Laboratory studies of interaction between trace gases and sulphuric acid or sulphate aerosols using flow-tube reactors

2003 ◽  
Vol 22 (2) ◽  
pp. 341-376 ◽  
Author(s):  
Ming-Taun Leu
Keyword(s):  
Sulphuric Acid ◽  
Trace Gases ◽  
Laboratory Studies ◽  
Flow Tube ◽  
Sulphate Aerosols

scholarly journals Evaporation of sulphate aerosols at low relative humidity

2016 ◽  
Author(s):  
Georgios Tsagkogeorgas ◽  
Pontus Roldin ◽  
Jonathan Duplissy ◽  
Linda Rondo ◽  
Jasmin Tröstl ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Thermodynamic Properties ◽  
Sulphuric Acid ◽  
Activity Coefficients ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Cloud Chamber ◽  
Aerosol Dynamics ◽  
Sulphate Aerosols

Abstract. Here we explore the vapour pressure of sulphuric acid at very low relative humidity, where evaporation of sulphuric acid from particles can be important in the atmospheres of Earth and Venus. We performed experiments in the CLOUD chamber at CERN forming sulphuric acid particles via nucleation and then measuring evaporation versus temperature and relative humidity. We modelled the experiments with the ADCHAM model to constrain the thermodynamic properties governing the evaporation of sulphuric acid. ADCHAM includes a thermodynamics module coupled to an aerosol dynamics module. We derived the mole fractions and activity coefficients of H2SO4, HSO4−, SO42− and SO3 in the particles and then simulated the condensation and evaporation of H2SO4 and SO3. We constrained the equilibrium constants for the dissociation of H2SO4 to HSO4− (KH2SO4) and the dehydration of H2SO4 to SO3 (xKSO3). Our results suggest that particle shrinkage is mainly governed by H2SO4 evaporation, however, we cannot dismiss a contribution from SO3 evaporation. We conclude that KH2SO4 = 2–4 ∙ 109 mol ∙ kg−1 at 288.8 ± 5 K and xKSO3 ≥ 1.4 ∙ 1010.

scholarly journals VOC measurements within a boreal forest during spring 2005: the role of monoterpenes and sulphuric acid in selected intense nucleation events

2009 ◽  
Vol 9 (3) ◽  
pp. 12781-12827 ◽  
Author(s):  
G. Eerdekens ◽  
N. Yassaa ◽  
V. Sinha ◽  
P. P. Aalto ◽  
V. Fiedler ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Sulphuric Acid ◽  
Trace Gases ◽  
Measurement Data ◽  
Event Type ◽  
Field Campaign ◽  
Back Trajectories ◽  
Made In

Abstract. In this study we present measurements of selected trace gases and aerosol made in a boreal forest during the BACCI-QUEST IV intensive field campaign in Hyytiälä, Finland in April 2005. Several clear aerosol "nucleation events" were observed and characterized. One type of "event" occurred synchronously with huge increases in monoterpenes, while a second event type correlated instead with sulphuric acid. Here we elucidate the origin of these two distinct forms of aerosol production at the Hyytiälä site using the measurement data, airmass back trajectories and the optical stereoisomery of monoterpenes.

scholarly journals The global lightning-induced nitrogen oxides source

2007 ◽  
Vol 7 (1) ◽  
pp. 2623-2818 ◽  
Author(s):  
U. Schumann ◽  
H. Huntrieser
Keyword(s):  
Nitrogen Oxides ◽  
Climate Changes ◽  
Trace Gases ◽  
Tropospheric Chemistry ◽  
Laboratory Studies ◽  
Mass Source ◽  
Uncertainty Range ◽  
Airborne Measurements ◽  
Model Studies ◽  
Uncertainty Factor

