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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. Overview Objectives Introduction to TM4/5 Coupling to ECMWF IFS (GEMS) Model evaluation
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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.
Overview • Objectives • Introduction to TM4/5 • Coupling to ECMWF IFS (GEMS) • Model evaluation • Some outstanding questions
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
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
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
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
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
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 !
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
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
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)
GEMS CTM beauty contest • 3 CTM's are evaluated for 2003 : • TM5 (KNMI) • MOZART (MPI-Hamburg / Julich) • MOCAGE (Meteo-France) Ozone column
GEMS CTM beauty contest CO column
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
Some outstanding problems we are interested in: • Impact of tropospheric ozone on Arctic climate change • Will methane continue to grow? • Stratospheric ozone-climate feedbacks
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
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
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
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
The end Questions?
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