Technical note: A new comprehensive SCAVenging submodel for global atmospheric chemistry modelling

Abstract. We present the new scavenging scheme SCAV, simulating the removal of trace gases and aerosol particles by clouds and precipitation in global atmospheric chemistry models. The scheme is quite flexible and can be used for various purposes, e.g. long term chemistry simulations as well as detailed cloud and precipitation chemistry calculations. The presence of clouds can substantially change the chemical composition of the atmosphere. We present a new method of mechanistically coupling gas phase, aerosol, cloud and precipitation chemistry, which enables studies of feedbacks between multiphase chemistry and transport processes.

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Air Chemistry

Bulletin of the American Meteorological Society ◽

10.1175/1520-0477-40.10.493 ◽

1959 ◽

Vol 40 (10) ◽

pp. 493-498 ◽

Cited By ~ 2

Author(s):

Christian E. Junge

Keyword(s):

Atmospheric Chemistry ◽

Aerosol Particles ◽

Trace Gases ◽

Special Importance ◽

Physical Processes ◽

Industrial Activities ◽

Cent Increase ◽

Air Chemistry

The field of atmospheric chemistry, which is defined as the chemistry of trace substances in the troposphere, is reviewed. Trace substances can be present as aerosols or as gases. Major sources of aerosols are the ocean and industrial activities. The chemical composition of the aerosol particles is not only determined by their source but also by various processes in the atmosphere—notably, reactions with gas traces. Only little is known about trace gases like SO2, H2S, NH3 or NO2. Of special importance for meteorology is CO2 and its long-term fluctuations. The facts and possible reasons for its 10 per cent increase during this century are discussed. The last part of the discussion is concerned with the physical processes by which the trace substances are removed from the atmosphere, primarily the role of precipitation.

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The Chemical Weather

Environmental Chemistry ◽

10.1071/en05014 ◽

2005 ◽

Vol 2 (1) ◽

pp. 6 ◽

Cited By ~ 20

Author(s):

Mark G. Lawrence ◽

Øystein Hov ◽

Matthias Beekmann ◽

Jørgen Brandt ◽

Hendrik Elbern ◽

...

Keyword(s):

Chemical Composition ◽

Atmospheric Chemistry ◽

Wind Direction ◽

Strong Influence ◽

Trace Gases ◽

Short Term ◽

Chemical Complexity ◽

Chemical Climate ◽

Short Term Variability

Environmental Context. Meteorological weather—temperature, pressure, wind direction—is familiar to all, and contrasts with meteorological climate in short-term (weather) versus long-term (climate) influence. From the atmospheric chemistry side, the focus has largely been on the chemical climate, the long-term mean concentrations of important trace gases and aerosols. An emerging new focus of study is the chemical weather—the tremendous short-term variability of the atmospheric chemical composition, resulting from the strong influence of meteorological variability, chemical complexity, and regionally and temporally varying emissions.

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Analysis of coherent structures and atmosphere-canopy coupling strength during the CABINEX field campaign: implications for atmospheric chemistry

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-21013-2011 ◽

2011 ◽

Vol 11 (7) ◽

pp. 21013-21054 ◽

Cited By ~ 6

Author(s):

