Corrigendum to “Measurements of PM10 aerosol and gas-phase nitrous acid during fall season in a semi-urban atmosphere”

Abstract. Nitrous acid (HONO) mixing ratios for the Houston metropolitan area were simulated with the Community Multiscale Air Quality (CMAQ) model for an episode during the Texas Air Quality Study (TexAQS) II in August/September 2006 and compared to in-situ MC/IC (mist-chamber/ion chromatograph) and long path DOAS (Differential Optical Absorption Spectroscopy) measurements at three different altitudes. Several HONO sources were accounted for in simulations, such as gas phase formation, direct emissions, nitrogen dioxide (NO2*) hydrolysis, photo-induced formation from excited NO2* and photo-induced conversion of NO2 into HONO on surfaces covered with organic materials. Compared to the gas-phase HONO formation there was about a tenfold increase in HONO mixing ratios when additional HONO sources were taken into account, which improved the correlation between modeled and measured values. Concentrations of HONO simulated with only gas phase chemistry did not change with altitude, while measured HONO concentrations decrease with height. A trend of decreasing HONO concentration with altitude was well captured with CMAQ predicted concentrations when heterogeneous chemistry and photolytic sources of HONO were taken into account. Heterogeneous HONO production mainly accelerated morning ozone formation, albeit slightly. Also HONO formation from excited NO2 only slightly affected HONO and ozone (O3) concentrations. Photo-induced conversion of NO2 into HONO on surfaces covered with organic materials turned out to be a strong source of daytime HONO. Since HONO immediately photo-dissociates during daytime its ambient mixing ratios were only marginally altered (up to 0.5 ppbv), but significant increase in the hydroxyl radical (OH) and ozone concentration was obtained. In contrast to heterogeneous HONO formation that mainly accelerated morning ozone formation, inclusion of photo-induced surface chemistry influenced ozone throughout the day.

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Key Role of Equilibrium HONO Concentration over the Soil

10.5194/egusphere-egu21-4166 ◽

2021 ◽

Author(s):

Fengxia Bao ◽

Hang Su ◽

Uwe Kuhn ◽

Yafang Cheng

Keyword(s):

Gas Phase ◽

Hydroxyl Radicals ◽

Nitrous Acid ◽

Measurement Method ◽

Oxidative Capacity ◽

Sources And Sinks ◽

Dynamic Chamber ◽

Open Question ◽

Actinic Radiation

<p>Nitrous acid (HONO) is an important component of the nitrogen cycle. HONO can also be rapidly photolyzed by actinic radiation to form hydroxyl radicals (OH) and exerts a primary influence on the oxidative capacity of the atmosphere. The sources and sinks of HONO, however, are not fully understood. Soil nitrite, produced via nitrification or denitrification, is an important source for the atmospheric HONO production. [HONO]*, the equilibrium gas phase HONO concentration over the soil,&#160;has been suggested as key to understanding the environmental effects of soil fluxes of HONO (Su et al., 2011). But if and how [HONO]* may exist and vary remains an open question. In this project, a measurement method using a dynamic chamber has been developed to derive [HONO]* and the atmospheric soil fluxes of HONO can accordingly be quantified. We demonstrate the existence of [HONO]* and determine its variation in the course of soil drying processes. We show that when [HONO]* is higher than the atmospheric HONO concentration, HONO will be released from soil; otherwise, HONO will be deposited on soil. This work advances the understanding of soil HONO emissions, and the evaluation of its impact on the atmospheric oxidizing capacity and the nitrogen cycling.</p>

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Formation of nitrous acid in a gas-phase stirred flow reactor

Journal of the Chemical Society Faraday Transactions 1 Physical Chemistry in Condensed Phases ◽

10.1039/f19726800683 ◽

1972 ◽

Vol 68 (0) ◽

pp. 683 ◽

Cited By ~ 13

Author(s):

R. F. Graham ◽

B. J. Tyler

Keyword(s):

Gas Phase ◽

Nitrous Acid ◽

Flow Reactor

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Atmospheric chemistry and physics in the atmosphere of a developed megacity (London): an overview of the REPARTEE experiment and its conclusions

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-3065-2012 ◽

2012 ◽

Vol 12 (6) ◽

pp. 3065-3114 ◽

Cited By ~ 94

Author(s):

R. M. Harrison ◽

M. Dall'Osto ◽

D. C. S. Beddows ◽

A. J. Thorpe ◽

W. J. Bloss ◽

...

