1. M=1.33 1.45 1.59 0.1 µm 0.2 0.3 0.4 White light

2. 0.5 µm 0.6 0.7 0.8 1.0 µm X=10 M=1.33 1.45 1.59

5. Deshler, T., Observations for Chemistry (In Situ): Particles, article for Encyclopedia of Atmospheric Science, Academic Press, 2002.

6. Wyoming Optical Particle Counter, r > 0.2 - 10.0  m White light Pump PMTs PHA  Processor Optical Chamber Aerosol in

7. Sources of Error Size Chromatic nature of light source Aerosol index of refraction and shape Uniformity of illumination PMT response – pulse width broadening Number concentration Flow rate Coincidence Poisson counting uncertainty Deshler, T., M. E. Hervig, D. J. Hofmann, J. M. Rosen, and J. B. Liley, Thirty years of in situ stratospheric aerosol size distribution measurements from Laramie, Wyoming (41  N), using balloon-borne instruments, J. Geophys. Res., 108(D5), 4167, doi:10.1029/2002JD002514, 2003

8. 1971 - 19901990 - present Post El Chichon

10. Low Gain Mid Gain High Gain

11. Eidhammer, T., D. C. Montague, and T. Deshler, Determination of Index of Refraction and Size of Supermicrometer Particles from Light Scattering Measurements at Two Angles, J. Geophys. Res., in press, May 2007.

12. SAGE II HALOE

13. Deshler et al., JGR, 2003

14. Comparison with SAGE II Extinction. Kovilakam and Deshler, 2014,

15. Comparison with HALOE Extinction. Kovilakam and Deshler, 2014,