1. Ship-Based Measurement of the Aerosol below the Southeastern Pacific Stratocumulus Deck
Jason Tomlinson, Run Jun Li, and Don Collins
24th Annual AAAR Conference
October 20, 2005
Texas A&M University
Acknowledgements: NOAA Atmospheric Climate and Chemistry Program, ETL, WHOI, and the crew of the R/V Revelle and Brown.

2. Motivation One of the most persistent stratocumulus cloud deck.
A profound cooling effect on the global climate.
Few in-situ measurements have been made. The most recent measurements were during Epic 2001 using a condensation nuclei counter.
The goal of the project was to study the interplay between aerosols and the stratocumulus cloud deck. 1
1. Klein and Hartmann, 1993
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

3. Cruise Overview November 2003 December 2004 78 Measurement Sequences
13 Volatility measurements
Brazil
Peru
Bolivia
Chile
Argentina
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

4. Measurement Sequence DMA Scan DMA FLOW Introduction Summary
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

5. Measurement Sequence TDMA Scan DMA FLOW Introduction Summary 85 % RH
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

6. Measurement Sequence Dry Volatility Scan DMA FLOW Introduction Summary
20 % RH
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

7. 2003 Number Distributions Trough Location 0.085 ± 0.014 mm
Number Concentration
395 ± 142 cm-3
Number Concentration
(> 2s discarded)
380 ± 113 cm-3
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

8. 2003 Growth Factors 0.013 mm 0.025 mm 0.050 mm 0.100 mm 0.200 mm
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

9. 2003 Growth Factors 0.013 mm 0.025 mm 0.050 mm 0.100 mm 0.200 mm
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

10. 2003 Growth Factors
0.2 mm
1.43 ± 0.07
0.05 mm
1.40 ± 0.07
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

11. 2004 Number Distributions Trough Location 0.091 ± 0.008 mm
Number Concentration
362 ± 210 cm-3
Number Concentration
(> 2s discarded)
331 ± 124 cm-3
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

12. 2004 Growth Factors
0.2 mm
1.49 ± 0.11
0.05 mm
1.43 ± 0.08
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

13. 2004 Volatility Measurements
0.050 mm
0.200 mm
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

14. 2004 Volatility Measurements
0.050 mm
Ammonium
Bisulfate
Sulfuric Acid
0.200 mm
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

15. 2004 Volatility Measurements
0.050 mm
0.200 mm
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

16. 2004 Volatility Measurements
Sulfuric Acid &
Ammonium Bisulfate Core
Ammonium Bisulfate Core
50 0C
150 0C ?
250 0C
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

17. 2004 Volatility Measurements (0.050 mm)
1.00 ± 0.02
0.86 ± 0.07
0.49 ± 0.11
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

18. 2004 Volatility Measurements (0.200 mm)
1.00 ± 0.01
0.62 ± 0.08
0.09 ± 0.01
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

19. 2004 NH4/S04 0.66 ± 0.15 0.22 ± 0.10 Introduction Summary 1. 2. 3.
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

20. CCN Concentration CCN Concentration 158 cm-3 Introduction Summary
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

21. 2003 CCN Concentration 184 ± 83 cm-3 Unperturbed: 162 ± 87 cm-3
Brazil
Unperturbed: 162 ± 87 cm-3
Peru
Bolivia
Chile
Argentina
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

22. 2004 CCN Concentration 179 ± 63 cm-3 Unperturbed: 170 ± 28 cm-3
Brazil
Unperturbed: 170 ± 28 cm-3
Peru
Bolivia
Chile
Argentina
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

23. Summary
A TDMA system was operated during November of 2003 and December of 2004 underneath the stratocumulus deck of the Southeastern Pacific.
In 2003, the average total number concentration was
395 ± 142 cm-3 while the unperturbed CCN concentration was 162 ± 87 cm-3.
In 2004, the average total number concentration was
362 ± 210 cm-3 while the unperturbed CCN concentration was 170 ± 28 cm-3.
The aerosol was composed of a mixture of sulfuric acid and ammonium bisulfate. The NH4/S04 ratio was calculated to be 0.66 ± 0.15 and 0.22 ± 0.10 for mm and mm particles, respectively.
Introduction
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Summary

24. 2003 Number to Volume Ratio Introduction Conclusion
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Conclusion

25. 2004 Number to Volume Ratio Introduction Conclusion
Distributions & Growth Factors
Volatility Measurements
CCN Concentration
Conclusion

26. 2003 Number Concentration
0.176 ± mm
0.050 ± mm

27. 2004 Number Concentration
0.214 ± mm
0.055 ± mm

28. 2003 Number Distribution

29. 2004 Number Distribution

30. 2003 & 2004 Number Concentration
2003
2004
2003 & 2004  
Average
Std Dev
Aitken
210.75
111.79
183.85
176.71
197.30
19.02
Accumulation
184.08
82.70
178.60
63.35
181.34
3.88
Total
394.83
142.07
362.45
210.00
378.64
22.90
2003
2004
2003 & 2004   
Average
Std Dev
Aitken
192.28
87.95
155.36
83.12
173.82
26.11
Accumulation
179.11
77.75
168.52
46.70
7.49
Total
379.97
112.99
331.37
124.02
355.67
34.37

31. 2003 Hygroscopic Growth Factor

32. 2004 Hygroscopic Growth Factor

33. Summary
A nucleation event was observed in 2003 and several mode mergers were observed between 2003 and 2004 as a result of anthropogenic emissions.
Average number concentration was ± for 2003 and 2004 add CCN.
Based on the change in particle diameter with increasing temperature, an NH4/S04 ratio for a mm and mm particle was calculated to be ± and ± 0.102
N/V relationship of N=162.52V was calculated for 2003 and for 2004 the relationship was N= x

34. Summary
A nucleation event was observed in 2003 and several mode mergers were observed between 2003 and 2004 as a result of anthropogenic emissions.
Average number concentration was ± for 2003 and 2004.
The aerosol is composed of a mixture of sulfuric acid and ammonium bisulfate. The NH4/S04 ratio was calculated to be ± and ± for a mm and mm particle, respectively.