Keyword(s):

Chemical Composition ◽

Gas Phase ◽

Atmospheric Chemistry ◽

Urban Atmosphere ◽

Trace Gas ◽

Chemical Components ◽

Chemical Transformations ◽

Specific Chemical ◽

Gas Dispersion ◽

Wide Range

Abstract. The REgents PARk and Tower Environmental Experiment (REPARTEE) comprised two campaigns in London in October 2006 and October/November 2007. The experiment design involved measurements at a heavily trafficked roadside site, two urban background sites and an elevated site at 160–190 m above ground on the BT Tower, supplemented in the second campaign by Doppler lidar measurements of atmospheric vertical structure. A wide range of measurements of airborne particle physical metrics and chemical composition were made as well as measurements of a considerable range of gas phase species and the fluxes of both particulate and gas phase substances. Significant findings include (a) demonstration of the evaporation of traffic-generated nanoparticles during both horizontal and vertical atmospheric transport; (b) generation of a large base of information on the fluxes of nanoparticles, accumulation mode particles and specific chemical components of the aerosol and a range of gas phase species, as well as the elucidation of key processes and comparison with emissions inventories; (c) quantification of vertical gradients in selected aerosol and trace gas species which has demonstrated the important role of regional transport in influencing concentrations of sulphate, nitrate and secondary organic compounds within the atmosphere of London; (d) generation of new data on the atmospheric structure and turbulence above London, including the estimation of mixed layer depths; (e) provision of new data on trace gas dispersion in the urban atmosphere through the release of purposeful tracers; (f) the determination of spatial differences in aerosol particle size distributions and their interpretation in terms of sources and physico-chemical transformations; (g) studies of the nocturnal oxidation of nitrogen oxides and of the diurnal behaviour of nitrate aerosol in the urban atmosphere, and (h) new information on the chemical composition and source apportionment of particulate matter size fractions in the atmosphere of London derived both from bulk chemical analysis and aerosol mass spectrometry with two instrument types.

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An evaluation of the mechanism of nitrous acid formation in the urban atmosphere

Research on Chemical Intermediates ◽

10.1163/156856794x00423 ◽

1994 ◽

Vol 20 (3-5) ◽

pp. 463-502 ◽

Cited By ~ 122

Author(s):

J. G. Calvert ◽

G. Yarwood ◽

A. M. Dunker

Keyword(s):

Nitrous Acid ◽

Urban Atmosphere ◽

Acid Formation

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Partitioning of hydrogen peroxide in gas-liquid and gas-aerosol phases

10.5194/acp-2020-34 ◽

2020 ◽

Author(s):

Xiaoning Xuan ◽

Zhongming Chen ◽

Yiwei Gong ◽

Hengqing Shen ◽

Shiyi Chen

Keyword(s):

Hydrogen Peroxide ◽

Liquid Phase ◽

Gas Phase ◽

Pure Water ◽

Average Concentration ◽

Effective Field ◽

Urban Atmosphere ◽

Ambient Atmosphere ◽

Henry's Law ◽

Henry’S Law

Abstract. Hydrogen peroxide (H2O2) is a vital oxidant in the atmosphere and plays critical roles in the oxidation chemistry of both liquid and aerosol phases. The partitioning of H2O2 between the gas and liquid phase or the aerosol phase could affect its abundance in these condensed phases and eventually the formation of secondary components. However, the partitioning processes of H2O2 in gas-liquid and gas-aerosol phases are still unclear, especially in the ambient atmosphere. In this study, field observations of gas-, liquid-, and aerosol-phase H2O2 were carried out in the urban atmosphere of Beijing during the summer and winter of 2018. The effective field-derived mean value of Henry's law constant (HAm, 2.1 × 105 M atm−1) was 2.5 times that of the theoretical value in pure water (HAt, 8.4 × 104 M atm−1) at 298 ± 2 K. The effective derived gas-aerosol partitioning coefficient (KPm, 3.8 × 10−3 m3 μg−1) was four orders of magnitude higher on average than the theoretical value (KPt, 2.8 × 10−7 M atm−1) at 270 ± 4 K. The partitioning of H2O2 in the gas-liquid and gas-aerosol phases in the ambient atmosphere does not only obey Henry's law or Pankow's absorptive partitioning theory but is also influenced by certain physical and chemical reactions. The average concentration of liquid-phase H2O2 in rainwater during summer was 44.12 ± 26.49 μM. In three-quarters of the collected rain samples, the measured H2O2 was greater than the predicted value in pure water calculated by Henry's law. In these samples, 46 % of the measured H2O2 was from gas-phase partitioning, and most of the rest may have come from residual H2O2 in raindrops. In winter, the level of aerosol-phase H2O2 was 0.093 ± 0.085 ng μg−1, which was much higher than the predicted value based on Pankow's absorptive partitioning theory. Almost all aerosol-phase H2O2 was not from the partitioning of the gas phase. The decomposition/hydrolysis of aerosol-phase organic peroxides could be responsible for 32 % of aerosol-phase H2O2 formation at the maximum rate of 3.65 ng μg−1. Furthermore, the heterogeneous uptake of H2O2 on aerosols contributed to less than 0.5 %.

