a european aerosol phenomenology: total carbon, elemental carbon and absorption coefficient
DESCRIPTION
A EUROPEAN AEROSOL PHENOMENOLOGY: TOTAL CARBON, ELEMENTAL CARBON AND ABSORPTION COEFFICIENT Fabrizia Cavalli European Commission – DG Joint Research Centre M. Zanatta Laboratory of Glaciology and Geophysics of Environment, St Martin d'Hères Cedex - PowerPoint PPT PresentationTRANSCRIPT
A EUROPEAN AEROSOL PHENOMENOLOGY: TOTAL CARBON, ELEMENTAL CARBON
AND ABSORPTION COEFFICIENT
Fabrizia CavalliEuropean Commission – DG Joint Research Centre
M. ZanattaLaboratory of Glaciology and Geophysics of Environment, St Martin d'Hères Cedex
Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, Villigen
The ACTRIS COMMUNITY
▪ TOTAL CARBON, ELEMENTAL CARBON, PM MASS, ABSORPTION COEFFICIENT AND THEIR RATIOS, in PM2.5 and in PM10
▪ 10 EUROPEAN REGIONAL BACKGROUND SUPER-SITES
▪ 4 YEARS of data: 2008 – 2011 (different data coverage across the network)
FINOKALIA
BIRKENES
VAVIHILL
ASPVRETEN
HARWELL MELPITZKOSETICE
PUY de DÔMEISPRA
MONTSENY
NORDIC
CONTINENTAL
HIGH ALTITUDE
MEDITERRANEAN
CONTENT of the STUDY:
COMMON STANDARDISED METHODOLOGY plus COMPARABILITY INFORMATION on:
• SAMPLING of CARBONACEOUS AEROSOLS on filters
• MEASUREMENT of:
TOTAL CARBON and ELEMENTAL CARBON CONCENTRATION
ABSORPTION COEFFICIENT
RESEARCH&DEVELOPMENT and INTEGRATION ACTIVITIES for ATMOSPHERIC MEASUREMENTS
within EUSAAR and ACTRIS EU-INTEGRATED INFRASTRUCTURES INITIATIVES (2006 – on going)
UNIQUE STUDY:
HIGHLY HARMONISED DATASET AT ALL SITES
A- DEVELOPMENT of a STANDARD method and ADOPTION
EUSAAR - ARTIFACT-FREE SAMPLING TRAIN Denuder efficiency from 40%-90% at different sites
1.1- DATA HARMONISATION: SAMPLING of CARBONACEOUS AEROSOLS
B- TESTS to assess SAMPLING ARTIFACT across the network, in winter and summer
Sampler 1TDQ
Sampler 2TQ
Sampler 3Q
Teflon filters
Quartz fiber filters
Front quartz filter
Denuder
Sampling Head
Carb
on h
oney
com
b m
onol
iths
Back-up filters
- HARMONISATION CORRECTIONS for POSITIVE ARTIFACT:
• Maximum average correction -30% for TC • no information for 3 sites
- NEGATIVE ARTIFACT NOT EXACERBATED BY DENUDER: <5%
A- DEVELOPMENT of a STANDARD method and ADOPTION
EUSAAR_2 protocol (CAVALLI et al., AMT 2010) for thermal-optical analysis
1.2- DATA HARMONISATION: ANALYSIS OF TOTAL, ORGANIC and ELEMENTAL CARBON
B- EXERCISES to assess INTER-LABORATORY COMPARABILITY within the NETWORK
Five inter-laboratory comparisons
- laboratory systematic BIASES and HARMONISATION FACTORS:
• max average deviation for EC/TC of 20% among sites using EUSAAR_2
• TC and EC with protocols other than EUSAAR_2 at two sites: max average deviation on EC/TC of a factor 2.3
1 2a 2b 3 6 7 8 12 13 16 17 25 26A
10A
18 E1 E2 E3
-4
-3
-2
-1
0
1
2
3
4
SPA-1 SPA-2HUN-1HUN-2ITA-1ITA-2
Laboratory
z-sc
ores
1.3- DATA HARMONISATION: MEASUREMENT of ABSORPTION COEFFICIENT
FILTER-BASED INSTRUMENTS :
