MOZART Development, Evaluation, and Applications

at GFDL

MOZART Users’ MeetingAugust 17, 2005

Boulder, CO

Arlene M. Fiore Larry W. Horowitz

Arlene.Fiore@noaa.gov Larry.Horowitz@noaa.gov

Outline: MOZART Development, Evaluation, and Applications at GFDL

• Surface Ozone Bias over the United States- Comparison with observations (EPA AQS; CASTNet)- Sensitivity- Policy-relevant background

• Evaluation with 2004 ICARTT observations*

• Vertically distributed biomass burning

• Trends (historical, future) in ozone and aerosols

• Methane control for climate and air quality– 1990-2004 CMDL CH4

*

*Special thanks to George Milly, the ICARTT Science Team, CMDL

MOZART-2 Comparison with AIRS: July 2001 1-5 p.m. Surface O3 (ppbv)

Mean Bias = 24±10 ppbv; r2 = 0.50

Fires Landbiosphere

Humanactivity

Ocean

NORTH AMERICA

Lightning

“ Background” air

Outside naturalinfluences

Long-range transportof pollution

Processes Contributing to Surface Ozone over North America

stratosphere

lightning

“POLICY RELEVANT BACKGROUND” (PRB) OZONE:Ozone concentrations that would exist in the absence of anthropogenic emissions from North America

X

Daily afternoon (1-5 p.m. mean) surface ozone from all CASTNet sites for March-October 2001:

PRB ozone over the U.S. is typically 20-35 ppbv

CASTNet sites

GEOS-CHEM Model

PRB 26±7 ppbvGEOS-CHEM PRB 29±9 ppbv

MOZART-2

Both models predict consistent PRB range despite large surface O3 bias in MOZART-2

MOZART-2 Model

MOZART-2 bias associated with domestic ozone production

MODEL – OBSERVED

Daily mean 1-5 p.m. June 1 – Aug 31 at CASTNet stations

-50 0 50 100 150

Bac

kgro

und

O3

Nor

th A

mer

ican

O3

80

60

40

20

0

200

150

100

50

0

-50 0 50 100 150

Slope = -0.14; intercept=25;r=-0.38

Slope = 0.81; intercept=33;r=0.65

Substantial O3 sensitivity to the uncertain fate (and yield) of organic isoprene nitrates

OH RO2 NO(very fast) NO2

High-NOx

Isoprene nitratesSink for NOx?ISOPRENE

O3

Change in July mean 1-5 p.m. surface O3 when isoprene nitrates (at 12% yield) act as a NOx sink

4-12 ppbv impact!

ppbv

MOZART-2

Fiore et al., JGR, 2005

MOZART-4 Fully Interactive Base case +21 ppbv

0

-3

1.5

2

-1

-1

-1.5

-2

-3

-7

-8 -3 2

Change in eastern U.S. surface ozone bias due to sensitivity simulations

Base case = simulation with isop. nitrates as a NOx sinkMOZART-2 Base case +19 ppbv

O3 deposition velocities*1.5PAN, NO2 dep vels. = O3

Including alkyl nitrate formationSYNOZNo isop. peroxide recyclingDaytime PBL increased to 2 km

Xactive phot/emis (not drydep)All Xactive; no clouds in phot.

Daytime PBL increased to 1 km

Xactive drydep/emis (not phot)

Outline: MOZART Development, Evaluation, and Applications at GFDL

• Surface Ozone Bias over the United States- Comparison with observations (EPA AQS; CASTNet)- Sensitivity- Policy-relevant background

• Evaluation with 2004 ICARTT observations

• Vertically distributed biomass burning

• Trends (historical, future) in ozone and aerosols

• Methane control for climate and air quality– 1990-2004 CMDL CH4

*

COMPARISON WITH ICARTT : Mean % BiasMOZART-4 (preliminary version) NCEP T62, 1999 NEI

vs. All INTEX DC-8 observations June-Aug 2004

-200-150-100-50

050

100150200

CO

_UC

IGC

OZO

NE

PAN

HN

O3_

CIT

CH

4_U

CIG

C

CH

2O_N

CA

RC

H2O

_UR

I

HC

HO

_GIT

H2O

2_U

RI

H2O

2_C

IT

HN

O3_

UN

H

CH

3OO

H_U

RI

CO

_MIX

ING

_RA

TIO

ISO

PREN

E

AC

ETA

LDEH

YDE

AC

ETO

NE

MEK NO

X

OH

HO

2

ETH

AN

E

PRO

PAN

E

HO

2NO

2

%

OZONE(ppb)

CO(ppb) H2O2_CIT

(ppt)

HNO3_CIT(ppt)

PAN(ppt)

NOx(ppt)

Altit

ude

(km

)

Campaign Mean Vertical ProfilesModel vs. INTEX DC-8 Observations

Ozone Chemical RegimeModel vs. INTEX DC-8 Observations (day; <2km; east of 100 °W)

Model more HOx-rich (i.e., NOx-sensitive) and shows a stronger HOx-NOx correlation than observed.

