Monique Teich et al. Correspondence to: Hartmut Herrmann

Transcription

1 Supplement of Atmos. Chem. Phys., 7, 5 7, 7 doi:.59/acp supplement Author(s) 7. CC Attribution. License. Supplement of Contributions of nitrated aromatic compounds to the light absorption of water-soluble and particulate brown carbon in different atmospheric environments in Germany and China Monique Teich et al. Correspondence to: Hartmut Herrmann (herrmann@tropos.de) The copyright of individual parts of the supplement might differ from the CC-BY. licence.

2 S Correction procedure for Aethalometer data The Aethalometer data was corrected against MAAP data (Multi Angle Absorption Photometer) to account for multiple scattering effects on the filter matrix. The time resolution of MAAP and Aethalometer was set to s. First, the particulate light absorption coefficient b abs was calculated for the MAAP using the following equation:, =..5 (S) Where [BC MAAP] is the mass concentration of black carbon (BC) derived from the instrument,. m g - is the mass absorption cross-section (MAC) for ambient aerosol particles determined for the wavelength 7 nm. The factor.5 accounts for an adjustment to the correct instruments operating wavelength of 7 nm (Müller et al., ). Accordingly, the particulate light absorption coefficient was calculated for the Aethalometer:, = (S) Where [BC Aetha] is the mass concentration of BC derived from the instrument and C is a normalization factor. MAC values used for the Aethalometer are given in Table S. Since the MAAP operates at 7 nm b abs, Aetha was interpolated to 7 nm using Eq. (S). The AAE was calculated using the wavelength pair of 59 and nm according to the following equation: #$& ' ('),*+,. '!= ('),--, #$/ *+, --, Now b abs,7 can be calculated as follows: (S), =,5 / 5 7 When b abs,7, Aetha is plotted against b abs,maap the slope of the regression line corresponds to the correction factor C, that is.9 for the TROPOS (winter) campaign and. for the Waldstein (summer) campaign (see Fig. S and Fig. S). S Figures and Tables (S) Table S. Mass absorption cross sections (MAC) for ambient aerosol at a given wavelength λ used to calculate the particulate light absorption coefficient b abs from Aethalometer data (Drinovec et al., 5). λ [nm] MAC [m g - ]

3 Table S. Molar extinction coefficients determined under acidic and alkaline conditions (in M - cm - ). Compound ε 7 ph ε 7 ph NSA NSA 9 7 NP 5 MNP 77 MNP 5,DMNP 575 9,DNP 9 75,DNP 5 5 Table S. Chemical parameters for each campaign. The concentrations are given as: minimum-maximum (mean±standard deviation) Waldstein (summer) Melpitz (summer) TROPOS (winter) PM [µg m - ] (7.±.9) (.±.57) (.9±.) OC [µg m - ] (.±.95) (.±.5) (.±.) EC [µg m - ] (.±.7) (.5±.) (.5±.9) WSOC [µg m - ] (.5±.) (.9±.) (.9±.) Levoglucosan [µg m - ].5-. (.±.) Melpitz (winter).-7. (.±.5).97-. (.±.5).-. (.-.5).-7. (.5±.5) Xianghe (summer) (±59.7) (.9±5.9).-7. (.7±.).-. (5.±.).-. (.±.) Wangdu (summer).- (.±7.) (7.±.9).-9.7 (.55±.7).5-. (7.±.7).-. (.9±.) b abs, 7, Aetha [Mm - ] y =.9x +. R =.99 b abs, MAAP [Mm - ] Figure S. Correlation plot of the particulate light absorption coefficient derived from the Aethalometer at 7 nm (b abs,7,aetha) and the particulate light absorption coefficient derived from the MAAP at 7 nm (b abs,maap) at the TROPOS (winter) campaign.

4 b abs, 7, Aetha [Mm - ] y =.x +. R = b abs, MAAP [Mm - ] Figure S. Correlation plot of the particulate light absorption coefficient derived from the Aethalometer at 7 nm (b abs,7,aetha) and the particulate light absorption coefficient derived from the MAAP at 7 nm (b abs,maap) at the Waldstein (summer) campaign. Red data points are excluded from the regression fit.

5 ... NSA R =.9 Slope= NSA R =.97 Slope=... Abs 7B [Mm - ] Contribution to Abs 7B [%] NPh. MNP R =.97 Slope=..5 R =.9 Slope= MNP,DMNP. R =.9 Slope=.95 R =.99 Slope= ,DNP. R =.99 Slope=.7. Abs 7 R =.97 Slope=. 5 5 Abs 7A [Mm - ]......, DNP R =.99 Slope= Contribution to Abs 7A [%] MAE 7 R =.9 Slope= MAE 7A [m g - ] MAE 7B [m g - ] Figure S. (Top) Correlation plot of the contribution to the aqueous light absorption coefficient Abs 7 for each target compound under alkaline (indicated by the subscript A ) and acidic (indicated by the subscript B ) conditions. (Bottom) Correlation plot of the aqueous light absorption coefficient and mass absorption efficiency (MAE) under alkaline conditions with acidic conditions. All data points were measured at 7 nm.

