B-WP3 - FAST-O3-II: Fast stratospheric ozone chemistry for global climate models II

Project aims:

The importance of interactions between climate change and the ozone layer has long been recognized (e.g. Thompson and Solomon, Science, 296, 895, 2002). Hence, it is desirable to account for these interactions in climate models. Usually, this is accomplished by coupling a full stratospheric chemistry module to a Global Climate Model (GCM). Since this approach is computationally very expensive, ozone is usually prescribed in climate models. SWIFT is a fast and accurate stratospheric chemistry scheme designed to enable interactions between climate and the ozone layer in these type of models which was developed in the first MiKlip project. In FAST-O3-II, the module will be implemented into the MPI-ESM1.1 model and ensemble simulations will be performed. Ozone fields will be provided and used as boundary conditions for the MiKlip prediction system.

Project structure and tasks of the project:

The project is divided into three workpackages and 9 tasks. WP 3.1 will be performed by AWI, WP 3.2 will be performed by FUB and WP 3.3 is a joint workpackage.

WP 3.1 Further improvement of the existing SWIFT module

Task 3.1.1 Include effects of changing emissions of N2O and CH4
Task 3.1.2 Update kinetic parameters based on recent progress in laboratory measurements
Task 3.1.3 Improve formulation of system of differential equations based on rates obtained from the ATLAS Chemistry and Transport Model

WP 3.2 Implementation into MPI-ESM1.1

Task 3.2.1 Implement SWIFT version developed during MiKlip into MPI-ESM1.1
Task 3.2.2 Implement SWIFT version developed in WP 3.1 into MPI-ESM1.1
Task 3.2.3 Production of ozone fields used as boundary conditions in the MiKlip prediction system


WP 3.3 Validation and evaluation of MPI-ESM1.1 coupled to SWIFT

Task 3.3.1 Testing and validation
Task 3.3.2 Ensemble simualtions with MPI-ESM1.1
Task 3.3.3 Decadal predictions with MiKlip-SWIFT


M3.1 Implementation of SWIFT into MPI-ESM1.1
M3.2 Runs with MPI-ESM1.1 coupled to SWIFT available

Figure 1: Performance of the SWIFT polar chemistry module. Interannual variability of vortex averaged ozone at the end of the north polar winter winter shortly before the break up of the polar vortex at 46 hPa altitude. Blue: Results of 35 runs of SWIFT as a polar chemistry module in the ATLAS Chemistry and Transport Model, driven by meteorological data from the ECMWF ERA Interim reanalysis. Red: MLS satellite measurements for comparison.


The development of the polar and extrapolar version of the SWIFT model has been finished and the models have been successfully validated with measurements of the MLS satellite instrument and the full chemistry model of the ATLAS Chemistry and Transport Model. The polar SWIFT model has been successfully coupled to the EMAC model. The model description of the polar SWIFT model has been published. EMAC with SWIFT chemistry has been validated against model simulations with full chemistry and observations.

Figure 2: Performance of the SWIFT polar chemistry module in EMAC. Polar vortex mean total column ozone [DU] variation for the southern hemispheric winter 2002. Blue: EMAC simulation with polar SWIFT chemistry. Green: EMAC simulation with full interactive chemistry. Black: observed total column ozone from Bodeker Scientific.


Alfred Wegener Institute for Polar and Marine Research
Markus Rex

FU Berlin, Institut für Meteorologie
Ulrike Langematz

The Extrapolar SWIFT model (version 1.0): fast stratospheric ozone chemistry for global climate models

2018 - Geosci. Model Dev., 11, 753–769

Kreyling, D. | Wohltmann, I., Lehmann, R., Rex, M.

A quantitative analysis of the reactions involved in stratospheric ozone depletion in the polar vortex core

2017 - Atmos. Chem. Phys., 17, 10535–10563

Wohltmann, I. | Lehmann, R., Rex, M.

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2)

2017 - Geosci. Model Dev., 10, 2671-2689

Wohltmann, I. | Lehmann, R., Rex, M.

Technical Note: SWIFT - A fast semi-empirical model for polar stratospheric ozone loss

2014 - Atmos. Chem. Phys., Vol. 14, pp. 6545-6555

Rex, M. | S. Kremser, P. Huck, G. Bodeker, I. Wohltmann, M. Santee, and P. Bernath