New MESSy scavenging subroutine to treat aerosol particles gas-phase partitioning in convective clouds

2021 ◽  
Author(s):  
Giorgio Taverna ◽  
Marc Barra ◽  
Holger Tost
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Phase Partitioning ◽  
Convective Clouds ◽  
Terrestrial Atmosphere ◽  
Deep Convective Clouds ◽  
High Level

<p>The Modular Earth Submodel System (MESSy) has been proven to be successful in the understanding of several processes which characterize the terrestrial atmosphere and climate.</p><p>However, the complexity of aerosol particles/gas phase partitioning of species in deep convective clouds together with the inherent problems of modelling sub-grid scale processes, make MESSy results significant underestimated, especially in case of SO<sub>2</sub>, when compared with available flight observations. For this reason, the subroutine which reproduce the scavenging of these species has been updated to include a more realistic treatment of liquid/phase partitioning of aerosol induced species in high level clouds.</p><p>Results obtained are shown in this poster.</p>

scholarly journals Coupling of Precipitation and Cloud Structures in Oceanic Extratropical Cyclones to Large-Scale Moisture Flux Convergence

2018 ◽  
Vol 31 (23) ◽  
pp. 9565-9584 ◽  
Author(s):  
Sun Wong ◽  
Catherine M. Naud ◽  
Brian H. Kahn ◽  
Longtao Wu ◽  
Eric J. Fetzer
Keyword(s):  
Large Scale ◽  
Moisture Flux ◽  
Extratropical Cyclones ◽  
Flux Divergence ◽  
Moisture Flux Convergence ◽  
Convective Clouds ◽  
Moisture Advection ◽  
Deep Convective Clouds ◽  
Stratiform Clouds ◽  
High Level

Precipitation (from TMPA) and cloud structures (from MODIS) in extratropical cyclones (ETCs) are modulated by phases of large-scale moisture flux convergence (from MERRA-2) in the sectors of ETCs, which are studied in a new coordinate system with directions of both surface warm fronts (WFs) and surface cold fronts (CFs) fixed. The phase of moisture flux convergence is described by moisture dynamical convergence Qcnvg and moisture advection Qadvt. Precipitation and occurrence frequencies of deep convective clouds are sensitive to changes in Qcnvg, while moisture tendency is sensitive to changes in Qadvt. Increasing Qcnvg and Qadvt during the advance of the WF is associated with increasing occurrences of both deep convective and high-level stratiform clouds. A rapid decrease in Qadvt with a relatively steady Qcnvg during the advance of the CF is associated with high-level cloud distribution weighting toward deep convective clouds. Behind the CF (cold sector or area with polar air intrusion), the moisture flux is divergent with abundant low- and midlevel clouds. From deepening to decaying stages, the pre-WF and WF sectors experience high-level clouds shifting to more convective and less stratiform because of decreasing Qadvt with relatively steady Qcnvg, and the CF experiences shifting from high-level to midlevel clouds. Sectors of moisture flux divergence are less influenced by cyclone evolution. Surface evaporation is the largest in the cold sector and the CF during the deepening stage. Deepening cyclones are more efficient in poleward transport of water vapor.

scholarly journals Contribution of gaseous and particulate species to droplet solute composition at the Puy de Dôme, France

2003 ◽  
Vol 3 (5) ◽  
pp. 1509-1522 ◽  
Author(s):  
K. Sellegri ◽  
P. Laj ◽  
A. Marinoni ◽  
R. Dupuy ◽  
M. Legrand ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Removal Rate ◽  
Chemical Species ◽  
Solute Concentration ◽  
Complex Nature ◽  
Gaseous Species ◽  
Phase Partitioning ◽  
Gas Phases ◽  
Set Up