• MAAP: MULTI ANGLE ABSORPTION PHOTOMETER (4)• PSAP: PARTICLE SOOT ABSORPTION PHOTOMETER (2)• AE: AETHALOMETER (2)
A- ADOPTION of STANDARDISED DATA CORRECTION PROCEDURES:
• MAAP: SHIFT OF THE OPERATIVE WAVELENGTH (MÜLLER et al., 2011) • PSAP: CORRECTION FOR RESPONSE TO ABSORPTION AND SCATTERING (BOND et al., 1999; OGREN, 2010)• AE: CORRECTION FOR MULTIPLE SCATTERING AND SHADOWING EFFECTS (WEINGARTNER et al., 2003)
- ADJUSTED OF ABSORPTION COEFFICIENT TO A COMMON WAVELENGTH 637 nm with constant Absorption Ångstrom Exponent of 1
B- WORKSHOPS to assess the INTER-INSTRUMENT COMPARABILITY within the NETWORK
- laboratory systematic BIASES and HARMONISATION FACTORS:
HFMAAP= 1 HFPSAP= 0.96-1.03 HFAE= 1.6
see Poster: Absorbing properties of BC over Europe, M. Zanatta
BIR MSY MLP OBK ISP0
2
4
6
8
10
12PM2.5
BIRASP
VHLHW
LPdD
MSYMLP ISP
FNK0
2
4
6
8
10
12PM10
BIR ASP VHL HWL MSY MLP ISP FNK0
5
10
15
20
25
30PM10
HARMONISED ANNUAL AVERAGE of PM MASS, TOTAL CARBON and ELEMENTAL CARBON
SIGNIFICANT POSITIVE GRADIENT from N to S6 μgm-3 (BIR) - 30 μgm-3 (ISP)
MAS
S μg
m-3
ELEM
ENTA
L C
AR
BO
NTO
TAL
CA
RB
ON
μg
m-3
BIR MSY MLP OBK ISP0
10
20
30
40
50
60PM2.5
• PM10 TOTAL CARBON and ELEMENTAL CARBON: SIGNIFICANT POSITIVE GRADIENT from N to S
TC: 1 μgm-3 (BIR) - 10 μgm-3 (ISP) EC: 0.1 μgm-3 (BIR) - 2 μgm-3 (ISP)
2.1 a,b RESULTS:
PdD high altitude site – special case!
NORTHWEST SOUTH
• PM10 Mass:
HARMONISED ANNUAL AVERAGE of ABSORPTION COEFFICIENT2.1 c RESULTS:
ABSO
RPTI
ON
CO
EFFI
CIEN
TM
m-1
• SIGNIFICANT POSITIVE GRADIENT from N to S: 0.8 Mm-1 (BIR) - 11 Mm-1 (ISP)
BIR VHL HWL PdD MSY MLP ISP FKL0
2
4
6
8
10
12PM10
2.2a RESULTS:
HARMONISED ANNUAL AVERAGE of TOTAL CARBON / MASS RATIO
LEAST CARBONACEOUS AEROSOL AT THE MEDITERRANEAN SITES, i.e. FINOKALIA and MONTSENY: 0.11 - 0.14
MOST CARBONACEOUS AEROSOL IN ISPRA: 0.30 - 0.40
FOR THE MAJORITY OF THE SITES, FAIRLY HOMOGENEOUS TOTAL CARBON / MASS RATIO: 0.16 - 0.24
BIR MSY MLP OBK ISP0.0
0.1
0.2
0.3
0.4
0.5PM2.5
BIR ASP VHL HWL MSY MLP ISP FNK0.0
0.1
0.2
0.3
0.4
0.5
0.6PM10
TOTA
L CA
RBO
N /
MAS
S
2.2b RESULTS:
HARMONISED ANNUAL AVERAGE of ELEMENTAL CARBON / TOTAL CARBON RATIO
FAIRLY HOMOGENEOUS (PUY DE DÔME EXCEPTED) ELEMENTAL CARBON / TOTAL CARBON RATIO: 0.12-0.23
ELEMENTAL CARBON / TOTAL CARBON RATIO DEPENDS ON THE PROXIMITY OF EMISSION SOURCES
BIR MSY MLP OBK ISP0.00
0.05
0.10
0.15
0.20
0.25
0.30PM2.5
BIR ASP VHLHWLPdD MSY MLP ISP FNK0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35PM10
ELEM
ENTA
L CA
RBO
N
/ TO
TAL
CARB
ON
2.2c RESULTS:
HARMONISED ANNUAL AVERAGE of ABSORPTION COEFFICIENT / ELEMENTAL CARBON, I.E. MASS ABSORPTION CROSS SECTION m2 g-1
MAC
m2 g
-1
BIR VHL HWL PdD MSY MLP ISP FKL0
2
4
6
8
10
12
14
16
18PM10
• HOMOGENEITY IN THE MAC VALUES: 6. 6 m2 g-1 (VHL) — 16.1 m2 g-1 (PdD) (PdD AND VHL HAVE A POORER DATA COVERAGE WITH LESS THAN 150 DATA POINTS)
• “EUROPEAN REGIONAL BACKGROUND” MAC = 10.8 ± 3.00
