interconfronto europeo particolato atmosferico
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Interconfronto europeo per modelli a recettore: risultati preliminari
QUINTO CONVEGNONAZIONALESUL PARTICOLATOATMOSFERICO (Perugia 16-18 May 2012)
F. KARAGULIAN, C.A. Belis, F. Amato, D.C.S. Beddows, V. Bernardoni, S. Carbone, D. Cesari, E. Cuccia, D. Contini, O. Favez, I. El Haddad, R.M. Harrison, T. Kammermeier, M.Karl, F. Lucarelli, S.Nava, J. K. Nøjgaard, M. Pandolfi, M.G. Perrone, J.E. Petit, A. Pietrodangelo, P. Prati, A.S.H. Prevot, U. Quass, X. Querol, D. Saraga, J. Sciare, A. Sfetsos, G. Valli, R. Vecchi, M. Vestenius, J.J. Schauer, J.R. Turner, P. Paatero, P.K. Hopke
Joint Research Centre – IES - ACU
Real world data base (DB) choice
Merged two DBs with inorganic and organic data with different time resolution (every day vs. every 6th day)
DB contained 178 samples spanning two years Missing values and values BDL were already treated in the inorganic DB, but not in the organic DB. Some data treatment was asked to the participants
•ILLINOIS•MISSOURI
Site Location: St. Louis Supersite (USA)
ORGANIZATION COUNTRY IDAEA CSIC SPAIN
Univ. Aahrus DENMARK
University of Genoa ITALY
Finnish Meteorological Institute FINLAND
INERIS/LSCE FRANCE
University of Birmingham UNITED KINGDOM
Norwegian Institute for Air Research (NILU) NORWAY
Department of Physics University of Florence
ITALY
University of Milan Bicocca ITALY
C.N.R. Institute for Atmospheric Pollution Research
ITALY
IUTA e.V. GERMANY
NCSR Demokritos, Environmental Research Laboratory
GREECE
Dept. of Physics - University of Milan ITALY
Paul Scherrer Institut Laboratory of Atmospheric Chemistry
SWITZERLAND
C.N.R - I.S.A.C. ITALY
JOINT RESEARCH CENTRE UE
Intercomparison participants
16 PARTICIPANTS
MODEL SOLUTIONSPMF3-EPA 8PMF-2 6CMB 4APCS 1COPREM 1ME-2 1PCA 1TOTAL 22
Lee, J. H., P. K. Hopke, and J. R. Turner (2006), Source identification of airborne PM2.5 at the St. Louis-Midwest Supersite,J. Geophys. Res., 111, D10S10,
Jaeckels JM, Bae M.S., Schauer JJ (2007) Positive matrix factorization Analysis of molecular markers measurements to quantify the sources of organic aerosols. EST. 41-5763
INORGANIC DBFrom June 2001 – May 2003 24h samples collected every dayReference
ORGANIC DBFrom May 2001 – July 2003 24h samples collected every dayReference
indeno(cd)pyrenebenzo(ghi)perylene
benz(a)anthracene
benzo(a)pyrene
fluoranthene
pyrene
coronene
benzo(b,k)fluoranthene
benzo(e)pyrene
benzo(j)fluoranthene
dibenz[a,h]anthracene
levoglucosan
OCTOC1OC2OC3OC4OPECT
EC1mEC2EC3SO4NO3NH4
AlAsBaCaCoCrCuFeHgK
MnNiP
PbRbSeSiSrTiVZnZr
DB compostion: mass concentrations of speciesand uncertainties
Structure of errors:
inorganic ions: high uncertainty Co, Cr, Hg, Ni, Rb, Ti, Va, Zr have many missing values Ca, Fe, Zn, K uncertainties below 5% there were differen MDLs, probably due to different analytical batches PAHs presented many BDL values.
