Meteorologisches Observatorium

Hohenpeißenberg

VOC MEASUREMENTS AT HOHENPEISSENBERG AS PART OF THE GAW PROGRAM

Christian Plass-Dülmer and Harald BerresheimMeteorologisches Observatorium Hohenpeißenberg, DWD, Germany

GAWexpert meeting Report 111, 1995• Global distribution, seasonality and trends• understanding the biogeochemical cycling (sources, sinks, chemistry)• impact on ozone, photooxidants, oxidising capacity, aerosol, climate, health

WMO (1995): WMO-BMBF Workshop on VOC - Establishment of a „World Calibration/Instrument Intercomparison Facility for VOC“ to Serve the WMO Global Atmosphere Watch (GAW) Programme, WMO Report, 111.

EMEPStrategic Plan 2004• European distribution and trends• Compliance monitoring (compliance with protocols)• understand physical and chemical processes• Support for EMEP model

EMEP (2003): The EMEP Monitoring Strategy 2004-2009 - Background document with justification and specification of the EMEP monitoring programme 2004-2009, eds. Kjetil Torseth and Oystein Hov, EMEP, CCC-Report 9/2003.

VOC Monitoring - Objectives

GAW-Program VOC:

•Stage 1: C2-C9 hydrocarbons HC•Stage 2: C10-C14 HC (biogenic)•Stage 3: oxygenated VOC (OVOC)

MOHp

•GC-FID•GC-MS/FID•GC-PDHID/FID

Detection limits: 1 ppt ... 10 pptAccuracy: C2-C9 HC 5-25%, Terpenes 20-40%QA and QC ProceduresVOC Intercomparisons: NOMHICE, AMOHA, and GAW

Measurements at1:00 and 13:00 CETca. 80 VOC

AMOHA - Task 4.2 - canister sampling at Hohenpeißenberg 04/2000

0.01

0.1

1

10

Eth

ane

Pro

pane

Eth

ene

Eth

yne

But

ane

Tolu

ene

2-M

ethy

lbut

ane

Ben

zene

2-M

ethy

lpro

pane

Pro

pene

Pen

tane

2+3-

Met

hylp

enta

ne

p,m

-Xyl

ene

2-M

ethy

lpro

pene

2-M

ethy

lpen

tane

Eth

ylbe

nzen

e

Hex

ane

Cyc

lohe

xane

o-X

ylen

e

1-B

uten

e

Hep

tane

Isop

rene

Pro

pyne

Tran

s-2-

bute

ne

Cis

-2-b

uten

e

1,3-

But

adie

ne

Tran

s-2-

pent

ene

Cis

-2-p

ente

ne

med

ian

mix

ing

ratio

, ppb

v X

AMOHA - Task 4.2 - canister sampling at Hohenpeißenberg 04/2000

0.1

1

10

100

Eth

an

e

Pro

pa

ne

Eth

en

e

Eth

yne

Bu

tan

e

Tolu

en

e

2-M

eth

ylb

uta

ne

Be

nze

ne

2-M

eth

ylp

rop

an

e

Pro

pe

ne

Pe

nta

ne

2+

3-M

eth

ylp

en

tan

e

p,m

-Xyl

en

e

2-M

eth

ylp

rop

en

e

2-M

eth

ylp

en

tan

e

Eth

ylb

en

zen

e

He

xan

e

Cyc

loh

exa

ne

o-X

yle

ne

1-B

ute

ne

He

pta

ne

Iso

pre

ne

Pro

pyn

e

Tra

ns-

2-b

ute

ne

Cis

-2-b

ute

ne

1,3

-Bu

tad

ien

e

Tra

ns-

2-p

en

ten

e

Cis

-2-p

en

ten

e

pa

rtic

ipa

nt r

esu

lts/ r

efe

ren

ce X

0.01

0.1

1

10

me

dia

n m

ixin

g r

ati

o, p

pb

70 % of data fulfil GAW - Quality Objectives

VOC - Trends at Hohenpeissenberg

10

100

1000

10000

1998 1999 2000 2001 2002 2003 2004 2005

Mix

ing

Ra

tio,

pp

tv X

Ethane

-1% /year

Acetylene

-2% /year

Ethene

0% /year

Benzene

-1% /year

Toluene

-5% /year

p,m-Xylene

-7% /year

Biogenic VOC at Hohenpeißenbergmonthly means of noon-time concentrations (preliminary data)

