performing configurations. This leads divergences seasonal diel profiles velocity 30% 13%, demonstrating accurate quantification deposition.