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Assessing indoor gas phase oxidation capacity through real-time measurements of HONO and NOxin Guangzhou, China

Environmental Science Processes & Impacts ◽

10.1039/c9em00194h ◽

2019 ◽

Vol 21 (8) ◽

pp. 1393-1402 ◽

Cited By ~ 13

Author(s):

Jiangping Liu ◽

Sheng Li ◽

Jiafa Zeng ◽

Majda Mekic ◽

Zhujun Yu ◽

...

Keyword(s):

Hydroxyl Radical ◽

Real Time ◽

Gas Phase ◽

Nitrous Acid ◽

Oxidation Capacity ◽

Phase Oxidation ◽

Gas Phase Oxidation

The photolysis of nitrous acid (HONO) is the main initiation source of hydroxyl radical (OH) which in turn is the main oxidant controlling the oxidation capacity of the indoor atmosphere.

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Heterogeneous conversion of nitric acid to nitrous acid on the surface of primary organic aerosol in an urban atmosphere

Atmospheric Environment ◽

10.1016/j.atmosenv.2008.12.024 ◽

2010 ◽

Vol 44 (33) ◽

pp. 4081-4089 ◽

Cited By ~ 55

Author(s):

Luke D. Ziemba ◽

Jack E. Dibb ◽

Robert J. Griffin ◽

Casey H. Anderson ◽

Sallie I. Whitlow ◽

...

Keyword(s):

Nitric Acid ◽

Nitrous Acid ◽

Organic Aerosol ◽

Urban Atmosphere

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Measurements of HONO during BAQS-Met

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-12285-2010 ◽

2010 ◽

Vol 10 (24) ◽

pp. 12285-12293 ◽

Cited By ~ 16

Author(s):

J. J. B. Wentzell ◽

C. L. Schiller ◽

G. W. Harris

Keyword(s):

Gas Phase ◽

Water Vapour ◽

Nitrous Acid ◽

Meteorological Parameters ◽

Border Region ◽

Night Time ◽

Mixing Ratios ◽

Oxidation Chemistry ◽

Absorption Photometer ◽

Shed Light

Abstract. Measurements of nitrous acid (HONO) were performed as part of the 2007 Border Air Quality and Meteorology Study (BAQS-Met) at the Harrow, Ontario, Canada supersite between 20 June and 10 July 2007. Nitrous acid is an important precursor of the hydroxyl radical and understanding its chemistry is important to understanding daytime oxidation chemistry. The HONO measurements were made using a custom built Long Path Absorption Photometer (LOPAP). The goal of this work was to shed light on sources of daytime HONO in the border region. During the course of the campaign HONO mixing ratios consistently exceeded expected daytime values by more than a factor of 6. Mean daytime mixing ratios of 61 pptv were observed. While HONO decay began at sunrise, minimum HONO values were measured during the late afternoon. There was little difference between the daytime (mean = 1.5%) and night-time (mean = 1.7%) ratios of HONO/NO2, thus there was a very strong daytime source of HONO which is consistent with other recent studies. Correlations of daytime HONO production with a variety of chemical and meteorological parameters indicate that production is dependent on UV radiation, NO2 and water vapour but is not consistent with a simple gas phase process. Apparent rate constants for the production of HONO from photolyticaly excited NO2 and water vapour vary from 2.8–7.8×10−13 cm3 molec−1 s−1, during the campaign. These results appear to be consistent with the heterogeneous conversion of NO2 enhanced by photo-excitation.

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