Synthetic ozone deposition and stomatal uptake at flux tower sites
<p>We develop and evaluate a method to estimate O<sub>3</sub> deposition and stomatal O<sub>3</sub> uptake across networks of eddy covariance flux tower sites where O<sub>3</sub> concentrations and O<sub>3</sub> fluxes have not been measured....
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-09-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/15/5395/2018/bg-15-5395-2018.pdf |
| _version_ | 1828759667346505728 |
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| author | J. A. Ducker C. D. Holmes T. F. Keenan T. F. Keenan S. Fares A. H. Goldstein I. Mammarella J. W. Munger J. Schnell |
| author_facet | J. A. Ducker C. D. Holmes T. F. Keenan T. F. Keenan S. Fares A. H. Goldstein I. Mammarella J. W. Munger J. Schnell |
| author_sort | J. A. Ducker |
| collection | DOAJ |
| description | <p>We develop and evaluate a method to estimate O<sub>3</sub>
deposition and stomatal O<sub>3</sub> uptake across networks of eddy
covariance flux tower sites where O<sub>3</sub> concentrations and
O<sub>3</sub> fluxes have not been measured. The method combines standard
micrometeorological flux measurements, which constrain O<sub>3</sub>
deposition velocity and stomatal conductance, with a gridded dataset of
observed surface O<sub>3</sub> concentrations. Measurement errors are
propagated through all calculations to quantify O<sub>3</sub> flux
uncertainties. We evaluate the method at three sites with O<sub>3</sub> flux
measurements: Harvard Forest, Blodgett Forest, and Hyytiälä Forest.
The method reproduces 83 % or more of the variability in daily stomatal
uptake at these sites with modest mean bias (21 % or less). At least
95 % of daily average values agree with measurements within a factor of 2
and, according to the error analysis, the residual differences from measured
O<sub>3</sub> fluxes are consistent with the uncertainty in the
underlying measurements.</p><p>The product, called synthetic O<sub>3</sub> flux or SynFlux, includes 43
FLUXNET sites in the United States and 60 sites in Europe, totaling 926 site
years of data. This dataset, which is now public, dramatically expands the
number and types of sites where O<sub>3</sub> fluxes can be used for ecosystem
impact studies and evaluation of air quality and climate models. Across these
sites, the mean stomatal conductance and O<sub>3</sub> deposition velocity is
0.03–1.0 cm s<sup>−1</sup>. The stomatal O<sub>3</sub> flux during the growing
season (typically April–September) is 0.5–11.0 nmol
O<sub>3</sub> m<sup>−2</sup> s<sup>−1</sup> with a mean of 4.5 nmol
O<sub>3</sub> m<sup>−2</sup> s<sup>−1</sup> and the largest fluxes generally occur where
stomatal conductance is high, rather than where O<sub>3</sub> concentrations
are high. The conductance differences across sites can be explained by
atmospheric humidity, soil moisture, vegetation type, irrigation, and land
management. These stomatal fluxes suggest that ambient O<sub>3</sub> degrades
biomass production and CO<sub>2</sub> sequestration by 20 %–24 % at
crop sites, 6 %–29 % at deciduous broadleaf forests, and
4 %–20 % at evergreen needleleaf forests in the United States and
Europe.</p> |
| first_indexed | 2024-12-11T01:01:52Z |
| format | Article |
| id | doaj.art-692b28186c40423b9571bdef171ca810 |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-11T01:01:52Z |
