Measurements of concentration gradients of HNO2 and HNO3 over a semi-natural ecosystem

Neftel, A.; Blatter, A.; Hesterberg, Rolf

doi:10.1016/1352-2310(96)00011-8

Cited by 95 publications

(49 citation statements)

References 18 publications

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“…Huebert et al, 1988;Erisman and Wyers, 1993;Neftel et al, 1996;Sutton et al, 1998;Nemitz et al, 2000). In general, however, concentrations, and therefore K m decline towards the ground, while K e is increased above warm vegetation.…”

Section: Apparent Particle Emission -A Measurement Artefact?mentioning

confidence: 98%

Gas-particle interactions above a Dutch heathland: II. Concentrations and surface exchange fluxes of atmospheric particles

et al. 2004

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Abstract. Size-dependent particle number fluxes measured by eddy-covariance (EC) and continuous fluxes of ammonium (NH -N dry deposition amounts to 20% of the dry input of NH 3 -N over the measurement period. These surface exchange fluxes are analyzed together with simultaneous gas-phase flux measurements for indications of gas-particle interactions. On warm afternoons the apparent fluxes of acids and aerosol above the heathland showed several coinciding anomalies, all of which are consistent with NH + 4 evaporation during deposition: (i) canopy resistances for HNO 3 and HCl of up to 100 s m −1 , (ii) simultaneous particle emission of small particles (D p <0.18 µm) and deposition of larger particles (D p >0.18 µm), (iii) NH + 4 deposition faster than derived from size-distributions and size-segregated EC particle fluxes. These observations coincide with the observations of (i) surface concentration products of NH 3 and HNO 3 well below the thermodynamic equilibrium value and (ii) Damköhler numbers that indicate chemical conversion to be sufficiently fast to modify exchange fluxes. The measurements imply a removal rate of volatile NH + 4 of 3−30×10 −6 s −1 averaged over the 1 km boundary-layer, while NH 3 deposition is underestimated by typically 20 ng m −2 s −1 (28%) and flux reversal may occur.

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Section: Apparent Particle Emission -A Measurement Artefact?mentioning

confidence: 98%

Gas-particle interactions above a Dutch heathland: II. Concentrations and surface exchange fluxes of atmospheric particles

et al. 2004

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“…Previous field and modelling studies have demonstrated that HONO photolysis contributes considerably to the daily OH production with an integrated contribution of up to 60%. [36][37][38][39][40][41][42][43] While the night time formation of HONO in the atmosphere is reasonably well explained by direct emissions and different heterogeneous conversion processes of NO 2 [44][45][46] on ground surfaces, 42 recent sensitive measurements have shown unexpectedly high HONO concentrations during the daytime. 36,38,41,43,47 The measured HONO levels were significantly higher than the values predicted on the basis of the available knowledge about daytime sources and sinks of HONO.…”

Section: ð1þmentioning

confidence: 99%

“…[36][37][38][39][40][41][42][43] While the night time formation of HONO in the atmosphere is reasonably well explained by direct emissions and different heterogeneous conversion processes of NO 2 [44][45][46] on ground surfaces, 42 recent sensitive measurements have shown unexpectedly high HONO concentrations during the daytime. 36,38,41,43,47 The measured HONO levels were significantly higher than the values predicted on the basis of the available knowledge about daytime sources and sinks of HONO. The experiments revealed the existence of a strong daytime source of HONO up to 60 times higher than the night time sources 43 and contributing up to 60% to the direct OH radical sources, 48 which was suggested to arise from the photolysis of adsorbed HNO 3 /nitrate 38,47,[49][50][51] or by heterogeneous photochemistry of NO 2 on organic substrates.…”

Section: ð1þmentioning

confidence: 99%

The photolysis of ortho-nitrophenols: a new gas phase source of HONO

Bejan

Aal

Barnes

et al. 2006

Phys. Chem. Chem. Phys.

240

291

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Formation of nitrous acid (HONO) in the gas phase has been observed for the first time in a flow tube photoreactor upon irradiation (l = 300-500 nm) of 2-nitrophenol and methyl substituted derivatives using a selective and sensitive instrument (LOPAP) for the detection of HONO. Formation of HONO by heterogeneous NO 2 photochemistry has been excluded, since production of NO 2 under the experimental conditions is negligible. Variation of the surface to volume ratio and the nitrophenol concentration showed that the photolysis occurred in the gas phase indicating that HONO formation is initiated by intramolecular hydrogen transfer from the phenolic OH group to the nitro group. From the measured linear dependence of the HONO formation rate on the reactant's concentration and photolysis light intensity, a non-negligible new HONO source is proposed for the urban atmosphere during the day. Unexpectedly high HONO mixing ratios have been observed recently in several field campaigns during the day. It is proposed that the photolysis of aromatic compounds containing the ortho-nitrophenol entity could help to explain, at least in part, this high contribution of HONO to the oxidation capacity of the urban atmosphere.