Abstract. Chemical reactions of dissolved gases in the liquid phase play a key role in atmospheric processes both in the formation of secondary atmospheric compounds and their wet removal rate but also in the regulation of the oxidizing capacity of the troposphere. The behavior of gaseous species and their chemical transformation in clouds are difficult to observe experimentally given the complex nature of clouds. During a winter field campaign at the summit of the Puy de Dôme (central France, 1465 m a.s.l), we have deployed an experimental set-up to provide a quantification of phase partitioning of both organic (CH3COOH, HCOOH, H2C2O4) and inorganic (NH3, HNO3, SO2, HCl) species in clouds. We found that nitric and hydrochloric acids can be considered close to Henry's law equilibrium, within analytical uncertainty and instrumental errors. On another hand, for NH3 and carboxylic acids, dissolution of material from the gas phase is kinetically limited and never reaches the equilibrium predicted by thermodynamics, resulting in significant sub-saturation of the liquid phase. On the contrary, SIV is supersaturated in the liquid phase, in addition to the presence of significant aerosol-derived SVI transferred through nucleation scavenging. Upon droplet evaporation, a significant part of most species, including SIV, tends to efficiently return back into the gas phase. Overall, gas contribution to the droplet solute concentration ranges from at least 48.5 to 98% depending on the chemical species. This is particularly important considering that aerosol scavenging efficiencies are often calculated assuming a negligible gas-phase contribution to the solute concentration. Our study emphasizes the need to account for the in-cloud interaction between particles and gases to provide an adequate modeling of multiphase chemistry systems and its impact on the atmospheric aerosol and gas phases.

scholarly journals The effect of phase partitioning of semivolatile compounds on the measured CCN activity of aerosol particles

2013 ◽  
Vol 6 (5) ◽  
pp. 8413-8433 ◽  
Author(s):  
S. Romakkaniemi ◽  
A. Jaatinen ◽  
A. Laaksonen ◽  
A. Nenes ◽  
T. Raatikainen
Keyword(s):  
Ammonium Nitrate ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Test Compound ◽  
Ambient Conditions ◽  
Compound A ◽  
Phase Partitioning ◽  
Maximum Water ◽  
Kinetics Of ◽  
Ccn Activity

Abstract. The effect of inorganic semivolatile aerosol compounds on the CCN activity of aerosol particles was studied by using a computational model for a DMT-CCN counter, a cloud parcel model for condensation kinetics and experiments to quantify the modelled results. Concentrations of water vapour and semivolatiles as well as aerosol trajectories in the CCN column were calculated by a computational fluid dynamics model. These trajectories and vapour concentrations were then used as an input for the cloud parcel model to simulate mass transfer kinetics of water and semivolatiles between aerosol particles and the gas phase. Two different questions were studied: (1) how big fraction of semivolatiles is evaporated from particles before activation in the CCN counter? (2) How much the CCN activity can be increased due to condensation of semivolatiles prior to the maximum water supersaturation in the case of high semivolatile concentration in the gas phase? The results show that, to increase the CCN activity of aerosol particles, a very high gas phase concentration (as compared to typical ambient conditions) is needed. We used nitric acid as a test compound. A concentration of several ppb or higher is needed for measurable effect. In the case of particle evaporation, we used ammonium nitrate as a test compound and found that it partially evaporates before maximum supersaturation is reached in the CCN counter, thus causing an underestimation of CCN activity. The effect of evaporation is clearly visible in all supersaturations, leading to an underestimation of the critical dry diameter by 10 to 15 nanometres in the case of ammonium nitrate particles in different supersaturations. This result was also confirmed by measurements in supersaturations between 0.1 and 0.7%.

scholarly journals Hydrogen Storage: Thermodynamic Analysis of Alkyl-Quinolines and Alkyl-Pyridines as Potential Liquid Organic Hydrogen Carriers (LOHC)

2021 ◽  
Vol 11 (24) ◽  
pp. 11758
Author(s):  
Sergey P. Verevkin ◽  
Sergey P. Safronov ◽  
Artemiy A. Samarov ◽  
Sergey V. Vostrikov
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Wood Preservation ◽  
Enthalpies Of Formation ◽  
Vapor Pressures ◽  
Liquid Phase Hydrogenation ◽  
Substituted Quinolines ◽  
Attractive Option ◽  
Substituted Pyridines ◽  
High Level

