*Institute for Environmental Studies, Charles University in Prague, Benátská 2, 128 01 Prague 2, Czech Republic

** Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic

J. Hovorka*, M.Braniš*, J.Schwarz**

DIURNAL VARIATION OF SUBMICRON PM SIZE DISTRIBUTIONS AND GASEOUS

POLLUTANT CONCENTRATIONS, PRAGUE 2004, POLLUTION SOURCE ESTIMATION

hovorka@cesnet.cz, branis@natur.cuni.cz, schwarz@icpf.cas.cz

Motivation of our work• three years of our air monitoring revealed frequent (30% of days) bimodal pattern of diurnal variation of NOx, NMHC, CH4, CO partially SO2

• first mode 8-9 a.m. traffic rush hours

• second mode 8-10 p.m. NO rush hours

? ARE THESE MEASUREMENTS SITE SPECIFIC ?

? DOES AEROSOL BEHAVE SIMILARY?

? WHAT ARE LIKELY SOURCES?

Parameters determined

5 mins averages

• 14 – 710 nm aerosol size distribution (SMPS)

15 mins averages

• NO, NO2 , CO, SO2, CH4, Non-Methane HC, O3 (Horiba 360)

• temperature, humidity, UV-A,B, wind speed/direction

hourly averages

• PM10 by -attenuator,

• traffic volumes

• natural gas consumption in near-by stationary sources

Sampling site

• roof-top aerosol/gasses sampling in University botanical garden in the Prague city center

• at height about 25 m above the street

• no street canyon conditions

• duration 1.9.2004 – 31.12.2004

University University Botanic garden Botanic garden sampling sitesampling site

PRAGUE 2

Wind dire

ction

Hospital heating plant

University Botanic garden, roof-top sampling inlets

Roof-top sampling configuration

Diurnal variation of CO, NO, NO2, SO2, NMHC, CH4 in Botanical garden in Prague center, 5.10.2004

0

20

40

60

80

100

120

140

160

180

2000:

15

1:30

2:45

4:00

5:15

6:30

7:45

9:00

10:1

5

11:3

0

12:4

5

14:0

0

15:1

5

16:3

0

17:4

5

19:0

0

20:1

5

21:3

0

22:4

5

0:00

Time of day / hours

NO

, NO

2, S

O2

/ ug

m-3

0

0.5

1

1.5

2

2.5

3

CO

, CH

4, N

MH

C /

ug

m-3

NO NO2 SO2

CH4 CO NMHC

Calculated from data: www.chmi.cz

Diurnal variation of PM10 concentrations averaged over half a year 2004 at the CHMI sites in Prague center

0

10

20

30

40

50

60

700

:00

1:3

0

3:0

0

4:3

0

6:0

0

7:3

0

9:0

0

10

:30

12

:00

13

:30

15

:00

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:30

18

:00

19

:30

21

:00

22

:30

Daytime / hours

PM

10

/ u

gm

-3

0

20

40

60

80

100

120

NO

x /

ug

m-3

avg Branik PM10 avg Branik NOx

avg Rieger NOx avg Rieger PM10

avg Veleslavin NOx avg Veleslavin PM10

Diurnal variation of PM10(Beta), PM0.72(SMPS) and total particle number (14-710 nm) in Botanical garden,

Prague center 5.10.2004

0

10

20

30

40

50

60

701

:00

3:0

0

5:0

0

7:0

0

9:0

0

11

:00

13

:00

15

:00

17

:00

19

:00

21

:00

23

:00

Time of day / hours

PM

10

(Be

ta),

PM

0.7(S

MP

S)

/ u

gm

-3

0.0E+00

5.0E+03

1.0E+04

1.5E+04

2.0E+04

2.5E+04

3.0E+04

3.5E+04

4.0E+04

Pa

rtic

le n

um

be

r / c

m-3

BetaSMPS Total massSMPS Total number

? SPECIFIC SITE ?

Recorded bimodal pattern is NOT site specific solely for our station but appeared at other sites situated near river valley

Similar pattern in diurnal variation also recorded in other cities in Europe with similar urban architecture and local geography

? AEROSOL TEMPORAL CHANGES?

