Results of the Ambient Air Experiments during the EUSAAR 2009 Absorption Photometer Workshop (Aethalometer)

Transcription

1 Results of the Ambient Air Experiments during the EUSAAR 2009 Absorption Photometer Workshop (Aethalometer) Agnes Filep, Aki Virkkula, Alessandro Dell Acqua, Alfred Wiedensohler, Angela Marinoni, Bas Henzing, Grisa Mocnik, Gerrit Leeuw, Kostas Eleftheriadis, Linda Rondo, Paulo Fialho and Thomas Müller

2 Objectives Develop methodologies to compensate for apparent absorption caused by scattering due to the use of filter matrix support. Development of an improved compensation technique for the AE s attenuation coefficient, s ANT-comp. Correlation of the s ANT-comp, with MAAP s absorption coefficient measurements, s abs, to evaluate the AE s C and R corrections for the sampled aerosol.

3 Instrumentation Setup The instruments used in all the experiments sampled simultaneously from a common chamber with continuously refreshed dried ambient air. Four High Sensitivity (HS) Aethalometers (AE) (370, 470, 520, 590, 660, 880, 950 nm) Four Extended Range (ER) Aethalometers (AE) (370, 470, 520, 590, 660, 880, 950 nm) Three Multi Angle Absorption Photometers (MAAP) (635 nm) One Particle Soot Absorption Photometer (PSAP) (565 nm) One Particle Soot Absorption Photometer (PSAP) (467, 530, 660 nm) One Multi Wavelength Photoacoustic system (MuWaPas) (266, 355, 532, 1064 nm) One Echotec Aurora Nephelometer (450, 520, 700 nm) Two TSI3563 Nephelometer (450, 550, 700 nm)

4 Instrumental Working Equations AE MAAP PSAP MuWaPas Nephelometer s s abs s s abs s sct m g m Mm C ng. m BC CBC ng. m 6.5 m / g Mm Mm Mm Mm nm

5 Experiment (Different Spot Time Loading) (08:20 03-July to 07:35 06-July-2009) The Aethalometers were divided in three different groups sampling with a time difference of 3 hours but with the same flow rate. AE-31 4 dm 3 /min HS#160; ER#408 HS#679; ER#427 HS#268; ER#945 MAAP dm 3 /min #080; #012; #140 PSAP DLR (3) 0.79 dm 3 /min Vespien (1) 0.84 dm 3 /min

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7 Virkkula et al., (2007),J. Air & Waste Manage. Assoc., 57, k s correct 1 s

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9 s s s s s s s Comp Comp Comp Comp Comp Comp Comp s Comp 1 k s,ref. AE a AE# 1 k,ae# s,ae# 0,ER#945 a0er#945 1 k,er#945s,er#945,er#945 a0hs#160 1 k,hs#160s,hs#160,er#945 a0hs#268 1 k,hs#268s,hs#268,er#945 a0hs#679 1 k,hs#679s,hs#679,er#945 a0er#408 1 k,er#408s,er#408,er#945 a ER#427 1 k,er#427s,er#427 0 ER#945 was choose as the reference Aethalometer a 0 (ER#945) = 1 N = Standard Error = 1.5 Mm -1 (nm) k() AE# a 0 (AE#) ER# HS# HS# HS# ER# ER#

10 a 0 (AE#) k k where k nm r (m)

11 s Comp s s s s s s k s,ref. AE a AE#,AE# 1 k s 1 s Comp 0 Comp Comp Comp Comp Comp Comp,ER#945 a ER#945, ER#945 a HS#160,ER#945 a HS#268, ER#945 a HS#679,ER#945 a ER#408,ER#945 a ER# ,ER#945 1 k,hs#160 1 k,hs#268 1 k,hs#679 1 k,er#408 1 k,er#427 1 k s s s s s s,er#945,hs#160,hs#268,hs#679,er#408, ER#427,AE# k = 1.51±0.15 nm N = Standard Error = 1.5 Mm -1 AE# a 0 (AE#) ±0.004 ER# HS# HS# HS# ER# ER#

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18 Correlating MAAP with AE MAAP #140 data was selected as the reference Data in Standard Pressure ( mbar) and Temperature ( K) MAAP #080 is too noisy MAAP #012 is slightly different from the other two and have less data then MAAP #140. AE31 ER#945 data is used as the reference data was convert to 635 nm by using the relation, were, a = 1.11±0.15 s -comp s scaled to Standard Pressure and Temperature by using the ambient aerosol temperature and pressure taken from the Nephelometer inlet sensors. comp a

19 sabs

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21 s -comabs MAAP s AE31 s -comp AE31 R R s C abs MAAP

22 sabs

23 Summary Information s comp s 1 k k nm s absae s comp C Aethalometer C HS# ±0.019 HS# ±0.021 HS# ±0.023 HS# ±0.021 ER# ±0.026 ER# ±0.024 ER# ±0.026 Average 4.41±0.38 (9%)

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30 Involved Institutions Aerosol d.o.o., Kamniska 41, SI-1000, Ljubljana, Slovenia Department of Optics and Quantum Electronics, University of Szeged, H-6701 Szeged, Hungary Environmental Radioactivity Laboratory, Institute of Nuclear Technology - Radiation Protection N.C.S.R. "Demokritos", Ag. Paraskevi Attiki, Greece Finnish Meteorological Institute, Climate Change Unit, Helsinki, Finland ISAC - CNR, Via Gobetti 101, Bologna, Italy JRC, Ispra site, via E. Fermi, 1, I Ispra, Italy Leibniz Institute for Tropospheric Research, Leipzig, Germany Netherlands Organisation for Applied Scientific Research, TNO, Utrecht, The Netherlands University of Azores, P Terra Cha, Portugal University of Helsinki, Dept of Physics, Helsinki, Finland Acknowledges EC project EUSAAR; Azores Regional Secretariat for Science and Technology (M3.2.1/I/082/2010) for the Portuguese participation Eurostars (E!4825) for the Slovene participation.