ACCENT Experiment 2

• 25 different models perform same experiments– 15 Europe:

• 4 UK (STOCHEM x2, UM_CAM, TOMCAT)• 3 Germany (MATCH-MPIC x2, MOZECH)• 2 France (LMDzINCA x2)• 2 Italy (TM5, ULAQ)• 1 Switzerland (GEOS-CHEM)• 1 Norway (UIO_CTM2)• 1 Netherlands (TM4)• 1 Belgium (IASB)

– 7 US:• GMI (x3), NCAR (MOZART4), GFDL (MOZART2), LLNL, GISS

– 3 Japan:• JAMSTEC – CHASER (x2), FRSGC/UCI

• Large ensemble reduces uncertainties, and allows them to be quantified

ACCENT Expt 2

• Consider 2030 – ‘the next generation’ – of direct interest for policymakers

• 3 Emissions scenarios– ‘Likely’: IIASA CLE (‘Current Legislation’)– ‘Low’: IIASA MFR (‘Maximum technically

Feasible Reductions’)

– ‘High’: IPCC SRES A2

• Also assess climate feedbacks – expected surface warming of ~0.7K by 2030

• Target IPCC-AR4

People & Organisation• Co-ordination; N+S-deposition, Tropospheric O3

– F. Dentener, D. Stevenson• Surface O3 - impacts on health/vegetation; web-site

– K. Ellingsen• NO2 columns – comparison of models and satellite data

– T. van Noije, H. Eskes• Emissions

– M. Amann, J. Cofala, L. Bouwman, B. Eickhout• Data handling and storage (SRB; ~1 TB of model output)

– J. Sundet• Other modellers and contributors:

– C.S. Atherton, N. Bell, D.J. Bergmann, I. Bey, T. Butler, W.J. Collins, R.G. Derwent, R.M. Doherty, J. Drevet, A. Fiore, M. Gauss, D. Hauglustaine, L. Horowitz, I. Isaksen, M. Krol, J.-F. Lamarque, M. Lawrence, V. Montanaro, J.-F. Müller, G. Pitari, M.J. Prather, J. Pyle, S. Rast, J. Rodriguez, M. Sanderson, N. Savage, M. Schultz, D. Shindell, S. Strahan, K. Sudo, S. Szopa, O. Wild, G. Zeng

Climate change/deposition

CO

IPCC-AR4-ACCENT ‘High’ Ship Emission Scenario

• Scenario S4: IPCC A2, but with ship emissions of the year 2000

• Scenario S4s: "Worst" case ship emission scenario in conjunction with S4.

Simulation ID emissions Meteo

S1 IIASA-CLE-2000 2000

S1c IIASA-CLE-2000 1990s/2000s

S2 IIASA-CLE-2030 2000

S2c IIASA-CLE-2030 1990s/2000s

S3 IIASA-MRF-2030 2000

S4SRES-A2-2030, but with ship emissions of the year 2000

2000

S4sSRES-A2-2030; Traffic A2s

Ship emissions increase with a flat increase of 2.2 % /year compared to the year 2000

2000

S5c IIASA-CLE-2030 2020s/2030s

SO2 High ship emissions: A2s "2030" NOx High ship emissions: A2s "2030"

SO2 emissions: A2 "2000" NOx emissions: A2 "2000"

2000 A2(2030) A2s(new) A2s-A2

SO2 in

Tg(SO2)/yr

11.23 31.7 38.84 7.14

NOx in

Tg(NO2)/yr

52.74 107.4 116.8 9.4

IPCC-AR4-ACCENT ‘High’ Ship Emission ScenarioCharacteristics:

The idea of comparing A2 to A2s:

1. What is the influence of ship emissions on tropospheric chemistry in 2030 if they were unabated?

2. Does an ensemble of models give approximately the same answer regarding the influence of ship emissions?

Status: Data analysis recently started

• Thanks to everybody who sent data so far (FRSGC_UCI, LMDz/INCA, MATCH-MPIC, TM4)

• We invite all other model groups to join in the inter-comparison

• If you are interested, please contact Veronika.Eyring@dlr.de and Axel.Lauer@dlr.de

Year 2000 Anthropogenic NOx Emissions

EDGAR database: Jos Olivier et al., RIVMPlot: Martin Schultz, MPI

Year 2000 tropospheric NO2 columns

Model(ensemble mean)

Observed (GOME)(mean of 3 methods)

Courtesy Twan van Noije, Henke Eskes – figure from Dentener et al, submitted

(10:30am local sampling in both cases)

Courtesy Twan van Noije

Modelled column NO2 vs GOME retrievals over Europe

NOy wet deposition zoom over Europe

Courtesy Frank Dentener

Global NOx emission scenarios

0.0

40.0

80.0

120.0

160.0

200.0

1990 2000 2010 2020 2030

Europe North AmericaAsia + Oceania Latin America

Africa + Middle East Maximum Feasible Reduction (MFR)

SRES A2 - World Total SRES B2 - World Total

Figure 1. Projected development of IIASA anthropogenic NOx emissions by SRES world region (Tg NO2 yr-1).

