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Understanding Observed Stratocumulus Variability and Implications for Aerosol Indirect Effects. Nathan Johnson. Outline. Effects of aerosols on Climate Susceptibility Observations of Microphysical Quantities MArine Stratocumulus Experiment Principle Components Analysis. Introduction.
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Understanding Observed Stratocumulus Variability and Implications for Aerosol Indirect Effects Nathan Johnson
Outline • Effects of aerosols on Climate • Susceptibility • Observations of Microphysical Quantities • MArine Stratocumulus Experiment • Principle Components Analysis
Introduction • Indirect Effects of Aerosols on Climate • Twomey / Albrecht / Dispersion
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)
N L k MASE
Principle Components Analysis % Variance Explained by Mode: 1 2 3 CDNC 0.746 0.226 0.028 LWC 0.879 0.001 0.120 k 0.767 0.191 0.042
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