Analysis of coherent structures and atmosphere-canopy coupling strength during the CABINEX field campaign

Steiner, Allison L.; Pressley, S. N.; Botros, A.; Jones, Edward O.; Chung, S. H.; Edburg, S. L.

doi:10.5194/acp-11-11921-2011

Cited by 49 publications

(62 citation statements)

References 51 publications

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“…The impact on aerosols, however, was not determined in this work. Enhanced accuracy of model simulations of biogenic trace gas surface concentrations and lifetimes may be gained by updating the model to include OVOCs that are not yet in the mechanism and by improving vertical mixing schemes for volatile compounds (70), especially near the canopy (71).…”

Section: Resultsmentioning

confidence: 99%

Rapid deposition of oxidized biogenic compounds to a temperate forest

Nguyen

Crounse

Teng

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

232

429

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We report fluxes and dry deposition velocities for 16 atmospheric compounds above a southeastern United States forest, including: hydrogen peroxide (H 2 O 2 ), nitric acid (HNO 3 ), hydrogen cyanide (HCN), hydroxymethyl hydroperoxide, peroxyacetic acid, organic hydroxy nitrates, and other multifunctional species derived from the oxidation of isoprene and monoterpenes. The data suggest that dry deposition is the dominant daytime sink for small, saturated oxygenates. Greater than 6 wt %C emitted as isoprene by the forest was returned by dry deposition of its oxidized products. Peroxides account for a large fraction of the oxidant flux, possibly eclipsing ozone in more pristine regions. The measured organic nitrates comprise a sizable portion (15%) of the oxidized nitrogen input into the canopy, with HNO 3 making up the balance. We observe that water-soluble compounds (e.g., strong acids and hydroperoxides) deposit with low surface resistance whereas compounds with moderate solubility (e.g., organic nitrates and hydroxycarbonyls) or poor solubility (e.g., HCN) exhibited reduced uptake at the surface of plants. To first order, the relative deposition velocities of water-soluble compounds are constrained by their molecular diffusivity. From resistance modeling, we infer a substantial emission flux of formic acid at the canopy level (∼1 nmol m −2 ·s −1 ). GEOS−Chem, a widely used atmospheric chemical transport model, currently underestimates dry deposition for most molecules studied in this work. Reconciling GEOS−Chem deposition velocities with observations resulted in up to a 45% decrease in the simulated surface concentration of trace gases.biosphere−atmosphere exchange | isoprene | dry deposition | OVOCs | fluxes

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Section: Resultsmentioning

confidence: 99%

Rapid deposition of oxidized biogenic compounds to a temperate forest

Nguyen

Crounse

Teng

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

232

429

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“…Steiner et al, 2011) due to heterogeneity in emissions (see e.g. Bryan et al, 2015) and chemistry (see e.g.…”

Section: Flux Calculationsmentioning

confidence: 99%

“…Bryan et al, 2015) and chemistry (see e.g. Butler et al, 2008), as well as the occurrence of coherent structures that can result in counter-gradient flow of matter (Steiner et al, 2011 and references therein).…”

Section: Flux Calculationsmentioning

confidence: 99%

Modelling bidirectional fluxes of methanol and acetaldehyde with the FORCAsT canopy exchange model

et al. 2016

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Abstract. The FORCAsT canopy exchange model was used to investigate the underlying mechanisms governing foliage emissions of methanol and acetaldehyde, two short chain oxygenated volatile organic compounds ubiquitous in the troposphere and known to have strong biogenic sources, at a northern mid-latitude forest site. The explicit representation of the vegetation canopy within the model allowed us to test the hypothesis that stomatal conductance regulates emissions of these compounds to an extent that its influence is observable at the ecosystem scale, a process not currently considered in regional-or global-scale atmospheric chemistry models.We found that FORCAsT could only reproduce the magnitude and diurnal profiles of methanol and acetaldehyde fluxes measured at the top of the forest canopy at Harvard Forest if light-dependent emissions were introduced to the model. With the inclusion of such emissions, FORCAsT was able to successfully simulate the observed bidirectional exchange of methanol and acetaldehyde. Although we found evidence that stomatal conductance influences methanol fluxes and concentrations at scales beyond the leaf level, particularly at dawn and dusk, we were able to adequately capture ecosystem exchange without the addition of stomatal control to the standard parameterisations of foliage emissions, suggesting that ecosystem fluxes can be well enough represented by the emissions models currently used.

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“…Coherent structure is well-organized ramp-like motion for scalar time series (Gao and Li, 1993). The typical duration of coherent structure above and within forest canopy is between 14-116 s by the wavelet analysis (Cava et al, 2004;Dias Júnior et al, 2013;Gao and Li, 1993;Lu and Fitzjarrald, 1994;Steiner et al, 2011;Thomas and Foken, 2005). However, some studies detected that the duration of coherent structure increased from unstable to stable conditions (Steiner et al, 2011) or varied within a day (Dias Júnior et al, 2013).…”

Section: Effects Of Time Averaging Of Co 2 Mixing Ratio On Co 2 Storamentioning

confidence: 99%

Improving the CO2 storage measurements with a single profile system in a tall-dense-canopy temperate forest

Wang

Guo

et al. 2016

Agricultural and Forest Meteorology

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a b s t r a c tThe CO 2 storage (F s ) measurement can contribute significantly to the estimation of the net ecosystem exchange of CO 2 (NEE) especially in tall-canopy forest ecosystems. The F s is often measured with a profile of CO 2 concentration or with an eddy covariance system at the tower top, but few studies investigated potential errors in the F s measurements. We assessed the errors in F s relevant to the vertical distribution of sampling levels and window sizes of averaging time of CO 2 mixing ratio and their effects on NEE in a temperate deciduous forest site in Northeast China using the standardized major axis method. The CO 2 storage per unit height typically decreased with the height increasing, suggesting that the below-canopy layer need a higher spatial resolution. CO 2 storage could be underestimated by up to one third based only on the tower-top measurement. The uncertainty (standard deviation) of the F s decreased with the length of the averaging time window increasing. However, taking time averaging of CO 2 mixing ratio caused significant underestimate of F s , and consequently led to significant underestimates of CO 2 uptake and release at a 30-min time scale. Our results highlight that appropriately combining spatial resolution and temporal resolution (response time for a whole sampling of all levels) is essential to improving the F s estimates with the existing CO 2 profile systems in forest ecosystems. Since the systematic bias and random error in F s estimate with a single profile system are irreconcilable, there is an urgent need to develop a fast response planar-averaging profile or measure the instantaneous vertical-mean concentration to improve the accuracy of F s measurement.

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Analysis of coherent structures and atmosphere-canopy coupling strength during the CABINEX field campaign

Cited by 49 publications

References 51 publications

Rapid deposition of oxidized biogenic compounds to a temperate forest

Rapid deposition of oxidized biogenic compounds to a temperate forest

Modelling bidirectional fluxes of methanol and acetaldehyde with the FORCAsT canopy exchange model

Improving the CO2 storage measurements with a single profile system in a tall-dense-canopy temperate forest

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