CLE

SRES A2

MFR

Figure 4. Regional emissions separated for sources categories in 1990, 2000, 2030-CLE and 2030-MFR for NO x [Tg NO2 yr-1]

Regional NOx emissions19

9020

0020

30 C

LE20

30 M

FR

Europe:falling

Asia:rising

USA:~flat

Ships/aircraft:unregulated;may become

larger than anyregional source

by 2030

Emission Changes 2030 CLE - 2000

Plots: Martin Schultz, MPI IIASA RAINS model: Markus Amann et al.

Year 2000 Annual Zonal Mean Ozone (24 models)

Year 2000Ensemble meanof 25 models

AnnualZonalMean

Annual TroposphericColumn

Ensemble meanof 25 models

AbsoluteStandard Deviation

of 25 models

%Standard Deviation

of 25 models

Year 2000 Annual Mean O3

Comparison of ensemble mean model with O3 sonde measurements

J F M A M J J A S O N D

Observed ±1SD

Model ±1SD

90-30°S 30°S-Eq 30°N-Eq 90-30°N

UT250 hPa

MT500hPa

LT750hPa

2030 CLE - 2000 2030 MRF - 2000 2030 A2 - 2000

+5 ppbv -5 ppbv +10 ppbv

-30

-20

-10

0

10

20

30

40

50

60

70

-20 -10 0 10 20 30

Change in NOx emissions / Tg-N/yr

Ch

ang

e in

O3

bu

rden

/ T

g-O

3

Tropospheric O3 scales ~linearly with NOx emissions

Radiative forcing implications

-500

0

500

1000

1500

mW

/ m

2

CO2 795 795 1035

CH4 116 0 141

O3 63 -43 155

CLE MRF A2

Forcings (mW m-2) 2000-2030 for the 3 scenarios:

-23% +37%

CO2

CH4

O3

Impact of Climate Change on Ozone by 2030(ensemble of 9 models)

MeanMean - 1SD Mean + 1SD

Negative watervapour feedback

Positive stratospheric

influx feedback

Positive and negative feedbacks – no clear consensus

Budgets ofmethane

andtropospheric

ozone

S1 Tropospheric O3 budget

-5000

50010001500200025003000350040004500500055006000650070007500

CH

AS

ER

_CT

M

CH

AS

ER

_GC

M

FR

SG

C

GE

OS

-CH

EM

GF

DL

GM

ICC

M

GM

IDA

O

gm

igis

LL

NL

-IM

PA

CT

LM

DzI

NC

A

LM

DzI

NC

Ac

MO

ZE

CH

NC

AR

ST

OC

HE

M_H

adA

M3

ST

OC

HE

M_H

adG

EM

TM

4

TM

5

UL

AQ

UM

_CA

M

Mea

n

Sta

nd

ard

Dev

iati

on

Med

ian

Tg

O3/

yr

P L P-L D Sinf

19 Models reported O3 budgets

Highest H2O+High Lightning NOx (8 TgN/yr)

Higher H2OHigher LNOx ?

Lower H2OLower LNOx ?

More complicated- other factors

CH4 lifetime / years

O3

chem

ical

loss

/ T

g-O

3 yr

-1

90S Eq 90N

Tro

po

sp

her

ic H

2O

co

lum

n /

g(H

2O

) m

-2

Tropospheric water vapour in 6 GCMs

Differences of± 10% in tropics

3000 ppb.h !!!

AOT40, May-June-July, mean model, ppb*hours

Courtesy Kjerstin Ellingsen

Change in AOT40 (CLE)

Change in AOT40 (MFR)

Change in AOT40 (A2)

Conclusions• Logistics:

– Large group participation – partly due to IPCC-AR4– Lot of work involved – relies on funding ‘goodwill’– Need well defined experiments and diagnostics– Central database and strict data format– Assume mistakes will be made in first attempts– Enforce deadlines if possible

• Science:– Multi-model ensemble allows uncertainties to be assessed– Sample large model parameter space– Get hints about the controls on internal model processes– Future work: – Water vapour, convection, lightning NOx, isoprene schemes– STE, biomass burning– Global HOx/NOx/NOy budgets, as well as O3 and CH4