Institut für

Physik der Atmosphäre

Ensemble Climate-Chemistry simulations for the past 40 years

Volker Grewe and the DLR/MPI Team

Institut für Physik der AtmophäreDLR-Oberpfaffenhofen

GermanyVolker.Grewe@dlr.de

Martin Dameris, Veronika Eyring, Fabian Mager, Michael Ponater, Tina Schnadt, Andrea Stenke - DLR Oberpfaffenhofen

Benedikt Steil, Christoph Brühl, Patrick Jöckel - MPI- Mainz

Marco Giorgetta, Claudia Timmreck, MPI-Hamburg

Institut für

Physik der Atmosphäre

ECHAM4.L39(DLR) = E39 Atmosphere circulation model

Global spectral model with semi-Lagrangian advection of water vapour,

cloud water and tracers

Resolution: T30, 39 layers, top layer centered at 10 hPa (30 km)

Parameterizations of radiation, clouds, precipitation, convection, diffusion

CHEM = C Chemistry-Module (family concept)

Transported species: H2O, CH4, N2O, HCl, H2O2, CO, CH3O2H, ClONO2,

HNO3+NAT, ICE, ClOx, NOX, OX

37 species and 107 gas-phase reaction

Methane oxidation, PSC formation, 4 heterogeneous reactions on PSCs

Parameterization of dry/wet deposition, lightning and surface emissions

Interactively coupled at every timestep

E39/C Climate-Chemistry Model

Institut für

Physik der Atmosphäre

Coupling of Dyamics and Chemsitry in E39/C

Institut für

Physik der Atmosphäre

Simulation of the Earth‘s atmosphere from 1960 to 2000

Simulation is based on climate chemistry model E39/C with additional forcings:

• Emissions of NOx, CO, CO2, N2O, CH4, CFCs, as observed or estimatd by

IPCC

• QBO nudged in tropical stratosphere

• Volcanoes regarded (Agung, El Chichon, Pinatubo) for chemistry and

radiation

• Observed sea surface temperatures (Hadley-GISS)

• 11 year solar cycle

• No other forcing, free running climate chemistry model

Institut für

Physik der Atmosphäre

Total Ozone [DU]

• High variability > than in time-slices • Solar cycle in tropics

• Ozone hole starts 80s

• Global ozone -15 DU

Institut für

Physik der Atmosphäre

Tropospheric ozone column (DU)

• High variability

• Global increase: 4 DU

• Small effects on SH

Institut für

Physik der Atmosphäre

Simulated evolution of cloud to ground lightning 1960 to 2000

El Nino events

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Physik der Atmosphäre

Ensemble 50 hPa temperature

Institut für

Physik der Atmosphäre

Ensemble total ozone

Institut für

Physik der Atmosphäre

Ensemble tropospheric total ozone

Institut für

Physik der Atmosphäre

Lightning

Institut für

Physik der Atmosphäre

Summary

• CCM/CTM Models are ready for transient simulations• ACCENT modelling acitivity: Ensemble simulations

Capability of models (-> Comparison to measurements) Attribution perhaps possible?

TemperatureTropospheric Ozone Column ?

BUT

Institut für

Physik der Atmosphäre

Fully coupled CCM simulations require additional diagnostics in orderto separate various effects.

E.g. NOx and ozone tagging diagnostics

Institut für

Physik der Atmosphäre

Approach: Tagging of NOy and ozone molecules

1st step: For each source i=1, ... , n (n=8) define a NOy tracer (Xi)2nd step: For each NOy tracer define an ozone tracer (Yi)

and an ozone tracer (Yn+1) for ozone production by O2 photolysis

photolysis Oby causedion concentrat O

8)n1,..,(i iemission by

causedion concentrat O and NO ,NO

loss Ozone ,photolysis Oby and

NOby production Ozone loss, NO ,

i sourceby NO ofEmission

O and NO ,NO Simulated ,,

231

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E

YxX

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dYX

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11

Attribution of ozone increase to NOx emissions

Institut für

Physik der Atmosphäre

Institut für

Physik der Atmosphäre

Institut für

Physik der Atmosphäre

Institut für

Physik der Atmosphäre

Tropical past ozone changes 30S-30N20

0-50

0 h

Pa

500-

1000

hP

aOzone tracer mass

• Lightning most important

source for tropical ozone

• In UT: stratospheric

intrusions also important

Institut für

Physik der Atmosphäre

Interannual variability in the tropics

• Solar cycle effects stratospheric ozone

leading to weak UT ozone variations (5%)

• Stratospheric O3 and lightning important

for inter-annual variations

• Industry and land transportation

responsible for trends

Upper troposphere

Lower troposphere