0.1

1

10

100

1000

7/2002 1/2003 7/2003 1/2004 7/2004 1/2005 7/2005

Mix

ing

rat

io,

pp

tv

isoprene a-pinene camphene sabinene

myrcene b-pinene 3-carene limonene

g-terpinene terpinolene b-phellandrene

Summer ratio day/night: t [OH] = 1-4 1010 s molec/cm³c(day) = c(night) exp(-k[OH]t)

1

10

100

1000

7/2002 1/2003 7/2003 1/2004 7/2004 12/2004 7/2005

mix

ing

rat

io,

pp

tv

benzene-day toluene-day p,m-xyl-day 1,2,4-triM-B-day

benzene-night toluene-night p,m-xyl-night 1,2,4-triM-B-night

Annual cycles of noon- and midnight monthly mean concentrations

arom atics

N O

N O 2

C O

C H 4+H 2

M AC R +M V K+

isoprenea-pineneb-pinenelim onene

a lkanesethene

other a lkenespropene

other te rpenes

sab inene*g-terp inene

isoprene

a-pineneb-pinene

lim oneneg-terp inene

N ON O 2

C O

C H 4+H 2

sab inene*

arom atics

M AC R +M V K+

other a lkenespropene

ethene

a lkanes

other te rpenes

Turn over-rates due to reactions with OH radicals

Jun-Aug Dec-Feb,10 106 molecules/(cm³s) 3.5 106 molecules/(cm³s)

(2004 data at noon time and measured OH)

• trends and distribution HC, OVOC‘s• oxidizing capacity VOC turn-over, radical precursors• aerosol formation and growth semi-volatile prod.• oxidant formation VOC turn-over• source attribution tracer, signature

Isoprene, monoterpenes, light alkenes, formaldehydesemi-volatile products of monoterpenes and aromaticsvarious C2-C10 hydrocarbons, OVOC‘s and halogenated VOC

Research Topics at Hohenpeißenberg with respect to VOC

•scientific user: analyse spatial distributions and

temporal evolution, sources and sinks

Future Requirements (presented at GAW workshop Tutzing 2004)

•SAG: establish DQO‘s, QA/QC procedures, Pilot

stations, SOP‘s, error assessment

•QA/SAC: support SAG, WCC, and stations;

motivate and coordinate

•WCC: continue audits+intercomp., provide

standards, SOP‘s, error assessment, data evaluation

•Stations: report VOC+errors to WDCGG/EMEP

•all: workshops/conferences to communicate

1

10

100

1000

10000

7/2002 1/2003 7/2003 1/2004 7/2004 1/2005 7/2005

mix

ing

rat

io,

pp

tv

acetone-day MVK-day MACR-day MEK-day

acetone-night MVK-night MACR-night MEK-night

Annual Cycles of OVOC‘s at Hohenpeissenberg

GC-2: sample in ozone trap He carrier gas

adsorption trap TenaxTA/Carboxen (303 K / 473 K)

He carrier gas

vent sample cryo focusvolume silcosteel line (87 K / 453 K)

ventGC column FID

BPX-550 m x 0.22 mm MS

GC-2Varian 3400CX MS/FID

C5-C14 HydrocarbonsHalocarbonsOxygenated VOC

GC-1: sample in ozone trap He carrier gas

cold trap dryer (233 K)

cryo trapglass beads (85 K / 473 K)

vent sample GC columnvolume Al2O3/KCl FID

50m x 0.53 mm

GC-1Varian 3600CX, FID

C2-C8 Hydrocarbons

Glass-Sampling Line

VOC patterns of boundary-layer and free troposphere air

1 10 100 1000

Ethan

Propan

i-Butan

n-Butan

i-Pentan

n-Pentan

2-M-Pentan

n-Hexan

n-Heptan

Ethen

Propen

1,3-Butadien

Isopren

Acetylen

Propin

Benzol

Toluol

Ethylbenzol

p,m-Xylol

o-Xylol

Mixing ratios, pptv

Boundary-layer

Free troposphere

Photochemical age:

about 8 days

Box:

OH O3

VOC-emissions = const.

