theefﬁciencyofsecondaryorganicaerosolparticlesactingasice ... · res. then a transfer is...

Supplement of Atmos. Chem. Phys., 18, 9393–9409, 2018https://doi.org/10.5194/acp-18-9393-2018-supplement© Author(s) 2018. This work is distributed underthe Creative Commons Attribution 4.0 License.

Supplement of

The efficiency of secondary organic aerosol particles acting as ice-nucleatingparticles under mixed-phase cloud conditionsWiebke Frey et al.

Correspondence to: Wiebke Frey ([email protected])

The copyright of individual parts of the supplement might differ from the CC BY 4.0 License.

1 Clean bag transfer

For a clean bag transfer, both chambers are cleaned according to the respective cleaning procedu-res. Then a transfer is performed by refilling MICC from the MAC bag. Aerosol numbers largerthan the numbers in the chambers before transfer are thus a result of introduction from leakagesin the system. These background aerosol need to be taken into account for any experiment per-formed on specified aerosol photochemically produced in the aerosol chamber. That means, incase of ice formation in very low numbers, nucleation of ice on these contaminant aerosol cannotbe ruled out.Aerosol concentrations in the aerosol and cloud chamber were both below 1 cm−3 prior to transfer.After the transfer 10.1 cm−3 aerosol particles were observed by the CPC in the cloud chamber.

acq

uis

itio

n f

au

lt

1000

900

800

700

p [hP

a]

250200150100500

time since expansion start [s]

252

250

248

246

244

T [K

]

50

40

30

20

10

0

N [cm

-3]

0.12

0.10

0.08

0.06

0.04

0.02

0.00

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [

µm

]

1

10

100

dN

/dlo

gD

p [c

m-3]

N TWC

a)

b)

c) p T

MVD

Figure S.1: First cloud activation run after the clean bag transfer (experiment 1, see Table 1 inmain manuscript). The panels show the time series of FSSP measurements of size distribution andmean volume diameter (MVD, panel a), total water content (TWC) and number concentration(N, panel b), and temperature and pressure (panel c) during evacuation.

1

1000

900

800

700

p [hP

a]

250200150100500


252

250

248

246

244

T [K

]

20

15

10

5

0

N [cm

-3]

0.08

0.06

0.04

0.02

0.00

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [

µm

]

1

10

100 dN

/dlo

gD

p [c

m-3]

N TWC

a)

b)

c) p T

MVD

Figure S.2: Second cloud activation run after the clean bag transfer (experiment 1, see Table 1in main manuscript). Panels as in Fig. S.1.

1000

900

800

700

p [hP

a]

250200150100500


252

250

248

246

244

T [K

]

20

15

10

5

0

N [cm

-3]

0.06

0.05

0.04

0.03

0.02

0.01

0.00

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [

µm

]

1

10

100

dN

/dlo

gD

p [c

m-3]

N TWC

p T

MVD

a)

b)

c)

Figure S.3: Third cloud activation run after the clean bag transfer (experiment 1, see Table 1 inmain manuscript). Panels as in Fig. S.1.

2

2 SOA background

Two types of SOA backgrounds were transferred, with varying levels of UV radiation. Thatmeans, all chemical substances as in a normal SOA experiment were used, without the actualprecursor. In the first background experiment filters were installed in front of the lamps re-sponsible for photochemical reactions to only allow tropospheric UV radiation to illuminate thechamber, whereas in the second background experiment, the filters were removed, allowing hardUV light into the chamber. This second background was used before SOA experiments with hep-tadecane and TMB precursors, as aerosol is harder to form from these precursors and strong UVlight fosters the SOA generation. Also ozone is added in the second SOA background experiment,thus, it can also be seen as a harsh cleaning experiment at the same time.

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

244

T [K

]

25

20

15

10

5

0

N [

cm

-3]

0.20

0.15

0.10

0.05

0.00

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [

µm

]

2

4

6

100

2

4

6

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

dN

/dlo

gD

p [c

m-3]

after transfer S1 before evacuation S2 before evacuation average SD

NSMPS = 20.7cm-3

SSMPS = 3.54�105nm cm

-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.4: First cloud activation run during first SOA background measurements (experiment3, see Table 1 in main manuscript). The uppermost panel shows the SMPS size distributionsobtained before the cloud expansion (panel a), followed by time series of FSSP measurements ofsize distribution and mean volume diameter (MVD, panel b), total water content (TWC) andnumber concentration (N, panel c), and temperature and pressure (panel d) during evacuation.

