INVESTIGADORES
OLCESE Luis Eduardo
congresos y reuniones científicas
Título:
Development of a secondary organic aerosols formation mechanism and simulations using a 0-D chemical model
Autor/es:
L. OLCESE; S. SILLMAN; J. PENNER
Lugar:
Viena, Austria
Reunión:
Congreso; General Assembly 2006 de la European Geosciences Union; 2006
Institución organizadora:
European Geosciences Union
Resumen:
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Formation
of secondary organic aerosols (SOA) is a highly uncertain factor in
current global chemical models, and consequently is one of the main
reasons models cannot properly reproduce aerosol field measurements.
A new approach to solve this problem is presented in this work,
involving a highly detailed gas-phase chemical mechanism and the
condensation of several hydrocarbons the aerosol-phase to produce
SOA. Is widely recognized that there are many uncertainties in the
mechanism that produces SOA (i.e. the sticking coefficient of
semi-volatile compounds on aerosols, enthalpy of vaporization of
several compounds, stabilization of the compounds in the aerosol
phase due to catalysis); the ultimate goal of this work involves the
use of a global 3-D model (IMPACT) to simulate the global production
of SOA, including updated emission inventories, a larger number of
compounds that can produce aerosols and detailed modeling of the
chemical reactions inside the particles.
A
module that simulates SOA formation was added to a 0-D model with
complete treatment of the chemistry, based on an analysis of odd
hydrogen (189 chemical species and 611 chemical reactions). The
production mechanism of SOA is through the reaction of selected
hydrocarbons with atmospheric oxidants (O3, OH and NO3)
to produce intermediate first generation products, which are
subsequently partitioned between the gas and aerosol phase, over an
absorptive medium like primary organic aerosols (mainly insoluble
black carbon). The included species with potential to produce SOA
are toluene, xylene, aromatic acids and several isoprenes.
The
results show the formation of SOA over the time, for different
initial conditions and the uncertainty due to uncertain parameters in
the formation mechanism.