Atmosphere

T-Winter MR-Winter

=1/(K[OH]+k[O3])

T-Summer MR-Summer=

Annual Cycle: Winter-Summer Ratios of selected VOC

OH O3Nov-Feb 0.2E6 cm-³ 32 ppbJun-Aug 1.7E6 cm-³ 51 ppb

1

10

Eth

an

Pro

pa

n

i-Bu

tan

n-B

uta

n

i-Pe

nta

n

n-P

en

tan

Eth

en

Pro

pe

n

t-2

-Bu

ten

1-B

ute

n

1,3

-Bu

tad

ien

Ace

tyle

n

Pro

pin

Be

nzo

l

To

luo

l

p,m

-Xyl

ol

Rat

ios

Win

ter/

Sum

me

r X

Measurement

Lifetime

Despite of chemical impacts, sources and meteorology are important

Propen gegen 1-Buten

y = 4.5899xR2 = 0.5729

1

10

100

1000

1 10 100 1000

Ethen gegen Acetylen

y = 1.0686xR2 = 0.8298

10

100

1000

10000

10 100 1000 10000

Benzol gegen Acetylen

y = 0.3042xR2 = 0.9493

10

100

1000

10 100 1000 10000

p,m-Xylol gegen o-Xylol

y = 2.071xR2 = 0.8979

1

10

100

1000

1 10 100 1000

Mixing Ratios 1998vs. reactivity with OH

1

10

100

1000

10000

1E-13 1E-12 1E-11 1E-10

k(OH), cm³/(s molecule)

me

an

mix

ing

ra

tio 1

99

8,

pp

tv X

Alkanes

Alkenes

Alkynes

Aromatics

0

200

400

600

800

1000

-10 -5 0 5 10 15 20 25 30

Temperature, °C

Mix

ing

Ra

tio,

pp

tv

Sum of Terpenes Isoprene

---> Emission driven by temperature (meteorology)

---> Ozone-smog

---> climate !

---> Particle-formation

Biogenic Emissions - mixing ratios versus temperature

-10%

-5%

0%

5%

1E-13 1E-12 1E-11 1E-10

k(OH), cm³/(s molecule)

linea

r T

rend

, %

/yea

r x

Alkanes

Alkenes

Alkynes

Aromatics

Do we see changes in the composition of anthropogenic VOC?Trends are still uncertain due to the short observation periode!

1.0E-13 1.0E-12 1.0E-11 1.0E-10

Ethan

Propan

n-Butan

n-Pentan

n-Hexan

n-Heptan

i-Butan

i-Pentan

2,3-DiM-Butan

2-M-Pentan

3-M-Pentan

3-M-Hexan

2,3-DiM-Pentan

Ethen

Propen

1-Buten

i-Buten

t-2-Buten

c-2-Buten

t-2-Penten

c-2-Penten

?-2-M-Buten-2

1,3-Butadien

Isopren

Acetylen

Benzol

Toluol

Ethylbenzol

p, m-Xylol

o-Xylol

reaction rate constant with OH, cm^3/molec/s

1 ppb 100 ppt 10 ppt 1 pptmixing ratio equivalent (1 ppb ethane)

40 days 4 days 10 h 1hlife time at OH=2.8 E6 cm^-3

10 000 km 1 000 km 100 km 10 kmdistance at 3 m/s wind speed

C2-C7 n-alkanes

C4-C7 i-alkanes

C2-C6 alkenes

C7-C8 aromatics

GAW• stage 1: C2-C9 hydrocarbons• stage 2: C10-C14 hydrocarbons• stage 3: oxygenated VOC

• establish 3 pilot stations

VOC Monitoring ProgramNMHC Measurements by GC/FID - canister / on-line

EMEP• level 2: C2-C7 hydrocarbons• level 2: C1-C6 carbonyls• level 3: C6-C12 hydrocarbons

• level 2 = approx 15 sites• level 3 = research stations

GAW/EMEP: 30 target compounds C2-C9

accuracy NMHC: 10 - 20 %

VOC Data Quality Objectives

accuracy NMHC 15-25%

GAW• Report 111, ...• Intercomp.+audits by WCC• training (GAWTEC)

VOC QA / QCEMEP• Manual (EMEP/CCC-1/95)• intercomp.+audits by NILU• data screening by NILU and local laboratories

no calibration gas standardsno QA / QC protocolSOP‘s ?

