M=1.33 1.45 1.5 0.1 µm 0.2 0.3 0.4 White light
M=1.33 1.45 1.59
0.1 µm
0.2
0.3
0.4
White light
0.5 µm
0.6
0.7
0.8
1.0 µm
X=10
M=1.33 1.45 1.59M=1.33 1.45 1.59
Deshler, T., Observations for Chemistry (In Situ): Particles, article for Encyclopedia of Atmospheric Science, Academic Press, 2002.
CR cl()d fl(,)d 2 2 i1(x, m,) i2 (x, m,) I() QE() d
0.3 m
0.7 m
fl2
fl2
cl2
cl2
Wyoming Optical Particle Counter, r > 0.2 - 10.0 m
Whitelight
PumpPMTs PHA
ProcessorOptical Chamber
Aerosolin
CR cl()d fl(,)d 2 2 i1(x, m,) i2 (x, m ,) I() QE() d
0.3 m
0.7 m
fl2
fl2
cl2
cl2
Sources of Error
Size Chromatic nature of light sourceAerosol index of refraction and shapeUniformity of illuminationPMT response – pulse width broadening
Number concentrationFlow rateCoincidencePoisson 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 (41N), using balloon-borne instruments, J. Geophys. Res., 108(D5), 4167, doi:10.1029/2002JD002514, 2003
1971 - 1990 1990 - present
PostEl Chichon
Low Gain
Mid Gain
High Gain
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.
SAGE II
HALOE
Deshler et al., JGR, 2003
0
2 ),,( drdr
dnmrQr
Comparison with SAGE II Extinction.
Kovilakam and Deshler, 2014,
0
2 ),,( drdr
dnmrQr
Comparison with HALOE Extinction.
Kovilakam and Deshler, 2014,
0
2 ),,( drdr
dnmrQr
0.1 1 10100
101
102
103
104
105
0.1 1 10100
101
102
103
104
105
EM OPC
UW OPC
b)C
ount
er R
espo
nse
Radius (µm)
Indices of refraction
1.350 1.400 1.450 1.500 1.592
23-123°, 405 nm
a) Index of refraction = 1.45
405 nm EM OPC 685 nm EM OPC White light UW OPC
Radius (µm)