Towards standards for measuring greenhouse gas fluxes from agricultural fields using instrumented towers

Pattey, E.; Edwards, Grant C.; Strachan, I. B.; Desjardins, Raymond L.; Kaharabata, S. K.; Wagner-Riddle, Claudia

doi:10.4141/s05-100

Cited by 63 publications

(34 citation statements)

References 141 publications

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“…For several research projects, the fluxes of trace gases with very low atmospheric concentrations (e.g. N 2 O, CH 4 ), were measured using the Relaxed Eddy Accumulation (REA) technique (Pattey et al, 2006). Details on the aircraft, the instrumentation and various sampling strategies are presented in Desjardins et al (2000).…”

Section: Aircraft-based Flux Measurementsmentioning

confidence: 99%

Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011

et al. 2016

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Abstract. Over the past 30 years, the Canadian Twin Otter research group has operated an aircraft platform for the study of atmospheric greenhouse gas fluxes (carbon dioxide, ozone, nitrous oxide and methane) and energy exchange (latent and sensible heat) over a wide range of terrestrial ecosystems in North America. Some of the acquired data from these projects have now been archived at the Flight Research Laboratory and Agriculture and Agri-Food Canada. The dataset, which contains the measurements obtained in eight projects from 1987 to 2011 are now publicly available. All these projects were carried out in order to improve our understanding of the biophysical controls acting on land-surface atmosphere fluxes. Some of the projects also attempted to quantify the impacts of agroecosystems on the environment. To provide information on the data available, we briefly describe each project and some of the key findings by referring to previously published relevant work. As new flux analysis techniques are being developed, we are confident that much additional information can be extracted from this unique data set.

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Section: Aircraft-based Flux Measurementsmentioning

confidence: 99%

Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011

et al. 2016

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“…The fluxes of BVOCs (F BVOC ) between vegetation and the atmosphere were calculated using the flux-gradient method (Pasquill, 1950;Businger et al, 1971;Arya, 2001;Pattey et al, 2006), which requires the knowledge of vertical gradients of BVOCs above the canopy and other auxiliary measurements. The vertical flux of BVOCs was calculated as follows:…”

Section: Vertical Fluxes Of Bvocsmentioning

confidence: 99%

Impacts of herbaceous bioenergy crops on atmospheric volatile organic composition and potential consequences for global climate change

et al. 2012

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The introduction of new crops to agroecosystems can change the chemical composition of the atmosphere by altering the amount and type of plant-derived biogenic volatile organic compounds (BVOCs). BVOCs are produced by plants to aid in defense, pollination, and communication. Once released into the atmosphere, they have the ability to influence its chemical and physical properties. In this study, we compared BVOC emissions from three potential bioenergy crops and estimated their theoretical impacts on bioenergy agroecosystems. The crops chosen were miscanthus (Miscanthus 9 giganteus), switchgrass (Panicum virgatum), and an assemblage of prairie species (mix of~28 species). The concentration of BVOCs was different within and above plant canopies. All crops produced higher levels of emissions at the upper canopy level. Miscanthus produced lower amounts of volatiles compared with other grasses. The chemical composition of volatiles differed significantly among plant communities. BVOCs from miscanthus were depleted in terpenoids relative to the other vegetation types. The carbon flux via BVOC emissions, calculated using the flux-gradient method, was significantly higher in the prairie assemblage compared with miscanthus and switchgrass. The BVOC carbon flux was approximately three orders of magnitude lower than the net fluxes of carbon measured over the same fields using eddy covariance systems. Extrapolation of our findings to the landscape scale leads us to suggest that the widespread adoption of bioenergy crops could potentially alter the composition of BVOCs in the atmosphere, thereby influencing its warming potential, the formation of atmospheric particulates, and interactions between plants and arthropods. Our data and projections indicate that, among at least these three potential options for bioenergy production, miscanthus is likely to have lower impacts on atmospheric chemistry and biotic interactions mediated by these volatiles when miscanthus is planted on the landscape scale.