A. L. Steiner ◽

S. N. Pressley ◽

A. Botros ◽

E. Jones ◽

S. H. Chung ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Coherent Structures ◽

Forest Canopy ◽

Chemical Exchange ◽

Large Fraction ◽

Trace Gases ◽

Primary Objective ◽

Transport Processes ◽

Heat Fluxes ◽

Field Campaign

Abstract. Intermittent coherent structures can be responsible for a large fraction of the chemical exchange between the vegetation canopy and the atmosphere. Quantifying their contribution to fluxes is necessary to interpret measurements of trace gases and aerosols within and above forest canopies. The primary objective of the Community Atmosphere-Biosphere Interactions Experiment (CABINEX) field campaign (10 July 2009 to 9 August 2009) was to study the chemistry of volatile organic compounds (VOC) within and above a forest canopy. In this manuscript, we provide an analysis of coherent structures and canopy-atmosphere exchange during CABINEX to support in-canopy gradient measurements of VOC. We quantify the number and duration of coherent structure events and their percent contribution to momentum and heat fluxes with two methods: (1) quadrant-hole analysis and (2) wavelet analysis. Despite differences in the duration and number of events, both methods predict that coherent structures contribute 40–50 % to total momentum fluxes and 44–65 % to total heat fluxes during the CABINEX campaign. Contributions associated with coherent structures are slightly greater under stable rather than unstable conditions. By comparing heat fluxes within and above the canopy, we determine the degree of coupling between upper canopy and atmosphere and find that they are coupled to the majority of the campaign time period. Uncoupled canopy-atmosphere events occur in the early morning (04:00–08:00 LT) approximately 30 % of the time. This study confirms that coherent structures contribute significantly to the exchange of heat and momentum between the canopy and atmosphere at the CABINEX site, and indicates the need to include these transport processes when studying the mixing and chemical reactions of trace gases and aerosols between a forest canopy and the atmosphere.

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Revisiting the factors that drive interannual variability in stratospheric entry water vapour

10.5194/egusphere-egu2020-5231 ◽

2020 ◽

Author(s):

Shlomi Ziskin Ziv ◽

Chaim I. Garfinkel

Keyword(s):

Water Vapor ◽

Interannual Variability ◽

Large Scale ◽

Trace Gases ◽

Transport Processes ◽

Tropospheric Temperature ◽

Stratospheric Water Vapor ◽

Cold Point ◽

Stratospheric Trace Gases

<p>Understanding the sinks, sources and transport processes of stratospheric trace gases can improve our prediction of mid to long term climate change. In this study we consider the processes that lead to variability in stratospheric water vapor. We perform a Multiple Linear Regression(MLR) on the SWOOSH combined anomaly filled water vapor product with ENSO, QBO, BDC, mid-tropospheric temperature, and CH4 as predictors, in an attempt to find the factors that most succinctly explain observed water vapor variability. We also consider the fraction of entry water vapor variability that can be accounted for by variations of the cold point temperature as an upper bound on how much water vapor variability is predictable from large scale processes. Several periods in which the MLR fails to account for interannual variability are treated as case studies in order to better understand variability in entry water not governed by these large scale processes.</p>

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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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Glass-Sensors: Assessment of Complex Corrosive Stresses in Conservation Research

MRS Proceedings ◽

10.1557/proc-185-239 ◽

1990 ◽

Vol 185 ◽

Cited By ~ 7

Author(s):

Dieter R. Fuchs ◽

Hannelore RÖmich ◽

Helmut Schmidt

Keyword(s):

Chemical Composition ◽

Ir Spectroscopy ◽

Environmental Stress ◽

Silicate Glass ◽

New Method ◽

Stained Glass ◽

Stress Situation ◽

Conservation Research ◽

Combined Impact

AbstractGlass sensors, based on K-Ca-silicate glass chips, with a low durability against corrosive stresses, offer a new method for assessing the complex environmental stress situation of monuments and pieces of art. The easy-tohandle technique is able to detect the combined impact of climatic stresses, pollution and microbiological effects as well as synergetic interactions.The chemical composition of the sensitive glasses enables judgements within few months. This way long-term estimates can be obtained without costly long-term investigations.The corrosion progress is determined by microscopy and IR-spectroscopy of the weathered glass sensor surfaces. The sensors are already operating in the field of stained glass window preservation. They monitor the efficiency of different kinds of external protective glazings and the remaining stresses from the in-door environment of cathedrals.

