VOC MEASUREMENTS AT HOHENPEISSENBERG AS PART OF
THE GAW PROGRAM
Christian Plass-Dülmer and Harald Berresheim
Meteorologisches Observatorium Hohenpeißenberg, DWD, Germany
Meteorologisches
Observatorium
Hohenpeißenberg
VOC Monitoring - Objectives
GAW
expert 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
EMEP
Strategic Plan 2004
• European distribution
and trends
• Compliance monitoring
(compliance with protocols)
• understand physical and
chemical processes
• Support for EMEP model
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.
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.
GAW-Program VOC:
MOHp
•Stage 1: C2-C9 hydrocarbons HC
•Stage 2: C10-C14 HC (biogenic)
•Stage 3: oxygenated VOC (OVOC)
•GC-FID
•GC-MS/FID
•GC-PDHID/FID
Measurements at
1:00 and 13:00 CET
ca. 80 VOC
Detection limits: 1 ppt ... 10 ppt
Accuracy: C2-C9 HC 5-25%, Terpenes 20-40%
QA and QC Procedures
VOC Intercomparisons: NOMHICE, AMOHA, and GAW
0.01
Cis-2-pentene
Trans-2-pentene
1,3-Butadiene
Cis-2-butene
Trans-2-butene
Propyne
Isoprene
Heptane
1-Butene
o-Xylene
Cyclohexane
Hexane
Ethylbenzene
2-Methylpentane
2-Methylpropene
p,m-Xylene
2+3-Methylpentane
Pentane
Propene
2-Methylpropane
Benzene
2-Methylbutane
Toluene
Butane
Ethyne
Ethene
Propane
Ethane
median mixing ratio, ppbv X
AMOHA - Task 4.2 - canister sampling at Hohenpeißenberg 04/2000
10
1
0.1
0.1
Cis-2-pentene
Trans-2-pentene
1,3-Butadiene
Cis-2-butene
Trans-2-butene
Propyne
Isoprene
Heptane
1-Butene
o-Xylene
Cyclohexane
Hexane
Ethylbenzene
2-Methylpentane
2-Methylpropene
p,m-Xylene
2+3-Methylpentane
Pentane
Propene
2-Methylpropane
Benzene
2-Methylbutane
Toluene
Butane
Ethyne
Ethene
Propane
Ethane
participant results/ reference X
100
10
1
1
0.1
0.01
median mixing ratio, ppb
AMOHA - Task 4.2 - canister sampling at Hohenpeißenberg 04/2000
10
70 % of data fulfil GAW - Quality Objectives
VOC - Trends at Hohenpeissenberg
Mixing Ratio, pptv X
10000
Ethane
-1% /year
Acetylene
-2% /year
Ethene
0% /year
1000
Benzene
-1% /year
Toluene
-5% /year
p,m-Xylene
-7% /year
100
10
1998
1999
2000
2001
2002
2003
2004
2005
Biogenic VOC at Hohenpeißenberg
monthly means of noon-time concentrations (preliminary data)
isoprene
a-pinene
camphene
sabinene
myrcene
g-terpinene
b-pinene
terpinolene
3-carene
b-phellandrene
limonene
Mixing ratio, pptv
1000
100
10
1
0.1
7/2002 1/2003 7/2003
1/2004
7/2004
1/2005
7/2005
Annual cycles of noon- and midnight monthly mean concentrations
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
mixing ratio, pptv
1000
100
10
1
7/2002 1/2003 7/2003 1/2004 7/2004 12/2004 7/2005
Summer ratio day/night: Dt [OH] = 1-4 1010 s molec/cm³
c(day) = c(night) exp(-k[OH]Dt)
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)
propene
other alkenes
ethene
aromatics
alkanes
CH4+H2
CH4+H2
MACR+MVK+
isoprene
a-pinene
b-pinene
CO
alkanesethene
propene
other alkenes
aromatics
CO
NO
limonene
g-terpinene
sabinene*
NO2
NO
other terpenes
NO2
MACR+MVK+
isoprene
a-pinene
b-pinene
limonene
sabinene*
g-terpinene
other
terpenes
Research Topics at Hohenpeißenberg with respect to VOC
• trends and distribution
• oxidizing capacity
• aerosol formation and growth
• oxidant formation
• source attribution
HC, OVOC‘s
VOC turn-over, radical precursors
semi-volatile prod.
