Fourier transform measurement of NO2 absorption cross-section in the visible range at room temperature

Abstract

New laboratory measurement of NO 2 absorption cross-sections were performed using a Fourier transform spectrometer at 2 and 16 cm -1 ( 0.03 and 0.26 nm at 400 nm) in the visible range (380-830 nm) and at room temperature. The use of a Fourier transform spectrometer leads to a very accurate wavenumber scale (0.005 cm -1 , 8x10-5 nm at 400 nm). The uncertainty on the new measurements is better than 4%. Absolute and differential cross-sections are compared with published data, giving an agreement ranging from 2% to 5% for the absolute values. The discrepancies in the differential cross-section can however reach 18%. The influence of the cross-sections on the ground-based measurement of the stratospheric NO 2 total amount is also investigated.

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume I - gas phase reactions of O<sub>x</sub>, HO<sub>x</sub>, NO<sub>x</sub> and SO<sub>x</sub> species

“…The most extensive study is that of Vandaele et al (1998), covering the wavelength range 238-1000 nm at 220 K and 294 K. It is in excellent agreement with a number of other high resolution studies. At temperatures close to 298 K the data of Vandaele et al (1996;, and all lie within ± 2% over most of the wavelength range covered by their measurements. All of the studies appear to be less reliable at the extremes of the wavelength range covered by each of them but there is sufficient overlap for this group of studies to provide a set of reliable cross-section data for the range 300-600 nm.…”

“…(h) This study combines the high resolution FT technique of Vandaele et al (1996), (Comment c) with the long path cell technique of , and Jenouvrier et al (1996). (Comments a, b, d, g).…”

“…Since our previous evaluation, IUPAC (1997), there have been several studies, mostly at high resolution, of the NO 2 spectrum at temperatures ranging from 298 K to 220 K (Vandaele et al, 1996;Jenouvrier et al, 1996;Yoshina et al, 1997;Burrows et al, 1998). The most extensive study is that of Vandaele et al (1998), covering the wavelength range 238-1000 nm at 220 K and 294 K. It is in excellent agreement with a number of other high resolution studies.…”

Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O

“…In the case of the stratospheric NO2, if a cross-section which does not correspond to the stratospheric conditions is chosen, for example, errors as large as 20 % can occur on the column abundance [8].…”

Ability of the MAX-DOAS method to derive profile information for NO<sub>2</sub>: can the boundary layer and free troposphere be separated?

“…The zenith spectrum observed at noon served as a reference (I noon α=90 • = I ref ). Apart from NO 2 (295 K, Vandaele et al, 1996) and O 4 (296 K, Hermans) the following absorbers were fitted: O 3 (223 K, Bogumil et al, 2003), H 2 O (Vandaele et al, 2005), along with a Ring spectrum (Chance and Spurr, 1997) This selection of viewing elevations is chosen to find a balance between on the one hand a sufficiently small total integration time needed for the scan of one vertical profile, which is important to prevent errors due to changing atmospheric conditions, and on the other hand to make optimal use of the differences in vertical sensitivity of the various elevations (Fig. 1).…”