The liquid organic hydrogen carriers (LOHC) are aromatic molecules, which can be considered as an attractive option for the storage and transport of hydrogen. A considerable amount of hydrogen up to 7–8% wt. can be loaded and unloaded with a reversible chemical reaction. Substituted quinolines and pyridines are available from petroleum, coal processing, and wood preservation, or they can be synthesized from aniline. Quinolines and pyridines can be considered as potential LOHC systems, provided they have favorable thermodynamic properties, which were the focus of this current study. The absolute vapor pressures of methyl-quinolines were measured using the transpiration method. The standard molar enthalpies of vaporization of alkyl-substituted quinolines and pyridines were derived from the vapor pressure temperature dependencies. Thermodynamic data on vaporization and formation enthalpies available in the literature were collected, evaluated, and combined with our own experimental results. The theoretical standard molar gas-phase enthalpies of formation of quinolines and pyridines, calculated using the quantum-chemical G4 methods, agreed well with the evaluated experimental data. Reliable standard molar enthalpies of formation in the liquid phase were derived by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporization. The liquid-phase hydrogenation/dehydrogenation reaction enthalpies of alkyl-substituted pyridines and quinolines were calculated and compared with the data for other potential liquid organic hydrogen carriers. The comparatively low enthalpies of reaction make these heteroaromatics a seminal LOHC system.

A bi-overlayer type plasmonic photocatalyst consisting of mesoporous Au/TiO2 and CuO/SnO2 films separately coated on FTO

2015 ◽  
Vol 17 (27) ◽  
pp. 18004-18010 ◽  
Author(s):  
Shin-ichi Naya ◽  
Takahiro Kume ◽  
Nozomi Okumura ◽  
Hiroaki Tada
Keyword(s):  
Liquid Phase ◽  
Visible Light ◽  
Gas Phase ◽  
Plasmonic Photocatalyst ◽  
Light Activity ◽  
High Level

A bi-overlayer type “plasmonic photocatalyst” consisting of Au/mp-TiO2 and CuO/mp-SnO2 separately formed on the FTO substrate exhibits a high level of visible-light activity for the gas-phase and liquid-phase reactions.

scholarly journals Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin

2018 ◽  
Vol 18 (2) ◽  
pp. 921-961 ◽  
Author(s):  
Meinrat O. Andreae ◽  
Armin Afchine ◽  
Rachel Albrecht ◽  
Bruna Amorim Holanda ◽  
Paulo Artaxo ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Amazon Basin ◽  
Deep Convection ◽  
Aerosol Particles ◽  
Condensation Nuclei ◽  
Upper Troposphere ◽  
Convective Clouds ◽  
Tropospheric Aerosol ◽  
Volatile Organic ◽  
Deep Convective Clouds

Abstract. Airborne observations over the Amazon Basin showed high aerosol particle concentrations in the upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (PBL) by 1 or 2 orders of magnitude. The measurements were made during the German–Brazilian cooperative aircraft campaign ACRIDICON–CHUVA, where ACRIDICON stands for Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems and CHUVA is the acronym for Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM (global precipitation measurement), on the German High Altitude and Long Range Research Aircraft (HALO). The campaign took place in September–October 2014, with the objective of studying tropical deep convective clouds over the Amazon rainforest and their interactions with atmospheric trace gases, aerosol particles, and atmospheric radiation. Aerosol enhancements were observed consistently on all flights during which the UT was probed, using several aerosol metrics, including condensation nuclei (CN) and cloud condensation nuclei (CCN) number concentrations and chemical species mass concentrations. The UT particles differed sharply in their chemical composition and size distribution from those in the PBL, ruling out convective transport of combustion-derived particles from the boundary layer (BL) as a source. The air in the immediate outflow of deep convective clouds was depleted of aerosol particles, whereas strongly enhanced number concentrations of small particles (< 90 nm diameter) were found in UT regions that had experienced outflow from deep convection in the preceding 5–72 h. We also found elevated concentrations of larger (> 90 nm) particles in the UT, which consisted mostly of organic matter and nitrate and were very effective CCN. Our findings suggest a conceptual model, where production of new aerosol particles takes place in the continental UT from biogenic volatile organic material brought up by deep convection and converted to condensable species in the UT. Subsequently, downward mixing and transport of upper tropospheric aerosol can be a source of particles to the PBL, where they increase in size by the condensation of biogenic volatile organic compound (BVOC) oxidation products. This may be an important source of aerosol particles for the Amazonian PBL, where aerosol nucleation and new particle formation have not been observed. We propose that this may have been the dominant process supplying secondary aerosol particles in the pristine atmosphere, making clouds the dominant control of both removal and production of atmospheric particles.

scholarly journals Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin

2017 ◽  
Author(s):  
Meinrat O. Andreae ◽  
Armin Afchine ◽  
Rachel Albrecht ◽  
Bruna Amorim Holanda ◽  
Paulo Artaxo ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Particle Production ◽  
Aerosol Particles ◽  
Convective Transport ◽  
Oxidation Products ◽  
Condensation Nuclei ◽  
Upper Troposphere ◽  
Convective Clouds ◽  
Tropospheric Aerosol ◽  
Deep Convective Clouds