VOC turn-over
tracer, signature
Isoprene, monoterpenes, light alkenes, formaldehyde
semi-volatile products of monoterpenes and aromatics
various C2-C10 hydrocarbons, OVOC‘s and halogenated VOC
Future Requirements
(presented at GAW workshop Tutzing 2004)
•Stations: report VOC+errors to WDCGG/EMEP
•SAG: establish DQO‘s, QA/QC procedures, Pilot
stations, SOP‘s, error assessment
•WCC: continue audits+intercomp., provide
standards, SOP‘s, error assessment, data evaluation
•QA/SAC: support SAG, WCC, and stations;
motivate and coordinate
•scientific user: analyse spatial distributions and
temporal evolution, sources and sinks
•all: workshops/conferences to communicate
Annual Cycles of OVOC‘s at Hohenpeissenberg
acetone-day
MVK-day
MACR-day
MEK-day
acetone-night
MVK-night
MACR-night
MEK-night
mixing ratio, pptv
10000
1000
100
10
1
7/2002 1/2003 7/2003 1/2004 7/2004 1/2005 7/2005
GC-2
Varian 3400CX MS/FID
C5-C14 Hydrocarbons
Halocarbons
Oxygenated VOC
GC-2:
sample in
ozone trap
He carrier gas
adsorption trap
TenaxTA/Carboxen (303 K / 473 K)
He carrier gas
vent
sample
volume
cryo focus
silcosteel line (87 K / 453 K)
vent
GC column
BPX-5
50 m x 0.22 mm
FID
MS
GC-1
Varian 3600CX, FID
C2-C8 Hydrocarbons
GC-1:
sample in
ozone trap
He carrier gas
cold trap dryer (233 K)
cryo trap
glass beads (85 K / 473 K)
vent
sample
volume
GC column
Al2O3/KCl
50m x 0.53 mm
FID
Glass-Sampling Line
VOC patterns of boundary-layer and free troposphere air
Ethan
Propan
i-Butan
n-Butan
i-Pentan
n-Pentan
Photochemical age:
2-M-Pentan
n-Hexan
n-Heptan
Ethen
about 8 days
Propen
1,3-Butadien
Isopren
Acetylen
Propin
Benzol
Toluol
Ethylbenzol
Boundary-layer
p,m-Xylol
Free troposphere
o-Xylol
1
10
100
Mixing ratios, pptv
1000
T-Winter = MR-Winter
T-Summer
MR-Summer
p,m-Xylol
Toluol
Benzol
Propin
Acetylen
1-Buten
t-2-Buten
Ethen
Propen
VOC-emissions = const.
n-Pentan
1
1,3-Butadien
Lifetime
Ethan
T=1/(K[OH]+k[O3])
Measurement
i-Pentan
O3
n-Butan
OH
i-Butan
Atmosphere
10
Propan
Box:
Ratios Winter/Summer X
Annual Cycle: Winter-Summer Ratios of selected VOC
OH impacts,
O3 sources
Despite of chemical
-³ 32 ppb
0.2E6are
cmimportant
andNov-Feb
meteorology
Jun-Aug 1.7E6 cm ³ 51 ppb
Ethen gegen Acetylen
Propen gegen 1-Buten
10000
1000
1000
100
y = 1.0686x
R2 = 0.8298
100
y = 4.5899x
R2 = 0.5729
10
10
1
10
100
1000
10000
1
Benzol gegen Acetylen
10
100
1000
p,m-Xylol gegen o-Xylol
1000
1000
100
y = 0.3042x
R2 = 0.9493
100
y = 2.071x
R2 = 0.8979
10
1
10
10
100
1000
10000
1
10
100
1000
mean mixing ratio 1998, pptv
X
Mixing Ratios 1998
vs. reactivity with OH
10000
1000
100
Alkanes
10
Alkenes
Alkynes
Aromatics
1
1E-13
1E-12
1E-11
k(OH), cm³/(s molecule)
1E-10
Biogenic Emissions - mixing ratios versus temperature
1000
Sum of Terpenes
Isoprene
800
Mixing Ratio, pptv
---> Emission driven by temperature (meteorology)
---> Ozone-smog
600
---> Particle-formation
---> climate !
400
200
0
-10
-5
0
5
10
15
Temperature, °C
20
25
30
Do we see changes in the composition of anthropogenic VOC?
