1. Understanding Observed Stratocumulus Variability and Implications for Aerosol Indirect Effects
Nathan Johnson

2. Outline Effects of aerosols on Climate
Susceptibility
Observations of Microphysical Quantities
MArine Stratocumulus Experiment
Principle Components Analysis

3. Introduction Indirect Effects of Aerosols on Climate
Twomey / Albrecht / Dispersion

4. Observational effect of N on k
k increases with increasing N
Pruppacher and Klett (1997)
Miles et al. (2000) ???
Yum and Hudson (1997)
Lu and Seinfeld (2006) (Modeling)
Feingold et al. (1997) (Modeling)
Lu et al. (2007)
k decreases with increasing N
Martin et al. (1994)
Ackerman et al. (2000)
McFarquhar and Heymsfield (2001) ???
Liu and Daum (2000, 2002)
Peng and Lohmann (2003) (Sensitivity)

5. MASE N L k

6. Data Description

7. Principle Components Analysis
% Variance Explained by Mode:
CDNC
LWC k

8. Principle Components Analysis: N0

9. EOF: N0

10. Principle Components Analysis: N

11. EOF: N

12. Principle Components Analysis: NR2

13. EOF: NR2

14. North Test
Weight
Color N0
Black N
Red
NR2
Green

15. Summary
Weighting of the data can influence the result obtained from PCA
Scattering - QNR2
Uncertain which method will yield most interesting results
Important implications for aerosol indirect effects