Pollution levels

plummet in clean air fight (but…)

Ian Longley

School of Earth, Atmospheric & Environmental Sciences

University of Manchester

Air Quality Objectives

UK-wide Automated Urban and Rural Networks

Bury (M60) Piccadilly Gardens North-West

SO2 ‘plummets’

0

5

10

15

20

25

2003 2004 2005 2006

SO

2 /

g

m-3

BoltonBuryPiccadillySouth

% change in annual mean SO2 2003-2006

-60%-55% -57% -60%

43%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

Bolton Bury Piccadilly South Eccles

The pollutants that matter:

The pollutants that matter:

0

10

20

30

40

50

60

1994 1996 1998 2000 2002 2004 2006 2008

NO

2 /

g

m-3

BoltonPiccadillyEcclesStockportShaw HeathLeigh

mean annual % change in annual mean NO2 1997-2006

-1.0% -0.8%

0.7%

7.0%

-2.0%-3.0%

-2.0%

-1.0%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

Bolton Bury Piccadilly South Eccles

0

5

10

15

20

25

30

35

40

45

1994 1996 1998 2000 2002 2004 2006 2008

PM

10 /

g

m-3

BoltonBuryPiccadillyEccles

Nitrogen Dioxide (NO2) Particulate Matter (PM10)

mean annual % change in annual mean PM10 1997-2006

-1.7% -1.8%

-1.4%

-0.9%

-3.0%

-2.5%

-2.0%

-1.5%

-1.0%

-0.5%

0.0%

Bolton Bury Piccadilly Eccles

PM10 2003 - 2006

0

5

10

15

20

25

30

35

40

2003 2004 2005 2006

PM

10

/ g

m-3

PM10 2004 - 2006

0

5

10

15

20

25

30

35

40

2003 2004 2005 2006

PM

10

/ g

m-3

BoltonBuryPiccadillyEccles

PM10 2003 - 2006

0

5

10

15

20

25

30

35

40

2003 2004 2005 2006

PM

10

/ g

m-3

BoltonBuryPiccadillyEccles

0

5

10

15

20

25

30

35

40

45

1994 1996 1998 2000 2002 2004 2006 2008

PM

10 /

g

m-3

BoltonBuryPiccadillyEccles

PM10 1996 - 2006

0

5

10

15

20

25

30

35

40

45

1994 1996 1998 2000 2002 2004 2006 2008

PM

10

/ g

m-3

BoltonBuryPiccadillyEccles

PM10 1996 - 2006

2003

Urban PM10 emission trends

UK urban traffic (billion vkt)

176.0

178.0

180.0

182.0

184.0

186.0

188.0

190.0

192.0

194.0

196.0

1994 1996 1998 2000 2002 2004 20060

5

10

15

20

25

30

35

40

45

1994 1996 1998 2000 2002 2004 2006 2008

PM

10 /

g

m-3

BoltonBuryPiccadillyEccles

UK urban traffic emissions

0

5

10

15

20

25

30

35

1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

PM

10 e

mis

sio

n /

kto

nn

es

Annual mean wind speed

0

1

2

3

4

5

6

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

U /

ms-

1

2003: a bad year for air quality

Is PM10 the right metric?

Above: number size distribution from Princess Street, Manchester

Dp / m

0.001 0.01 0.1 1 10 100

dN/d

log(Dp)

/ cm

-3

1e-1

1e+0

1e+1

1e+2

1e+3

1e+4

1e+5

1e+6

Is PM10 the right metric?

381600 381800 382000 382200 382400 382600 382800 383000 383200 383400

393600

393800

394000

5000

6000

7000

8000

9000

10000

11000

12000

13000

14000

15000

16000

17000

18000

19000

20000

381600 381800 382000 382200 382400 382600 382800 383000 383200 383400

393600

393800

394000

Below: spatial variability in ultrafine particle concentration in a district of Manchester