6 MAE 7, BrC, particle [m g - ] TROPOS (winter) (a).5... Waldstein (summer) (d) WSOC / OC.5.5. (b) Jan 5 Jan Jan 7 Jan Jan 9 Jan Jan Jan Feb Feb Feb Feb 5 Feb Feb 7 Feb Feb Jul 7 Jul Jul 9 Jul Jul Jul Jul Jul Jul 5 Jul Jul (e) (*Abs 7A ) / b abs,, 7, BrC (c) (f) Figure S. Temporal variation of MAE 7, BrC, particle for particulate BrC, the WSOC/OC fraction and the fraction of aqueous extract light absorption to particulate BrC light absorption for the campaigns TROPOS (winter) (a-c) and Waldstein (summer) (d-f). For comparability of aqueous extract light absorption and the particulate BrC light absorption, Abs 7A (acidic conditions) was multiplied by a factor of, according to the method mentioned in the main text. MAE 7, BrC, particle was determined by normalizing b abs, 7, BrC by the according OC content of the sample.

7 NAC concentration [ng m - ] NAC concentration [ng m - ] (a) (c) Sum NAC R =.7 TROPOS (winter) Sum NAC R =. Wangdu (summer) BB episode Levoglucosan [ng m - ] (b) (d) Sum NAC R =.5 Sum NAC R =.55 Xianghe (summer) Wangdu (summer) Non-BB episode Levoglucosan [ng m - ] Figure S5. Correlation plot of nitrated aromatic compound (NAC) concentration with levoglucosan concentration for the campaigns (a) TROPOS (winter,), (b) Xianghe (summer), (c) Wangdu (summer, BB episode) and (d) Wangdu (summer, non-bb episode). Abs 7 is given for acidic conditions (indicated by the subscript A, black squares) and for alkaline conditions (indicated by the subscript B, red dots).

8 Contribution to Abs λ [%] Contribution to Abs λ [%] Contribution to Abs λ [%] (a) Melpitz (winter) Alkaline conditions. 5 (e). Xianghe (summer).5 (b) TROPOS (winter) 5 5 (c) (d).7. Melpitz (summer) Waldstein (summer) (f) Wangdu (summer) 5 NP MNP MNP,DMNP,DNP,DNP NSA 5NSA Figure S. Relative contribution of NACs to Abs λ over the spectral range of to 5 nm for each measurement campaign (a-f) under alkaline conditions. The data is presented as campaign averages. Due to instrumental issues, data for lower wavelengths is not always available.

9 Acidic conditions (a) (b) 9 Melpitz (winter) 9 TROPOS (winter) Abs λ [Mm - ] Abs λ [Mm - ] Abs λ [Mm - ] (c) (e) Melpitz (summer) (d). (f) Xianghe (summer) Waldstein (summer). 5 Wangdu (summer) 5 5 Figure S7. Abs λ over the spectral range of to 5 nm for each measurement campaign (a-f) under acidic conditions. The data is presented as campaign averages. Due to instrumental issues, data for lower wavelengths is not always available.

10 Alkaline conditions (a) (b) 5 Melpitz (winter) TROPOS (winter) Abs λ [Mm - ] 9 9 Abs λ [Mm - ] Abs λ [Mm - ] (c) (e) (d). Melpitz (summer).5 (f) Xianghe (summer) Waldstein (summer). 5 Wangdu (summer) 5 5 Figure S. Abs λ over the spectral range of to 5 nm for each measurement campaign (a-f) under alkaline conditions. The data is presented as campaign averages. Due to instrumental issues, data for lower wavelengths is not always available. References Drinovec, L., Mocnik, G., Zotter, P., Prevot, A.S.H., Ruckstuhl, C., Coz, E., Rupakheti, M., Sciare, J., Muller, T., Wiedensohler, A., Hansen, A.D.A., The "dual-spot" Aethalometer: an improved measurement of aerosol black carbon with real-time loading compensation, in: Atmos. Meas. Tech.,, , 5 Müller, T., Henzing, J.S., de Leeuw, G., Wiedensohler, A., Alastuey, A., Angelov, H., Bizjak, M., Coen, M.C., Engstrom, J.E., Gruening, C., Hillamo, R., Hoffer, A., Imre, K., Ivanow, P., Jennings, G., Sun, J.Y., Kalivitis, N., Karlsson, H., Komppula, M., Laj, P., Li, S.M., Lunder, C., Marinoni, A., dos Santos, S.M., Moerman, M., Nowak, A., Ogren, J.A., Petzold, A., Pichon, J.M., Rodriquez, S., Sharma, S., Sheridan, P.J., Teinila, K., Tuch, T., Viana, M., Virkkula, A., Weingartner, E., Wilhelm, R., Wang, Y.Q., Characterization and intercomparison of aerosol absorption photometers: result of two intercomparison workshops, in: Atmos. Meas. Tech.,, 5-,.