A new time-independent formulation of fractional release

  • 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.

Download full text files

Export metadata

Metadaten
Author:Jennifer Ostermöller, Harald BönischORCiDGND, Patrick JöckelORCiDGND, Andreas EngelORCiD
URN:urn:nbn:de:hebis:30:3-442482
DOI:https://doi.org/10.5194/acp-17-3785-2017
ISSN:1680-7324
Parent Title (English):Atmospheric chemistry and physics
Publisher:European Geosciences Union
Place of publication:Katlenburg-Lindau
Contributor(s):Jens-Uwe Grooß
Document Type:Article
Language:English
Date of Publication (online):2017/05/22
Date of first Publication:2017/03/20
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2017/05/22
Volume:17
Issue:6
Page Number:13
First Page:3785
Last Page:3797
Note:
© Author(s) 2017. CC Attribution 3.0 License.
HeBIS-PPN:424008726
Institutes:Geowissenschaften / Geographie / Geowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 3.0