Fixed monitor data does not characterise exposure

0

50000

100000

150000

200000

250000

300000

350000

09:18 09:21 09:24 09:27 09:30 09:33 09:36 09:38 09:41 09:44

N /

cm

-3

pedetrian

on tram

get ontram

St Peters Sq

Moseley Street (canyon)near buses

get off

past busstation

Portland Str

Ultrafine particle (UFP) exposure diary

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

00:00 06:00 12:00 18:00 00:00

N /

cm

-3

Commuting exposure to UFP

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

00:00 06:00 12:00 18:00 00:00

N /

cm

-3

Mean 10 x residential, 30% of daily dose in 5% of time, 100% of >100 000 cm-3

0

50000

100000

150000

200000

250000

300000

350000

400000

07:26 07:33 07:40 07:48 07:55 08:02 08:09 08:16

N /

cm

-3

walk 1buswalk 2

Typical bus commute exposure to UFP

Elements of example bus commute exposure to UFP

0

50000

100000

150000

200000

250000

300000

350000

400000

07:26 07:33 07:40 07:48 07:55 08:02 08:09 08:16

N /

cm-3

walk 1buswalk 2

Suburban indoors = 6 000 cm-3

Central indoors = 4 000 cm-3

Suburban outdoors = 11 000 cm-3

Central outdoors = 20–40 000 cm-3

On-bus = 50–100 000 cm-3

peaks = up to 400 000 cm-3

BUS concentrations 10 – 20 times INDOORS

PEAK concentrations up to 100 times INDOORS

Our AIM is to understand what controls EACH of these segments

CityFlux

•NERC 2004-7

•investigating the transport and chemical transformation of pollutants (gases and aerosols) in urban areas, through measurements at three spatial scales:

Individual plumes

Street canyons

Emission from an urban area

Oxford Road, Manchester (2006)

3 800 scheduled bus movements per day

Every 14 seconds in daytime (Mon-Fri)

CO concentrations at Oxford Road northbound bus stops (Mon-Fri 7am – midnight)

0

1000

2000

3000

4000

5000

6000

7000

0 90 180 270 360

wind direction

CO

* r

efer

ence

win

d s

pee

d

CO and particles at Oxford Road

0

200

400

600

800

1000

1200

1400

1600

1800

2000

13-Jun 14-Jun 15-Jun 16-Jun 17-Jun 18-Jun 19-Jun

CO

/ p

pb

0

10000

20000

30000

40000

50000

60000

N /

cm

-3

CODMPS N

Are particles formed or transformed within the canyon space?

Above: TOF-AMS

Below: DMPS, PTR-MS and CO

CityFlux: emission from the city centre (2005,6)

Regular emission cycles Sheltering, recirculation, deposition, thermal stability & inversions

Total particle number

Particles 50 nm < Dp < 32 m in 100+ size bins

CO2, H2O

AMS fluxes (with CEH Edinburgh)

VOC (PTR-MS, Univ. Lancaster)

Flux

CityFlux: emission from the city centre

0

1

2

3

4

5

6

04-Jul 11-Jul 18-Jul 25-Jul 01-Aug

M /

g

m-3

organicssulphatenitrate

Urban canopy particle turbulent ventilation fluxes

-100000

-50000

0

50000

100000

150000

200000

250000

300000

04-Jul 11-Jul 18-Jul 25-Jul 01-Aug

FN /

cm

-2s-1

0

10000

20000

30000

40000

50000

60000

00:00 06:00 12:00 18:00 00:00local time

FN /

cm

-2s-1

0

40

80

120

160

200

240

H /

W m

-2

particles

sensible heat

0

10000

20000

30000

40000

50000

60000

70000

00:00 06:00 12:00 18:00 00:00

N2

5 /

cm

-3

0

2000

4000

6000

8000

10000

12000

14000

N2 /

cm

-3

25 m

2 m

All data from NERC CityFlux project, Manchester

Above: fluxesBelow: concentrations

0

20000

40000

60000

80000

100000

120000

140000

160000

0 6 12 18 24

hour / GMT

Nfl

ux /

cm

-2s-1

summer winter

Questions we will address in analysis

• Do urban street canyons act as reaction chambers?

• How does the amount and composition of the particles we breathe depend upon meteorology?

• At what rates are particles emitted by urban processes and formed in the urban atmosphere?

• What do Manchester (and other cities) add to the regional and global atmosphere?

To be continued…

Thanks for your attention

Urban air is cleaner than it was – isn’t it?

What PM10 levels do we experience?

weekly means 1999-2005 incl.

0

5

10

15

20

25

30

35

40

45

50

PM

10 /

g m

-3

EcclesPiccadillyShaw Heath

December 2001

0

50

100

150

200

01-Dec 06-Dec 11-Dec 16-Dec 21-Dec 26-Dec 31-Dec

PM

10 /

g

m-3

EcclesStockport

wind speed

0

2

4

6

8

10

12

14

16

01-Dec 06-Dec 11-Dec 16-Dec 21-Dec 26-Dec 31-Dec

U /

m s

-1

1999-2005 Means:

Piccadilly 27

Eccles 23

Stockport 22