146 Encyclopedia of the Solar System
FIGURE 8 Cloud profiles
obtained by the particle size
spectrometer onPioneer Venus
Large Probe.The three curves
indicate different properties:
number of particles per cubic
centimeter, extinction coefficient
or optical depth per kilometer of
height, and mass per cubic
centimeter. (From Hunten et al.,
1984.)
FIGURE 9 Particle size spectra at
four of the heights shown in Fig. 8.
Only very mall sizes occur in the
upper cloud and lower haze; the
layers in between have three
different populations or “modes”
with sizes around 1 (or less), 3, and
7 μm. (From Hunten et al., 1984.)