3

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

T [K

]

20

15

10

5

0

N [

cm

-3]

0.16

0.12

0.08

0.04

0.00

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [

µm

]

10

100

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

dN

/dlo

gD

p [c

m-3]


NSMPS = 25.4cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.5: As above for the second cloud activation run in the first SOA background experiment(experiment 3, see Table 1 in main manuscript).

4

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

T [K

]

1200

1000

800

600

400

200

0

N [cm

-3]

0.4

0.3

0.2

0.1

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

1000

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 948cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.6: First cloud activation run on ’harsh UV’ SOA background (experiment 5, see Table1 in main manuscript), panels as in Fig. S.4.

5

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

T [K

]

1000

800

600

400

200

0

N [cm

-3]

0.4

0.3

0.2

0.1

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

1000

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 831cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.7: Second cloud activation run on ’harsh UV’ SOA background (experiment 5, see Table1 in main manuscript), panels as in Fig. S.4.

6

3 SOA experiments

In the following all cloud activation runs performed during the measurement period are shown,except those already shown in the main manuscript.

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

T [K

]

101

102

103

104

105

N [cm

-3]

0.001

0.01

0.1

1

10

100

TW

C [g

m-3]

40

30

20

10Dp o

r M

VD

[µ

m]

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

101

10

3 10

5

dN

/dlo

gD

p [c

m-3]


NSMPS = 8316cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.8: First cloud activation run performed on SOA from α-pinene precursor (experiment4, see Table 1 in main manuscript), panels as in Fig. S.4.

7

1000

900

800

700

p [

hP

a]

5004003002001000


256

254

252

250

248

T [K

]

100

101

102

103

104

N [cm

-3]

10-5

10-4

10-3

10-2

10-1

100

TW

C [g

m-3]

40

30

20

10Dp o

r M

VD

[µ

m]

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

100

101

102

103

104

dN

/dlo

gD

p [c

m-3]


NSMPS = 8090cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.9: Second cloud activation run performed on SOA from α-pinene precursor (experiment4, see Table 1 in main manuscript), panels as in Fig. S.4.

8

1000

900

800

700

p [

hP

a]

5004003002001000


256

254

252

250

248

T [K

]

1000

800

600

400

200

0

N [cm

-3]

0.25

0.20

0.15

0.10

0.05

0.00

TW

C [g

m-3]

40

30

20

10Dp o

r M

VD

[µ

m]

101

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 2052cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.10: First cloud activation run performed on SOA from heptadecane precursor (experi-ment 6, see Table 1 in main manuscript), panels as in Fig. S.4.

9

1000

900

800

700

p [

hP

a]

5004003002001000


253

252

251

250

249

248

247

T [K

]

1000

800

600

400

200

0

N [cm

-3]

0.25

0.20

0.15

0.10

0.05

0.00

TW

C [g

m-3]

40

30

20

10Dp o

r M

VD

[µ

m]

101

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 1852cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.11: Second cloud activation run performed on SOA from heptadecane precursor (expe-riment 6, see Table 1 in main manuscript), panels as in Fig. S.4.

10

1000

900

800

700

p [

hP

a]

5004003002001000


258

256

254

252

250

248

T [K

]

2000

1500

1000

500

0

N [cm

-3]

0.5

0.4

0.3

0.2

0.1

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

101

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 1621cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.12: First cloud activation run performed on SOA from TMB precursor (experiment 7,see Table 1 in main manuscript), panels as in Fig. S.4.

11

1000

900

800

700

p [

hP

a]

5004003002001000


256

254

252

250

248

T [K

]

1200

800

400

0

N [cm

-3]

0.30

0.25

0.20

0.15

0.10

0.05

0.00

TW

C [g

m-3]

40

30

20

10Dp o

r M

VD

[µ

m]

100

101

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 1419cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.13: Second cloud activation run performed on SOA from TMB precursor (experiment7, see Table 1 in main manuscript), panels as in Fig. S.4.

12

1000

900

800

700

p [

hP

a]

5004003002001000


254

252

250

248

T [K

]

4000

3000

2000

1000

0

N [cm

-3]

1.0

0.8

0.6

0.4

0.2

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

10-1

101

103

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

100

101

102

103

104

dN

/dlo

gD

p [c

m-3]


NSMPS = 2766cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.14: First cloud activation run performed on α-pinene aerosol precursor (experiment 8,see Table 1 in main manuscript), panels as in Fig. S.4.The second cloud activation run from this experiment is shown in main manuscript.