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50BIRASPVHLHWLMSYMLPISPFNK
HARMONISED SEASONAL AVERAGES of TOTAL CARBON / MASS RATIO
WIN
TER
SPRI
NG
SUM
MER
FALL
WIN
TER
SPRI
NG
SUM
MER
FALL
PM2.5 PM10
TOTA
L CA
RBO
N /
MAS
S
SEASON-SPECIFIC SOURCES OF CARBONACEOUS AEROSOL RESULT IN:
• MOST CARBONACEOUS AEROSOL IN WINTER-FALL DUE TO DOMESTIC HEATING (MORE EVIDENT AT CENTRAL SITES)
• BIOGENIC AEROSOL PEAKS IN SUMMER
• LEAST CARBONACEOUS AEROSOL IN SPRING AT ALL SITES BUT FINOKALIA
• INVERSE CYCLE AT FINOKALIA DUE TO AGRICULTURAL WASTE BURNING AND FOREST FIRES IN SPRING AND SUMMER
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
BIRMSYMLPISPOBK
2.3a RESULTS:
HARMONISED SEASONAL AVERAGES of ELEMENTAL CARBON / TOTAL CARBON RATIO
ELE
MEN
TAL
CARB
ON
/ TO
TAL
CARB
ON
WIN
TER
SPRI
NG
SUM
MER
FALL
WIN
TER
SPRI
NG
SUM
MER
FALL
PM2.5 PM10
ELEMENTAL CARBON / TOTAL CARBON RATIO SEASONAL CYCLE:
MAXIMUM IN FALL-WINTER (TRAFFIC + DOMESTIC HEATING) AND MINIMUM IN SUMMER (TRAFFIC + BIOGENIC SOURCES)
REMARKS:
- LESS PRONOUNCED CYCLE AT CONTINENTAL SITES DUE TO WEAKER BIOGENIC SOURCES
- AT FINOKALIA: MAXIMA IN SPRING-SUMMER DUE TO FIRES
- AT PUY DE DÔME: CYCLE DETERMINED MAINLY BY THE BOUNDARY LAYER DYNAMIC
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
BIRMSYMLPISPOBK
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30 BIRASPVHLHWLPdDMSYMLPISPFNK
2.3b RESULTS:
HARMONISED SEASONAL AVERAGES of ABSORPTION COEFFICIENT / ELEMENTAL CARBON, I.E. MASS ABSORPTION CROSS SECTION
WIN
TER
SPRI
NG
SUM
MER
FALL
MAC
m2 g
-1
MAC SEASONAL CYCLE:
- MAXIMUM IN SUMMER AT THE MAJORITY OF SITES
- IN CORRESPONDENCE TO THE MINIMUM OF THE EC/TC RATIO (I.E. MAXIMUM ABUNDANCE OF ORGANIC CARBON)
- THIS WOULD INDICATE AN AMPLIFICATION OF EC ABSORPTIVITY BY THE THICKER ORGANIC CARBON COATING
2.3c RESULTS:
0
2
4
6
8
10
12
14
16
18
20
BIR
HWL
PdD
MSY
MLP
ISP
FNK
3. CONCLUSIONSMETHODOLOGICAL
- IMPORTANCE OF COMMON STANDARDISED PROCEDURES FROM SAMPLING TO DATA SUBMISSION- THIS IS A MORE EFFICIENT AND ACCURATE APPROACH THAN APPLYING a-posteriori CORRECTION
FACTORS- PERIODICAL CHECKS OF COMPARABILITY
HIGHLY INTEGRATED NETWORK AND A BIAS-FREE DATASET ALLOW UNDERSTANDING SOURCES AND TRANSFORMATION OF AEROSOLS
PHENOMENOLOGICAL
ON A EUROPEAN REGIONAL BACKGROUND SCALE:
- CLEAR POSITIVE SPATIAL GRADIENT – FROM N TO S – FOR ALL EXTENSIVE AEROSOL PROPERTIES: PM MASS, TOTAL CARBON & ELEMENTAL CARBON AND ABSORPTION COEFFICIENT
- HOMOGENEITY FOR ALL INTENSIVE AEROSOL PROPERTIES: TOTAL CARBON / MASS, ELEMENTAL CARBON / TOTAL CARBON AND MAC - SEASONALITY OF INTENSIVE AEROSOL PROPERTIES AND SOURCES:
- TOTAL CARBON / MASS: MAXIMA IN FALL-WINTER (DOMESTIC HEATING) AND IN SUMMER (BIOGENIC AEROSOL)
- ELEMENTAL CARBON / TOTAL CARBON: MAXIMUM IN FALL-WINTER AND MINIMUM IN SUMMER- ABSORPTION COEFFICIENT / ELEMENTAL CARBON: MINIMUM IN FALL-WINTER AND MAXIMUM IN SUMMER