Influence of plant ecophysiology on ozone dry deposition: comparing between multiplicative and photosynthesis-based dry deposition schemes and their responses to rising CO<sub>2</sub> level
<p>Dry deposition is a key process for surface ozone (O<span class="inline-formula"><sub>3</sub>)</span> removal. Stomatal uptake is a major component of O<span class="inline-formula"><sub>3</sub></span> dry deposition, which...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-03-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/19/1753/2022/bg-19-1753-2022.pdf |
| Summary: | <p>Dry deposition is a key process for surface ozone
(O<span class="inline-formula"><sub>3</sub>)</span> removal. Stomatal uptake is a major component of O<span class="inline-formula"><sub>3</sub></span> dry
deposition, which is parameterized differently in current land surface
models and chemical transport models. We developed and used a standalone
terrestrial biosphere model, driven by a unified set of prescribed
meteorology, to evaluate two widely used dry deposition modeling frameworks,
Wesely (1989) and Zhang et al. (2003), with different configurations of
stomatal resistance: (1) the default multiplicative method in the Wesely
scheme (W89) and Zhang et al. (2003) scheme (Z03), (2) the traditional
photosynthesis-based Farquhar–Ball–Berry (FBB) stomatal algorithm, and (3) the
Medlyn stomatal algorithm (MED) based on optimization theory. We found that
using the FBB stomatal approach that captures ecophysiological responses to
environmental factors, especially to water stress, can generally improve the
simulated dry deposition velocities compared with multiplicative schemes.
The MED stomatal approach produces higher stomatal conductance than FBB and
is likely to overestimate dry deposition velocities for major vegetation
types, but its performance is greatly improved when spatially varying slope
parameters based on annual mean precipitation are used. Large discrepancies
were also found in stomatal responses to rising CO<span class="inline-formula"><sub>2</sub></span> levels from 390
to 550 ppm: the multiplicative stomatal method with an empirical CO<span class="inline-formula"><sub>2</sub></span>
response function produces reduction (<span class="inline-formula">−</span>35 %) in global stomatal
conductance on average much larger than that with the photosynthesis-based
stomatal method (<span class="inline-formula">−</span>14 %–19 %). Our results show the potential biases in
O<span class="inline-formula"><sub>3</sub></span> sink caused by errors in model structure especially in the Wesely
dry deposition scheme and the importance of using photosynthesis-based
representation of stomatal resistance in dry deposition schemes under a
changing climate and rising CO<span class="inline-formula"><sub>2</sub></span> concentration.</p> |
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| ISSN: | 1726-4170 1726-4189 |