EC-earth Atmospheric chemistry module TM

1. EC-earth Atmospheric chemistry module TM KNMI Chemistry and Climate division Peter van Velthoven, Twan van Noije, Michiel van Weele, Jason Williams, Arjo Segers, Henk Eskes, a.o.

2. Overview • Objectives • Introduction to TM4/5 • Coupling to ECMWF IFS (GEMS) • Model evaluation • Some outstanding questions

3. Objectives TM5-ECearth coupling • Description of atmospheric chemical cycles for long-term future integrations (IPCC 5AR) • Improve meteorological part of TM • Process studies: chemistry-climate feedbacks

4. TM4 / TM5 • TM4: global atm. chemistry-transport model coupled off-line to archived 3/6 hourly ECMWF meteorology (winds, temperature, clouds, humidity, precipitation, surface fields) • TM5: additionally several multilevel zoom regions • Both use same meteo-preprocessor TM5pp

5. TM4/5 chemistry • Simulate life cycles of non-CO2 greenhouse gases, aerosols and their precursors: • natural and anthropogenic sources • transport (advection, convection, turbulence) • gas phase and heterogeneous chemical conversions & photolysis • dry and wet removal • data assimilation & emission inversions • Modules : • TM4/5-trop: O3, CH4, optionally aerosols • TM5-strat-trop: N2O, CH4, O3, CFCs, strat H2O

6. TM history • CTMK (based on Heimann’s TM2) 1993-1995 • TM3 model 1995 – 2000 • IPCC TAR • ERA-15 chemical reanalysis • Data assimilation total ozone satellite observations • TM4 model 2000 – today (for applications) • IPCC AR4 • ERA-40 chemical reanalysis (RETRO) • Data assimilation of ozone, NO2, aerosol, …. • TM5 model 2000 – today (model development) • Coupling to IFS: PRISM, GEMS, EC Earth Application in EU-projects: QUANTIFY, HYMN, SCOUT, GEOMON, AMMA • Joint model development within international community: • Un. Utrecht/Un.Wageningen, JRC Ispra, NOAA, Un. Crete, Un. Toulouse, more

7. EU-GEMS integrated project • Global and regional Earth-system Monitoring using Satellite and in-situ data • Will create operational systems for: • global monitoring of atmospheric chemistry and dynamics • producing improved medium-range & short-range air-chemistry forecasts • through much improved exploitation of satellite data • Coordinated by ECMWF

8. GEMS reactive gases subprojectIFS - TM5 coupling • Target: assimilation reactive gases: O3, NO2, CO, CH4, CH2O, SO2 • no chemistry in IFS model itself, but coupling with TM5 by OASIS4 IFS -high resolution -few tracers -no chemistry -assimilation meteo (assimilated IFS tracers) TM5 -low resolution -many tracers -chemistry coupler chemical tendencies Simplified chemistry in ECMWF will likely run away without assimilation !

9. EC-earthIFS - TM5 coupling • Target: radiative coupling O3, CH4, N2O, … CFCs, aerosols • no tracers in IFS model itself, but coupling with TM5 by OASIS4 IFS - moderate resolution - no tracers - radiative coupling meteo TM5 -low resolution -many tracers -chemistry coupler chemical concentrations First step: connect to IFS radiative scheme – investigate impact

10. Present IFS-TM5 coupling • IFS in ERA40 setup • TM5 at 3x2 deg, L60, tropospheric chemistry, 8 pe – to be replaced by new strat-trop chemistry • Coupling: • hourly exchange of fields • each model uses “old” exchanged fields

11. Need for atmospheric chemistry model evaluation • Atmospheric chemistry progress is “observation-limited” • Need to gain credibility in future scenarios by reconstructing the past by: • Case & process studies • Chemical data assimilation (e.g. EU-GEMS) • Chemical re-analyses (e.g. EU-RETRO)

12. GEMS CTM beauty contest • 3 CTM's are evaluated for 2003 : • TM5 (KNMI) • MOZART (MPI-Hamburg / Julich) • MOCAGE (Meteo-France) Ozone column

13. GEMS CTM beauty contest CO column

14. Other beauty contests, e.g. EU-Quantify Ozone sondes: Edmonton, Canada Courtesy: Tina Schnadt, ETH-Zurich Nudged CCM #1 TM Offline CTM #2 Nudged CCM #2

15. Some outstanding problems we are interested in: • Impact of tropospheric ozone on Arctic climate change • Will methane continue to grow? • Stratospheric ozone-climate feedbacks

16. Tropospheric ozone Atmospheric Chemistry (trace gases): Fuel: CO, Hydrocarbons (HCs) Catalysts: NOX(=NO+NO2), HOX End Products: O3, CO2, HNO3 Emissions via ’O3 precursors’: NOX, CO, HCs Today the ozone increase is on a hemispheric scale! 1850 -1950 1950 -1990 in DU

17. Arctic climate forcing by tropospheric ozone Shindell et al., 2006 paper: • Tropospheric ozone is currently responsible for one-third to half of the observed warming trend in the Arctic during winter and spring • Ozone is transported from the industrialized countries in the Northern Hemisphere to the Arctic quite efficiently during these seasons • The North Polar region remained at normal temperatures until ~1950

18. Will methane continue to grow? SCIAMACHY 2-year mean Difference: SCIAMACHY – TM • SCIAMACHY observations point to underestimation • of tropical CH4 emissions (Science, 2005) • Trend in methane during past 20 years not understood • HYMN project (2006-2009): • - TM modeling natural exchanges with the biosphere • (CH4, N2O, H2) • - TM assimilation of SCIAMACHY and ground-based • observations to constrain (natural) sources

19. Ozone layer  climate feedbacks • Chemistry-climate couplings in the stratosphere. Examples. • Ozone => Radiation => Temperature => Dynamics = > Ozone • Greenhouse gas increases CO2, CH4, N2O,CFCs  O3 layer trend; • only CO2 increase cools the stratosphere! • Ozone layer => UV radiation => CH4 lifetime and tropospheric ozone • Stratosphere-troposphere exchange of constituents (O3, H2O) • Polar ozone loss by CFCs => T decrease => PSCs => ozone loss etc EC Earth vs ERA40: Temperature biases in the stratosphere

20. The end Questions?

21. Other beauty contests, e.g. Quantify CTMK

22. Human Dimension / Policy Applications • EU QUANTIFY • Impact of emissions from transport: • NOx emitted by aviation relatively efficient in producing ozone • Road traffic ~ equally important as aviation at cruise levels • Ships have relatively large impact on methane Aircraft Road traffic Ships All transport