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“…Annual patterns of N 2 O flux can be most effectively captured using the micrometeorological plus Tunable Diode Laser (TDL) Trace Gas Analyzer approach (Groffman et al 2000;Wagner-Riddle et al 1997;Pattey et al 2005). This quasi-continuous data is critical for defining the duration of emissions, their relationship to soil and climatic factors, and for comparisons to process-model simulations of emissions (e.g., Grant and Pattey 2003).…”

Section: Temporal Samplingmentioning

confidence: 99%

“…Although knowledge gaps exist in our temporal sampling and interpolation procedures these can be readily filled through the application of the micrometeorological plus TDL approach (Groffman et al 2000;Pattey et al 2005). Issues surrounding sampling for short-duration events or the presence of diurnal cycles can be evaluated using the micrometeorological plus TDL approach and then used to determine the optimum deployment program for chamberbased measurements at non-instrumented sites.…”

Section: Sources Of Uncertaintymentioning

confidence: 99%

Towards optimum sampling for regional-scale N₂O emission monitoring in Canada

Pennock

Yates²,

Braidek³

2006

Can. J. Soil. Sci.

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. 2006. Towards optimum sampling for regional-scale N 2 O emission monitoring in Canada. Can. J. Soil Sci. 86: 441-450. There is an increasing need for field monitoring studies of N 2 O emissions to assess the reliability of process models. Our goal is to review the issues surrounding the design of monitoring and regional upscaling of fieldmeasured N 2 O emissions for Canadian conditions. Management history creates a range of controlling conditions and emission responses for each land use present in the study region and multiple fields should be sampled within each land use class. The requirement for multiple sample fields necessitates chamber-based sampling designs (ideally in conjunction with site-specific micrometeorological measurements). Uniformly minimum variance unbiased (UMVU) estimators have been recommended for estimation of the mean and variance of the sample distributions, but use of these estimators is limited where zero or negative values occur. Three basic annual emission patterns are observed across a range of N 2 O studies: background, seasonal, and event + seasonal. The event + seasonal pattern (where short duration, high emission events are superimposed on an underlying seasonal pattern) is common in Canadian agroecosystems. Background and seasonal annual patterns can be effectively captured with biweekly or even triweekly samplings. For the event + seasonal patterns more frequent samplings at periods when emission are believed to be higher (e.g., snow melt or post-fertilization events) are required. Linear interpolation of emissions between the sporadic measurements is the simplest and most reproducible method of temporal interpolation. Spatial extrapolation of the measured emissions is typically done by a measure and multiply approach, where the measured emissions for a given class are multiplied by the area of the class. The methods used to define the soil wetness, land use, and management classes should be clearly defined and consistently applied. The lack of information on the duration and magnitude of event-based emissions and the diurnal pattern of emissions is a major limitation to temporal interpolation. Les auteurs examinent les difficultés associées à la conception de modèles permettant de suivre régionalement les émissions de N 2 O mesurées sur le terrain dans les conditions typiques au Canada. La succession des pratiques culturales engendre diverses conditions régulatrices et réactions au niveau des émissions pour chaque type de terre présent dans la région à l'étude et l'on devrait échantillonner de nombreux terrains pour chaque classe d'utilisation des terres. L'échantillonnage de nombreux terrains nécessite le prélèvement d'échantillons en cellule (de préférence avec la prise de relevés micrométéorologiques sur le site même). On recommande l'utilisation d'estimateurs uniformes non biaisés à variance minimum pour estimer la moyenne et la variance de la distribution des échantillons, mais l'utilité de tels estimateurs est limitée avec les valeurs nulles ou négatives. On remarque ...

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Towards standards for measuring greenhouse gas fluxes from agricultural fields using instrumented towers

Cited by 63 publications

References 141 publications

Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011

Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011

Impacts of herbaceous bioenergy crops on atmospheric volatile organic composition and potential consequences for global climate change

Towards optimum sampling for regional-scale N₂O emission monitoring in Canada

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Towards standards for measuring greenhouse gas fluxes from agricultural fields using instrumented towers

Cited by 63 publications

References 141 publications

Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011

Flux measurements by the NRC Twin Otter atmospheric research aircraft: 1987–2011

Impacts of herbaceous bioenergy crops on atmospheric volatile organic composition and potential consequences for global climate change

Towards optimum sampling for regional-scale N2O emission monitoring in Canada

Contact Info

Product

Resources

About

Towards optimum sampling for regional-scale N₂O emission monitoring in Canada