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A new time-independent formulation of fractional release
- Source :
- Atmospheric chemistry and physics, 17 (6), 3788-3797, Atmospheric Chemistry and Physics, Vol 17, Iss 6, Pp 3785-3797 (2017)
- Publication Year :
- 2017
- Publisher :
- European Geosciences Union, 2017.
-
Abstract
- The fractional release factor (FRF) gives information on the amount of a halocarbon that is released at some point into the stratosphere from its source form to the inorganic form, which can harm the ozone layer through catalytic reactions. The quantity is of major importance because it directly affects the calculation of the ozone depletion potential (ODP). In this context time-independent values are needed which, in particular, should be independent of the trends in the tropospheric mixing ratios (tropospheric trends) of the respective halogenated trace gases. For a given atmospheric situation, such FRF values would represent a molecular property.We analysed the temporal evolution of FRF from ECHAM/MESSy Atmospheric Chemistry (EMAC) model simulations for several halocarbons and nitrous oxide between 1965 and 2011 on different mean age levels and found that the widely used formulation of FRF yields highly time-dependent values. We show that this is caused by the way that the tropospheric trend is handled in the widely used calculation method of FRF.Taking into account chemical loss in the calculation of stratospheric mixing ratios reduces the time dependence in FRFs. Therefore we implemented a loss term in the formulation of the FRF and applied the parameterization of a mean arrival time to our data set.We find that the time dependence in the FRF can almost be compensated for by applying a new trend correction in the calculation of the FRF. We suggest that this new method should be used to calculate time-independent FRFs, which can then be used e.g. for the calculation of ODP.
- Subjects :
- ECHAM
Atmospheric Science
010504 meteorology & atmospheric sciences
Meteorology
Context (language use)
010502 geochemistry & geophysics
Ozone depletion potential
01 natural sciences
fractional release factors
lcsh:Chemistry
Troposphere
chemistry.chemical_compound
ozone depletion potential
Ozone layer
Erdsystem-Modellierung
ddc:550
Applied mathematics
Stratosphere
0105 earth and related environmental sciences
Mathematics
EMAC
lcsh:QC1-999
Trace gas
chemistry climate model
Earth sciences
lcsh:QD1-999
chemistry
Atmospheric chemistry
stratosphere
halocarbons
ECHAM/MESSy Atmospheric Chemistry
Earth System Chemistry integrated Modelling (ESCiMo)
lcsh:Physics
Subjects
Details
- Language :
- English
- ISSN :
- 16807316 and 16807324
- Database :
- OpenAIRE
- Journal :
- Atmospheric chemistry and physics, 17 (6), 3788-3797, Atmospheric Chemistry and Physics, Vol 17, Iss 6, Pp 3785-3797 (2017)
- Accession number :
- edsair.doi.dedup.....4a861ebe513575ebc6a06f5f4b292c8f