Abstract. Airborne observations over the Amazon Basin showed high aerosol particle concentrations in the upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (PBL) by one or two orders of magnitude. The measurements were made during the German-Brazilian cooperative aircraft campaign ACRIDICON-CHUVA on the German High Altitude and Long Range Research Aircraft (HALO). The campaign took place in September/October 2014, with the objective of studying tropical deep convective clouds over the Amazon rainforest and their interactions with atmospheric trace gases, aerosol particles, and atmospheric radiation. Aerosol enhancements were observed consistently on all flights during which the UT was probed, using several aerosol metrics, including condensation nuclei (CN) and cloud condensation nuclei (CCN) number concentrations and chemical species mass concentrations. The UT particles differed in their chemical composition and size distribution from those in the PBL, ruling out convective transport of combustion-derived particles from the BL as a source. The air in the immediate outflow of deep convective clouds was depleted in aerosol particles, whereas strongly enhanced number concentrations of small particles ( 90 nm) particles in the UT, which consisted mostly of organic matter and nitrate and were very effective CCN. Our findings suggest a conceptual model, where production of new aerosol particles takes place in the UT from volatile material brought up by deep convection, which is converted to condensable species in the UT. Subsequently, downward mixing and transport of upper tropospheric aerosol can be a source of particles to the PBL, where they increase in size by the condensation of biogenic volatile organic carbon (BVOC) oxidation products. This may be an important source of aerosol particles in the Amazonian PBL, where aerosol nucleation and new particle formation has not been observed. We propose that this may have been the dominant process supplying secondary aerosol particles in the pristine atmosphere, making clouds the dominant control of both removal and production of atmospheric particles.

scholarly journals Contribution of gaseous and particulate species to droplet solute composition

2003 ◽  
Vol 3 (1) ◽  
pp. 479-519 ◽  
Author(s):  
K. Sellegri ◽  
P. Laj ◽  
A. Marinoni ◽  
R. Dupuy ◽  
M. Legrand ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Carboxylic Acids ◽  
Chemical Transformation ◽  
Removal Rate ◽  
Multiphase System ◽  
Complex Nature ◽  
Gaseous Species ◽  
Phase Partitioning ◽  
Hygroscopic Properties

Abstract. Chemical reactions of dissolved gases in the liquid phase play a key role in atmospheric processes both in the formation of secondary atmospheric compounds and their wet removal rate but also in the regulation of the oxidizing capacity of the troposphere (Lelieveld and Crutzen, 1991). The behaviour of gaseous species and their chemical transformation in clouds are difficult to observe experimentally given the complex nature of clouds. In this study, we have deployed an experimental set-up to provide an in-situ quantification of phase partitioning and chemical transformation of both organic (CH3COOH, HCOOH, H2C2O4) and inorganic (NH3, HNO3, SO2, HCl) species in clouds. We found that, carboxylic acids, nitrate, and chloride can be considered close to Henry's law equilibrium, within analytical uncertainty and instrumental errors. On another hand, for reduced nitrogen species, dissolution of material from the gas phase is kinetically limited and never reaches the equilibrium predicted by thermodynamics, resulting in significant sub-saturation of the liquid phase. On the contrary, sulfate is supersaturated in the liquid phase, indicating the presence of significant aerosol-derived material transferred through nucleation scavenging. Upon droplet evaporation, most species, including SO2, tend to efficiently return back into the gas phase. In that sense, these species contribute to acidification (for carboxylic acids) or neutralization (for NH3) of the liquid-phase but not totally of the processed aerosols. The only species that appears to be modified in the multiphase system is nitrate. A fraction of at least 10 to 40% of the liquid phase NO3 originates from dissolved HNO3 of which only a fraction evaporates back to the gas phase upon evaporation, resulting in an NO3 enrichment of the aerosol phase. In-cloud gas-to-particle transfer of HNO3 possibly plays a key role in aerosol acidification and in the modification of their hygroscopic properties. Our study emphasizes the need to account for the in-cloud interaction between particles and gases to provide an adequate modeling of multiphase chemistry systems and its impact on the atmospheric aerosol and gas phases.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

Sign in / Sign up

Export Citation Format

Share Document