Ozone dry deposition through plant stomata: multi-model comparison with flux observations and the role of water stress as part of AQMEII4 Activity 2
<p>A substantial portion of tropospheric <span class="inline-formula">O<sub>3</sub></span> dry deposition occurs after diffusion of <span class="inline-formula">O<sub>3</sub></span> through plant stomata. Simulating stomatal u...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-08-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/25/8613/2025/acp-25-8613-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p>A substantial portion of tropospheric <span class="inline-formula">O<sub>3</sub></span> dry deposition occurs after diffusion of <span class="inline-formula">O<sub>3</sub></span> through plant stomata. Simulating stomatal uptake of <span class="inline-formula">O<sub>3</sub></span> in 3D atmospheric chemistry models is important in the face of increasing drought-induced declines in stomatal conductance and enhanced ambient <span class="inline-formula">O<sub>3</sub></span>. Here, we present a comparison of the stomatal component of <span class="inline-formula">O<sub>3</sub></span> dry deposition (<span class="inline-formula">eg<sub>s</sub></span>) from chemical transport models and estimates of <span class="inline-formula">eg<sub>s</sub></span> from observed <span class="inline-formula">CO<sub>2</sub></span>, latent heat, and <span class="inline-formula">O<sub>3</sub></span> flux. The dry deposition schemes were configured as single-point models forced with data collected at flux towers. We conducted sensitivity analyses to study the impact of model parameters that control stomatal moisture stress on modeled <span class="inline-formula">eg<sub>s</sub></span>. Examining six sites around the Northern Hemisphere, we find that the seasonality of observed flux-based <span class="inline-formula">eg<sub>s</sub></span> agrees with the seasonality of simulated <span class="inline-formula">eg<sub>s</sub></span> at times during the growing season, with disagreements occurring during the later part of the growing season at some sites. We find that modeled water stress effects are too strong in a temperate–boreal transition forest. Some single-point models overestimate summertime <span class="inline-formula">eg<sub>s</sub></span> in a seasonally water-limited Mediterranean shrubland. At all sites examined, modeled <span class="inline-formula">eg<sub>s</sub></span> was sensitive to parameters that control the vapor pressure deficit stress. At specific sites that experienced substantial declines in soil moisture, the simulation of <span class="inline-formula">eg<sub>s</sub></span> was highly sensitive to parameters that control the soil moisture stress. The findings demonstrate the challenges in accurately representing the effects of moisture stress on the stomatal sink of <span class="inline-formula">O<sub>3</sub></span> during observed increases in dryness due to ecosystem-specific plant–resource interactions.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |