1 at a polluted urban location supplementary information ... · 1 supplementary information of 2...

1 Supplementary Information of

2 Highly time resolved chemical characterization of submicron organic aerosols

3 at a polluted urban location

4 Authors: N.V.S Bharath Kumar 1, Abhishek Chakraborty 1, S.N.Tripathi1, 2* and Deepika

5 Bhattu1

6 Author affiliation: 1. Department of Civil Engineering Indian Institute of Technology, Kanpur

7 2. Centre of Environmental Science and Engineering, CESE, IIT Kanpur

8 *Corresponding author(s) E-mail: snt@iitk.ac.in9

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11 Figures: S1-S9

12 Page: S1-S8

13 Tables: S1

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Electronic Supplementary Material (ESI) for Environmental Science: Processes & Impacts.This journal is © The Royal Society of Chemistry 2016

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27 Fig. S1: AMS vs SMPS mass concentration plot to justify the choice of CE value of 0.5. SMPS 28 mass is obtained from volume concentration by assuming a density of 1.4 g/cc as reported in 29 previous studies 1,2 from this location.

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32 Fig. S2: f44 vs f60 plot to demonstrate the oxidation of biomass burning organic aerosol. Grey 33 dashed line denotes the background f60 value taken from Cubison et al., (2011)3.

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35 1. Organic PMF Diagnostics:

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2/12 2/15 2/18 2/21 2/24 2/27 3/2 3/5 3/8 3/11 3/14 3/17 3/20

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10

0

(

Res

id2 /

2 )/Q

exp Total Residual/Total Variance/Qexp

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Q/Q

expe

cted

87654321P

Q for fPeak 0 Current Solution min Q for p

5.3

5.2

5.1

5.0

Q/Q

expe

cted

-4 -2 0 2 4fPeak

Q for p 6 Current Solution min Q for fpeakOrSeed

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50 Fig.S3: Diagnostic information for the PMF analysis.

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No. of factors Remarks

<5 No HOA or SVOOA factor was identified, one HOA like factor with

hydrocarbon dominated mass spectra also has higher m/z 60 signals.

Several factors have identical mass spectra with very similar O/C

ratios. Some key m/z’s like, 43,44 and 60 have high residuals.

5 Still, no clear HOA and SVOOA factors were seen. One HOA looks

alike factor has high O/C ratio and m/z 44 signals. m/z 60 still have a

high residual in spite of 3 BBOA factors.

6 (Chosen solution) One clear HOA factor was identified along with one oxygenated POA

factor. Types of primary BBOA factors were now reduced to 2.

Significant reduction in residuals of key m/z’s was observed.

7 BBOA factors now started splitting but without any change in m/z’s

residuals or diurnal patterns

> 8 Now, OOA factors were also started splitting.

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58 Table S1: Rationale of choosing optimum PMF factors.

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60 Fig. S4: Comparison between inter/external tracers and the different OA factors.

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62 Figure S5 (a): Factor profiles of 5 factor PMF solution.

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64 Figure S5 (b): Factor profiles of 5 7 factor PMF solution.

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66 Fig. S6: Diurnal pattern for a) 5 factor and b) 7 factor PMF solution, c) residuals for 5,6 and 7 67 factor PMF solutions.

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71 Fig. S7: Relative contributions of different NR-PM1 aerosol species and various OAs in the 72 different air masses. C1..C6 are denoting back trajectory air masses cluster 1 to 6 (Fig. 5).

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75 Fig. S8: Van Krevelen diagram (H/C vs. O/C plot) showing the difference in the slopes of OA 76 evolution from HPE (High pollution events) and LPE (Low pollution events).

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78 Fig. S9: RH vs O/C correlation during DJ & FM nights.