HO2 vs. NO2

Outline: MOZART Development, Evaluation, and Applications at GFDL

• Surface Ozone Bias over the United States- Comparison with observations (EPA AQS; CASTNet)- Sensitivity- Policy-relevant background

• Evaluation with 2004 ICARTT observations

• Vertically distributed biomass burning

• Trends (historical, future) in ozone and aerosols

• Methane control for climate and air quality– 1990-2004 CMDL CH4

*

Vertically Distributed Biomass Burning (BMB) Emissions

1. IPCC AR-4 BASE CASE (met year 2000) -- monthly 1997-2002 mean van der Werf emissions -- levels with tops at 0.1, 0.5, 1, 2, 3, and 6 km

2. ICARTT Summer 2004 -- daily emissions from Rynda Hudman & Solene

Turquety, Harvard-- distributed up to 4 km, with 50% below 1 km

Change in SON composite max* CO concentrations (ppb) (Vertically distributed) – (All at surface)

300 hPa

750 hPa 995 hPa

500 hPa

*Composite max = daily max per grid point

increases just above the boundary layer decreases at surface and higher altitudes;

interplay btw emissions and convection?

Change in Tropospheric O3 Columns (DU)Composite Seasonal Maxima*

(Vertically distributed) - (All BMB emissions at surface)

JJA

SON

DJF

MAM

Maximum impact ~10% near source region*Composite max = daily max per grid point

-3 -2 -1 0 1 2 3

Outline: MOZART Development, Evaluation, and Applications at GFDL

• Surface Ozone Bias over the United States- Comparison with observations (EPA AQS; CASTNet)- Sensitivity- Policy-relevant background

• Evaluation with 2004 ICARTT observations*

• Vertically distributed biomass burning

• Trends (historical, future) in ozone and aerosols

• Methane control for climate and air quality– 1990-2004 CMDL CH4

*

NOx Emissions

0

20

40

60

80

100

120

SO2 Emissions

0

50

100

150

200

250

BC Emissions

0

5

10

15

20

25

30

0 0 0 0 0 0 0 0 0 0 0 0 0

1860

1880

1900

1920

1940

1960

1980

2000

2020

2040

2060

2080

2100

NOxEmissions

(Tg N)

SO2Emissions(Tg SO2)

BC Emissions

(Tg C)

120

100

80

60

40

20

250

200

150

100

50

0

25

20

15

10

5

0

O3 Burden

0

5

10

15

20

25

30

35

40

45

50

SO4 Burden

0

1

2

3

4

5

6

7

8

0 0 0 0 0 0 0 0 0 0 0 0 0

BC Burden

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

1860

1880

1900

1920

1940

1960

1980

2000

2020

2040

2060

2080

2100

BC Burden(Tg C)

SO4 Burden(Tg S)

O3 Burden(DU)

5045403530252015105876543210

1.61.41.21.0.80.60.40.20

Historical A2 A1B B1

Emissiontrends inMOZART-2and resultingtroposphericburdens,used to drive GFDL climatemodelsimulationsfor IPCC

[Horow itz, in prep.]

1860: Mean=24.1 DU 2000: Mean= 34.0 DU

A2 2100: Mean 45.4 DU

Trends in Tropospheric O3 Columns

[Horow itz, in prep.]