| publishDate | 2018-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-692b28186c40423b9571bdef171ca8102022-12-22T01:26:18ZengCopernicus PublicationsBiogeosciences1726-41701726-41892018-09-01155395541310.5194/bg-15-5395-2018Synthetic ozone deposition and stomatal uptake at flux tower sitesJ. A. Ducker0C. D. Holmes1T. F. Keenan2T. F. Keenan3S. Fares4A. H. Goldstein5I. Mammarella6J. W. Munger7J. Schnell8Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, Florida, USADepartment of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, Florida, USALawrence Berkeley National Laboratory, University of California, Berkeley, California, USADepartment of Environmental Science, Policy, and Management, University of California, Berkeley, California, USACouncil of Agricultural Research and Economics (CREA), Research Centre for Forestry and Wood, Arezzo, ItalyDepartment of Environmental Science, Policy, and Management, University of California, Berkeley, California, USAInstitute for Atmosphere and Earth System Research/Physics, P.O. Box 68, Faculty of Science, University of Helsinki, FinlandDepartment of Earth and Planetary Sciences, Northwestern University, Evanston, Illinois, USANOAA Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey, USA<p>We develop and evaluate a method to estimate O<sub>3</sub> deposition and stomatal O<sub>3</sub> uptake across networks of eddy covariance flux tower sites where O<sub>3</sub> concentrations and O<sub>3</sub> fluxes have not been measured. The method combines standard micrometeorological flux measurements, which constrain O<sub>3</sub> deposition velocity and stomatal conductance, with a gridded dataset of observed surface O<sub>3</sub> concentrations. Measurement errors are propagated through all calculations to quantify O<sub>3</sub> flux uncertainties. We evaluate the method at three sites with O<sub>3</sub> flux measurements: Harvard Forest, Blodgett Forest, and Hyytiälä Forest. The method reproduces 83 % or more of the variability in daily stomatal uptake at these sites with modest mean bias (21 % or less). At least 95 % of daily average values agree with measurements within a factor of 2 and, according to the error analysis, the residual differences from measured O<sub>3</sub> fluxes are consistent with the uncertainty in the underlying measurements.</p><p>The product, called synthetic O<sub>3</sub> flux or SynFlux, includes 43 FLUXNET sites in the United States and 60 sites in Europe, totaling 926 site years of data. This dataset, which is now public, dramatically expands the number and types of sites where O<sub>3</sub> fluxes can be used for ecosystem impact studies and evaluation of air quality and climate models. Across these sites, the mean stomatal conductance and O<sub>3</sub> deposition velocity is 0.03–1.0 cm s<sup>−1</sup>. The stomatal O<sub>3</sub> flux during the growing season (typically April–September) is 0.5–11.0 nmol O<sub>3</sub> m<sup>−2</sup> s<sup>−1</sup> with a mean of 4.5 nmol O<sub>3</sub> m<sup>−2</sup> s<sup>−1</sup> and the largest fluxes generally occur where stomatal conductance is high, rather than where O<sub>3</sub> concentrations are high. The conductance differences across sites can be explained by atmospheric humidity, soil moisture, vegetation type, irrigation, and land management. These stomatal fluxes suggest that ambient O<sub>3</sub> degrades biomass production and CO<sub>2</sub> sequestration by 20 %–24 % at crop sites, 6 %–29 % at deciduous broadleaf forests, and 4 %–20 % at evergreen needleleaf forests in the United States and Europe.</p>https://www.biogeosciences.net/15/5395/2018/bg-15-5395-2018.pdf |
| spellingShingle | J. A. Ducker C. D. Holmes T. F. Keenan T. F. Keenan S. Fares A. H. Goldstein I. Mammarella J. W. Munger J. Schnell Synthetic ozone deposition and stomatal uptake at flux tower sites Biogeosciences |
| title | Synthetic ozone deposition and stomatal uptake at flux tower sites |
| title_full | Synthetic ozone deposition and stomatal uptake at flux tower sites |
| title_fullStr | Synthetic ozone deposition and stomatal uptake at flux tower sites |
| title_full_unstemmed | Synthetic ozone deposition and stomatal uptake at flux tower sites |
| title_short | Synthetic ozone deposition and stomatal uptake at flux tower sites |
| title_sort | synthetic ozone deposition and stomatal uptake at flux tower sites |
| url | https://www.biogeosciences.net/15/5395/2018/bg-15-5395-2018.pdf |
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