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| Titel |
Kinetic model framework for aerosol and cloud surface chemistry and gas-particle interactions – Part 2: Exemplary practical applications and numerical simulations |
| VerfasserIn |
M. Ammann, U. Pöschl |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 7, no. 23 ; Nr. 7, no. 23 (2007-12-10), S.6025-6045 |
| Datensatznummer |
250005272
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| Publikation (Nr.) |
 copernicus.org/acp-7-6025-2007.pdf |
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| Zusammenfassung |
A kinetic model framework with consistent and unambiguous
terminology and universally applicable rate equations and parameters
for aerosol and cloud surface chemistry and gas-particle
interactions has been presented in the preceding companion paper by
Pöschl, Rudich and Ammann (Pöschl et al., 2007), abbreviated
PRA. It allows to describe mass transport and chemical reaction at
the gas-particle interface and to link aerosol and cloud surface
processes with gas phase and particle bulk processes. Here we
present multiple exemplary model systems and calculations
illustrating how the general mass balance and rate equations of the
PRA framework can be easily reduced to compact sets of equations
which enable a mechanistic description of time and concentration
dependencies of trace gas uptake and particle composition in systems
with one or more chemical components and physicochemical processes.
Time-dependent model scenarios show the effects of reversible
adsorption, surface-bulk transport, and chemical aging on the
temporal evolution of trace gas uptake by solid particles and
solubility saturation of liquid particles. They demonstrate how the
transformation of particles and the variation of trace gas
accommodation and uptake coefficients by orders of magnitude over
time scales of microseconds to days can be explained and predicted
from the initial composition and basic kinetic parameters of model
systems by iterative calculations using standard spreadsheet
programs. Moreover, they show how apparently inconsistent
experimental data sets obtained with different techniques and on
different time scales can be efficiently linked and mechanistically
explained by application of consistent model formalisms and
terminologies within the PRA framework.
Steady-state model scenarios illustrate characteristic effects of
gas phase composition and basic kinetic parameters on the rates of
mass transport and chemical reactions. They demonstrate how
adsorption and surface saturation effects can explain non-linear gas
phase concentration dependencies of surface and bulk accommodation
coefficients, uptake coefficients, and bulk solubilities (deviations
from Henry's law). Such effects are expected to play an important
role in many real atmospheric aerosol and cloud systems involving a
wide range of organic and inorganic components of concentrated
aqueous and organic solution droplets, ice crystals, and other
crystalline or amorphous solid particles. |
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