First step; next we’ll examineclimate impacts on chemistrywith GFDL chemistry-climate model

Ozone Budgets in IPCC-AR4 from 19 Tropospheric Chemistry Models for Base Year 2000

PROD LOSS DEP STRAT

Ozo

ne (T

g yr

-1)

Budgets from Stevenson et al., 2005

X 19-Model MeanMOZART-2MOZART-4

X MOZECHGEOS-CHEM

Scenarios for 2030:• Current Legislation (CLE)• Maximum Feasible Reductions • SRES A2• Climate change (CLE emissions)

Emissions for 2000:• EDGAR 3.2• GFED 1997-2002 mean

for biomass burning

Outline: MOZART Development, Evaluation, and Applications at GFDL

• Surface Ozone Bias over the United States- Comparison with observations (EPA AQS; CASTNet)- Sensitivity- Policy-relevant background

• Evaluation with 2004 ICARTT observations

• Vertically distributed biomass burning

• Trends (historical, future) in ozone and aerosols

• Methane control for climate and air quality– 1990-2004 CMDL CH4

*

MOZART-2 Methane Study

Motivation: Methane controls benefit global air quality and climate by lowering background tropospheric O3

Question: Are prior results from steady-state simulations with uniform, fixed CH4 concentrations directly relevant to real-world emission controls?

Approach: Multi-decadal transient simulationsReduce global anthrop. CH4 emissions by 40%:

(1) All in Asia(2) Everywhere in the globe

(All simulations use 1990-2004 T62 NCEP winds, recycled as needed)

Methane Emissions in EDGAR inventory: early 1990s (Tg CH4 yr-1)

Anthropogenic: 248

Based on values in the literature, we increased biogenic CH4 emissions by 60 Tg

Energy,landfills,wastewaterRuminants

Rice

BiomassBurning

Ocean

Biogenic

9593

6086

204

10 Total: 548

Seasonal cycle, inter-annualvariability,increasing trend largelycaptured at remote sites

Underestimatespost-1998; indicating emissionsincrease?

MODEL CH4 CMDL CH4

1990 1992 1994 1996 1998 2000 2002

1780

1760

1740

1720

1700

1760

1740

1720

1700

1680

1780176017401720170016801660

High Bias at high northern latitudes

Low bias at high southern latitudes1990 1992 1994 1996 1998 2000 2002

MODEL CH4 CMDL CH4

1720

1700

1680

1660

1640

1800

1780

1760

1740

1720

1900

1850

1800

1750

1990 1992 1994 1996 1998 2000 2002

1990 1992 1994 1996 1998 2000 2002

Low Bias at high southern latitudes

Inter-hemispheric gradient too high

050

100150200250300350400

1990 2000 2010 2020

Change inMethaneConcentration(ppbv)

0

5

10

15

20

25

30

35

1990 1995 2000 2005 2010 2015 2020

Tg

CO

Decrease in Tropospheric CO Burden

140014501500155016001650170017501800

1990 2000 2010 2020

Met

hane

(ppb

v)

Standard

-40% Anthrop.Emissions

Transient simulations with EDGAR 1990 emissions, beginning 1990:(1) Standard (2) 40% decrease in global anthrop. emissions

(18% of total CH4 emissions)

0123456789

1990 2000 2010 2020

Tg O

zone

Difference (STD -GLOB40)

Global surface CH4 conc. Decrease in global surface CH4 conc.(standard – 40% anth. emis. decrease

Decrease in Tropospheric O3 Burden

Difference (STD -GLOB40)

CLIMATE IMPACTS: Change in July 2000 Trop. O3 Columns (to 200 hPa)

40% decrease in global anthrop.CH4 emissions

Zero CH4 emissions from Asia(= 40% decrease in global anthrop.)

No Asia – (40% global decrease)

Tropospheric O3 column response is independent of CH4 emission location except for small (~10%) local changes

Dobson Units

DU

U.S. Surface Afternoon Ozone Response in Summer also independent of methane emission location

MEAN DIFFERENCE MAX DIFFERENCE(Composite max daily afternoon mean JJA) NO ASIAN CH4

GLOBAL 40% DECREASE IN ANTHROP. CH4

Stronger sensitivity in NOx-saturated regions (Los Angeles),partially due to local ozone production from methane

Summary: MOZART Development, Evaluation, and Applications at GFDL

• Surface Ozone Bias over the United States– Typically 15-20 ppbv; sensitive to local chemistry

• Evaluation with 2004 ICARTT observations– Generally good; many species too high in boundary layer

• Vertically distributed biomass burning– Small mean effect, up to ~10% episodically

• Trends (historical, future) in ozone and aerosols– Past increases, future increases under some scenarios– First step towards studying chemistry-climate interactions– MOZART-2 near ensemble mean in IPCC 2030 comparisons

• Methane control for climate and air quality– Good agreement btw transient runs and remote surface obs.– Nearing steady-state after 30 years (~3 e-folding lifetimes) – 40% anthrop. CH4 decrease -9 Tg O3; -(1-3) ppbv U.S. JJA – Ozone response largely independent of CH4 source location