Temporal variations of aerosol mass/number concentrations also exhibit similar pattern as gaseous components measured

? SOURCES ?

• nucleation: NO up to 10 of true nucleation events (banana shape) recorded within measured period

• long-range transport: NO particle residence time too short, fast changes of number concentrations, bimodal pattern during low wind speed

• primary emissions from:

traffic

natural gas burning in major sources in proximity to the sampling site: Hospital heating plant Botanical garden boiler apartment/office boilers

0.0E+00

5.0E+03

1.0E+04

1.5E+04

2.0E+04

2.5E+04

3.0E+04

3.5E+04

4.0E+04

4.5E+04

5.0E+04

10 100 1000

Dp / nm

dN/d

logD

p / c

m-3

1:002:003:004:005:006:007:008:009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:000:00

Hourly averages of particle number size distribution 5.10.2005, Prague.

Number

Hourly averages of particle mass size distribution 5.10.2005, Prague.

0

10

20

30

40

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90

100

10 100 1000

Dp / nm

dm

/dlo

gD

p /

ug

m-3

1:002:003:004:005:006:007:008:009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:000:00

Mass

0

200

400

600

800

1000

1200

1400

1600

1800

7-8 8-9 9-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19

Daytime / hours

tra

ffic

de

ns

ity

/ c

ars

ho

ur-1

Hourly averages of traffic volumes at the intersection near University Botanical garden during working days (yellow)

and weekends (green)

Data source: www.udi.cz

0

100

200

300

400

500

6000

:00

1:1

2

2:2

4

3:3

6

4:4

8

6:0

0

7:1

2

8:2

4

9:3

6

10

:48

12

:00

13

:12

14

:24

15

:36

16

:48

18

:00

19

:12

20

:24

21

:36

22

:48

0:0

0

Time of day / hours

Na

tura

l g

as

co

ns

um

pti

on

/ m

3

0

5

10

15

20

25

30

35

40

Na

tura

l g

as

co

ns

um

pti

on

/ m

3

HospitalBotanic garden

Diurnal variation of natural gas burnup in Hospital heating plant and Botanic garden boiler in Prague center

on 5.10.2004

0

2

4

6

8

10

12

0:0

0

1:2

0

2:4

0

4:0

0

5:2

0

6:4

0

8:0

0

9:2

0

10

:40

12

:00

13

:20

14

:40

16

:00

17

:20

18

:40

20

:00

21

:20

22

:40

Time of day / hours

na

tura

l g

as

co

ns

um

pti

on

/ m

-3Diurnal pattern of 20 min values (Sep-Dec 2004) of natural

gas burnup by heating boiler in the Botanic garden

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%0:

00

2:24

4:48

7:12

9:36

12:0

0

14:2

4

16:4

8

19:1

2

21:3

6

0:00

Time of day / hours

bo

iler

ou

tpu

tEstimated diurnal pattern of output of gas burning boilers in

residential districts

First Second

Item Time of day / hours

Gaseous precursors 5:30-9:00 18:00-22:00

Aerosol Number 6:30-11:00 18:00-23:00

Aerosol Mass 6:30-11:00 18:00-23:00

Traffic volumes 7:00-9:00 15:00-18:30

Hospital heating plant 4:00-7:00

Botanic garden boiler 5:30-10:00

Residential boilers 4:00-6:00 18:00-22:00

Summary of peak values of gaseous precursors, aerosol concentrations and different sources outputs in Prague

CONCLUSIONS• bimodal pattern of diurnal variation of aerosol concentration can be ascribed to traffic and natural gas burning as primary aerosol emission sources

• precise traffic and gas burning apportionment of total aerosol burden in urban atmosphere requires further data on gas burning boilers in residential areas

Acknowledgment

Traffic counts performed by L.Betuš and V.Klapšťová. The station was built and maintained with help of M.Civiš.

The study was done within the scheme of project “Comprehensive characterization of atmospheric aerosol in Prague” No. 205/03/1560 of the Czech Grant Agency.