Abstract. The knowledge of the lightning-induced nitrogen oxides (LNOx) source is important for understanding and predicting the nitrogen oxides and ozone distributions in the troposphere and their trends, the oxidising capacity of the atmosphere, and the lifetime of trace gases destroyed by reactions with OH. This knowledge is further required for the assessment of other important NOx sources, in particular from aviation, the stratosphere, and from surface sources, and for understanding the possible feedback between climate changes and lightning. This paper reviews more then 3 decades of research. The review includes laboratory studies as well as surface, airborne and satellite-based observations of lightning and of NOx and related species in the atmosphere. Relevant data available from measurements in regions with strong LNOx influence are identified, including recent observations at midlatitudes and over tropical continents where most lightning occurs. Various methods to model LNOx at cloud scales or globally are described. Previous estimates are re-evaluated using the global annual mean flash frequency of 44±5 s−1 reported from OTD satellite data. From the review, mainly of airborne measurements near thunderstorms and cloud-resolving models, we conclude that a "typical" thunderstorm flash produces 15 (2–40)×1025 NO molecules per flash, equivalent to 250 mol NOx or 3.5 kg of N mass per flash with uncertainty factor from 0.13 to 2.7. Mainly as a result of previous global model studies for various LNOx parameterisations tested with related observations, the best estimate of the annual global LNOx nitrogen mass source and its uncertainty range is (5±3) Tg a−1 in this study. An accuracy of order 1 Tg a−1 or 20%, as necessary in particular for understanding tropical tropospheric chemistry, is still a challenging goal.

Trace gases in breath of healthy volunteers when fasting and after a protein-calorie meal: a preliminary study

1999 ◽  
Vol 87 (5) ◽  
pp. 1584-1588 ◽  
Author(s):  
David Smith ◽  
Patrik Spanel ◽  
Simon Davies
Keyword(s):  
Trace Gases ◽  
Ambient Air ◽  
Ammonia Concentration ◽  
Steady Increase ◽  
Flow Tube ◽  
Ion Flow ◽  
Selected Ion Flow Tube ◽  
Baseline Values ◽  
Preliminary Study ◽  
Breath Acetone

The selected ion flow tube technique was used to quantify in breath the trace gases acetone, ammonia, ethanol, isoprene, and methanol during single exhalations while fasting and in response to feeding. Six normal volunteers were fasted for 12 h, and, after baseline breath samples were obtained, were fed a liquid protein-calorie meal to provide 0.47 g/kg of protein (Fortisip). Further breath samples were obtained at 20, 40, and 60 min, and then hourly for a further 5 h. Breath acetone concentrations fell from a maximum during fasting, reaching their nadir between 4 and 5 h. Breath ammonia concentrations fell immediately to one-half their fasting levels before a steady increase to two or three times baseline values at 5 h. There was a brief increase in breath ethanol concentrations after feeding, reflecting detectable ethanol contamination of the food. Subsequently, breath ethanol levels remained low throughout the experimental protocol. Isoprene concentrations did not change significantly, whereas changes in methanol concentrations reflected those in the ambient air. This preliminary study indicates that the selected ion flow tube technique may be used to detect changes in the trace gases present in breath and define their concentrations in the fasting and replete state. Of particular interest is the biphasic response of the breath ammonia concentration after feeding.

scholarly journals Growth of sulphuric acid nanoparticles under wet and dry conditions

2013 ◽  
Vol 13 (9) ◽  
pp. 24087-24125
Author(s):  
L. Škrabalová ◽  
D. Brus ◽  
T. Anttila ◽  
V. Ždímal ◽  
H. Lihavainen
Keyword(s):  
Relative Humidity ◽  
Sulphuric Acid ◽  
Ammonium Sulphate ◽  
Residence Time ◽  
Growth Rates ◽  
Initial Growth ◽  
Flow Tube ◽  
H2so4 Concentration ◽  
Wall Losses ◽  
Dry Conditions