Yearly „Trend“ of anthropogenic VOC: Measurements and Estimates

(National Emission-Inventory Germany - 2002, UBA, 31/07/03)

DWD Hohenpeißen-

bergUBA/EMEP

Waldhof

estimated emissions

(UBA )

estimated emissions

(UBA )

1998-2003 1992-2002 1990-2001 2000-2001

Measurements -4% -5%

Transport Emissions -12% 0%

total (without solvents) -10% 0%

Plass-Dülmer und Berresheim, Meteorologisches Observatorium Hohenpeißenberg

10

100

1000

10000

Ethan

Propa

n

i-Buta

n

n-But

an

i-Pent

an

n-Pen

tan

n-Hex

an

n-Hep

tan

n-Okt

anEth

en

Prope

n

t-2-B

uten

1-But

en

i-Bute

n

c-2-

Buten

t-2-P

ente

n

2-M

-But

en-2

2-M

-But

en-1

c-2-

Pente

n

Benzo

l

Toluol

Ethylb

enzo

l

m,p

-Xylo

l

o-Xylo

l

mix

ing

ratio

s, p

ptvjf

measured profiletraffic-emissions

Annual winter (Nov-Feb) median concentrations of hydrocarbons at Waldhof (DE), Kosetice (CZ) and Donon (FR), red letters are results by NILU analysis, blue by national lab.

Reference:VOC Measurements 2002

Sverre Solberg, NILU, Kjeller, Norway

EMEP / CCC-Report 8/2004Reference O-92016

Mixing ratios 1998 versus reactivity towards OH

1

10

100

1000

10000

1E-13 1E-12 1E-11 1E-10

k(OH), cm³/(s Molekül)

mitt

lere

Mis

chun

gsve

rhäl

tnis

se 1

998,

X

pptv

Alkane

Alkene

Alkine

Aromaten

QC - Recent International Intercomparison Experiments

NOMHICE - NonMethane Hydrocarbon InterComparison ExperimentTasks 1 - 5 (Apel et al., JGR, 1994, 1999, 2003)

AMOHA - Accurate Measurements of Hydrocarbons in the AtmosphereTasks 1 - 3 (Slemr et al., 2002)Task 4 (Plass-Dülmer et al., in preparation)

First GAW - WCC - VOC - Intercomparison 2003B. Rappenglück et al.

NOMHICE: analytical preformance of participating labsAMOHA: analytical preformance + canisters + sampling procedureGAW-WCC: analytical preformance + on-line / canister

First GAW - VOC Intercomparison 2003Task-1: Synthetic Mixture (73 components, 0.2-10 ppb)

Task-2: ambient air - parallel sampling participant / WCC

Task-1• 62 % within Data Quality Objectives (30 Target Compounds)

See poster by Rappenglück et al.

VOC Monitoring in Europe - EMEP network (since 1992)

Mace Head, since 2001 ?

Pallas, since 1992

Hohenpeissenberg, since 1998

Izana, no VOC

GAW Global Stations

Birkenes

Zeppelin

VOC Distribution (median) in Winter-Months 2002 (EMEP VOC Report, 2004)

Lifetime: ca. 60 days

EMEP Trend Results

no clear trends in Northern Europe (Finnish sites)

decreasing concentrations in Central Europe(20-50% / 1992-2000)

and a levelling off after 2000

Caution: Trends are uncertain

Summary

• GAW and EMEP: similar objectives, VOC compounds, and QA /QC

•Results of European monitoring: - higher concentrations in Central and Eastern Europe - trends of anthr. VOC in Central Europe by 0-10% / year

•VOC intercomparisons: - Data Quality Objectives are met by 2/3 of results - data quality varies substantially from lab to lab - problem: error assessment (DQO)•European VOC monitoring is mainly provided by EMEP