Purpose of the work
Participants performed receptor modeling using one or more model approach
Complete DB with uncertainties was provided to each participant - MDLs and analytical uncertainties were provided to allow estimation of uncertainties (upon participant’s choice) - Emission inventory and source profiles (SPECIATE) were provided for CMB’s users
According to participants’ results, 15 source types were identified and compared
Biomass burningGasolineDieselBrakesTrafficDust
SulphatesNitrates
Zn SmelterCu metallurgy
Pb smelterSteel processing
Industry & CombustionShip emissions
Secondary inorganic sources
• Preliminary Test: • evaluate if the factors within each source
category are homogeneous
• Proficiency test: • evaluate if the quantitative source contribution
estimations (SCE) fall within an established quality objective
Summary preliminary test
FACTORS Pearson raw data and log transformed
and weighted difference (WD)
FACTOR VS MEASURED SOURCESPearson raw data and log transformed
and weighted difference (WD)
CONTRIBUTIONS (TIME TRENDS)Pearson raw data
Test to identify the correspondence of participants factor profiles to each source category
If 4 out of 7 tests were nor meetthen
factor was considered dubious
Z’(SCE)
Participants’ performance
Model paerformance
New methodology to compare different chemical profiles
INTER-COMPARISON methodology I:
0.6
0.0
1.0
0.6
0.0
1.0
NOT OK OK
Rmax
INTER-COMPARISON methodology I:Weighted difference (WDij)
1. Weighted difference (WD) between two factors was calculated using the following equation:
where xi and xj are the relative concentrations of the n species in the profiles i and j, respectively, and si and sj are their uncertainties.
2. The range of acceptability for the weighted difference was set between0 and 2.
2.0
0.0
4.0
0.0 OK NOT OK
3.0
2.0
4.0
3.0
1.0 1.0
WDij
n
1a2ja
2ia
jaiaij
ss
xx1/nWD
Defining an assigned (reference) value X (source contribution estimation SCE) and its uncertainty uX as reference value to compare with participant’s run average xi.
Defining the standard deviation for proficiency assessment p as criterion to evaluate participants’ performance (ISO 13528) (p = 50%, total mass annual mean)
SCE of participant’s source profile are optimal if:
considered coherent and satisfactory if:
“OK”
2z1
3z2 results are considered questionable if: “Warning”
results are unsatisfactory if: 3z “Action”
Proficiency test (ISO 13528)
2p2X
i'
Xσu
Xx(SCE)z
“acceptable”
1z ‘‘
‘
‘
‘
EPA PMF-3.0 PMF-2 PCA ME-2 COPREM CMB APCS
8 6 1 1 1 4 1
PMF-3 = EPA PMF 3.0No tri-linear PMF model!!!!
Preliminary screening
number of factors
number of participants
6 47 28 49 4
10 211 312 213 1
average number of solution ranged from 7 and 11
Modeled PM2.5 mass vs measured PM2.5 mass
0.8 < R2 < 1
R2 < 0.7
0.7 < R2 < 0.8
Low intercept and slope close to 1
high intercept and low slope
High intercept and high slope
PM total mass = 18000 ng/m3
Sources categories identified by the majority of the participants:
1. Biomass Burning (22), 2. Dust - Re-Suspended Soil (21),
3. Traffic (16),4. Industry & Combustion (16)
5. Cu metallurgy (14) 6. Zn-smelter (11),
7.Sulphates (10)8. Nitrates, Diesel (9)9. Pb-smelter, Steel, Secondary (8)10. Gasoline, Brakes, ships (<=6)
Source Categories
PARTICIPANTS’ Z’(SCE)all factors grouped by category
action
acceptable
warning
OK
MODEL Z’(SCE)all factors grouped by category
action
acceptable
warning
OK6
6
64
54
7
7
12
PARTICIPANTS’ Z’(SCE)factors grouped by category:
Excluded no-matching factors
action
acceptable
warning
OK
Excluded no-matching factors
PARTICIPANTS’ Z’(SCE)factors grouped by category
action
acceptable
warning
OK
6 6
68
57 87
13
1) The methodology used for the evaluation of the IE appears effective to test the comparability between factors in terms of both chemical composition and time trend.
2) The weighted difference is useful to provide an independent estimation of the comparability between factors and makes it possible to check if the uncertainties have been correctly estimated.
3) There is a reasonable quantitative agreement between SCE. 90% of the factors meet the acceptability criteria (OK or acceptable).
4) The participant bias in the SCEs appears to be consistent with the 50% maximum uncertainty acceptability criterion used in this evaluation.
Conclusion I
6) Many of the factors are comparable with those reported by Lee & Hopke in the original publication of results using only inorganic species.
7) There is a considerable variability in the number of factors identified by participants.
8) Some models were used by only one or two participants, therefore it is not possible to draw conclusions about the performace of these models.
9) The noise of the experimental data, the variety of methodological approaches and the little knowledge about the sampling site shall be taken into account when interpreting the intercomparison outcome.
Conclusion II
