The TM5 atmospheric chemistry module in EC-Earth Twan van Noije

EC-Earth consortium EC-Earth is an ESM developed by a consortium of European weather services, research institutes, and computing centres: Netherlands: KNMI, WUR, IMAU, Utrecht U., VU Amsterdam Sweden: SMHI, Stockholm U., Lund U. Denmark: DMI Norway: NMI Ireland: Met Éireann, U. College Dublin, ICHEC Spain: AEMet, Barcelona SC Portugal: IM, U. Lisbon Italy: ICTP Switzerland: ETH Zürich Belgium: UC Leuven Observer: ECMWF

Working Group on Atmospheric Chemistry and Aerosols KNMI (myself, Peter van Velthoven) Wageningen Univ. (Maarten Krol, Laurens Ganzeveld) ETH Zürich (Ulrike Lohmann, Trude Storelvmo, chair) SMHI (Michael Kahnert, V. Foltescu) Stockholm Univ. (Annica Ekman) Lund Univ. (Almut Arneth, Guy Schurgers)

Modules OASIS Integrated Forecasting System (IFS) Atmospheric chemistry: TM5 Vegetation: Lund-Potsdam-Jena model (LPJ / LPJ-GUESS) OASIS Louvain-la-Neuve sea-ice model (LIM) Land surface: H-TESSEL GCM: OPA GCM: ECMWF Nucleaus for European Modelling of the Ocean Integrated Forecasting System (IFS) T159 (~ 1.125o) or T95 (~ 1.875o) L62 (<5 hPa) or L40 (<10 hPa) ORCA1 (1o) or ORCA2 (2o) grid

Joint Code Development A new baseline version is released ~ once every half year: PrepIFS version @ ECMWF Standalone version for distribution Each development team implements and tests their extension in the latest baseline version. Extensions that pass the EC-Earth test suite will become part of the next baseline version. The extensions are tested for acceptance by the EC-Earth system manager. New extensions are integrated (one by one) into the baseline system and the new baseline version is prepared for distribution by the EC-Earth system manager. The EC-Earth test suite is extended with the test suites of all accepted extensions. Version management: Perforce @ ECMWF If other systems are used by partners, a tar archive of the source code can be merged into the next Perforce baseline version.

Current and Next Release Integrated Forecasting System (IFS) Cycle 31r1 (with modifications) → Cycle 33r1 Atmospheric chemistry: TM5 GCM: ECMWF Land surface: H-TESSEL OASIS v3 Nucleaus for European Modelling of the Ocean v2 → v3 GCM: OPA Louvain-la-Neuve sea-ice model (LIM)

TM5 in EC-Earth Current version: Second phase (beyond AR5): Tropospheric chemistry with modal aerosol scheme and linearized stratospheric ozone chemistry Natural emissions parameterized; CH4 concentrations prescribed at the surface Radiative forcing based on simulated O3, CH4, and aerosols Second phase (beyond AR5): Stratospheric-tropospheric chemistry Improved stratospheric water vapor source from oxidation of simulated methane (and hydrogen) CH4 emissions from wetlands parameterized Radiative forcing based on simulated N2O and halocarbon species (CFC-11, CFC-12, CFC-113, CCl4, etc.) as well

TM5 extensions TM5 has recently been extended with: Online emission routine for isoprene (MEGAN) and terpenes Online emission routine for soil NOx (Yienger and Levy, 1995) The Cariolle scheme (Cariolle and Teyssèdre, 2007) The M7 aerosol scheme (Vignati et al., 2004) M7 aerosol optics Planned before end 2009: Online emission routine for mineral dust

Online coupling with OASIS3 IFS TM5 meteo soil+vegetation parameters concentrations aerosol optical fields

Synchronisation Meteo exchanged @ end coupling interval: IFS TM5 t=0 t=Δt (6h or 3h) time Meteo exchanged @ end coupling interval: Time averaged fields Surface pressure @ end: linearly interpolated in TM5 Other instantaneous fields @ middle IFS restart file IFS TM5 TM5 restart file, incl. surface pressure

M7 mass and number concentrations Feedback to IFS TM5 IFS Cloud-aerosol scheme McRad O3, CH4 concentrations Optics code M7 optical fields M7 M7 mass and number concentrations Interfaces to McRad and cloud scheme to be included in next release (v3) based on IFS cy33 For performance optimization we intend to use pseudo-parallel exchange on a field-by-field basis (latest OASIS3 version)

Coupling with DGVM IFS TM5 LPJ -GUESS meteo soil parameters concentrations deposition fluxes vegetation parameters CH4 emissions from wetlands biogenic VOC emissions fire emissions (SPITFIRE) allows e.g. to include O3 indirect forcing by reduced CO2 uptake LPJ -GUESS