Trends are still uncertain due to the short observation periode!
linear Trend, %/year x
5%
0%
-5%
-10%
1E-13
Alkanes
Alkenes
Alkynes
Aromatics
1E-12
1E-11
k(OH), cm³/(s molecule)
1E-10
reaction rate constant with OH, cm^3/molec/s
1.0E-13
1.0E-12
1.0E-11
1.0E-10
Ethan
Propan
n-Butan
C2-C7 n-alkanes
n-Pentan
n-Hexan
n-Heptan
i-Butan
i-Pentan
2,3-DiM-Butan
C4-C7 i-alkanes
2-M-Pentan
3-M-Pentan
3-M-Hexan
2,3-DiM-Pentan
Ethen
Propen
1-Buten
i-Buten
C2-C6 alkenes
t-2-Buten
c-2-Buten
t-2-Penten
c-2-Penten
?-2-M-Buten-2
1,3-Butadien
1 ppb
100 ppt
10 ppt
mixing ratio equivalent (1 ppb ethane)
1 ppt
Isopren
40 days
Acetylen
Benzol
Toluol
4 days
10 h
life time at OH=2.8 E6 cm^-3
1h
C7-C8 aromatics
Ethylbenzol
p, m-Xylol
10
000 km
o-Xylol
1 000 km
100 km
distance at 3 m/s wind speed
10 km
VOC Monitoring Program
NMHC Measurements by GC/FID - canister / on-line
GAW
• stage 1: C2-C9 hydrocarbons
• stage 2: C10-C14 hydrocarbons
• stage 3: oxygenated VOC
EMEP
• level 2: C2-C7 hydrocarbons
• level 2: C1-C6 carbonyls
• level 3: C6-C12 hydrocarbons
• establish 3 pilot stations
• level 2 = approx 15 sites
• level 3 = research stations
GAW/EMEP: 30 target compounds C2-C9
VOC QA / QC
GAW
• Report 111, ...
• Intercomp.+audits by WCC
• training (GAWTEC)
EMEP
• Manual (EMEP/CCC-1/95)
• intercomp.+audits by NILU
• data screening by NILU and
local laboratories
VOC Data Quality Objectives
accuracy NMHC: 10 - 20 %
accuracy NMHC 15-25%
no calibration gas standards
no QA / QC protocol
SOP‘s ?
Yearly „Trend“ of anthropogenic VOC: Measurements and Estimates
UBA/EMEP
Waldhof
estimated
emissions
(UBA )
estimated
emissions
(UBA )
1998-2003
1992-2002
1990-2001
2000-2001
-4%
-5%
Transport Emissions
-12%
0%
total (without solvents)
-10%
0%
Measurements
DWD
Hohenpeißenberg
(National Emission-Inventory Germany - 2002, UBA, 31/07/03)
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mixing ratios, pptvjf
Plass-Dülmer und Berresheim, Meteorologisches Observatorium Hohenpeißenberg
10000
measured profile
traffic-emissions
1000
100
10
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 8/2004
Reference O-92016
mittlere Mischungsverhältnisse 1998, X
pptv
Mixing ratios 1998 versus reactivity towards OH
10000
1000
100
Alkane
10
Alkene
Alkine
Aromaten
1
1E-13
1E-12
1E-11
k(OH), cm³/(s Molekül)
1E-10
QC - Recent International Intercomparison Experiments
NOMHICE: analytical preformance of participating labs
AMOHA: analytical preformance + canisters + sampling procedure
GAW-WCC: analytical preformance + on-line / canister
NOMHICE - NonMethane Hydrocarbon InterComparison Experiment
Tasks 1 - 5 (Apel et al., JGR, 1994, 1999, 2003)
AMOHA - Accurate Measurements of Hydrocarbons in the Atmosphere
Tasks 1 - 3 (Slemr et al., 2002)
Task 4 (Plass-Dülmer et al., in preparation)
First GAW - WCC - VOC - Intercomparison 2003
B. Rappenglück et al.
First GAW - VOC Intercomparison 2003
Task-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)
GAW Global Stations
Zeppelin
Pallas, since 1992
Birkenes
Mace Head,
since 2001 ?
Izana, no VOC
Hohenpeissenberg,
since 1998
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
•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
•Results of European monitoring:
- higher concentrations in Central and Eastern Europe
- trends of anthr. VOC in Central Europe by 0-10% / year