INTERCONTINENTAL TRANSPORT OF OZONE AND ITS SEASONAL VARIATIONS IN EUROPE

Dick Derwent

rdscientific

2nd ICAP Workshop

Chapel Hill, North Carolina

October 21st -22nd 2004

This work was sponsored by the United Kingdom Department for Environment, Food and Rural Affairs under contract CPEA 7.

STOCHEM

• three-dimensional global Lagrangian chemistry transport model

• fully coupled to Hadley Centre global atmosphere-ocean climate model• or run from operational analyses from Met Office NWP model

• full chemistry of methane, ozone, 10 emitted VOCs, NOx, acid rain and secondary aerosol formation from SO2, DMS, NH3

OZONE LABELLING TECHNIQUES

d/dt [O3] = k1[HO2][NO] + k2[RO2][NO] – losses

If air parcel is over North America then

d/dt[O3 America] = k1[HO2][NO] + k2[RO2][NO] – losses

Otherwise

d/dt[O3 America] = - losses

Origins of European Ozone

The origins of tropospheric background air across Europe

8 ppb

20 ppb

5 ppb

10 ppb

STOCHEM MODEL VS OBSERVATION FOR A RURAL LOCATION IN THE UNITED KINGDOM

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10 11 12

Month of the Year

O3

, pp

b O3

Obs

Harwell, Oxfordshire 1998

INTERCONTINENTAL ATTRIBUTION OF THE OZONE AT A RURAL UNITED KINGDOM LOCATION

0

10

20

30

40

50

60

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

O3

, p

pb

Asia

America

Europe

Stratosphere

Harwell, Oxfordshire 1998

HOW CAN THESE MODEL PREDICTION OF INTERCONTINENTAL TRANSPORT BE VALIDATED ?

• Biomass burning during 1998

• Halocarbon transport to Mace Head, Ireland

Mace Head,

Ireland

1000s km uninterrupted fetch across North Atlantic Ocean

Long range transport brings polluted air from Europe

BASELINE CONCENTRATIONS OF CO AND H2 AT MACE HEAD, IRELAND

50

70

90

110

130

150

170

190

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

CO

CO

NC

(pp

b)

465

485

505

525

545

565

585

H2

CO

NC

(pp

b)

CO MONTHLY MEANS CO 12-MONTH AVERAGEH2 MONTHLY MEANS H2 12-MONTH AVERAGE

BASELINE CONCENTRATIONS OF CO2 AND CH4 AT MACE HEAD, IRELAND

1760

1780

1800

1820

1840

1860

1880

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

CH

4 C

ON

C (

PP

B)

345

355

365

375

385

395

CO

2 C

ON

C (

PP

M)

CH4 MONTHLY MEANS CH4 12-MONTH AVERAGECO2 MONTHLY MEANS CO2 12-MONTH AVERAGE

BASELINE CONCENTRATIONS OF OZONE AT MACE HEAD, IRELAND

15

20

25

30

35

40

45

50

55

Jan-

87

Jan-

88

Jan-

89

Jan-

90

Jan-

91

Jan-

92

Jan-

93

Jan-

94

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Jan-

03

Jan-

04

OZ

ON

E C

ON

C (P

PB

)

Ozone Baseline monthly means 12-month moving average

MONTHLY MEAN BASELINE O3 CONCENTRATIONS EXPRESSED AS ANOMALIES FROM 1990-1999 MEANS

-2

-1

0

1

2

3

4

5

6

Jan-98

Mar-98

May-98

Jul-98

Sep-98

Nov-98

Jan-99

Mar-99

May-99

Jul-99

Sep-99

Nov-99

Ozo

ne

ano

mal

y ,

pp

b

Mace Head, Ireland, all hours

MONTHLY MEAN DAILY MAXIMUM O3 CONCENTRATIONS FOR THE 54 EMEP STATIONS EXPRESSED AS ANOMALIES FROM

THE 1990-1999 MEANS

Average anomaly from the 10-year mean for 54 surface EMEP sites during 1998 and 1999

