A study to explain the emission of nitric oxide from a marsh soil

Abstract. Nitrogen dioxide (NO2) plays an important role in atmospheric pollution, in particular for tropospheric ozone production. However, the removal processes involved in NO2 deposition to terrestrial ecosystems are still the subject of ongoing discussion. This study reports NO2 flux measurements made over a meadow using the eddy covariance method. The measured NO2 deposition fluxes during daytime were about a factor of two lower than a priori calculated fluxes using the Surfatm model without taking into account an internal (also called mesophyllic or sub-stomatal) resistance. Neither an underestimation of the measured NO2 deposition flux due to chemical divergence or an in-canopy NO2 source nor an underestimation of the resistances used to model the NO2 deposition explained the large difference between measured and modelled NO2 fluxes. Thus, only the existence of the internal resistance could account for this large discrepancy between model and measurements. The median internal resistance was estimated to be 300 s m−1 during daytime, but exhibited a large variability (100–800 s m−1). In comparison, the stomatal resistance was only around 100 s m−1 during daytime. Hence, the internal resistance accounted for 50–90% of the total leaf resistance to NO2. This study presents the first clear evidence and quantification of the internal resistance using the eddy covariance method; i.e. plant functioning was not affected by changes of microclimatological (turbulent) conditions that typically occur when using enclosure methods.

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“…According to Remde et al (1993) and Warneck (2000), the main gas-phase reactions for the NO-O 3 -NO 2 triad are…”

Section: Chemical Reactions and Transport Timesmentioning

confidence: 99%

Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO2

et al. 2013

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“…In this case, the determination of surface exchange fluxes by the dynamic chamber method has to take into account the relevant chemical sources and sinks in the chamber volume. For the specific case of NO, NO 2 , and O 3 the main gas-phase reactions outside and inside the chamber are (Remde et al, 1993;Warneck, 2000):…”

Section: Chemical Reactions Inside the Chambermentioning

confidence: 99%

“…The development of this system is based on previous (partly automated) systems used for NO, NO 2 , and O 3 exchange of marshland, heath, and wheat fields (Remde et al, 1993;Ludwig, 1994;Meixner, 1994) and forest soil (Gut et al, 2002a, b;Lehmann, 2002), as well as for the reactive organic trace gas exchange of tree branches (Kesselmeier et al, 1997;Kuhn et al, 2002). Main features of our system are (a) highly transparent chamber walls consisting of chemically inert material to minimise wall loss of reactive trace gases, (b) individual purging flow units for each chamber, and (c) an automated lid so that the chamber can be kept open except for the short measurement periods.…”

Section: Introductionmentioning

confidence: 99%

An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems

et al. 2009

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Abstract. We present an automated dynamic chamber system which is optimised for continuous unattended flux measurements of multiple non-reactive and reactive trace gases on grassland ecosystems. Main design features of our system are (a) highly transparent chamber walls consisting of chemically inert material, (b) individual purging flow units for each chamber, and (c) a movable lid for automated opening and closing of the chamber. The purging flow rate was chosen high enough to keep the mean residence time of the chamber air below one minute. This guarantees a proven efficient mixing of the chamber volume and a fast equilibration after lid closing. The dynamic chamber system is able to measure emission as well as deposition fluxes of trace gases. For the latter case, the modification of the turbulent transport by the chamber (compared to undisturbed ambient conditions) is quantitatively described by a bulk resistance concept.Beside a detailed description of the design and functioning of the system, results of field applications at two grassland sites are presented. In the first experiment, fluxes of five trace gases (CO 2 , H 2 O, NO, NO 2 , O 3 ) were measured simultaneously on small grassland plots.It showed that the dynamic chamber system is able to detect the characteristic diurnal cycles with a sufficient temporal resolution. The results also demonstrated the importance of considering the chemical source/sink in the chamber due to gas phase reactions for the reactive compounds of the NO-NO 2 -O 3 triad. In a second field experiment, Correspondence to: L. Pape (llehmann@mpch-mainz.mpg.de) chamber flux measurements of CO 2 and methanol were compared to simultaneous independent eddy covariance flux measurements on the field scale. The fluxes obtained with the two methods showed a very good agreement indicating a minimal disturbance of the chambers on the physiological activity of the enclosed vegetation.

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“…NO was analysed by chemiluminescence technique. Because O 3 interacts with the NO emitted from the soil it was analysed simultaneously and any loss of NO due to this reaction was corrected for (Remde et al, 1993). N 2 O was measured using manual and/or automatic static chambers.…”

Section: Flux Measurementsmentioning

confidence: 99%

Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O)

Pilegaard¹,

Skiba

Ambus³

et al. 2006

Biogeosciences

228

186

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Abstract. Soil emissions of NO and N 2 O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous) and different nitrogen loads. Geographically they range from Finland in the north to Italy in the south and from Hungary in the east to Scotland in the west.The highest NO emissions were observed from coniferous forests, whereas the lowest NO emissions were observed from deciduous forests. The NO emissions from coniferous forests were highly correlated with N-deposition. The site with the highest average annual emission (82 µg NO-N m −2 h −1 ) was a spruce forest in South-Germany (Höglwald) receiving an annual N-deposition of 2.9 g m −2 . NO emissions close to the detection limit were observed from a pine forest in Finland where the N-deposition was 0.2 g N m −2 a −1 . No significant correlation between N 2 O emission and N-deposition was found. The highest average annual N 2 O emission (20 µg N 2 O-N m −2 h −1 ) was found in an oak forest in the Mátra mountains (Hungary) receiving an annual N-deposition of 1.6 g m −2 . N 2 O emission was significantly negatively correlated with the C/N ratio.The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by differences in characteristics of the litter layer and soil. NO was mainlyCorrespondence to: K. Pilegaard (kim.pilegaard@risoe.dk) derived from nitrification whereas N 2 O was mainly derived from denitrification. In general, soil moisture is lower at coniferous sites (at least during spring time) and the litter layer of coniferous forests is thick and well aerated favouring nitrification and thus release of NO. Conversely, the higher rates of denitrification in deciduous forests due to a compact and moist litter layer lead to N 2 O production and NO consumption in the soil.The two factors soil moisture and soil temperature are often explaining most of the temporal variation within a site. When comparing annual emissions on a regional scale, however, factors such as nitrogen deposition and forest and soil type become much more important.

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A study to explain the emission of nitric oxide from a marsh soil

Cited by 79 publications

References 40 publications

Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO<sub>2</sub>

Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO<sub>2</sub>

An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems

Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N<sub>2</sub>O)

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A study to explain the emission of nitric oxide from a marsh soil

Cited by 79 publications

References 40 publications

Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO&lt;sub&gt;2&lt;/sub&gt;

Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO&lt;sub&gt;2&lt;/sub&gt;

An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems

Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N&lt;sub&gt;2&lt;/sub&gt;O)

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Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO<sub>2</sub>

Measurements of nitrogen oxides and ozone fluxes by eddy covariance at a meadow: evidence for an internal leaf resistance to NO<sub>2</sub>

Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N<sub>2</sub>O)