Abstract. New particle formation, which greatly influences the number concentrations and size distributions of an atmospheric aerosol, is often followed by a rapid growth of freshly formed particles. The initial growth of a newly formed aerosol is the crucial process determining the fraction of nucleated particles growing into cloud condensation nuclei sizes, which have a significant influence on climate. In this study, we report the laboratory observations of the growth of nanoparticles produced by nucleation of H2SO4 and water in a laminar flow tube at temperatures of 283, 293 and 303 K, under dry (a relative humidity of 1%) and wet conditions (relative humidity of 30%) and residence times of 30, 45, 60 and 90 s. The initial H2SO4 concentration spans the range from 2 × 108 to 1.4 × 1010 molecule cm−3 and the calculated wall losses of H2SO4 were assumed to be diffusion limited. The detected particle number concentrations, measured by the Ultrafine Condensation Particle Counter (UCPC) and Differential Mobility Particle Sizer (DMPS), were found to depend strongly on the residence time. Hygroscopic particle growth, presented by growth factors, was found to be in good agreement with the previously reported studies. The experimental growth rates ranged from 20 nm h−1 to 890 nm h−1 at RH 1% and from 7 nm h−1 to 980 nm h−1 at RH 30% and were found to increase significantly with the increasing concentration of H2SO4. Increases in the nucleation temperature had a slight enhancing effect on the growth rates under dry conditions. The influence of relative humidity on growth was not consistent – at lower H2SO4 concentrations, the growth rates were higher under dry conditions while at H2SO4 concentrations greater than 1×109molecule cm−3 the growth rates were higher under wet conditions. The growth rates show only a weak dependence on the residence time. The experimental observations were compared with predictions made using a numerical model, which investigates the growth of particles with three different extents of neutralization by the ammonia NH3: (1) pure H2SO4 – H2O particles (2) particles formed by ammonium bisulphate, (NH4)HSO4 (3) particles formed by ammonium sulphate, (NH4)2SO4. The highest growth rates were found for ammonium sulphate particles. Since the model accounting for the initial H2SO4 concentration predicted the experimental growth rates correctly, our results suggest that the commonly presumed diffusional wall losses of H2SO4 are not so significant. We therefore assume that there are not only losses of H2SO4 on the wall but also a flux of H2SO4 molecules from the wall into the flow tube, the effect being more profound under dry conditions and at higher temperatures of the tube wall. Based on a comparison with the atmospheric observations, our results indicate that sulphuric acid alone can not explain the growth rates of particles formed in the atmosphere.

scholarly journals Sensitivity of thermal infrared sounders to the chemical and micro-physical properties of UTLS secondary sulphate aerosols

2015 ◽  
Vol 8 (8) ◽  
pp. 8439-8481 ◽  
Author(s):  
P. Sellitto ◽  
B. Legras
Keyword(s):  
Radiative Transfer ◽  
Physical Properties ◽  
Sulphuric Acid ◽  
Thermal Infrared ◽  
Radiative Transfer Model ◽  
Spectral Signature ◽  
Transfer Model ◽  
Absorption Bands ◽  
Sulphate Aerosols ◽  
The Impact

Abstract. Monitoring upper tropospheric-lower stratospheric (UTLS) secondary sulphate aerosols and their chemical and micro-physical properties from satellite nadir observations is crucial to better understand their formation and evolution processes and then to estimate their impact to the UTLS chemistry, and on regional and global radiative balance. Here we present a study aimed at the evaluation of the sensitivity of thermal infrared (TIR) satellite nadir observations to the chemical composition and the size distribution of idealized UTLS sulphate aerosol layers. The extinction properties of sulphuric acid/water droplets, for different sulphuric acid mixing ratios and temperatures, are systematically analysed. The extinction coefficients are derived by means of a Mie code, using refractive indexes taken from the GEISA (Gestion et Étude des Informations Spectroscopiques Atmosphériques: Management and Study of Spectroscopic Information) spectroscopic database and log-normal size distributions with different effective radii and number concentrations. IASI (Infrared Atmospheric Sounding Interferometer) pseudo-observations are generated using forward radiative transfer calculations performed with the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model, to estimate the impact of the extinction of idealized aerosol layers, at typical UTLS conditions, on the brightness temperature spectra observed by this satellite instrument. We found a marked and typical spectral signature of these aerosol layers between 700 and 1200 cm−1, due to the absorption bands of the sulphate and bi-sulphate ions and the undissociated sulphuric acid, with the main absorption peaks at 1170 and 905 cm−1. The dependence of the aerosol spectral signature to the sulphuric acid mixing ratio, and effective number concentration and radius, as well as the role of interferring parameters like the ozone, sulphur dioxide, carbon dioxide and ash absorption, and temperature and water vapour profile uncertainties, are analyzed and critically discussed.

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