-10

-8

-6

-4

-2

0

2

4

6

8

10

Ja

n-9

8

Ma

r-98

Ma

y-9

8

Ju

l-98

Se

p-9

8

No

v-9

8

Ja

n-9

9

Ma

r-99

Ma

y-9

9

Ju

l-99

Se

p-9

9

No

v-9

9

An

om

aly

oz

on

e ,

pp

b

MONTHLY MEAN DAILY MAXIMUM O3 CONCENTRATIONS FOR THE UK RURAL SITES EXPRESSED AS ANOMALIES FROM

THE 1990-1999 MEANS

-20

-15

-10

-5

0

5

10

15

Ja

n-9

8

Ma

r-98

Ma

y-9

8

Ju

l-98

Se

p-9

8

No

v-9

8

Ja

n-9

9

Ma

r-99

Ma

y-9

9

Ju

l-99

Se

p-9

9

No

v-9

9

Oz

on

e a

no

ma

ly ,

pp

b

Eskdalemuir

Lough Navar

Yarner Wood

High Muffles

Strath Vaich

Ashton Hill

Bottesford

Bush Estate

Glazebury

Harwell

Ladybower

Lullington Heath

Sibton

NO2-O3-Ox-NOx ANALYSES FOR BRIDGE PLACE, LONDON

0

10

20

30

40

50

60

0 20 40 60 80 100 120

[NOX] (ppb)

[NO

2],

[O3]

, [O

X]

(ppb

) Bridge Place London (1991-1999)

1999

Jenkin et al. (2004)

CH2Cl2 AT MACE HEAD, IRELAND DURING 1998

0

50

100

150

200

250

CH

2Cl2

, p

pt

January December

GC-MS observations from Prof Peter Simmonds

CH2Cl2 IN STOCHEM WITH INTERCONTINENTAL LABELLING

0

40

80

120

160

20001

/01/

98

01/0

2/98

01/0

3/98

01/0

4/98

01/0

5/98

01/0

6/98

01/0

7/98

01/0

8/98

01/0

9/98

01/1

0/98

01/1

1/98

01/1

2/98

CH

2Cl2

, p

pt Tot

EU

AM

AS

Peaks are European in origin

CH2Cl2 FLUCTUATIONS CLOSE TO THE BASELINE

0

40

01/0

1/98

01/0

2/98

01/0

3/98

01/0

4/98

01/0

5/98

01/0

6/98

01/0

7/98

01/0

8/98

01/0

9/98

01/1

0/98

01/1

1/98

01/1

2/98

CH

2Cl2

, p

pt Tot

EU

AM

AS

Transport from North America

LAGRANGIAN DISPERSION MODEL NAME

• employs same meteorological fields as STOCHEM• simulates transport and dispersion using upwards of a million air parcels• released at unit density in a model domain that stretches across the North Atlantic Ocean• plots show air concentration at Mace Head produced by unit density emissions at that point

GC-MS OBSERVATIONS OF CH2Cl2 DURING MARCH 1998

40

41

42

43

44

45

46

47

48

49

50

CH

2C

l2,

pp

t

Prof Peter Simmonds

Intercontinental transport from USA

HALOCARBONS AS TRACERS OF INTERCONTINENTAL TRANSPORT

• Short atmospheric lifetimes means that their baseline concentrations are low compared to current global annual emission rates• GC-MS has the sensitivity to observe them at ppt levels• current USA emission rates are significant for some halocarbons, particularly HFCs

INTERCONTINENTAL TRANSPORT OF OZONE ON 14-15 JULY 2004 FROM NEW YORK-BOSTON TO MACE HEAD

-4

-2

0

2

4

6

8

10

12

00:00:00 12:00:00 00:00:00 12:00:00 00:00:00

Co

nc

-0.5

0

0.5

1

1.5

2

2.5

HFC-134a

HCFC-22

O3 in ppb

HFC-152a

HCFC-124

HCFC-142b

HCFC-123

HCFC-141b

CH2Cl2

CCl2CCl2

14th July 15th July

CONCLUSIONS

• Modelling studies point to the importance of intercontinental transport in influencing the distribution of ozone in Europe

• This influence extends to its seasonal variations and trends with time

• The observations of reactive halocarbons are now available at Mace Head to study intercontinental transport on a systematic basis

• Aim is the validate the models of intercontinental transport across the North Atlantic Ocean