Field investigations of nitrogen dioxide (NO<sub>2</sub>) exchange between plants and the atmosphere

Abstract

Abstract. The nitrogen dioxide (NO 2 ) exchange between the atmosphere and needles of Picea abies L. (Norway Spruce) was studied under uncontrolled field conditions using a dynamic chamber system. This system allows measurements of the flux density of the reactive NO-NO 2 -O 3 triad and additionally of the non-reactive trace gases CO 2 and H 2 O. For the NO 2 detection a highly NO 2 specific blue light converter was used, which was coupled to chemiluminescence detection of the photolysis product NO. This NO 2 converter excludes known interferences with other nitrogen compounds, which occur by using more unspecific NO 2 converters. Photo-chemical reactions of NO, NO 2 , and O 3 inside the dynamic chamber were considered for the determination of NO 2 flux densities, NO 2 deposition velocities, as well as NO 2 compensation point concentrations. The calculations are based on a bi-variate weighted linear regression analysis (y-and x-errors considered). The NO 2 deposition velocities for spruce, based on projected needle area, ranged between 0.07 and 0.42 mm s −1 . The calculated NO 2 compensation point concentrations ranged from 2.4 ± 9.63 to 29.0 ± 16.30 nmol m −3 (0.05-0.65 ppb) but the compensation point concentrations were all not significant in terms of compensation point concentration is unequal to zero. These data challenge the existence of a NO 2 compensation point concentration for spruce. Our study resulted in lower values of NO 2 gas exchange flux densities, NO 2 deposition velocities and NO 2 compensation point concentrations in comparison to most previous studies. It is essential to use a more specific NO 2 analyzer than used in previous studies and to consider photo-chemical reactions between NO, NO 2 , and O 3 inside the chamber.

Measurement report: Leaf-scale gas exchange of atmospheric reactive trace species (NO<sub>2</sub>, NO, O<sub>3</sub>) at a northern hardwood forest in Michigan

“…5c). Generally, the leaf-level NO2 and O3 deposition velocity can largely be inferred from the stomatal conductance of water only, as also concluded from earlier studies for European tree species (Breuninger et al, 2013;Rondón and Granat, 1994).…”

“…Although the development stages of the trees, PAR, humidity and temperature conditions are different, the results are comparable, ranging from 0.76 to 1.6 mm s -1 from this work 410 and 0.4-1.8 mm s -1 from earlier work. We also compare our results to those of several native European trees -scots pine, evergreen oak, common oak, European beech, and silver birch, measured under the conditions of PAR = 900 mol m -2 s -1 , maximum temperature 27.7C, and relative humidity 31.2-99.9% (Breuninger et al, 2013). The maximum NO2 deposition https://doi.org/10.5194/acp-2020-149 Preprint.…”

“…Instead, the forest provides 80 an additional atmospheric NOx source. This conundrum, discussed by Lerdau et al (2000), seemed to be resolved in the past decade when additional leaf-scale experiments were made using a new NOx measurement instrument (Breuninger et al, 2012(Breuninger et al, , 2013Chaparro-Suarez et al, 2011). The improved NO2 detection specificity of the instrument prevented artifacts caused by augmentation of the NO2 signal from other nitrogen compounds such as nitrous acid (HONO), nitric acid (HNO3) and peroxyacyl nitrates (PANs).…”

Dry deposition of nitrogen compounds (NO<sub>2</sub>, HNO<sub>3</sub>, NH<sub>3</sub>), sulfur dioxide and ozone in west and central African ecosystems using the inferential method

“…Phys., 13, 11351-11374, 2013 www.atmos-chem-phys.net/13/11351/2013/ Coe and Gallagher, 1992;Gao et al, 1996). Previous studies reported NO 2 compensation point concentrations ranging from 0.05 to 3 ppb depending on tree species and environmental conditions (Sparks et al, 2001;Raivonen et al, 2009;Breuninger et al, 2013, and references therein). However, the existence of such a compensation point is questionable (Lerdau et al, 2000;Chaparro-Suarez et al, 2011).…”

The lifetime of nitrogen oxides in an isoprene-dominated forest

“…The deposition of both peroxy nitrates and ANs, as well as the uptake of NO x by plants, also leads to the loss of NO SL . Based on the deposition velocity of NO x over vegetation measured by Breuninger et al (2013), the rate of NO x uptake was calculated to be approximately 1 ppt h −1 . A 50 % uncertainty in the AN hydrolysis rate, combined in quadrature with the uncertainties from the other NO SL loss processes, gives the overall uncertainty in the NO SL loss rate of ±25 ppt h −1 .…”