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Atmospheric chemistry of bioaerosols: heterogeneous and multiphase reactions with atmospheric oxidants and other trace gases

Chemical Science ◽

10.1039/c6sc02353c ◽

2016 ◽

Vol 7 (11) ◽

pp. 6604-6616 ◽

Cited By ~ 57

Author(s):

Armando D. Estillore ◽

Jonathan V. Trueblood ◽

Vicki H. Grassian

Keyword(s):

Atmospheric Chemistry ◽

Aerosol Particles ◽

Trace Gases ◽

Multiphase Reactions

Once airborne, biologically-derived aerosol particles are prone to reaction with various atmospheric oxidants such as OH, NO3, and O3.

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Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-983-2013 ◽

2013 ◽

Vol 13 (1) ◽

pp. 983-1044

Author(s):

T. Berkemeier ◽

A. J. Huisman ◽

M. Ammann ◽

M. Shiraiwa ◽

T. Koop ◽

...

Keyword(s):

Mass Transfer ◽

Gas Phase ◽

Atmospheric Chemistry ◽

Classification Scheme ◽

Transport Processes ◽

Heterogeneous Reactions ◽

Diffusion Reaction ◽

Systematic Classification ◽

Gas Uptake ◽

Reaction Systems

Abstract. Heterogeneous reactions are important to atmospheric chemistry and are therefore an area of intense research. In multiphase systems such as aerosols and clouds, chemical reactions are usually strongly coupled to a complex sequence of mass transport processes and results are often not easy to interpret. Here we present a systematic classification scheme for gas uptake by aerosol or cloud particles which distinguishes two major regimes: a reaction-diffusion regime and a mass-transfer regime. Each of these regimes includes four distinct limiting cases, characterized by a dominant reaction location (surface or bulk) and a single rate-limiting process: chemical reaction, bulk diffusion, gas-phase diffusion or mass accommodation. The conceptual framework enables efficient comparison of different studies and reaction systems, going beyond the scope of previous classification schemes by explicitly resolving interfacial transport processes and surface reactions limited by mass transfer from the gas phase. The use of kinetic multi-layer models instead of resistor model approaches increases the flexibility and enables a broader treatment of the subject, including cases which do not fit into the strict limiting cases typical of most resistor model formulations. The relative importance of different kinetic parameters such as diffusion, reaction rate and accommodation coefficients in this system is evaluated by a quantitative global sensitivity analysis. We outline the characteristic features of each limiting case and discuss the potential relevance of different regimes and limiting cases for various reaction systems. In particular, the classification scheme is applied to three different data sets for the benchmark system of oleic acid reacting with ozone. In light of these results, future directions of research needed to elucidate the multiphase chemical kinetics in this and other reaction systems are discussed.

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Technical Note: simulation of detailed aerosol chemistry on the global scale using MECCA-AERO

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-3301-2007 ◽

2007 ◽

Vol 7 (2) ◽

pp. 3301-3331

Author(s):

A. Kerkweg ◽

R. Sander ◽

H. Tost ◽

P. Jöckel ◽

J. Lelieveld

Keyword(s):

Gas Phase ◽

Particle Number ◽

Global Scale ◽

Technical Note ◽

Double Counting ◽

Dynamical Models ◽

Aerosol Chemistry ◽

Gas Phase Chemistry ◽

Phase Chemistry

Abstract. We present the MESSy submodel MECCA-AERO, which simulates both aerosol and gas phase chemistry with the same mechanism. Including the aerosol phase into the chemistry mechanism increases the stiffness of the resulting set of differential equations. The numerical aspects of the approach followed in MECCA-AERO are presented. MECCA-AERO requires input of an aerosol dynamical/microphysical model to provide the aerosol size and particle number information of the modes/bins for which the chemistry is explicitly calculated. Additional precautions are required to avoid the double counting of processes, especially for sulphate in the aerosol dynamical and the chemistry model. This coupling is explained in detail. To illustrate the capabilities of the new aerosol submodel, examples for species usually treated in aerosol dynamical models are shown. The aerosol chemistry as provided by MECCA-AERO is very sumptuous and not readily applicable for long-term simulations, though it provides a reference to evaluate simplified approaches.

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