Field investigations of nitrogen dioxide (NO2) exchange between plants and the atmosphere Max Planck Institute for Chemistry, Biogeochemistry and Air Chemistry Departments, P.O. Box 3060, 55020 Mainz, Germany
22 Jan 2013
Received: 28 June 2012 – Published in Atmos. Chem. Phys. Discuss.: 23 July 2012 Abstract. The nitrogen dioxide (NO2) 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-NO2-O3 triad and additionally of
the non-reactive trace gases CO2 and H2O. For the NO2
detection a highly NO2 specific blue light converter was used, which
was coupled to chemiluminescence detection of the photolysis product NO.
This NO2 converter excludes known interferences with other nitrogen
compounds, which occur by using more unspecific NO2 converters.
Photo-chemical reactions of NO, NO2, and O3 inside the dynamic
chamber were considered for the determination of NO2 flux densities,
NO2 deposition velocities, as well as NO2 compensation point
concentrations. The calculations are based on a bi-variate weighted linear
regression analysis (y- and x-errors considered). The NO2 deposition
velocities for spruce, based on projected needle area, ranged between 0.07
and 0.42 mm s−1. The calculated NO2 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
NO2 compensation point concentration for spruce. Our study resulted in
lower values of NO2 gas exchange flux densities, NO2 deposition
velocities and NO2 compensation point concentrations in comparison to
most previous studies. It is essential to use a more specific NO2
analyzer than used in previous studies and to consider photo-chemical
reactions between NO, NO2, and O3 inside the chamber.
Revised: 17 December 2012 – Accepted: 11 January 2013 – Published: 22 January 2013
Citation: Breuninger, C., Meixner, F. X., and Kesselmeier, J.: Field investigations of nitrogen dioxide (NO2) exchange between plants and the atmosphere, Atmos. Chem. Phys., 13, 773-790, doi:10.5194/acp-13-773-2013, 2013.