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“…The gas-phase reaction of NO with the OH radical (Stuhl and Niki, 1972;Pagsberg et al, 1997) mostly determines the daytime HONO concentration. However, recent field measurements (Neftel et al, 1996;Kleffmann et al, 2005;Sörgel et al, 2011;Li et al, 2012Li et al, , 2014Wong et al, 2012) and laboratory studies (Akimoto et al, 1987;Rohrer et al, 2005) reported much larger HONO concentrations than predicted by the gas-phase reactions. These findings imply some missing daytime sources of HONO.…”

Section: Introductionmentioning

confidence: 99%

MAX-DOAS measurements of HONO slant column densities during the MAD-CAT campaign: inter-comparison, sensitivity studies on spectral analysis settings, and error budget

et al. 2017

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Abstract. In order to promote the development of the passive DOAS technique the Multi Axis DOAS -Comparison campaign for Aerosols and Trace gases (MAD-CAT) was held at the Max Planck Institute for Chemistry in Mainz, Germany, from June to October 2013. Here, we systematically compare the differential slant column densities (dSCDs) of nitrous acid (HONO) derived from measurements of seven different instruments. We also compare the tropospheric difference of SCDs (delta SCD) of HONO, namely the difference of the SCDs for the non-zenith observations and the zenith observation of the same elevation sequence. Different research groups analysed the spectra from their own instruments using their individual fit software. All the fit errors of HONO dSCDs from the instruments with cooled large-size detectors are mostly in the range of 0.1 to 0.3 × 10 15 molecules cm −2 for an integration time of 1 min. The fit error for the mini MAX-DOAS is around 0.7 × 10 15 molecules cm −2 . Although the HONO delta SCDs are normally smaller than 6 × 10 15 molecules cm −2 , consistent time series of HONO delta SCDs are retrieved from the measurements of different instruments. Both fits with a sequential Fraunhofer reference spectrum (FRS) and a daily noon FRS lead to similar consistency. Apart from the mini-MAX-DOAS, the systematic absolute differences of HONO delta SCDs between the instruments are smaller than 0.63 × 10 15 molecules cm −2 . The correlation coefficients are higher than 0.7 and the slopes of linear regressions deviate from unity by less than 16 % for the elevation angle of 1 • . The correlations decrease with an increase in elevation angle. All the participants also analysed synthetic spectra using the same baseline DOAS settings toPublished by Copernicus Publications on behalf of the European Geosciences Union. Y. Wang et al.: MAX-DOAS measurements of HONO slant column densitiesevaluate the systematic errors of HONO results from their respective fit programs. In general the errors are smaller than 0.3 × 10 15 molecules cm −2 , which is about half of the systematic difference between the real measurements.The differences of HONO delta SCDs retrieved in the selected three spectral ranges 335-361, 335-373 and 335-390 nm are considerable (up to 0.57 × 10 15 molecules cm −2 ) for both real measurements and synthetic spectra. We performed sensitivity studies to quantify the dominant systematic error sources and to find a recommended DOAS setting in the three spectral ranges. The results show that water vapour absorption, temperature and wavelength dependence of O 4 absorption, temperature dependence of Ring spectrum, and polynomial and intensity offset correction all together dominate the systematic errors. We recommend a fit range of 335-373 nm for HONO retrievals. In such fit range the overall systematic uncertainty is about 0.87 × 10 15 molecules cm −2 , much smaller than those in the other two ranges. The typical random uncertainty is estimated to be about 0.16 × 10 15 molecules cm −2 , which is only 25 % of the total syst...

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Measurements of concentration gradients of HNO2 and HNO3 over a semi-natural ecosystem

Cited by 95 publications

References 18 publications

Gas-particle interactions above a Dutch heathland: II. Concentrations and surface exchange fluxes of atmospheric particles

Gas-particle interactions above a Dutch heathland: II. Concentrations and surface exchange fluxes of atmospheric particles

The photolysis of ortho-nitrophenols: a new gas phase source of HONO

MAX-DOAS measurements of HONO slant column densities during the MAD-CAT campaign: inter-comparison, sensitivity studies on spectral analysis settings, and error budget

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