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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