13

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

244

T [K

]

1600

1200

800

400

0

N [cm

-3]

0.5

0.4

0.3

0.2

0.1

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

102

103

104

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 2635cm-3


-3

N TWC

p T

MVD

a)

b)

c)

d)

Figure S.15: First cloud activation run performed on SOA from heptadecane precursor (experi-ment 10, see Table 1 in main manuscript), panels as in Fig. S.4.The second cloud activation run from this experiment is shown in main manuscript.

14

4 Control experiments with ammonium sulfate

1000

900

800

700

p [hP

a]

300250200150100500


254

252

250

248

246

244

T [K

]

10x103

8

6

4

2

0

N [

cm

-3]

3.0

2.0

1.0

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [

µm

]100

1000

dN

/dlo

gD

p [cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

100

101

102

103

104

dN

/dlo

gD

p [c

m-3]

SMPS data faulty

N TWC

a)

b)

c)

d) p T

MVD

Figure S.16: First cloud activation run performed on ammonium sulfate aerosol (experiment 2,see Table 1 in main text), panels as in Fig. S.4.

15

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

244

T [K

]

6000

4000

2000

0

N [cm

-3]

2.0

1.5

1.0

0.5

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

1000

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

100

101

102

103

104

dN

/dlo

gD

p [c

m-3]

S1 before evacuation S2 before evacuation average SD

NSMPS = 2257cm-3


-3

N TWC

a)

b)

c)

d)

MVD

p T

Figure S.17: Second cloud activation run performed on ammonium sulfate aerosol (experiment2, see Table 1 in main text), panels as in Fig. S.4.

16

1000

900

800

700

p [

hP

a]

300250200150100500


254

252

250

248

246

244

T [K

]

8000

6000

4000

2000

0

N [cm

-3]

3.0

2.5

2.0

1.5

1.0

0.5

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

1000

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

100

101

102

103

104

dN

/dlo

gD

p [c

m-3]


NSMPS = 1957cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.18: Third cloud activation run performed on ammonium sulfate aerosol (experiment 2,see Table 1 in main text), panels as in Fig. S.4.

17

1000

900

800

700

p [

hP

a]

4003002001000


254

252

250

248

246

T [K

]

2000

1500

1000

500

0

N [cm

-3]

0.5

0.4

0.3

0.2

0.1

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

1000

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 1799cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.19: First cloud activation run performed on ammonium sulfate aerosol (experiment 9,see Table 1 in main text), panels as in Fig. S.4.

18

1000

900

800

700

p [

hP

a]

4003002001000


1500

1000

500

0

N [cm

-3]

0.4

0.3

0.2

0.1

0.0

TW

C [g

m-3]

40

30

20

10Dp

or

MV

D [µ

m]

100

2

4

1000

2

4

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

252

250

248

246

T [K

]

1

10

100

1000

dN

/dlo

gD

p [c

m-3]


NSMPS = 1681cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.20: Second cloud activation run performed on ammonium sulfate aerosol (experiment9, see Table 1 in main text), panels as in Fig. S.4.

19

5 Sensitivity experiment with kaolinite

1000

900

800

700

p [

hP

a]

5004003002001000


254

252

250

248

246

T [K

]

250

200

150

100

50

0

N [cm

-3]

0.12

0.08

0.04

0.00

TW

C [g

m-3]

40

30

20

10Dp o

r M

VD

[µ

m]

10

100

1000

dN

/dlo

gD

p [

cm

-3]

102 3 4 5 6 7 8 9

1002 3 4 5 6 7 8 9

Dp [nm]

1

10

100

1000

dN

/dlo

gD

p [c

m-3]

after first run S1 before evacuation average SD

NSMPS = 366cm-3


-3

N TWC

a)

b)

c)

d) p T

MVD

Figure S.21: Second cloud activation run performed on dust (experiment 11, see Table 1 in mainmanuscript), panels as in Fig. S.4.The first cloud activation run from this experiment is shown in main manuscript.

20

Table 1: Mean mode diameters (MMD) of the aerosol size distributions before the cloud activationruns.

system run # MMD [nm]Exp 2 ammonium sulfate 1 data faulty

2 49.73 50.4

Exp 3 SOA background 1 37.52 38.8

Exp 4 α-pinene 1 244.42 250.4

Exp 5 SOA background 1 92.52 92.5

Exp 6 heptadecane 1 455.92 455.9

Exp 7 TMB 1 187.82 201.7

Exp 8 α-pinene 1 204.22 209.2

Exp 9 ammonium sulfate 1 33.72 39.5

Exp 10 heptadecane 1 376.32 371.8

Exp 11 dust (kaolinite) 1 16.72 14.1

21

theefﬁciencyofsecondaryorganicaerosolparticlesactingasice ... · res. then a transfer is...

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